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Sample records for range province geochemical

  1. Geochemical conditions and the occurrence of selected trace elements in groundwater basins used for public drinking-water supply, Desert and Basin and Range hydrogeologic provinces, 2006-11: California GAMA Priority Basin Project

    Science.gov (United States)

    Wright, Michael T.; Fram, Miranda S.; Belitz, Kenneth

    2015-01-01

    The geochemical conditions, occurrence of selected trace elements, and processes controlling the occurrence of selected trace elements in groundwater were investigated in groundwater basins of the Desert and Basin and Range (DBR) hydrogeologic provinces in southeastern California as part of the Priority Basin Project (PBP) of the Groundwater Ambient Monitoring and Assessment (GAMA) Program. The GAMA PBP is designed to provide an assessment of the quality of untreated (raw) groundwater in the aquifer systems that are used for public drinking-water supply. The GAMA PBP is being conducted by the California State Water Resources Control Board in collaboration with the U.S. Geological Survey and the Lawrence Livermore National Laboratory.

  2. A Low-Li Geochemical Province in the NE Atlantic

    DEFF Research Database (Denmark)

    Bailey, J. C.; Gwozdz, R.

    1978-01-01

    Lithium was analysed in 392 basalts and related igneous rocks from the North Atlantic Tertiary-Recent province using activation analysis and Čerenkov counting. Monotonous Li values of 5.5±2 ppm in NE Atlantic basalts define a low-Li geochemical province which has persisted for 60 million years...... basalt series. No whole-rock coherence is observed between Li and Mg, K, Rb or Ca. Mantle phlogopite is considered to play an insignificant rôle in controlling the Li levels of NE Atlantic basalts....

  3. Flinders Mountain Range, South Australia Province, Australia

    Science.gov (United States)

    1983-01-01

    Classic examples of folded mountain ranges and wind erosion of geologic structures abound in the Flinders Mountain Range (30.5S, 139.0E), South Australia province, Australia. Winds from the deserts to the west gain speed as they blow across the barren surface and create interesting patterns as they funnel through the gullies and valleys.

  4. Basin and Range Province, Western US, USGS Grids #4

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  5. Basin and Range Province, Western US, USGS Grids #5

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  6. Basin and Range Province, Western US, USGS Grids #3

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  7. Basin and Range Province, Western US, USGS Grids, #1

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These grid files were used to produce gravity and basin depth maps of the Basin and Range Province, western United States. The maps show gravity values and modeled...

  8. Evaluation of geothermal potential of the basin and range province of New Mexico. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Landis, G.P.; Callender, J.F.; Elston, W.E.; Jiracek, G.R.; Kudo, A.M.; Woodward, L.A.; Swanberg, C.A.

    1976-06-01

    This continuing research is designed to provide an integrated geological, geophysical, and geochemical study of the geothermal energy potential of promising thermal anomalies in the Rio Grande rift, Basin and Range province, the Mogollon--Datil volcanic field of New Mexico. Specific objectives undertaken in this study include the following: (a) reconnaissance and detailed geologic mapping (Animas Valley, Radium Springs, Alum Mountain, Truth or Consequences, Ojo Caliente, Albuquerque---Belene basin, and San Ysidro); (b) geochemical studies including reconnaissance water sampling (Animas Valley, Radium Springs and Alum Mountain); and (c) geophysical surveys using deep electric-resistivity, gravity, and magnetic techniques (Radium Springs, Animas Valley and Truth or Consequences). The results of one and one-half summer field seasons and approximately two years of analytical work, laboratory research, and development of research equipment and facilities are covered. Publications, communications, and public service resulting from the first years of U.S.G.S. and State funding are listed in Appendix A.

  9. Petrological and geochemical study of doleritic intrusions of Moatize area, Tete Province, Mozambique

    Science.gov (United States)

    Ilídio Mário, Rui; Mendes, Maria Helena; Francisco Santos, Jose; Ribeiro, Sara

    2017-04-01

    The dolerite samples studied in this work are part of drilling cores, obtained during exploration campaigns by the Ncondezi Coal Company, in the prospect area 805L, located at NE of Moatize, Tete Province, Mozambique. The dolerite bodies are intrusive into sedimentary formations of the Karoo Supergroup. The intrusions have a probable Jurassic age, around 180 Ma, based on a geochronological information (GTK Consortium, 2006) from a similar body cropping out in another area of the Tete Province. The studied rocks were affected by hydrothermal alteration, testified by the pervasive occurrence of the assemblage serpentine + chlorite + sericite + sphene + calcite ± epidote ± tremolite-actinolite, and by filling of vesicles and fractures by calcite, pyrite or calcite + pyrite ± quartz. However, the selected samples preserve igneous intergranular textures. Petrographic evidence suggests that the primary mineral associations included plagioclase, titanaugite, olivine, apatite, opaques, biotite and hornblende. These assemblages are variably preserved and, in the samples most intensely altered, the igneous minerals were almost totally replaced. Whole-rock major and trace element data, with particular emphasis on immobile elements, indicate that the analysed samples are basic and that they can be seen as cogenetic, belonging to the alkaline series and showing compositions similar to present-day intraplate basalts. The Rb-Sr and Sm-Nd data seem to confirm the cogenetic nature of the studied dolerites. In fact, in the least altered samples, both [87Sr/86Sr]180Ma and ɛNd180Ma define relatively small ranges: +0.7050 ≥ [87Sr/86Sr]180Ma ≥ 0.7038 +10 ≥ ɛSr180Ma ≥ -7 and +3.6 ≥ ɛNd180Ma ≥ +1.7. In addition, this clearly indicates that parental melts were generated in a mantle source and that magmas did not undergo significant crustal contamination during their ascent and emplacement. The described isotopic compositions, besides plotting in an area common to OIB, are

  10. Petrological and geochemical characterization of the plutonic rocks of the Sierra de La Aguada, Province of San Luis, Argentina: Genetic implications with the Famatinian magmatic arc

    Directory of Open Access Journals (Sweden)

    E. Cristofolini

    2017-07-01

    Full Text Available This study presents a synthesis on the geology of the crystalline complex that constitute the Sierra de la Aguada, San Luis province, Argentine, from an approach based on field relations, petrologic and structural features and geochemical characteristic. This mountain range exposes a basement dominated by intermediate to mafic calcalkaline igneous rocks and peraluminous felsic granitoids, both emplaced in low to medium grade metamorphic rocks stabilized under low amphibolite facies. All this lithological terrane has been grouped in the El Carrizal-La Aguada Complex. Field relations, petrographic characterization and geochemical comparison of the plutonic rocks from the study area with those belonging to the Ordovician Famatinian suit exposed in the Sierra Grande de San Luis, suggest a genetic and temporal relation linked to the development of the Famatinian magmatic arc.

  11. The Basin and Range Province in Utah, Nevada, and California

    Science.gov (United States)

    Nolan, Thomas B.

    1943-01-01

    In this report an attempt has been made to summarize and in places to interpret the published information that was available through 1938 on the geology of those parts of Nevada, California, and Utah that are included in the geologic province known as the Basin and Range province. This region includes most of the Great Basin, from which no water flows to the sea, as well as part of the drainage basin of the lower Colorado River. It is characterized by numerous parallel, linear mountain ranges that are separated from one another by wide valleys or topographic basins. All the major divisions of geologic time are represented by the rocks exposed in this region. The oldest are of pre-Cambrian age and crop out chiefly along the eastern and southern borders. They have been carefully studied at only a few localities, and the correlation and extent of the subdivision so far recognized is uncertain. There appear to be at least three series of pre-Cambrian rocks which are probably separated from one another by profound unconformities. Large masses of intrusive igneous rocks have been recognized only in the oldest series. During the Paleozoic era the region was a part of the Cordilleran geosyncline, and sediments were deposited during all of the major and most of the minor subdivisions of the era. There are thick and widespread accumulations of Cambrian and Ordovician strata, the maximum aggregate thickness possibly exceeding 23,000 feet. The eastern and western boundaries of the province were approximately those of the area of rapid subsidence within the geosyncline, though the axes of maximum subsidence oscillated back and forth during the two periods. The Silurian and Devonian seas, on the other hand, extended beyond the province and, possibly as a consequence, are represented by much thinner sections - of the order of 6,000 feet. At the end of the Devonian period the geosyncline was split by the emergence of a geanticline in western Nevada, and Mississippian and

  12. Petrographic and geochemical characterization of pale and dark brown coal from Yunnan Province, China

    Energy Technology Data Exchange (ETDEWEB)

    Ming, Q.; Xilin, R.; Dazhong, T.; Jian, X.; Wolf, M. [Aachen University, Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle

    1994-01-01

    Fifteen lignite samples from the province of Yunnan were analysed by organic petrography and geochemistry. Twelve of the samples represent the very pale (yellow) Baipao coal, the other three were normal coals of a medium brown colour. The Baipao coal consists mainly of mineral-bituminous groundmass, whereas the normal coal is characterised by well-preserved tissues derived from gymnosperm wood. Up to 190 mg/g C{sub org} of extract is extractable from the Baipao coal; only 63 mg/g C{sub org} from the normal coal. The n-alkaline fraction of the Baipao coal extract consists of high amounts of hopanes and shows the predominance of nor-abietane within the diterpenoids present. The first group of compounds points to intensive bacterial activity, while the second compound indicates not only that gymnosperms are present but also that a relatively oxygen-rich environment existed at the time of deposition. From the petrographic and organic geochemical characteristics it is concluded that the Baipao coal was formed from the same plant source material as the normal coal, but underwent stronger decay. 22 refs., 11 figs., 2 plates, 8 tabs.

  13. Organic geochemical study of lignite coal from Salt Range Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Fazeelat, T.; Asif, M. [University of Engineering & Technology, Lahore (Pakistan). Dept. of Chemistry

    2005-04-01

    Coal sample from Salt Range-Pakistan has been analyzed to investigate its rank, hydrocarbon composition and most likely source of hydrocarbons. The rank of coal has been determined by general and chemical parameters. High percentage of volatile matter and sulfur content, low thermal characteristics and carbon and hydrogen content 62 and 5 respectively reveal that Salt Range coal is lignite in rank. In order to determine hydrocarbon composition, bitumen was extracted from the coal and was fractionated into saturated, aromatic and NSO (nitrogen, sulfur and oxygen containing compounds) fractions by liquid chromatography employing silica gel. Further fractionation of aromatic fraction by TLC yielded two sub fractions called aromatic fraction No. 1 and aromatic fraction No. 2 respectively. Analysis of these fractions by capillary GC-FID showed a profile with high abundance of peaks that were characterized as thiophenic compounds. The identifications were based on the comparison of GC retention data with the literature. Dibenzothiophenes are the most abundant compounds in the Salt Range coal. Their methyl- and dimethyl substituted derivatives are also present in high concentration. Naphthalene and phenanthrene are present in minor amount but their alkyl-substituted derivatives have relatively high concentration. The most likely source of aromatic hydrocarbons could be terpenoid precursors; however polynuclear aromatic thiophenes, could be formed from sulfur containing aromatic moieties of macromolecules during later stage of diagenesis of the sediments. The incorporation of hydrogen sulfide into the precursor molecules could not be ruled out which is abundant in reducing environment.

  14. GEOCHEMICAL AND ISOTOPIC INVESTIGATION OF LAKES IN THE TRENTO PROVINCE (ITALY

    Directory of Open Access Journals (Sweden)

    Marco Natale

    2013-09-01

    Full Text Available We present the geochemical composition and the stable isotope signature (18O/16O and 2H/1H of waters sampled from six lakes (Caldonazzo, Levico, Lases, Santa Colomba, Lamar and Santo located in the Province of Trento. The chemical compositions invariably revealed a HCO3-Ca hydrochemical facies; however slight differences were observed among the lakes, in relation to the lithologies distinguishing each lakes’drainage basin. Elemental ratios and in particular the Rb/Sr provide a discriminative tool to recognize the rocks that have been weathered; for example this ratio is high in water that interacted with volcanic ignimbrites (rhyolites, and low in rocks that interacted with carbonate rocks. Many other trace elements were analyzed, thus providing baseline data, and only arsenic displayed concentrations higher than the legislative threshold defined for drinking water (10mg/l, especially in Lake Levico (10-19 mg/l. As concerns the stable isotopes δD and δ18O, the obtained results approach the meteoric signature for waters sampled during the 2012 winter season. The waters sampled during two summers (2011 and 2012 displayed distinctive trends, reflecting the significant influence of evaporative processes. We emphasize that the annual differences recorded in the isotopic composition of distinct years are plausibly related to temperature changes and type of precipitation that recharged the lakes. In this light, the peculiar isotopic signature recorded in the year 2011 is possibly related to a significant snowy period, which greatly contributed to the lakes’ water budget. Interestingly, waters from Lake Santa Colomba were systematically different from all the other samples, possibly due to more effective evaporative processes, or to the involvement of deep underground recharge including fossil waters.

  15. Geochemical modeling of orogenic gold deposit using PCANN hybrid method in the Alut, Kurdistan province, Iran

    Science.gov (United States)

    Mohammadzadeh, Mohammadjafar; Nasseri, Aynur

    2018-03-01

    In this paper stream sediments based geochemical exploration program with the aim of delineating potentially promising areas by a comprehensive stepwise optimization approach from univariate statistics, PCA, ANN, and fusion method PCANN were under taken for an orogenic gold deposit located in the Alut, Kurdistan province, NW of Iran. At first the data were preprocessed and then PCA were applied to determine the maximum variability directions of elements in the area. Subsequently the artificial neural network (ANN) was used for quick estimation of elemental concentration, as well as discriminating anomalous populations and intelligent determination of internal structure among the data. However, both the methods revealed constraints for modeling. To overcome the deficiency and shortcoming of each individual method a new methodology is presented by integration of both "PCA & ANN" referred as PCANN method. For integrating purpose, the detected PCs pertinent to ore mineralization selected and intruded to neural network structure, as a result different MLPs with various algorithms and structures were produced. The resulting PCANN maps suggest that the gold mineralization and its pathfinder elements (Au, Mo, W, Bi, Sb, Cu, Pb, Ag & As) are associated with metamorphic host rocks intruded by granite bodies in the Alut area. In addition, more concealed and distinct Au anomalies with higher intensity were detected, confirming the privileges of the method in evaluating susceptibility of the area in delineating new hidden potential zones. The proposed method demonstrates simpler network architecture, easy computational implementation, faster training speed, as well as no need to consider any primary assumption about the behavior of data and their probability distribution type, with more satisfactory predicting performance for generating gold potential map of the area. Comparing the results of three methods (PCA, ANN and PCANN), representing the higher efficiency and more

  16. The Alto Paraguay Alkaline Province: petrographic, geochemical and geochronological characteristics; Provincia alcalina Alto Paraguai: caracteristicas petrograficas, geoquimicas e geocronologicas

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Fernandez, Victor

    1996-12-31

    The Alto Paraguay Province is located at the border of the State of Mato Grosso do Sul and Paraguay, between the coordinates 21 deg 10{sup `}to 23 deg 25{sup `}of Southern latitude and 57 deg 10{sup `} to 58 deg 00{sup `}, having the city of Porto Murtinho as the main reference point. The geotectonic domain of the area is governed by the precambric units of the Southern extreme of the Amazonic craton which developed a long and accentuated activity, giving rise to folds and important faults, that in several cases seem to have exerted an effective control of the magmatic manifestations. Radiometric data indicate that the emplacement of the syenitic bodies took place in the Permo-Triassic period, with a major incidence in the interval 260-240 Ma, representing thus, an important phase of alkaline magmatic affinity associated to the Parana Basin which is believed is to be unique, since the other known areas (Central, Amambay and Rio Apa Provinces, Paraguay, Velasco Province, Bolivia) are considerably younger (140-120 Ma). Syenitic rocks from the Alto Paraguay Province show wide variation in the ratio {sup 87} Sr/{sup 86} Sr (0.703361 - 0.707734). Excluding the Cerro Boggiani rocks (0.703837-0.707734), values for the nepheline syenites (0.703361-0.703672) general lower than those of the other syenites types. Alkaline syenites cover the interval 0.703510- 0.703872, while quartz syenites and syenogranites are 0.704562 and 0.707076, respectively. geologic evidence, in addition to petrographic, geochemical and isotopic (Sr) data, suggest that the syenitic rocks have been derived from an unique mantelic parental liquid, by fractional crystallization and assimilation processes, which are assumed to be occurred during the emplacement of the magma in the crust. (author) 124 refs., 52 figs., 7 tabs.

  17. Study on mineralization at Jian copper deposit, Fars province, using petrographical and geochemical data

    Directory of Open Access Journals (Sweden)

    Mohamad Ali Rajabzade

    2013-04-01

    Full Text Available Jian Cu deposit is hosted by Surian volcano-sedimentary complex of Permo-Triassic age on the eastern edge of the Sanandaj-Sirjan metamorphic zone at a distance of 195 km from Shiraz, southwestern Iran. The complex consists mainly of metabasalt, chlorite-quartz schist, chlorite-muscovite schist, mica schist and graphite schist. Pyrite is the most important sulfide and chalcopyrite is the major Cu-bearing mineral occurring as disseminated grains and veinlets in host chlorite-quartz schist and chlorite-muscovite schist. Chondrite-normalized REE pattern of metabasalt with La/LuN=2/9 indicates mantle tholeiitic basalt as the source of metamorphosed igneous rocks. Geochemical data on the metabasalts, especially the content of immobile elements (e.g., Ti and High Field Strength Elements (HFSE (e.g., Zr، Nb and Y, show low degree of partial melting for parental magma with E-MORB affinity. Chloritic, silicification and minor sericitic assemblages are the main alteration types associated with the Jian Cu deposit. The Y/Ho ratio of Cu ores varies from 29.9 to 32.5, indicating the important role of sea water in the mineralizing system. Petrographical and geochemical data indicate that the Jian Cu deposit was formed as volcano-sedimentary hosted massive sulfide. The Ishikawa alteration index (AI in association with chlorite-carbonate-pyrite index (CCP is useful for the geochemical exploration of Cu deposits in the study area.

  18. A Mesoproterozoic continental flood rhyolite province, the Gawler Ranges, Australia: the end member example of the Large Igneous Province clan

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    M. J. Pankhurst

    2011-03-01

    Full Text Available Rhyolite and dacite lavas of the Mesoproterozoic upper Gawler Range Volcanics (GRV (>30 000 km3 preserved, South Australia, represent the remnants of one of the most voluminous felsic magmatic events preserved on Earth. Geophysical interpretation suggests eruption from a central cluster of feeder vents which supplied large-scale lobate flows >100 km in length. Pigeonite inversion thermometers indicate eruption temperatures of 950–1100 °C. The lavas are A-type in composition (e.g. high Ga/Al ratios and characterised by elevated primary halogen concentrations (~1600 ppm fluorine, ~400 ppm chlorine. These depolymerised the magma such that temperature-composition-volatile non-Arrhenian melt viscosity modelling suggests they had viscosities of <3.5 log η (Pa s. These physicochemical properties have led to the emplacement of a Large Rhyolite Province, which has affinities in emplacement style to Large Basaltic Provinces. The low viscosity of these felsic magmas has produced a unique igneous system on a scale which is either not present or poorly preserved elsewhere on the planet. The Gawler Range Volcanic Province represents the erupted portion of the felsic end member of the family of voluminous, rapidly emplaced terrestrial magmatic provinces.

  19. The Survey of hydro-geochemical and health related of water quality in Ramian city, Golestan province

    Directory of Open Access Journals (Sweden)

    fahimeh Khanduzi

    2015-12-01

    Full Text Available Background and Purpose: Investigation of water quality is an important step for the suitable use of water resources in order to drinking and irrigation. Water quality affects agriculture programming.  Hence the need of the study of water quality is strongly considered in the water resources management. Material and Methods: In this study Hydro-geochemical quality of ground water resources in the Ramian city -Golestan province has been studied for drinking and agriculture purpose. For this purpose, 15 qualitative characteristics of the 13 wells of Golestan province in two dry and wet seasons in 2011-2012 were analyzed by Aua Chem and Aq-qa. Results: The results showed that the ground water in the study area is classified in hard and very hard water. The original cations and anions in water are Ca2+> Mg2+> Na+ and HCO3-> Cl-> SO42-. Based on hydro-chemical diagram the dominant of water type is classified as Ca-HCO3. Salinity index of water indicated that more samples in two seasons are in the middle class. According to Schuler and Wilcox groundwater quality index, they are moderate suitable for agricultural and drinking consumption and in for agricultural purpose and 77% cases are in C3-S1 category. Conclusion: The results show that too much salt is one of the most important problems of water supply in the Ramian city for irrigation. This reduced plant growth or even stops the growth of some plant. If water resources in this area do not manage, after shortly time the soil will be suffered and polluted.

  20. Petrological and geochemical evolution of the Central Gneissic Belt, Rengali Province, eastern India: Implications for the Neoarchean growth and orogenesis

    Science.gov (United States)

    Dasgupta, Arnab; Bose, Sankar; Das, Kaushik; Ghosh, Gautam

    2017-09-01

    This study focuses on the evolution of the Central Gneissic Belt of the Archean Rengali Province which evolved as a craton-margin orogenic belt. The Central Gneissic Belt is constituted of charnockite gneiss, migmatitic hornblende gneiss and granite gneiss often showing gradational contacts. While mafic granulite occurs as enclave within the charnockite gneiss, amphibolite and calc-silicate granofels enclaves are present within the granite gneiss. Mafic granulite shows peak metamorphic assemblage of garnet + clinopyroxene + plagioclase + quartz ± orthopyroxene which was stabilized at 10.6 ± 0.5 kbar and 860 ± 20 °C. Charnockite gneiss with the peak assemblage of orthopyroxene + quartz + plagioclase + K-feldspar was metamorphosed at 792 ± 48 °C and 7.6 ± 0.4 kbar. Amphibolite and migmatitic hornblende gneiss contain hornblende along with plagioclase and garnet and these rocks were metamorphosed at 800 ± 20 °C, 8.5 ± 0.2 kbar and 695 °C, 8 kbar respectively. Later meta-dolerite dikes exhibit relic igneous textures which are slightly modified by greenschist-facies metamorphism. Charnockite gneiss, migmatitic hornblende gneiss and granite gneiss show similar trace and REE characteristics (moderate fractionation in terms of La and Yb, LREE enrichment and flat HREE pattern) implying the same protolith composition for these rock groups. Based on the field, petrographic and geochemical data, we propose that the protoliths for the charnockite gneiss, the migmatitic hornblende gneiss and the granite gneiss crystallized as fractionated magma in within-plate syncollisional setting during the ca. 2860-2780 Ma orogeny at the Rengali Province.

  1. Geothermal prospecting by geochemical methods in the Quaternary volcanic province of Dhamar (central Yemen)

    Science.gov (United States)

    Minissale, Angelo; Vaselli, Orlando; Mattash, Mohamed; Montegrossi, Giordano; Tassi, Franco; Ad-Dukhain, Abdulsalam; Kalberkamp, Ulrich; Al-Sabri, Ali; Al-Kohlani, Taha

    2013-01-01

    This paper deals with geothermal prospecting carried out in the Quaternary volcanic field of Dhamar, which is located almost in the centre of the main Oligo-Miocene basaltic trap plateau of Yemen. By applying geochemical and thermometric techniques in domestic wells producing water from the shallow unconfined aquifer in the area, which is prevalently hosted inside the Quaternary volcano-clastic material, a closed thermal anomaly associated with the Quaternary volcanic activity was well delineated. Although the aquifer(s) has a Ca-Na-HCO3 composition, that is typical of shallow groundwater, there are several chemical anomalies in the hotter central area compared to typical aquifers: i) the pH is lower and, consequently, the calculated partial pressure of CO2 in solution is higher, ii) the electrical conductivity is higher, iii) the total salinity is higher and iv) the fluoride ion concentration is higher. Such chemical anomalies in the hotter part of the aquifer do not seem to be generated by the rising and/or mixing of deep hydrothermal components rising into the shallow aquifer, but rather produced by enhanced water-rock interaction processes resulting from the higher temperature of the aquifer and its greater acidity. By applying some speculative calculations, based on the likely temperature of rainfall in the area and the depth and temperature of individual wells, the local thermal gradients in the area have been calculated. The thermal gradient varies from less than the average Earth gradient at the periphery of the delimitated thermal anomaly, to more than 250 °C/km, within an extensive area (exceeding 200 km2) where the gradient is greater than 100/120 °C/km.

  2. Secondary Magnetization of ZEBRA Dolomites in the Basin and Range Province of Eastern Nevada

    Science.gov (United States)

    Elmore, R. D.; Dulin, S. A.

    2013-12-01

    Zebra dolomites within the Devonian Guilmette Formation of the southern Basin and Range Province, Nevada, are the focus of a paleomagnetic study to determine if a characteristic magnetization exists that will yield insight into the timing of zebra dolomite formation. Zebra dolomites consist of alternating bands of light and dark dolomite, and are found throughout Nevada, often associated with mineralized ore deposits. Although a variety of mechanisms have been suggested for formation, the zebra dolomite throughout Nevada is likely associated with hydrothermal fluid migration. The current study focuses on zebra dolomites that have formed in close stratigraphic proximity and within the Alamo Breccia in the Delamar Range in southeastern Nevada. The Alamo Breccia is an impact generated mega-breccia zone within the Devonian Guilmette Formation. The zebra dolomites, including those in the Alamo Breccia, and host Guilmette in the Delamar Range have a characteristic remanent magnetization (ChRM) with maximum laboratory unblocking temperatures of 480°C that is interpreted to reside in magnetite. The rocks were structurally rotated to remove Cenozoic extension, and the stratigraphic mean direction of the ChRM has a declination of 164.4°, with an inclination of -3°. The calculated pole is at 51.6°N, 90.7°E (dp = 2.2, dm = 4.3) which lies near the late Triassic portion of the apparent polar wander path (APWP) for North America. Based on low burial temperatures, this ChRM is interpreted as a chemical remanent magnetization (CRM) that was acquired due to the mobilization of brines possibly associated with the Triassic Sonoma orogeny. Geochemical data are consistent with alteration by externally derived fluids. The presence of a late Triassic magnetization indicates that the zebra dolomite can be no younger than Late Triassic. Preliminary results from zebra dolomites in other areas in southeastern Nevada indicate a more complex magnetization; some locations contain both

  3. Lead poisoning in shooting-range workers in Gauteng Province ...

    African Journals Online (AJOL)

    private indoor shooting range in greater Johannesburg. Blood lead levels were determined using a LeadCare II (Magellan Diagnostics,. USA) portable testing system, with a 50 μL aliquot of whole blood obtained from a finger prick following the thorough washing of hands with soap and water. Ethical approval for this work, ...

  4. The evolution of the Cappadocia Geothermal Province, Anatolia (Turkey): geochemical and geochronological evidence

    Science.gov (United States)

    Şener, M. Furkan; Şener, Mehmet; Uysal, I. Tonguç

    2017-12-01

    Cappadocia Geothermal Province (CGP), central Turkey, consists of nine individual geothermal regions controlled by active regional fault systems. This paper examines the age dating of alteration minerals and the geochemistry (trace elements and isotopes) of the alteration minerals and geothermal waters, to assess the evolution of CGP in relation to regional tectonics. Ar-Ar age data of jarosite and alunite show that the host rocks were exposed to oxidizing conditions near the Earth's surface at about 5.30 Ma. Based on the δ18O-δD relationhip, water samples had a high altitude meteoric origin. The δ34S values of jarosite and alunite indicate that water samples from the southern part of the study area reached the surface after circulation through volcanic rocks, while northern samples had traveled to the surface after interacting with evaporates at greater depths. REY (rare earth elements and yttrium) diagrams of alteration minerals (especially illite, jarosite and alunite) from rock samples, taken from the same locations as the water samples, display a similar REY pattern to water samples. This suggests that thermal fluids, which reached the surface along a fault zone and caused the mineral alteration in the past, had similar chemical composition to the current geothermal water. The geothermal conceptual model, which defines a volcanically heated reservoir and cap rocks, suggests there are no structural drawbacks to the use of the CGP geothermal system as a resource. However, fluid is insufficient to drive the geothermal system as a result of scanty supply of meteoric water due to evaporation significantly exceeding rainfall.

  5. Deciphering the geochemical and mineralogical changes of a Miocene sedimentary basin infill, Mendoza Province, Argentina

    Science.gov (United States)

    Hunger, Gabriel; Moscariello, Andrea; Ventra, Dario

    2017-04-01

    low to moderate weathering values (CIA = 45-65) and shows the evolution of the composition towards the illite pole, in agreement with the QEMSCAN results. The evolution of the source rock composition shows a trend towards more mafic sources. La Pilona Fm. is characterized by more scarce composition certainly due to the advance of the thrust front coupled with inputs from the uplifting Frontal Cordillera, a tectonic province feeding the basin with different igneous sources. The integration of heavy mineral and isotopic data to constrain the source area changes will also allow us to have a better understanding of the evolution of the uplifting Andes.

  6. Compositional data analysis and geochemical modeling of CO2-water-rock interactions in three provinces of Korea.

    Science.gov (United States)

    Kim, Seong Hee; Choi, Byoung-Young; Lee, Gyemin; Yun, Seong-Taek; Kim, Soon-Oh

    2017-12-20

    The CO 2 -rich spring water (CSW) occurring naturally in three provinces, Kangwon (KW), Chungbuk (CB), and Gyeongbuk (GB) of South Korea was classified based on its hydrochemical properties using compositional data analysis. Additionally, the geochemical evolution pathways of various CSW were simulated via equilibrium phase modeling (EPM) incorporated in the PHREEQC code. Most of the CSW in the study areas grouped into the Ca-HCO 3 water type, but some samples from the KW area were classified as Na-HCO 3 water. Interaction with anorthite is likely to be more important than interaction with carbonate minerals for the hydrochemical properties of the CSW in the three areas, indicating that the CSW originated from interactions among magmatic CO 2 , deep groundwater, and bedrock-forming minerals. Based on the simulation results of PHREEQC EPM, the formation temperatures of the CSW within each area were estimated as 77.8 and 150 °C for the Ca-HCO 3 and Na-HCO 3 types of CSW, respectively, in the KW area; 138.9 °C for the CB CSW; and 93.0 °C for the GB CSW. Additionally, the mixing ratios between simulated carbonate water and shallow groundwater were adjusted to 1:9-9:1 for the CSW of the GB area and the Ca-HCO 3 -type CSW of the KW area, indicating that these CSWs were more affected by carbonate water than by shallow groundwater. On the other hand, mixing ratios of 1:9-5:5 and 1:9-3:7 were found for the Na-HCO 3 -type CSW of the KW area and for the CSW of the CB area, respectively, suggesting a relatively small contribution of carbonate water to these CSWs. This study proposes a systematic, but relatively simple, methodology to simulate the formation of carbonate water in deep environments and the geochemical evolution of CSW. Moreover, the proposed methodology could be applied to predict the behavior of CO 2 after its geological storage and to estimate the stability and security of geologically stored CO 2 .

  7. Field and geochemical constraints on the relationship between the Apoteri basalts (northern Brazil, southwestern Guyana) and the Central Atlantic Magmatic Province

    Science.gov (United States)

    Pinto, Viter M.; Santos, João Orestes S.; Ronchi, Luiz H.; Hartmann, Léo A.; Bicudo, Carlos Alberto; de Souza, Vladimir

    2017-11-01

    In northern Brazil, Roraima state and southwestern Guyana, basalt flows characterized by inflated pahoehoe structure occur along the margins of the Tacutu Rift Valley, dykes intrude the Paleoproterozoic basement close to the boundary of the rift system with concordant, NE-trend. The dykes and flows belong to Apoteri magmatism. New field, geochemical data (major, trace and rare-earth elements) and chemical stratigraphy of the Apoteri magmatism indicate petrographic and chemical homogeneity characteristic of continental tholeiitic basalts. The basalt flows of Morro Redondo and Nova Olinda sites show two distinct chemical groups: a) the lower flows with intermediate TiO2 content (ITi group) ranging from 1.09 to 1.41 wt%, MgO (5.64-6.46 wt%) and Ni (43-53 ppm) contents; and b) the upper flows with lower TiO2 content (LTi group) = 0.75 to 0.78 wt%, higher MgO = 7.95-8.85 wt% and Ni = 105-115 ppm. The two magma types share many characteristics in high field strength elements (HFSE) and rare earth elements (REE), but in detail significant differences exist in REE ratios, e.g. (La/Yb)N of ∼4.0 for ITi and 3.2 for LTi and this may be explained by fractional crystallization. The chemical compositions of the Apoteri dykes are similar the ITi group analyses, suggesting that they have the same origin. The La/Ba versus La/Nb diagram is indicative of large ion lithophile elements (LILE) enrichment and LILE/HFSE fractionation in the mantle source, and the data favor a dominant subcontinental lithospheric mantle (SCLM) component in the origin of the Apoteri flows and dykes. These data show consistent similar chemical characteristics and correspond to other tholeiitic flows from the large Central Atlantic Magmatic Province (CAMP), especially eastern USA.

  8. Mineralogical and geochemical studies on borate deposits from the Shahr- e - Babak playa (Khatoonabad and Robat - Marvast, Kerman province - Iran

    Directory of Open Access Journals (Sweden)

    Atefeh Ghaedi

    2017-11-01

    , boron is very abundant. Good correlation between the elements, such as B and Ca confirms the formation of Calcium bearing borate mineral in the studied areas. Origin Field observations show that in the studied areas, borate bearing basins are fed by rivers which have originated from the Sanandaj – Sirjan metamorphic rocks, Nain – Baft colored mélanges and igneous rocks of the Urumieh – Dokhtar magmatic belt. Result The XRD results show that the studied borate minerals mainly are hydrated ones and contain ulexite, borax, gowerite, sassolite and inyoite. Geochemichal data confirm the frequency of boron in the playa. Good correlation between the elements such as B and Ca verifies the formation of Calcium bearing borate mineral in the studied areas. Acknowledgements The authors wish to thank IMIDRO for performing XRD analyses. References ‏‏ Allen, R.D. and Kramer, H., 1957. Ginorite and sassolite from Death Valley, California. American Mineralogist, 42(1-2: 56-61.‏ Christ, C.L., 1953. Studies of borate minerals, 2. X-ray crystallography of inyoite and meyerhofferite -x-ray and morphological crystallography of 2CaO. 3B2O3. 9H2O. American Mineralogist, 38(1 - 11: 912-918. Erd, R.C., McAllister, J.F. and Almond, H., 1959. Gowerite, a new hydrous calcium borate, from the Death Valley Region, California. American Mineralogist, 44(9-10: 911-919.‏ Floyd, P.A., Helvaci, C. and Mittwede, S.K., 1998. Geochemical discrimination of volcanic rocks associated with borate deposits: an exploration tool? Journal of Geochemical Exploration, 60(3: 185-205.‏ Garrett, D.E., 1998. Borates: handbook of deposits, processing, properties, and use. Academic Press, USA, 483 pp. Ghaedi, A., Moradian, A. and Ahmadipour, H., 2014. Reviewing and introduction of mineralogical properties of Ulexite an unknown gem in Khatoonabad (Shahr Babak, Kerman Province. The 1st National Symposium of Gemology- Crystallography of Iran, Shahid Bahonar University of Kerman, Kerman, Iran. Ghose, S., Wan, C

  9. Structural provinces of the northeastern Brooks Range, Arctic National Wildlife Refuge, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.K.; Hanks, C.L. (Univ. of Alaska, Fairbanks (USA))

    1990-07-01

    The dominant Cenozoic structures of the northeastern Brooks Range are anticlinoria with cores of sub-Mississippian rocks, reflecting a regional north-vergent duplex with a floor thrust in the sub-Mississippian sequence and a roof thrust in the Mississippian Kayak Shale. The number of horses forming each anticlinorium and the structural style of the overlying Mississippian and younger cover sequence varies regionally, providing a basis for dividing the northeastern Brooks Range into structural provinces. In the western province, each anticlinorium contains a single horse, and shortening above the Kayak Shale was accommodated mainly by detachment folds. To the north in the Sadlerochit Mountains, the Kayak Shale is depositionally discontinuous and rocks elsewhere separated by this detachment deformed together. In the eastern province, each anticlinorium contains multiple horses, and shortening above the Kayak Shale was accommodated largely by thrust duplication of Mississippian through Triassic rocks. In the narrow central province, the Devonian Okpilak batholith was detached from its roots, internally shortened along shear zones and by penetrative strain, and transported northward. Because the Kayak Shale is locally absent, the Mississippian and younger cover sequence deformed in part penetratively along with the batholith. 13 figs.

  10. Evaluation of geothermal potential of Rio Grande rift and Basin and Range province, New Mexico. Final technical report, January 1, 1977-May 31, 1978

    Energy Technology Data Exchange (ETDEWEB)

    Callender, J.F.

    1985-04-01

    A study was made of the geological, geochemical and geophysical characteristics of potential geothermal areas in the Rio Grande rift and Basin and Range province of New Mexico. Both regional and site-specific information is presented. Data was collected by: (1) reconnaissance and detailed geologic mapping, emphasizing Neogene stratigraphy and structure; (2) petrologic studies of Neogene igneous rocks; (3) radiometric age-dating; (4) geochemical surveying, including regional and site-specific water chemistry, stable isotopic analyses of thermal waters, whole-rock and mineral isotopic studies, and whole-rock chemical analyses; and (5) detailed geophysical surveys, using electrical, gravity and magnetic techniques, with electrical resistivity playing a major role. Regional geochemical water studies were conducted for the whole state. Integrated site-specific studies included the Animas Valley, Las Cruces area (Radium Springs and Las Alturas Estates), Truth or Consequences region, the Albuquerque basin, the San Ysidro area, and the Abiquiu-Ojo Caliente region. The Animas Valley and Las Cruces areas have the most significant geothermal potential of the areas studied. The Truth or Consequences and Albuquerque areas need further study. The San Ysidro and Abiquiu-Ojo Caliente regions have less significant geothermal potential. 78 figs., 16 tabs.

  11. Geochemical and geochronologic data from the Hall Creek caldera, Toiyabe Range, Nevada

    Science.gov (United States)

    Colgan, Joseph P.; Henry, Christopher D.

    2017-01-01

    The magmatic, tectonic, and topographic evolution of what is now the northern Great Basin remains controversial, notably the temporal and spatial relation between magmatism and extensional faulting. This controversy is exemplified in the northern Toiyabe Range of central Nevada, where previous geologic mapping suggested the presence of a caldera that sourced the late Eocene (34.0 mega-annum [Ma]) tuff of Hall Creek. This region was also inferred to be the locus of large-magnitude middle Tertiary extension (more than 100 percent strain) localized along the Bernd Canyon detachment fault, and to be the approximate location of a middle Tertiary paleodivide that separated east and west-draining paleovalleys. Geologic mapping, 40Ar/39Ar dating, and geochemical analyses document the geologic history and extent of the Hall Creek caldera, define the regional paleotopography at the time it formed, and clarify the timing and kinematics of post-caldera extensional faulting. During and after late Eocene volcanism, the northern Toiyabe Range was characterized by an east-west trending ridge in the area of present-day Mount Callaghan, probably localized along a Mesozoic anticline. Andesite lava flows erupted around 35–34 Ma ponded hundreds of meters thick in the erosional low areas surrounding this structural high, particularly in the Simpson Park Mountains. The Hall Creek caldera formed ca. 34.0 Ma during eruption of the approximately 400 cubic kilometers (km3) tuff of Hall Creek, a moderately crystal-rich rhyolite (71–77 percent SiO2) ash-flow tuff. Caldera collapse was piston-like with an intact floor block, and the caldera filled with thick (approximately 2,600 meters) intracaldera tuff and interbedded breccia lenses shed from the caldera walls. The most extensive exposed megabreccia deposits are concentrated on or close to the caldera floor in the southwestern part of the caldera. Both silicic and intermediate post-caldera lavas were locally erupted within 400 thousand

  12. Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

    Science.gov (United States)

    Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

    2015-01-01

    The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical

  13. Geochemical and palaeontological evidence for the definition of the Silurian/Devonian boundary in the Changwantang Section, Guangxi Province, China

    Directory of Open Access Journals (Sweden)

    Wen-jin Zhao

    2015-02-01

    Full Text Available Southern Guangxi Province is one of the important areas for the study of the Silurian/Devonian boundary (SDB in South China. Despite attempts to define the exact level of the SDB in the Yulin (Guangxi Province area using biostratigraphy, no consensus has been reached as the indicator fossils (e.g. graptolite Monograptus uniformis uniformis, conodont Icriodus woschmidti woschmidti and trilobite Warburgella rugulosa rugosa are not coexistent in South China. Since Mann et al. (2001: Dynamics of the Silurian/Devonian boundary sequence: sedimentary cycles vs. organic matter variation. Terra Nostra, 2001, 44–48 reported the first isotope curve based on organic carbon for the SDB at Klonk in the Czech Republic (GSSP, some comparable variation curves of δ13Corg across the SDB have been obtained at several locations including sections in Turkey and China. This distinct variation curve of the isotopic composition of organic carbon across the SDB provides a chemostratigraphic reference for a worldwide correlation of the SDB. In this study, organic geochemistry together with graptolite biostratigraphy is applied as a tool for identifying the SDB at the Changwantang Section in Yulin (Guangxi Province. The results suggest that the variations in some indexes of organic geochemistry can be correlated to the representative curve of the SDB in the Klonk and Esenyali sections. The exact level of the SDB in the Changwantang Section is positioned within the upper part of the Fangcheng Formation, which is consistent with the available palaeontological data from graptolites (e.g. Colonograptus colonus, Plectograptus sp., Monograptus uniformis, M. cf. M. praehercynicus and M. aequabilis.

  14. Geochemical characterization of Neogene sediments from onshore West Baram Delta Province, Sarawak: paleoenvironment, source input and thermal maturity

    Science.gov (United States)

    Togunwa, Olayinka S.; Abdullah, Wan H.

    2017-08-01

    The Neogene strata of the onshore West Baram Province of NW Borneo contain organic rich rock formations particularly within the Sarawak basin. This basin is a proven prolific oil and gas province, thus has been a subject of great interest to characterise the nature of the organic source input and depositional environment conditions as well as thermal maturation. This study is performed on outcrop samples of Lambir, Miri and Tukau formations, which are of stratigraphic equivalence to the petroleum bearing cycles of the offshore West Baram delta province in Sarawak. The investigated mudstone samples are organic rich with a total organic carbon (TOC) content of more than 1.0 wt.%. The integration of elemental and molecular analyses indicates that there is no significant variation in the source input between these formations. The investigated biomarkers parameters achieved from acyclic isoprenoids, terpanes and steranes biomarkers of a saturated hydrocarbon biomarkers revealed that these sediments contain high contribution of land plants with minor marine organic matter input that was deposited and preserved under relatively oxic to suboxic conditions. This is further supported by low total sulphur (TS), high TOC/TN ratios, source and redox sensitive trace elements (V, Ni, Cr, Co and Mo) concentrations and their ratios, which suggest terrigenous source input deposited under oxic to suboxic conditions. Based on the analysed biomarker thermal maturity indicators, it may be deduced that the studied sediments are yet to enter the maturity stage for hydrocarbon generation, which is also supported by measured vitrinite reflectance values of 0.39-0.48% Ro.

  15. U-Pb zircon, geochemical and Sr-Nd-Hf isotopic constraints on the age and origin of Early Palaeozoic I-type granite from the Tengchong-Baoshan Block, Western Yunnan Province, SW China

    Science.gov (United States)

    Liu, Shen; Hu, RuiZhong; Gao, Shan; Feng, CaiXia; Huang, Zhilong; Lai, Shaocong; Yuan, Honglin; Liu, Xiaoming; Coulson, Ian M.; Feng, Guangying; Wang, Tao; Qi, YouQiang

    2009-09-01

    Herein we present new U-Pb zircon ages, whole-rock geochemical data and Nd-Sr-Hf isotopic data for an Early Palaeozoic monzogranite batholith from the Tengchong-Baoshan Block, Western Yunnan Province, China. Mineralogical and geochemical features suggest that this granitoid is a high-K, calc-alkaline, I-type granite. SHRIMP and laser ablation ICP-MS (LA-ICP-MS) analysis of zircon yields ages of between 499 ± 5 Ma and 502 ± 5 Ma, for three samples from the batholith. The monzogranite is characterised by high initial 87Sr/ 86Sr (0.7132-0.7144), negative ɛNd( t) (-9.7 to -9.40) and ɛHf( t) (-10 to -13.1), and is interpreted to derive from remelting of pre-existing Palaeoproterozoic, high-K, metabasaltic rocks of the upper crust. The granitoid magma underwent extensive fractional crystallisation of biotite ± hornblende, ilmenite, titanite, K-feldspar and plagioclase during emplacement. The crystallisation temperature of the magma lies in the range 633-733 °C, however, there is no evidence to suggest crustal assimilation occurred during its ascent. Like the ˜500 Ma, I-type granite of this study, there occur numerous granitoid rocks of Early Palaeozoic age (490-470 Ma) in adjacent regions across the entire Tengchong-Baoshan Block ( Chen et al., 2004, 2005; Song et al., 2007). This episode of plutonism is coeval with the widespread granitoid magmatism found throughout the Indian Plate and the Himalayan Orogenic Belt that are both subordinate parts of the ancient, Gondwana supercontinent. We infer, therefore, that the Tengchong-Baoshan Block may also have formed part of Gondwana, and that it separated from this supercontinent along with other crustal blocks during the Late Palaeozoic. Moreover, based on the findings of this study, we document the occurrence of arc-related magmatism in the Tengchong-Baoshan Block during the late Palaeoproterozoic.

  16. Temperature Range for Metasomatism at the Bakalskoe Siderite Deposits with Use of Geochemical Data

    Directory of Open Access Journals (Sweden)

    M. T. Krupenin

    2017-06-01

    Full Text Available The data obtained with the quantitative microprobe ankerite–siderite composition analysis of seven samples from the different parts of Bakalskoe field showed that the wallrock ankerites in the western and central parts of the ore field differ in average concentrations of FeCO 3 (respectively 14.21 and 20.84 wt.%. However, there is no significant difference in composition of siderites. The calculation of the Mg-Fe metasomatism temperatures based on ankerite-siderite and ankerite-breinerite geothermometers showed the close agreement of the values of both methods at temperatures of 250 °C and above. The average temperatures of siderite metasomatism in the central part of the Bakalskoe ore field are in range 250-270 ° C, and, in the peripheral part, the determined temperature does not exceed 190-220 ° C. These values do not depend on the position of the siderite deposits in stratigraphic level of the Bakalskaya Suite.

  17. Geochemical stratigraphy and correlation within large igneous provinces: The final preserved stages of the Faroe Islands Basalt Group

    Science.gov (United States)

    Millett, J. M.; Hole, M. J.; Jolley, D. W.; Passey, S. R.

    2017-08-01

    The Faroe Islands Basalt Group (FIBG) comprises a gross stratigraphic thickness of over 6.5 km of dominantly extrusive basaltic facies erupted during the Late Palaeocene to Early Eocene. In this study we present 140 major and trace element analyses from flow by flow field and borehole sample profiles, through the Enni Formation, which comprises the final phase of volcanism preserved on the Faroe Islands. The sample profiles target geographically spaced and overlapping stratigraphic sequences tied relative to a 3D ArcGIS surface for the regionally extensive volcaniclastic Argir Beds marker unit. From these profiles five geochemical groups including one low TiO2 (Low-Ti 1.5 wt%) groups differentiated by Nb, Zr, Y and V variations are identified in conjunction with previous studies. The spatial and stratigraphic distribution of these groups is mapped across the islands and demonstrates a complex inter-digitated flow field evolution. Within the finer scale variations, broad spatial and temporal development trends are identified demonstrating the potential for correlation within the volcanic succession at the local, tens of kilometers scale. Low-Ti lavas formed in association with lithospheric thinning and developed extensive flow fields between the Faroe Islands and East Greenland contemporaneous to the eruption of High-Ti smaller melt fraction lava flows in both locations. The progression of High-Ti lava groups preserved on either side of the developing rift zone is very similar, but is not, however, chronostratigraphic due to multiple inter-digitations of the chemical types. We tentatively suggest that a previously proposed rift-oblique transfer zone between the Faroe Islands and East Greenland enabled non-uniform lithospheric thinning and the preservation of a near-continuous High-Ti melting region between these areas beyond the onset of Low-Ti eruptions which were initially fed from the west. This study highlights the complex nature of late stage flood basalt

  18. The geochemical effects of olivine slurry replenishment and dolostone assimilation in the plumbing system of the Franklin Large Igneous Province, Victoria Island, Arctic Canada

    Science.gov (United States)

    Hayes, Ben; Lissenberg, C. Johan; Bédard, Jean H.; Beard, Charlie

    2015-02-01

    The Neoproterozoic (~723-716 Ma) Franklin Large Igneous Province exposed on Victoria Island in the Canadian Arctic is comprised of a sill-dominated magma plumbing system overlain by the coeval Natkusiak flood basalts. We have investigated three sections, separated by a total of >50 km of distance, of a sill (the Fort Collinson Sill Complex) emplaced just above a prominent sedimentary marker unit. The sill is characterized by a basal olivine-enriched layer (OZ: up to 55 % olivine) and an upper gabbroic unit. The observed diversity of olivine compositions in the OZ implies that bulk-rock MgO versus FeO arrays reflect accumulation of a heterogeneous olivine crystal cargo. We suggest that the OZ was formed as a late olivine slurry replenishment in a partially crystallized gabbroic sill, propagating for over 50 km along strike. This interpretation is consistent with Pb-isotope data, which show that at least three geochemically distinct magmas were emplaced into the Fort Collinson Sill Complex. The OZs exhibit a gradual westward evolution toward more Fe-rich bulk compositions. This is best explained by progressive mixing of the replenishing olivine slurry with a resident gabbroic mush during westward flow. Pb-isotopic signatures suggest that magmas near the inferred conduit feeder assimilated small amounts (rock, which may have locally buffered olivine compositions to high-Fo contents.

  19. A systematic regional trend in helium isotopes across the northernbasin and range province, Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack; van Soest, Matthijs C.

    2006-05-01

    An extensive study of helium isotopes in fluids collectedfrom surface springs, fumaroles and wells across the northern Basin andRange Province reveals a systematic trend of decreasing 3He/4He ratiosfrom west to east. The western margin of the Basin and Range ischaracterized by mantle-like ratios (6-8 Ra) associated with active orrecently active crustal magma systems (e.g., Coso, Long Valley,Steamboat, and the Cascade volcanic complex). Moving towards the east,the ratios decline systematically to a background value of ~;0.1 Ra. Theregional trend is consistent with extensive mantle melting concentratedalong the western margin and is coincident with an east-to-west increasein the magnitude of northwest strain. The increase in shear strainenhances crustal permeability resulting in high vertical fluid flow ratesthat preserve the high helium isotope ratios at the surface. Superimposedon the regional trend are "helium spikes," local anomalies in the heliumisotope composition. These "spikes" reflect either local zones of mantlemelting or locally enhanced crustal permeability. In the case of theDixie Valley hydrothermal system, it appears to be a combination ofboth.

  20. Geological and geochemical characteristics of high arsenic coals from endemic arsenosis areas in southwestern Guizhou Province, China

    Science.gov (United States)

    Ding, Z.; Zheng, B.; Long, J.; Belkin, H.E.; Finkelman, R.B.; Chen, C.; Zhou, D.; Zhou, Y.

    2001-01-01

    Southwest Guizhou Province is one of the most important areas of disseminated, sediment-hosted-type Au deposits in China and is an important area of coal production. The chemistry of most of the coals in SW Guizhou is similar to those in other parts of China. Their As content is near the Chinese coal average, but some local, small coal mines contain high As coals. The highest As content is up to 3.5 wt.% in the coal. The use of high As coals has caused in excess of 3000 cases of As poisoning in several villages. The high As coals are in the Longtan formation, which is an alternating marine facies and terrestrial facies. The coals are distributed on both sides of faults that parallel the regional anticlinal axis. The As content of coal is higher closer to the fault plane. The As content of coal changes greatly in different coal beds and different locations of the same bed. Geological structures such as anticlines, faults and sedimentary strata control the distribution of high As coals. Small Au deposits as well as Sb, Hg, and Th mineralization, are found near the high As coals. Although some As-bearing minerals such as pyrite, arsenopyrite, realgar (?), As-bearing sulfate, As-bearing clays, and phosphate are found in the high As coals, their contents cannot account for the abundance of As in some coals. Analysis of the coal indicates that As mainly exists in the form of As5+ and As3+, perhaps, combined with organic compounds. The occurrence of such exceptionally high As contents in coal and the fact that the As is dominantly organically associated are unique observations. ?? 201 Elsevier Science Ltd.

  1. Geochemical Features of Shale Hydrocarbons of the Central Part of Volga-Ural Oil and Gas Province

    Science.gov (United States)

    Nosova, Fidania F.; Pronin, Nikita V.; Plotnikova, Irina N.; Nosova, Julia G.

    2014-05-01

    This report contains the results of the studies of shale hydrocarbons from carbonate-siliceous rocks on the territory of South-Tatar arch of Volga-Ural oil and gas province of the East European Platform. The assessment of the prospects of shale hydrocarbon in Tatarstan primarily involves finding of low permeable, poor-porous shale strata that would be rich in organic matter. Basing on the analysis of the geological structure of the sedimentary cover, we can distinguish three main objects that can be considered as promising targets for the study from the point of the possible presence of shale hydrocarbons: sedimentary deposits Riphean- Vendian; Domanicoid high-carbon rocks of Devonian time; sedimentary strata in central and side areas of Kama-Kinel deflection system. The main object of this study is Domanicoid high-carbon rocks of Devonian time. They are mainly represented by dark gray, almost black bituminous limestones that are interbedded with calcareous siliceous shales and cherts. Complex studies include the following: extraction of bitumen from the rock, determination of organic carbon content, determination of the group and elemental composition of the bitumen, gas chromatographic studies of the alkanoic lube fractions of bitumoid and oil, gas chromato-mass spectrometry of the naphthenic lube fractions of bitumoid and oil, pyrolysis studies of the rock using the Rock -Eval method (before and after extraction), study of trace-element composition of the rocks and petrologen, comparison in terms of adsorbed gas and studying of the composition of adsorbed gases. Group and elemental analyses showed that hydrocarbons scattered in the samples contain mainly resinous- and asphaltene components, the share lube fraction is smaller. The terms sediment genesis changed from weakly to strongly reducing. According to the results of gas chromatography, no biodegradation processes were observed. According to biomarker indicators in the samples studied there is some certain

  2. The Kharapeh orogenic gold deposit: Geological, structural, and geochemical controls on epizonal ore formation in West Azerbaijan Province, Northwestern Iran

    Science.gov (United States)

    Niroomand, Shojaeddin; Goldfarb, Richard J.; Moore, Farib; Mohajjel, Mohammad; Marsh, Erin E.

    2011-01-01

    The Kharapeh gold deposit is located along the northwestern margin of the Sanandaj–Sirjan Zone (SSZ) in the West Azerbaijan province, Iran. It is an epizonal orogenic gold deposit formed within the deformed zone between central Iran and the Arabian plate during the Cretaceous–Tertiary Zagros orogeny. The deposit area is underlain by Cretaceous schist and marble, as well as altered andesite and dacite dikes. Structural analysis indicates that the rocks underwent tight to isoclinal recumbent folding and were subsequently co-axially refolded to upright open folds during a second deformation. Late- to post-tectonic Cenozoic granites and granodiorites occur northeast of the deposit area. Mineralization mainly is recognized within NW-trending extensional structures as veins and breccia zones. Normal faults, intermediate dikes, and quartz veins, oriented subparallel to the axial surface of the Kharapeh antiform, indicate synchronous extension perpendicular to the fold axis during the second folding event. The gold-bearing quartz veins are >1 km in length and average about 6 m in width; breccia zones are 10–50 m in length and ≤1 m in width. Hydrothermal alteration mainly consists of silicification, sulfidation, chloritization, sericitization, and carbonatization. Paragenetic relationships indicate three distinct stages—replacement and silicification, brecciation and fracture filling, and cataclastic brecciation—with the latter two being gold-rich. Fluid inclusion data suggest mineral deposition at temperatures of at least 220–255°C and depths of at least 1.4–1.8 km, from a H2O–CO2±CH4 fluid of relatively high salinity (12–14 wt.% NaCl equiv.), which may reflect metamorphism of passive margin carbonate sequences. Ore fluid δ18O values between about 7‰ and 9‰ suggest no significant meteoric water input, despite gold deposition in a relatively shallow epizonal environment. Similarities to other deposits in the SSZ suggest that the deposit formed as

  3. [Thyrotropin reference ranges during pregnancy in the province of Huelva, Spain].

    Science.gov (United States)

    Ortega Carpio, A; Vázquez Rico, I; Castaño López, M A; Duarte González, L; Montilla Álvaro, M; Ruiz Reina, A

    2017-11-18

    The correct diagnosis of hypothyroidism during pregnancy requires knowledge of the local trimester-specific thyrotropin (TSH) reference ranges. When these are not available, the guidelines recommend upper limits of 2.5, 3.0, and 3.0μU/ml for the 1 st , 2 nd , and 3 rd trimesters, respectively. The aim is to establish the reference range for our local population. A population-based observational study was performed on healthy pregnant women from 11 healthcare centres in the province of Huelva. Women were recruited consecutively during 2016 through the pregnancy process. Women were excluded who had a history of thyroid or medical disease, a poor obstetric history, multiple pregnancy, thyroid autoimmunity, and extreme TSH values (10μU/ml), as well as women treated with levothyroxine for thyroid dysfunction. The study included a total of 186 pregnant women, with a mean age of 30.7 years (95% CI: 29.8-31.6) and a body mass index (BMI) of 23.6 (95% CI: 23.2-24.0). Most of them had the first laboratory tests performed before week 11 of pregnancy. Valid subjects for analysis were 145, 105, and 67 pregnant women in the 1 st , 2 nd , and 3 rd trimesters, respectively, after excluding those due to abortion (18.9%), autoimmunity (6.5%), hypo/hyperthyroidism (2.2%), and levothyroxine treatment during the 2 nd /3 rd trimester (18.6%). The 97.5% TSH percentile for the 1 st , 2 nd , and 3 rd trimester was 4.68, 4.83, and 4.57μU/ml, respectively. Thyroid dysfunction was identified in 80 women (55.2%), 33 of whom received treatment with Levothyroxine (22.7%). With the new criteria, thyroid dysfunction prevalence would be reduced to 6.2%, and the need for treatment to 4.1%. The reference range for TSH in our population differs from that proposed by the guidelines. Unnecessary treatment was being given to 18.6% of pregnant women. Copyright © 2017 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Pre-collisional, Tonian (ca. 790 Ma) continental arc magmatism in southern Mantiqueira Province, Brazil: Geochemical and isotopic constraints from the Várzea do Capivarita Complex

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    Martil, Mariana Maturano Dias; de Fátima Bitencourt, Maria; Nardi, Lauro Valentim Stoll; Koester, Edinei; Pimentel, Márcio Martins

    2017-03-01

    This paper focuses on the pre-collisional mature arc magmatism (ca. 790 Ma) recorded in orthogneisses from the Várzea do Capivarita Complex (VCC), southern Mantiqueira Province (PM), Brazil. The complex comprises ortho- and paragneisses tectonically interleaved during a transpressive high grade regime (ca. 650 Ma), possibly related to oblique collision. The VCC orthogneisses are metaluminous to peraluminous calc-alkaline rocks, with high 87Sr/86Sr(i) ratios from 0.71628 to 0.72509 and εNd(790) values from - 7.19 to - 10.06. The VCC magmatism is correlated with other ca. 800 Ma arc sequences from southern PM, as the Porongos Metamorphic Complex (PMC) metavolcanic rocks and the orthogneisses from Cerro Bori (CB), Uruguay. All associations show signatures typical of accretionary orogens, TDM and Meso to Paleoproteroic inheritance ages, and strong evidence of crustal assimilation/contamination. Their high K contents, and the tendency to move toward the post-collisional field in geotectonic diagrams suggest that they were generated in thick-crust, mature arc environments. In contrast, the CB sequence exhibits a less mature continental-arc character, suggestive of thinner crust or shorter distance to the active margin. VCC and CB orthogneisses, and part of the PMC metavolcanic rocks may be interpreted as part of the same magmatism, or at least as fragments of similar magmatic arcs. However, VCC magmatism is distinct from continental arc sequences in the São Gabriel Block (ca. 700-750 Ma). Isotope signatures for this younger magmatism indicate major contribution of Neoproterozoic juvenile sources, with only little amounts of reworked, old continental crust. Geochemical and Sr-Nd signatures presented in this paper suggest that at least part of the PMC metavolcanic rocks are the protoliths of the VCC orthogneisses. This, together with the isotope evidence of similarity between VCC and PMC igneous and sedimentary fractions, corroborates the hypothesis that the VCC and PMC

  5. Geochemical Characteristics of Overbank Deposits after a Flood Event in a Small, Mountainous River System in the Oregon Coast Range, USA

    Science.gov (United States)

    Guerrero, F. J.; Hatten, J. A.; Goni, M. A.; Gray, A. B.; Pasternack, G. B.

    2014-12-01

    The geochemical characteristics of particulate organic matter (POM) transported by rivers has broad implications in our understanding of aquatic nutrient dynamics, the fate of contaminants, environmental change in watersheds, and carbon export to depositional environments. The major fraction of this POM is mobilized during storms, especially in small mountainous river systems (SMRS) producing complex spatial-temporal POM patterns poorly documented due to logistical difficulties. In this study, we examine the use of overbank flood deposits as a surrogate of a quasi-Lagrangian POM sampling scheme to supplement the conventional Eulerian sampling scheme for POM. We report on the geochemical characteristics of 11 overbank deposits created after a significant flood (10 X mean discharge) along 80 km in the Alsea River, a SMRS in the Oregon Coast Range. We measure organic carbon, nitrogen, stable isotopes, and biomarkers such as lignin-derived phenols as well as particle size distribution and surface area of the deposited sediments. We compared those characteristics with the POM sampled during several storms at a fixed location. Our results suggest that despite the differences in local depositional conditions inferred from particle size distributions and texture, the geochemical properties of overbank deposits resemble the properties of the material in transport, mainly derived from a terrestrial source with a clear signal of gymnosperm wood. Furthermore, the normalized ranges of the geochemical indicators measured across space for one single event are comparable to, or even higher than, the normalized range of the same indicators measured along time at the fixed location. The implications of the amount and quality of the additional information offered by the overbank deposits in POM dynamics in watershed is discussed.

  6. Mineralogical and geochemical studies on apatites and phosphate host rocks of Esfordi deposit, Yazd province, to determine the origin and geological setting of the apatite

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    Mohammad Ali Rajabzadeh

    2014-10-01

    Full Text Available Introduction Iron-apatite ore deposits well known as Kiruna iron type formed in association with calc-alkaline volcanism from Proterozoic to Tertiary (Hitzman et al., 1992. Liquid immiscibility in an igneous system was proposed to explain the formation of the iron oxides accompanying apatite in mineralized zones (Förster and Jafarzadeh, 1994; Daliran, 1999. The mode of ore formation however, is a matter in debate. Bafq region in Central Iran is one of the greatest iron mining regions in Iran with 750 million tons of reservoir. The majority of the iron deposits contains apatite as minor mineral and underwent metamorphism-alteration in varying degrees. The mode of formation and geological setting of Esfordi iron-apatite deposit in this region with an average of 13.9 wt% apatite are discussed using geochemical and mineralogical data along with field description. Materials and methods Fifty-three samples of mineralized zones and host rocks collected from 7 cross sections were studied by conventional microscopic methods. Seven representative samples were determined by XRD at Department of Physics, Shiraz University. Fifteen and six samples were also analyzed for major and trace elements using XRF at Binaloud Co. Iran, and ICP-MS at Labwest Minerals Analysis, Australia, respectively. Microprobe analyses were carried out on apatite in Geo Forschungs Zentrum Telegrafenberg at Potsdam University, Germany. Results Field observation shows that igneous host rocks in Esfordi were intensively altered by hydrothermal fluids. The ores are surrounded by wide altered halos. Petrographic investigation indicated that the most important alterations are of potassic, carbonatitic and silicification types. Magnetite and apatite occur as major minerals, accompanied by minor hematite and goethite in the mineralized zones. Rare Earth Element (REE minerals are present as minor phases in the ores. Three apatite mineralization types (vein, massive, and disseminated were

  7. Parasitic Infections of Free –Range Chickens from Golestan Province, Iran

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    S Rahbari

    2009-07-01

    Full Text Available "nBackground: The aim of this study was to determine the prevalence, intensity, and species of internal and external parasites of native fowls from Golestan Province, north of Iran. "nMethods: During 2007, different organs of 26 and 24  adult female native fowls  collected   from hu­mid parts (Gorgan, Kord Kooy, Ramian and Bandar Gaz and dry regions  (Gonbad Kavoos, and Ban­dar Torkaman of Golestan Province,  respectively were searched for parasite. Two blood smears taken from each bird were stained with Geimsa. External parasites and nematodes were preserved in 70 % alcohol containing 5% glycerin. Cestodes were fixed in 10% formalin and stained with carmine acid for further studies. "nResults: Fifteen species of parasites were collected from alimentary canals, lungs, feathers and subcu­ta­neous nodules as follows: Alimentary canal: Ascaridia galli (56%, Heterakis gallinarum (24%, Capil­laria anatis (4%, Cheilospirura hamulosa (4%, Raillietina tetragona (58%, R. echinobothrida (6%, and Choanotaenia infundibulum (8%; Lungs: Syngamus trachea (16%; Feathers: Monopon gallinae (40%, Menacanthus stramineus (40%, Liperus caponis (32%, Goniodes dissimilis (38%, Cuclogaster heterographus (8%, Dermanissus gallinae (20% and subcutaneous nodules: Lami­nosioptes cysticola (6%. "nConclusion: The frequency distribution of most species was low. L. cysticola is the first host and distri­bution record for Iran

  8. Short-range variability of soil pH in a regional geochemical survey, communicating uncertainty to the data user

    Science.gov (United States)

    Ander, Louise; Knights, Kate; Lark, Murray

    2015-04-01

    The north of Ireland is well-furnished with geochemical data after completion of the Tellus survey of Northern Ireland and the Tellus Border survey of six northern counties of the Republic of Ireland. These data are of considerable interest to the agricultural sector, in particular the data on soil pH. However, a geochemical survey at regional scale cannot resolve significant variation of soil pH, in particular effects of soil management and fine-scale variation of superficial material. This leads to uncertainties in the mapped soil pH which must be accounted for when making decisions about management interventions, including more detailed local sampling. In this poster we show how uncertainty of predicted soil pH, relative to established threshold values, can be quantified by disjunctive kriging. The uncertainty is expressed in terms of probabilities. We show how this can be communicated to the data user by means of the calibrated phrases of the IPCC, using results from recent research on its efficacy to modify its presentation.

  9. Modeling the geochemical distribution of rare earth elements (REEs using multivariate statistics in the eastern part of Marvast placer, the Yazd province

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    Amin Hossein Morshedy

    2017-07-01

    Full Text Available Introduction Nowadays, exploration of rare earth element (REE resources is considered as one of the strategic priorities, which has a special position in the advanced and intelligent industries (Castor and Hedrick, 2006. Significant resources of REEs are found in a wide range of geological settings, including primary deposits associated with igneous and hydrothermal processes (e.g. carbonatite, (per alkaline-igneous rocks, iron-oxide breccia complexes, scarns, fluorapatite veins and pegmatites, and secondary deposits concentrated by sedimentary processes and weathering (e.g. heavy-mineral sand deposits, fluviatile sandstones, unconformity-related uranium deposits, and lignites (Jaireth et al., 2014. Recent studies on various parts of Iran led to the identification of promising potential of these elements, including Central Iran, alkaline rocks in the Eslami Peninsula, iron and apatite in the Hormuz Island, Kahnouj titanium deposit, granitoid bodies in Yazd, Azerbaijan, and Mashhad and associated dikes, and finally placers related to the Shemshak formation in Marvast, Kharanagh, and Ardekan indicate high concentration of REE in magmatogenic iron–apatite deposits in Central Iran and placers in Marvast area in Yazd (Ghorbani, 2013. Materials and methods In the present study, the geochemical behavior of rare earth elements is modeled by using multivariate statistical methods in the eastern part of the Marvast placer. Marvast is located 185 km south of the city of Yazd in central Iran between Yazd and Mehriz. This area lies within the southeastern part of the Sanandaj-Sirjan Zone (Alipour-Asll et al., 2012. The samples of 53 wells were analyzed for Whole-rock trace-element concentrations (including REE by inductively coupled plasma-mass spectrometry (ICP-MS (GSI, 2004. The clustering techniques such as multivariate statistical analysis technique can be employed to find appropriate groups in data sets. One of the main objectives of data clustering

  10. Shallow subsurface temperature surveys in the basin and range province, U.S.A.-I. Review and evaluation

    Science.gov (United States)

    Olmsted, F.H.; Welch, A.H.; Ingebritsen, S.E.

    1986-01-01

    Temperature surveys at depths of 1-2 m have had varying success in geothermal exploration in the Basin and Range province. The most successful surveys have identified patterns of near-surface thermal-fluid flow within areas of less than 2 km2. Results have been less consistent in larger areas where zones of hydrothermal upflow are less well known, nongeothermal perturbing factors are significant and lateral variations in shallow subsurface temperature are small. Nongeothermal perturbations can be minimized by use of mean annual temperatures instead of synoptic temperatures, by physically based simulation of ground temperatures or by statistical modeling. ?? 1986.

  11. EFFECT OF COMPOSITION OF SELECTED GROUNDWATERS FROM THE BASIN AND RANGE PROVINCE ON PLUTONIUM, NEPTUNIUM, AND AMERICIUM SPECIATION.

    Science.gov (United States)

    Rees, Terry F.; Cleveland, Jess M.; Nash, Kenneth L.

    1984-01-01

    The speciation of plutonium, neptunium, and americium was determined in groundwaters from four sources in the Basin and Range Province: the lower carbonate aquifer, Nevada Test Site (NTS) (Crystal Pool); alluvial fill, Frenchman Flat, NTS (well 5C); Hualapai Valley, Arizona (Red Lake south well); and Tularosa Basin, New Mexico (Rentfrow well). The results were interpreted to indicate that plutonium and, to a lesser extent, neptunium are least soluble in reducing groundwaters containing a large concentration of sulfate ion and a small concentration of strongly complexing anions. The results further emphasize the desirability of including studies such as this among the other site-selection criteria for nuclear waste repositories.

  12. New insights into the petrogenesis of the Jameson Range layered intrusion and associated Fe-Ti-P-V-PGE-Au mineralisation, West Musgrave Province, Western Australia

    Science.gov (United States)

    Karykowski, Bartosz T.; Polito, Paul A.; Maier, Wolfgang D.; Gutzmer, Jens; Krause, Joachim

    2017-02-01

    The Mesoproterozoic Jameson Range intrusion forms part of the Giles Complex, Musgrave Province, Western Australia. It is predominantly mafic in composition comprising olivine-bearing gabbroic lithologies with variable amounts of magnetite and ilmenite. Lithologies containing more than 50 vol% magnetite and ilmenite are classified as magnetitites. The Jameson Range hosts several of these magnetitites forming laterally extensive layers, which can be traced for at least 19 km as continuous magnetic anomalies. Similar occurrences of magnetitites are known from the upper parts of other layered intrusions, such as the Bushveld Complex. In addition, the intrusion hosts several P-rich zones, one of which is at least 59 m in thickness containing 1.0 wt% P2O5. The P-rich zones are not directly associated with the magnetitites, but they mostly occur slightly above them. The mineral chemistry of the Jameson Range cumulates is relatively evolved with olivine compositions ranging from Fo44 to Fo60 and plagioclase compositions varying between An56 and An59. The Mg# (100 × Mg / (Mg + Fe)) of ortho- and clinopyroxene ranges from 60 to 61 and from 70 to 75, respectively. Magnetite compositions are characterised by low TiO2 concentrations varying from 0.39 to 3.04 wt% representing near end-member magnetite with up to 1.2 wt% Cr and 1.3 wt% V, respectively. The basal magnetite layer reaches up to 68.8 wt% Fe2O3(t) and 24.2 wt% TiO2, and it is also markedly enriched in Cu (up to 0.3 wt% Cu), V (up to 1.05 wt% V2O5) and platinum-group elements (PGE) (up to 2 ppm Pt + Pd). Sulphide minerals comprising bornite, chalcopyrite and minor pentlandite occur finely disseminated in the magnetitite and account for the elevated base metal and PGE concentrations. Modelling indicates that the PGE mineralisation was formed at very high R factors of up to 100,000, which is typical for PGE reefs in layered intrusions. Whole rock geochemical and mineralogical data of the magnetite layers and their host

  13. Fluoride concentrations in a range of ready-to-drink beverages consumed in Heilongjiang Province, north-east China.

    Science.gov (United States)

    Liu, Ying; Maguire, Anne; Tianqui, Guan; Yanguo, Shi; Zohoori, Fatemeh V

    2017-03-01

    Consumption of ready-to-drink beverages, as a potential source of fluoride (F), has increased considerably in China over the last decade. To help inform the public and policy makers, this study aimed to measure F concentration of ready-to-drink beverages on sale in Heilongjiang province, north east China. Three batches of 106 drink products manufactured by 26 companies were purchased from the main national supermarkets in Harbin, Heilongjiang province, China. The F concentration of all samples was determined, in triplicate, using a fluoride ion-selective electrode in conjunction with a meter and a direct method of analysis. The products were categorised into 10 groups according to product type. F concentrations of the samples ranged from 0.012-1.625 mg/l with a mean of 0.189 mg/l and a median of 0.076 mg/l. More than half of the products (55%) had an F concentration of ≤0.1 mg/l, while 0.7 mg/l. The 'tea with milk' group contained the highest mean F concentration (1.350 mg/l), whereas the lowest mean F concentration (0.027 mg/l) was found for the 'fruit juice' group. For some products, such as tea, fruit juice and carbonated beverages, there were substantial variations in F concentration between batches, manufacturers and production sites. In conclusion, ready-to-drink products (apart from tea), sold in Heilongjiang province, China, when consumed in moderation are unlikely to constitute a substantial risk factor for the development of dental or skeletal fluorosis.

  14. Lead poisoning in shooting-range workers in Gauteng Province, South Africa: Two case studies.

    Science.gov (United States)

    Mathee, A; De Jager, P; Naidoo, S; Naicker, N

    2017-03-29

    Lead exposure constitutes a major public health concern globally. Relative to developed nations, lead exposure is understudied and poorly addressed in Africa, and there is a dearth of information available to inform lead poisoning prevention strategies, even in high-risk groups such as workers in shooting ranges who are potentially exposed to lead daily. Two workers at a private shooting range in Gauteng, South Africa (SA), had blood lead levels and exposure histories taken. Workers had highly elevated blood lead levels and clinical symptoms associated with elevated blood lead levels. Workers in private SA shooting ranges are vulnerable to lead exposure and poisoning, and scaled-up action is required to protect them and their families, as well as shooting-range users, from lead and the related health risks.

  15. Lead poisoning in shooting-range workers in Gauteng Province, South Africa: Two case studies

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    S Naidoo

    2017-04-01

    Full Text Available Background. Lead exposure constitutes a major public health concern globally. Relative to developed nations, lead exposure is understudied and poorly addressed in Africa, and there is a dearth of information available to inform lead poisoning prevention strategies, even in high-risk groups such as workers in shooting ranges who are potentially exposed to lead daily. Methods. Two workers at a private shooting range in Gauteng, South Africa (SA, had blood lead levels and exposure histories taken. Results. Workers had highly elevated blood lead levels and clinical symptoms associated with elevated blood lead levels. Conclusion. Workers in private SA shooting ranges are vulnerable to lead exposure and poisoning, and scaled-up action is required to protect them and their families, as well as shooting-range users, from lead and the related health risks.

  16. ATTENUATION OF SEISMIC WAVES IN THE LITHOSPHERE OF THE NORTHERN PART OF THE BASIN AND RANGE PROVINCE

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    А. А. Dobrynina

    2013-01-01

    Full Text Available This paper presents results of the study of attenuation of seismic waves in the lithosphere and upper mantle of the northern part of the Basin and Range Province (BRP (Fig. 1. In this study, the coda-wave method [Aki, Chouet, 1975] is applied to process data collected in the seismic experiment conducted in 1988–1989, PASSCAL Basin and Range Passive Seismic Experiment [Owens, Randall, 1989], including records of 66 earthquakes and explosions (Mb=1.1–5.0 which occurred in BRP (Fig. 2.The effective seismic quality factor by the coda is calculated using the single-backscattering model [Aki, Chouet, 1975]. The QC values are calculated for 18 values of the lapse time window W from 10 to 95 sec with the step of 5 sec at six (6 central frequencies (0.3, 0.75, 1.5, 3.0, 6.0, and 12.0 Hz. In total, 7776 individual measurements of QC were done. It is observed that the quality factor QC is strongly dependent on the frequency and the lapse time window W: QC increases from 12±6 to 359±17 for the central frequencies of 0.3 and 12.0 Hz when the lapse time window is W=10 sec and from 87±6 to 1177±87 for the same frequencies when W=95 sec (Fig. 6. On the basis of the QС values obtained for all the lapse time windows W empirical relationships of quality factors and frequencies are calculated according to [Mitchell, 1981], and values of quality factor Q0 at reference frequency f0 (f0=1 Hz and frequency parameter n (which is close to 1 and varies depending on the heterogeneity of the medium [Aki, 1981] are obtained. In this study, Q0 varies from 60±8 to 222±17, the frequency parameter ranges from 0.57±0.04 to 0.84±0.05, and the attenuation coefficient δ varies from 0.015 to 0.004 km–1, depending on W (Fig. 8; similar values of attenuation parameters are typical of regions with high tectonic activity [Mak et al., 2004].In the single-backscattering model, the dependence of the attenuation parameters from the lapse time window can be explained in terms

  17. Mafic microgranular enclaves (MMEs) in amphibole-bearing granites of the Bintang batholith, Main Range granite province: Evidence for a meta-igneous basement in Western Peninsular Malaysia

    Science.gov (United States)

    Quek, Long Xiang; Ghani, Azman A.; Chung, Sun-Lin; Li, Shan; Lai, Yu-Ming; Saidin, Mokhtar; Amir Hassan, Meor H.; Muhammad Ali, Muhammad Afiq; Badruldin, Muhammad Hafifi; Abu Bakar, Ahmad Farid

    2017-08-01

    Mafic microgranular enclaves (MMEs) with varying sizes are a common occurrence in porphyritic amphibole-bearing granite of the Bintang batholith, which is part of the Main Range granite province. The MMEs of the amphibole-bearing granite are significant as they are related to the I-type granitoids within the Main Range granite province. Petrographic observations indicate the MMEs are mantled with coarse mafic crystals on the rim and contain similar minerals to the host (biotite + plagioclase + K-feldspar + pyroxene + amphibole), but in different proportions. Geochemical analyses indicate the MMEs are shoshonitic with mg# comparable to the granite host. Substantial similarities exist between the MMEs and granite with regards to the normalized rare earth element patterns and trace elements variation diagrams. The MMEs and granite are not completely coeval as the MME zircon U-Pb age (224.3 ± 1.2 Ma) is slightly older than its granite host zircon U-Pb age (216.2 ± 1.0 Ma). The age difference is also observed from the unusual 500 m-long Tiak MME and another amphibole-bearing granite sample from the south of the pluton, which yield 221.8 ± 1.1 Ma and 217.4 ± 1.0 Ma respectively. The oldest inherited zircons found in the MME and granite are 2.0 Ga and 1.3 Ga respectively, while the oldest xenocrystic zircons found in the MME and granite are 2.5 Ga and 1.5 Ga respectively. Identical negative εHf(t) values from zircon U-Pb and Lu-Hf analysis for a MME-granite pair indicates the rocks were generated from a similar, ancient source in the basement. Combining the results, we suggest that incongruent melting of an ancient protolith played an important part in the evolution of the MMEs and granite and the MMEs characteristics are best explained as restite. The zircon Hf model age (two-stage) and the I-type peritectic and restitic mineral assemblages in the MMEs further describe the protolith as Early Proterozoic-Late Archean (≈2.5 Ga) meta-igneous rock. This shows the

  18. A Systematic Regional Trend in Helium Isotopes Across the NorthernBasin and Range Province, Western North America

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack; van Soest, Matthijs C.

    2005-03-22

    An extensive study of helium isotopes in fluids collectedfrom surface springs, fumaroles and wells across the northern Basin andRange Province reveals a systematic trend of decreasing 3He/4He ratiosfrom west to east. The western margin of the Basin and Range ischaracterized by mantle-like ratios (6-8 Ra) associated with active orrecently active crustal magma systems (e.g. Coso, Long Valley, Steamboat,and the Cascade volcanic complex). Moving towards the east, the ratiosdecline systematically to a background value of ~;0.1 Ra. The regionaltrend is consistent with extensive mantle melting concentrated along thewestern margin and is coincident with an east-to-west increase in themagnitude of northwest strain. The increase in shear strain enhancescrustal permeability resulting in high vertical fluid flow rates thatpreserve the high helium isotope ratios at the surface. Superimposed onthe regional trend are "helium spikes", local anomalies in the heliumisotope composition. These "spikes" reflect either local zones of mantlemelting or locally enhanced crustal permeability. In the case of theDixie Valley hydrothermal system, it appears to be a combination ofboth.

  19. Range of soil and climate characteristics appropriate for Pistacia atlantica forest development and rehabilitation (case study: Fars province, Iran

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    Nejabat Masoud

    2017-03-01

    Full Text Available Investigation of ranges of soil and climate characteristics appropriate for the tolerant species: Pistacia atlantica subsp. mutica according to field study was the main objective of this research. This study was carried out based on random sampling across 20×20 km wild pistachio forests of Fars province (Iran. Results showed that mountainous and hilly lands are the main land types that pistachio species have evolved on. Statistical analysis of physical and chemical soil characteristics based on principal component analysis (PCA method showed that wide ranges in soil characteristics, even up to about 40% differentiation in some measured properties, did not restricts this subspecies natural growth. The main growth limiting factors were shallow soil depth and light soil texture that decreased storage capacity of soil moisture, necessary for wild pistachios survival during drought and long dry periods. Climatic elements were analysed through the same approach and showed that temperature, precipitation and wind with overall variability of 85.9% were the most effectual factors. Pistacia atlantica subsp. mutica is one of the species refractory to various soil conditions and adapted to weak soils for the establishment and rehabilitation of forests in semi-arid regions.

  20. Carbon monoxide degassing from seismic fault zones in the Basin and Range province, west of Beijing, China

    Science.gov (United States)

    Sun, Yutao; Zhou, Xiaocheng; Zheng, Guodong; Li, Jing; Shi, Hongyu; Guo, Zhengfu; Du, Jianguo

    2017-11-01

    Degassing of carbon monoxide (CO), which plays a significant role in the contribution of deep carbon to the atmosphere, commonly occurs within active fault zones. CO degassing from soil to the atmosphere in the Basin and Range province, west of Beijing (BRPB), China, was investigated by in-situ field measurements in the active fault zones. The measured concentrations of CO in soil gas in the BRPB ranged from 0.29 × 10-6 to 1.1 × 10-6 with a mean value of 0.6 × 10-6, which is approximately twice as large as that in the atmosphere. Net fluxes of CO degassing ranged from -48.6 mg m-2 d-1 to 12.03 mg m-2 d-1. The diffusion of CO from soil to the atmosphere in the BRPB was estimated to be at least 7.6 × 103 ton/a, which is comparable to the corresponding result of about 1.2 × 104 ton/a for CO2. CO concentrations were spatially heterogeneous with clearly higher concentrations along the NE-SW trending in the BRPB. These elevated values of CO concentrations were also coincident with the region with low-velocity and high conductivity in deep mantle, and high Poisson's ratio in the crust, thereby suggesting that CO degassing from the soil might be linked to upwelling of the asthenospheric mantle. Other sources of CO in the soil gas are suggested to be dominated by chemical reactions between deep fluids and carbonate minerals (e.g., dolomite, limestone, and siderite) in country rocks. Biogenic processes may also contribute to the CO in soil gas. The spatial distribution patterns of CO concentrations are coincident with the stress field, suggesting that the concentrations of CO could be a potential indicator for crustal stress field and, hence is potential useful for earthquake monitoring in the BRPB.

  1. Geochemical Evidence of Island-Arc Origin for Sumatra Island; A New Perspective based on Volcanic Rocks in Lampung Province, Indonesia

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    Iskandar Zulkarnain

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v6i4.128Since decades, Sumatra Island is considered as the Eurasia continental margin where the Indian Ocean plate has been subducted oblique beneath the continental plate of Sumatra. But, the occurrences of volcanic rocks in almost all areas of Lampung Province in the southernmost of Sumatra Island, as the presence of the Quaternary Tanggamus Volcano in the western part of the province together with the Quaternary Rajabasa Volcano in the eastern area cannot be justified using the consideration. Spider diagrams of trace and rare earth elements of volcanic rocks from the western and eastern areas of the province reveal that the rocks come from three different tectonic settings, namely island-arc, active continental margin (ACM, and intra continental plate. All basalt and one dacite of western volcanic rocks show a character of island-arc origin, while the eastern volcanic rocks are reflecting characters of ACM and intra continental plate. Plot of the rocks in the diagram of Ta/Yb versus Ce/P and in Ta/Yb versus Th/Yb confirmed the tectonic environments and specifically classify the intra continental plate into Within Plate Volcanic Zone (WPVZ. The island-arc group is characterized by Ta/Yb ratio of less than 2.0 and Ce/P less than 1.8. The ACM group is recognized having Ta/Yb ratio between 2 and 4 with Ce/P more 1.8, while the WPVZ group is defined as a group having Ta/Yb more than 6 and Ce/P more than 1.0. The result indicates that the western part of Sumatra is an island-arc fragment and the eastern part belongs to the Eurasia continental margin. The concentration of volcanics having ACM character from areas around the Sumatra Fault System to the east indicates that the collision zone between the Sumatra island-arc fragments with the Eurasia continental margin is probably located along the SFS. More statistical data is still needed from other Sumatra volcanics to confirm this conclusion.

  2. Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste. Part I. Introduction and guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Bedinger, M.S.; Sargent, K.A.; Reed, J.E.

    1984-12-31

    The US Geological Survey`s program for geologic and hydrologic evaluation of physiographic provinces to identify areas potentially suitable for locating repository sites for disposal of high-level nuclear wastes was announced to the Governors of the eight states in the Basin and Range Province on May 5, 1981. Representatives of Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, and Utah, were invited to cooperate with the federal government in the evaluation process. Each governor was requested to nominate an earth scientist to represent the state in a province working group composed of state and US Geological Survey representatives. This report, Part I of a three-part report, provides the background, introduction and scope of the study. This part also includes a discussion of geologic and hydrologic guidelines that will be used in the evaluation process and illustrates geohydrologic environments and the effect of individual factors in providing multiple natural barriers to radionuclide migration. 27 refs., 6 figs., 1 tab.

  3. Foraging range and habitat use by Cape Vulture Gyps coprotheres from the Msikaba colony, Eastern Cape province, South Africa

    Directory of Open Access Journals (Sweden)

    Morgan B. Pfeiffer

    2015-03-01

    Full Text Available Despite the extent of subsistence farmland in Africa, little is known about endangered species that persist within them. The Cape Vulture (Gyps coprotheres is regionally endangered in southern Africa and at least 20% of the population breeds in the subsistence farmland area previously known as the Transkei in the Eastern Cape province of South Africa. To understand their movement ecology, adult Cape Vultures (n = 9 were captured and fitted with global positioning system/global system for mobile transmitters. Minimum convex polygons (MCPs,and 99% and 50% kernel density estimates (KDEs were calculated for the breeding and non breeding seasons of the Cape Vulture. Land use maps were constructed for each 99% KDE and vulture locations were overlaid. During the non-breeding season, ranges were slightly larger(mean [± SE] MCP = 16 887 km2 ± 366 km2 than the breeding season (MCP = 14 707 km2 ± 2155 km2. Breeding and non-breeding season MCPs overlapped by a total of 92%. Kernel density estimates showed seasonal variability. During the breeding season, Cape Vultures used subsistence farmland, natural woodland and protected areas more than expected. In the non-breeding season, vultures used natural woodland and subsistence farmland more than expected, and protected areas less than expected. In both seasons, human-altered landscapes were used less, except for subsistence farmland.Conservation implications: These results highlight the importance of subsistence farm land to the survival of the Cape Vulture. Efforts should be made to minimise potential threats to vultures in the core areas outlined, through outreach programmes and mitigation measures.The conservation buffer of 40 km around Cape Vulture breeding colonies should be increased to 50 km.

  4. Late Paleozoic to Mesozoic extension in southwestern Fujian Province, South China: Geochemical, geochronological and Hf isotopic constraints from basic-intermediate dykes

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    Sen Wang

    2017-05-01

    Full Text Available The tectonic evolution of SE China block since late Paleozoic remains debated. Here we present a new set of zircon U-Pb geochronological, Lu-Hf isotopic data and whole-rock geochemistry for two stages of basic-intermediate dykes from the southwestern Fujian. The samples were collected from the NE-trending (mainly diabases and NW-trending (mainly diabasic diorites dykes and yielded zircon U-Pb ages of 315 and 141 Ma, with εHf (t values of −8.90 to 7.49 and −23.39 to −7.15 (corresponding to TDM2 values of 850 to 1890 Ma and 737 to 2670 Ma, respectively. Geochemically these rocks are characterized by low TiO2 (0.91–1.73 wt.% and MgO (3.04–7.96 wt.%, and high Al2O3 (12.5–16.60 wt.% and K2O (0.60–3.63 wt.%. Further they are enriched in LREEs and LILEs (Rb, Ba, Th and K, but depleted in HFSEs (Nb, Ta and Zr. The tectonic discrimination analysis revealed that the dykes were formed in an intraplate extensional environment. However, the NW trending dykes show crust-mantle mixed composition, which indicate an extensional tectonic setting with evidence for crustal contamination. The SE China block experienced two main stages of extensional tectonics from late Carboniferous to early Cretaceous. The tectonic evolution of the SE China block from late Devonian to Cretaceous is also evaluated.

  5. Discrimination between long-range transport and local pollution sources and precise delineation of polluted soil layers using integrated geophysical-geochemical methods.

    Science.gov (United States)

    Magiera, Tadeusz; Szuszkiewisz, Marcin; Szuszkiewicz, Maria; Żogała, Bogdan

    2017-04-01

    The primary goal of this work was to distinguish between soil pollution from long-range and local transport of atmospheric pollutants using soil magnetometry in combination with geochemical analyses and precise delineation of polluted soil layers by using integrated magnetic (surface susceptibility, gradiometric measurement) and other geophysical techniques (conductivity and electrical resistivity tomography). The study area was located in the Izery region of Poland (within the "Black Triangle" region, which is the nickname for one of Europe's most polluted areas, where Germany, Poland and the Czech Republic meet). The study area was located in the Forest Glade where the historical local pollution source (glass factory) was active since and of 18th until the end of 19th century. The magnetic signal here was the combination of long-range transport of magnetic particles, local deposition and anthropogenic layers containing ashes and slags and partly comprising the subsoil of modern soil. Application of the set of different geophysical techniques enabled the precise location of these layers. The effect of the long-range pollution transport was observed on a neighboring hill (Granicznik) of which the western, northwestern and southwestern parts of the slope were exposed to the transport of atmospheric pollutants from the Czech Republic and Germany and Poland. Using soil magnetometry, it was possible to discriminate between long-range transport of atmospheric pollutants and anthropogenic pollution related to the former glasswork located in the Forest Glade. The magnetic susceptibility values (κ) as well as the number of "hot-spots" of volume magnetic susceptibility is significantly larger in the Forest Glade than on the Granicznik Hill where the κ is pollution originating from lignite power plants along the Polish border, while the southeastern part of the hill was shielded by crag and tail formation. Also the set of chemical elements connected with magnetic particles

  6. Hantaan virus surveillance targeting small mammals at nightmare range, a high elevation military training area, Gyeonggi Province, Republic of Korea.

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    Terry A Klein

    Full Text Available Rodent-borne disease surveillance was conducted at Nightmare Range (NM-R, near the demilitarized zone in northeast Gyeonggi Province, Republic of Korea, to identify hemorrhagic fever with renal syndrome (HFRS risks for a mountainous high-elevation (500 m military training site. Monthly surveys were conducted from January 2008-December 2009. A total of 1,720 small mammals were captured belonging to the Orders Rodentia [Families, Sciuridae (1 species and Muridae (7 species] and Soricomorpha [Family, Soricidae (1species]. Apodemus agrarius, the primary reservoir for Hantaan virus (HTNV, accounted for 89.9% (1,546 of all small mammals captured, followed by Myodes regulus (4.0%, Crocidura lasiura (3.9%, Micromys minutus (1.4%, Mus musculus (0.3%, Microtus fortis (0.2%, Apodemus peninsulae (0.2%, Tamias sibiricus (0.1%, and Rattus norvegicus (<0.1%. Three species were antibody-positive (Ab+ for hantaviruses: A. agrarius (8.2%, M. minutus (4.2%, and C. lasiura (1.5%. HTNV specific RNA was detected in 93/127 Ab+ A. agrarius, while Imjin virus specific RNA was detected in 1/1 Ab+ C. lasiura. Overall, hantavirus Ab+ rates for A. agrarius increased with weight (age and were significantly higher among males (10.9% than females (5.1% (P<0.0001. High A. agrarius gravid rates during the fall (August-September were associated with peak numbers of HFRS cases in Korea that followed high gravid rates. From 79 RT-PCR positive A. agrarius, 12 HTNV RNA samples were sequenced and compared phylogenetically based on a 320 nt sequence from the GC glycoprotein-encoding M segment. These results demonstrate that the HTNV isolates from NM-R are distinctly separated from HTNV isolated from the People's Republic of China. These studies provide for improved disease risk assessments that identify military activities, rodent HTNV rates, and other factors associated with the transmission of hantaviruses during field training exercises.

  7. Long-range correlation and nonlinearity in geochemical time series of gas discharges from Mt. Etna, and changes with 2001 and 2002–2003 eruptions

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    A. Paonita

    2010-12-01

    Full Text Available In this paper, spectral and detrended fluctuation analyses, as well as time reversibility and magnitude-sign decomposition, have been applied to the 10-year time-series data resulting from geochemical monitoring of gas emissions on the flanks of Mt. Etna, and gases from a CO2 exploitation well located tens of kilometers from the volcano. The analysis of the time series which showed main effects of fractionation between gases due to selective dissolution in aquifers (e.g., the CO2 concentration series, revealed the occurrence of random fluctuations in time, typical of systems where several processes combine linearly. In contrast, the series of He isotopic composition exhibited power-law behavior of the second-order fluctuation statistics, with values of the scaling exponent close to 0.9. When related to the spectral exponent, this value indicates that the isotopic series closely resemble fractal flicker-noise signals having persistent long-range correlations. The isotopic signals also displayed asymmetry under time reversal and long-range correlation of the associated magnitude series, therefore it was statistically proved the presence of nonlinearity. Both long-range correlation and nonlinearity in time series have been generally considered as distinctive features of dynamic systems where numerous processes interact by feedback mechanisms, in accordance with the paradigm of self-organized criticality (SOC. Thus, it is here proposed that the system that generated the isotope series worked under conditions of SOC. Since the fluctuations of the isotope series have been related to magma degassing, the previous results place constraints on the dynamics of such process, and suggest that nonequilibrium conditions must be dominant. It remains unclear whether the signature of SOC is directly due to volatile degassing from magma, or if it derives from the interaction between melt and the stress field, which certainly influences magma

  8. Geochemical evidences for palaeoclimatic fluctuations at the Triassic-Jurassic boundary: southwestern margin of the Neotethys in the Salt Range, Pakistan

    Science.gov (United States)

    Iqbal, Shahid; Wagreich, Michael; Jan, Irfanullah; Kürschner, Wolfram Michael; Gier, Susanne

    2017-04-01

    The Triassic-Jurassic boundary interval reveals a change from warm-arid to a warm and humid climate in the Tethyan domain. Sea-level reconstruction records across the European basins during this interval reveal an end-Triassic global regression event and is linked to the Central Atlantic Magmatic Province (CAMP) activity and Pangaea breakup. In the Tethyan Salt Range of Pakistan a succession of Upper Triassic dolomites/green-black mudstones (Kingriali Formation), overlying quartzose sandstone, mudstones, laterites and Lower Jurassic conglomerates/pebbly sandstones (Datta Formation) provides information on the palaeoclimatic evolution of the area. Preliminary palynological results from the mudstones indicate a Rhaetian age for the Kingriali Formation and a Hettangian age for the Datta Formation. X-ray diffraction (XRD) analysis of the mudstones (upper part of the Kingriali Formation) indicates the presence of mainly illite while kaolinite is a minor component. The kaolinite content, a reflection of the advanced stage of chemical weathering and hence warm-humid conditions, increases up-section in the overlying sandstone-mudstone succession. The overlying laterite-bauxite horizons lack illite/smectite and are entirely composed of kaolinite, boehmite and haematite. At places these kaolinite rich horizons are mined in the area (Western Salt Range). The bulk rock geochemistry of the succession confirms a similar trend. The Chemical Index of Alteration (CIA) displays an increasing trend from the Upper Triassic shales (CIA 75-80) through the overlying sandstones/mudstones-laterites to the overlying quartz rich sandstones and mudstones (CIA 90-97). The overall results for the succession reveal an increasing chemical maturity trend (increase in the intensity of chemical weathering) from Rhaetian to Hettangian thereby supporting a change from warm-arid to a warm-humid palaeoclimate, probably extreme greenhouse conditions.

  9. Evidence from carbonate clumped isotope (Δ47) thermometry for the Late Cretaceous `Nevadaplano' in the northern Basin and Range Province

    Science.gov (United States)

    Snell, K. E.; Koch, P. L.; Eiler, J.

    2010-12-01

    From the middle Mesozoic to the present, the topography of the Basin and Range province (BRP) of the western Cordillera of North America has evolved in response to diverse tectonic forces, though the details are unclear for most of this period over most of this area. Much of the research on this region has focused on the Cenozoic record of paleoelevation during extension in the BRP. Some geodynamic models of this episode require high elevation prior to extension, but few studies have quantified the elevation of the pre-existing topography that developed during the Mesozoic in response to sustained convergence along the western coast of North America. Some workers have argued that the region was a high elevation plateau, the ‘Nevadaplano,’ analogous to the South American Altiplano. We tested this hypothesis using carbonate clumped isotope (Δ47) temperature estimates from Late Cretaceous lacustrine and paleosol carbonates. These samples come from the Sheep Pass Formation in east-central Nevada (presumed from geologic indications to be atop the plateau), and the North Horn Formation in central Utah on the eastern edge of the Sevier fold and thrust belt (presumably lower elevation). The textural characteristics, stable isotope compositions and carbonate clumped isotope temperature estimates from secondary carbonates in these units suggest that, despite moderate burial, primary carbonate samples have undergone little diagenetic alteration. Average temperatures from these two sites (23°C for the NV suite and 38°C for the UT suite) suggest that during the late Cretaceous (~66.5 Ma for the NV suite and 72 Ma for the UT suite), the NV site was ~15°C cooler than the UT site. This thermal gradient implies an elevation difference between the two sites of ~2.5 km, given certain assumptions: 1) there was little global or regional climate change during the ~5 million years between formation of these samples, 2) precipitation of both the lacustrine and paleosol carbonates

  10. The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range

    Science.gov (United States)

    Brown, Rafe M.; Siler, Cameron D.; Oliveros, Carl. H; Welton, Luke J.; Rock, Ashley; Swab, John; Weerd, Merlijn Van; van Beijnen, Jonah; Jose, Edgar; Rodriguez, Dominic; Jose, Edmund; Diesmos, Arvin C.

    2013-01-01

    Abstract We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study. PMID:23653519

  11. The amphibians and reptiles of Luzon Island, Philippines, VIII: the herpetofauna of Cagayan and Isabela Provinces, northern Sierra Madre Mountain Range.

    Science.gov (United States)

    Brown, Rafe M; Siler, Cameron D; Oliveros, Carl H; Welton, Luke J; Rock, Ashley; Swab, John; Weerd, Merlijn Van; van Beijnen, Jonah; Jose, Edgar; Rodriguez, Dominic; Jose, Edmund; Diesmos, Arvin C

    2013-01-01

    We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.

  12. More than one way to stretch: a tectonic model for extension along the plume track of the Yellowstone hotspot and adjacent Basin and Range Province

    Science.gov (United States)

    Parsons, Tom; Thompson, George A.; Smith, Richard P.

    1998-04-01

    The eastern Snake River Plain of southern Idaho poses a paradoxical problem because it is nearly aseismic and unfaulted although it appears to be actively extending in a SW-NE direction continuously with the adjacent block-faulted Basin and Range Province. The plain represents the 100-km-wide track of the Yellowstone hotspot during the last ˜16-17 m.y., and its crust has been heavily intruded by mafic magma, some of which has erupted to the surface as extensive basalt flows. Outside the plain's distinct topographic boundaries is a transition zone 30-100 km wide that has variable expression of normal faulting and magmatic activity as compared with the surrounding Basin and Range Province. Many models for the evolution of the Snake River Plain have as an integral component the suggestion that the crust of the plain became strong enough through basaltic intrusion to resist extensional deformation. However, both the boundaries of the plain and its transition zone lack any evidence of zones of strike slip or other accommodation that would allow the plain to remain intact while the Basin and Range Province extended around it; instead, the plain is coupled to its surroundings and extending with them. We estimate strain rates for the northern Basin and Range Province from various lines of evidence and show that these strains would far exceed the elastic limit of any rocks coupled to the Basin and Range; thus, if the plain is extending along with its surroundings, as the geologic evidence indicates, it must be doing so by a nearly aseismic process. Evidence of the process is provided by volcanic rift zones, indicators of subsurface dikes, which trend across the plain perpendicular to its axis. We suggest that variable magmatic strain accommodation, by emplacement and inflation of dikes perpendicular to the least principal stress in the elastic crust, allows the crust of the plain to extend nearly aseismically. Dike injection releases accumulated elastic strain but

  13. Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste: Part I, Introduction and guidelines

    Science.gov (United States)

    Bedinger, M.S.; Sargent, Kenneth A.; Reed, J.E.

    1984-01-01

    The U.S. Geological Survey's program for geologic and hydrologic evaluation of physiographic provinces to identify areas potentially suitable for locating repository sites for disposal of high-level nuclear wastes was announced to the Governors of the eight States in the Basin and Range Province on May 5, 1981. Representatives of Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, and Utah, were invited to cooperate with the Federal Government in the evaluation process. Each Governor was requested to nominate an Earth scientist to represent the State in a province working group composed of State and U.S. Geological Survey representatives. This report, Part I of a three-part report, provides the background, introduction and scope of the study. This part also includes a discussion of geologic and hydrologic guidelines that will be used in the evaluation process and illustrates geohydrologic environments and the effect of individual factors in providing multiple natural barriers to radionuclide migration.Part II is a reconnaissance characterization of the geologic and hydrologic factors to be used in the initial screening of the Basin and Range Province. Part III will be the initial evaluation of the Province and will identify regions that appear suitable for further study.The plan for study of the Province includes a stepwise screening process by which successively smaller land units are considered in increasing detail. Each step involves characterization of the geology and hydrology and selection of subunits for more intensive characterization. Selection of subunits for further study is by evaluation of geologic and hydrologic conditions following a set of guidelines. By representation on the Province Working Group, the States participate in a consultation and review role in: (1) Establishing geologic and hydrologic guidelines, and (2) characterizing and evaluating the Province. The States also participate in compilation of geologic and hydrologic data

  14. Geochemical Potamology

    Science.gov (United States)

    Gaillardet, J.

    2007-12-01

    The surface of our planet has been reworked by erosion and weathering processes throughout its geological history. Erosion processes are so fast that only 10's of millions years are necessary to remove major reliefs formed by plate tectonics. The material of the surface of the Earth has been recycled many times and the only visible remains of the ancient continental crust are in the sediments, in the atmosphere, or dissolved in the ocean. The chemical action of water on rocks and the associated physical gravity-driven processes are the key features of the « weathering engine ». Rivers are messengers from the surface of the Earth and integrate weathering processes at various scales of time and space. They provide a unique opportunity to have average information about the chemical interactions between surface waters and rocks, about their kinetics and about the major geochemical fractionations created by this major geological process. The study of rivers has been focused on small- and large-scale approaches, both giving different information. Although the sampling of small river basin allows us to simplify nature and separate the potential controlling parameters by fixing them (climate, vegetation, type of rock, slopes), the study of large rivers give global information about the composition of sediments, oceanic budgets, the significance of isotopic proxies. A geochemical potamology has developed over the last decades and we now more fully understand the critical questions that have to be solved. Numerous isotopic and elemental proxies have been developed to shed light on weathering processes, deciphering their control and calculate rates and timescales of erosion based on river products. A coupling between physical and chemical processes of erosion is now clear at different scales but probably the most important factor in controlling weathering style and rates are the protons. Low pH solutions are much more aggressive than neutral waters, as confirmed by

  15. Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste: Part II, Geologic and hydrologic characterization

    Science.gov (United States)

    Sargent, Kenneth A.; Bedinger, M.S.

    1985-01-01

    The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective areas for further study of geohydrologic environments for isolation of high-level radioactive waste. The data sets include: (1) Average precipitation and evaporation; (2) surface distribution of selected rock types; (3) tectonic conditions; and (4) surface- and ground -water hydrology and Pleistocene lakes and marshes.Rocks mapped for consideration as potential host media for the isolation of high-level radioactive waste are widespread and include argillaceous rocks, granitic rocks, tuffaceous rocks, mafic extrusive rocks, evaporites, and laharic breccias. The unsaturated zone, where probably as thick as 150 meters (500 feet), was mapped for consideration as an environment for isolation of high-level waste. Unsaturated rocks of various lithologic types are widespread in the Province.Tectonic stability in the Quaternary Period is considered the key to assessing the probability of future tectonism with regard to high-level radioactive waste disposal. Tectonic conditions are characterized on the basis of the seismic record, heat-flow measurements, the occurrence of Quaternary faults, vertical crustal movement, and volcanic features. Tectonic activity, as indicated by seismicity, is greatest in areas bordering the western margin of the Province in Nevada and southern California, the eastern margin of the Province bordering the Wasatch Mountains in Utah and in parts of the Rio Grande valley. Late Cenozoic volcanic activity is widespread, being greatest bordering the Sierra Nevada in California and Oregon, and bordering the Wasatch Mountains in southern Utah and Idaho.he arid to semiarid climate of the Province results in few perennial streams and lakes. A large part of the surface drainage is interior and the many closed basins commonly are occupied by playas or dry lake

  16. Mise en évidence de Provinces géochimiques dans les schistes bitumeux du Toarcien de l'est du bassin de Paris Geocheminical Provinces Revealed in Toarcien Oil Shales in the Eastern Paris Basin. Analysis of the Soluble Organic Fraction

    Directory of Open Access Journals (Sweden)

    Huc A. Y.

    2006-11-01

    Full Text Available L'étude de la matière organique soluble dans le chloroforme des schistes du Toarcien de la partie orientale du bassin de Paris met en évidence l'existence d'une province géochimique nord et d'une province géochimique sud dont la frontière commune se trouve dans la région de Fécocourt. La province septentrionale se caractérise par une influence du domaine continental (massif des Ardennes au niveau de l'apport organique. Alors que la province méridionale se révèle exempt d'apport terrestre. Ces résultats sont en accord avec les indications sédimentologiques fournies par la littérature et apportent une dimension géochimique à la paléogéographie de ce bassin. An anaalysis of soluble organic motter in the chloroform from Toarcian shales from the eastern part of the Paris Basin reveals the existence of a northern geochemical province and a southern geochemical province whose commun boundary lies in the Fecocourt region. The northern province is characterized by the influence of the continental domain (Ardennes range with regard to organic influx, whereas no terrestrial influx is found in the southern province. These findings agree with the sedimentological indications supplied by the literature and add a geochemical dimension to the paleogeography of this basin.

  17. Prevalence of ectoparasites in free-range backyard chickens, domestic pigeons (Columba livia domestica) and turkeys of Kermanshah province, west of Iran.

    Science.gov (United States)

    Rezaei, Farid; Hashemnia, Mohammad; Chalechale, Abdolali; Seidi, Shahin; Gholizadeh, Maryam

    2016-06-01

    This study was carried out on free-range backyard chickens, domestic pigeons (Columba livia domestica) and turkeys from May 2012 to April 2013 to determine the prevalence and identify the species of ectoparasites in Kermanshah province, west of Iran. Of the total of 600 free-range backyard chickens (185 ♂ and 415 ♀), 700 domestic pigeons (278 ♂ and 422 ♀) and 150 turkeys (53 ♂ and 97 ♀), 389 (64.83 %), 608 (86.85 %) and 54 (36 %) were infected with one or more parasites respectively. Eleven ectoparasites species including five of lice (50.16 % Menacanthus stramineus, 13.66 % Menopon gallinae, 4.83 % Cuclotogaster heterographus, 5.16 % Goniocotes gallinae, 2.33 % Goniodes gigas), three of mites (26.33 % Dermanyssus gallinae, 8.5 % Ornithonyssus bursa, 7 % Cnemidocoptes mutans), one of tick (78.66 % Argas persicus) and two of flea (12.33 % Echidnophaga gallinacea, 2 % Pulex irritans) were found in the backyard chickens. The domestic pigeons were infected with six species of parasites including: Columbicola columbae (61.7 %), M. gallinae (10.43 %), M. stramineus (9 %), D. gallinae (8.28 %), Argas reflexus (74.14 %) and Pseudolynchia canariensis (27.7 %). The ectoparasites species recorded in turkeys were M. gallinae (14 %), M. stramineus (8 %), D. gallinae (12.66 %), C. mutans (6 %), A. persicus (24.66 %) and E. gallinacean (6 %). This is the first survey to determine the prevalence and identify the species of ectoparasites among free-range backyard chicken, domestic pigeons and turkeys in Kermanshah province. The high prevalence rate of ectoparasites in free-range backyard chickens and domestic pigeons indicates that parasitic infection is a common problem in this area.

  18. Baltazor KGRA and vicinity, Nevada: geothermal reservoir assessment case study, northern Basin and Range province. Final report, 1 October 1978-31 January 1983

    Energy Technology Data Exchange (ETDEWEB)

    Wright, T.C.

    1983-01-01

    The Baltazor KGRA and McGee/Painted Hills geothermal prospects are located in northern Humboldt County, Nevada along the northwestern margin of the Basin and Range province. Exploration work other than drilling has included groundwater sampling, a microearthquake study, a geologic literature search and photogeologic mapping, compilation of aeromagnetic and gravity mapping, soil mercury surveying, electrical resistivity and self-potential surveys and detailed hydrothermal alteration mapping. Exploration drilling included 27 shallow temperature gradient holes, four intermediate-depth gradient wells and one 3703-foot deep test, Baltazor 45-14. The deep test penetrated Miocene rhyolite, andesite, basalt and andesitic basalt flows before excessive hold deviation forced an end to drilling and completion as a deep temperature observation well. A temperature survey two weeks after completion obtained a 119.7/sup 0/C (247.4/sup 0/F) reading at survey total depth, 1110 m (3640 feet).

  19. The role of active and ancient geothermal processes in the generation, migration, and entrapment of oil in the basin and Range Province, western USA. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Hulen, J.B.; Collister, J.W.; Curtiss, D.K. [and others

    1997-06-01

    The Basin and Range (B&R) physiographic province of the western USA is famous not only for its geothermal and precious-metal wealth, but also for its thirteen oil fields, small but in some cases highly productive. The Grant Canyon field in Railroad Valley, for example, for years boasted production of more than 6000 barrels of oil (BO) per day from just two wells; aggregate current production from the Blackburn field in Pine Valley commonly exceeds 1000 BO per day. These two and several other Nevada oil fields are unusually hot at reservoir depth--up to 130{degrees}C at depths as shallow as 1.1 km, up to three times the value expected from the prevailing regional geothermal gradient.

  20. Hydrothermal alteration maps of the central and southern Basin and Range province of the United States compiled from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data

    Science.gov (United States)

    Mars, John L.

    2013-01-01

    Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operator algorithms were used to map hydrothermally altered rocks in the central and southern parts of the Basin and Range province of the United States. The hydrothermally altered rocks mapped in this study include (1) hydrothermal silica-rich rocks (hydrous quartz, chalcedony, opal, and amorphous silica), (2) propylitic rocks (calcite-dolomite and epidote-chlorite mapped as separate mineral groups), (3) argillic rocks (alunite-pyrophyllite-kaolinite), and (4) phyllic rocks (sericite-muscovite). A series of hydrothermal alteration maps, which identify the potential locations of hydrothermal silica-rich, propylitic, argillic, and phyllic rocks on Landsat Thematic Mapper (TM) band 7 orthorectified images, and geographic information systems shape files of hydrothermal alteration units are provided in this study.

  1. Sustaining Biodiversity in the Oregon Coast Range: Potential effects of Forest Policies in a Multi-ownership Province

    Directory of Open Access Journals (Sweden)

    Brenda C. McComb

    2007-12-01

    Full Text Available To understand the potential effects of forest policies on sustaining biological diversity at broad scales, we used spatial simulation models to evaluate current and potential future habitat availability over 100 yr for three focal species: Pacific Fisher (Martes pennanti, Pileated Woodpecker (Dryocopus pileatus, and Warbling Vireo (Vireo gilvus. The habitats of these species represent a broad range of spatial scales and forest types. Area of habitat for fishers and Pileated Woodpeckers is predicted to increase over time under current forest land management policies. Habitat for Warbling Vireos is predicted to decline. These patterns are consistent with past analyses that predicted declines in diverse early successional forests and hardwood forests and increases in late-successional forests under current and two alternative policies. Land ownership influenced the spatial arrangement of habitat for all three focal species. Public lands subsidized habitat for wide-ranging species on adjacent private lands. A land use policy that required greater green tree retention on private lands seemed to result in modest increases in habitat quality over 100 yr for Pileated Woodpeckers. Thinning of plantations on federal lands had little effect on these focal species. Policy analyses such as these highlight incongruities between historic habitat patterns and contemporary spatial and temporal scales of habitat in managed landscapes. This information can be used to assess risks and inform the policy debates surrounding biodiversity conservation.

  2. Studies of geology and hydrology in the Basin and Range Province, Southwestern United States, for isolation of high-level radioactive waste - Basis of characterization and evaluation

    Science.gov (United States)

    Bedinger, M.S.; Sargent, K.A.; Langer, William H.; Sherman, Frank B.; Reed, J.E.; Brady, B.T.

    1989-01-01

    The geologic and hydrologic factors in selected regions of the Basin and Range province were examined to identify prospective areas for further study that may provide isolation of high-level radioactive waste from the accessible environment. The six regions selected for study were characterized with respect to the following guidelines: (1) Potential repository media; (2) Quaternary tectonic conditions; (3) climatic change and geomorphic processes; (4) ground-water conditions; (5) ground-water quality; and (6) mineral and energy resources.The repository medium will function as the first natural barrier to radionuclide travel by virtue of associated slow ground-water velocity. The principal rock types considered as host media include granitic, intermediate, and mafic intrusive rocks; argillaceous rocks; salt and anhydrite; volcanic mudflow (laharic) breccias; some intrusive rhyolitic plugs and stocks; partially zeolitized tuff; and metamorphic rocks. In the unsaturated zone, the permeability and hydrologic properties of the rocks and the hydrologic setting are more important than the rock type. Media ideally should be permeable to provide drainage and should have a minimal water fluxThe ground-water flow path from a repository to the accessible environment needs to present major barriers to the transport of radionuclides. Factors considered in evaluating the ground-water conditions include ground-water traveltimes and quality, confining beds, and earth materials favorable for retardation of radionuclides. Ground-water velocities in the regions were calculated from estimated hydraulic properties of the rocks and gradients. Because site-specific data on hydraulic properties are not available, data from the literature were assembled and synthesized to obtain values for use in estimating ground-water velocities. Hydraulic conductivities for many rock types having granular and fracture permeability follow a log-normal distribution. Porosity for granular and very weathered

  3. Paleoclimatic implications of fossil shoreline deposits in the southern basin and range province during the Pleistocene-Holocene transition

    Science.gov (United States)

    Kowler, A. L.

    2010-12-01

    Paleolake shoreline deposits throughout the southern Basin and Range (SBAR) signify past intervals of steady-state climatic conditions occuring during the late Pleistocene slightly before, as well as after the Last Glacial Maximum (LGM; ~23-19 Ka). Unfortunately, a lack of knowledge about the age of fossil shoreline deposits—due to C-14 related uncertainties and incomplete dating of shorelines—has resulted in a large gap in our knowledge about past climatic and surface hydrologic conditions in the SBAR. Several studies collectively reveal multiple lake level oscillations during the LGM and last part of the Pleistocene, with reasonably well dated shoreline deposits existing for only four paleolakes: one in central New Mexico (Estancia), two in southwestern New Mexico (Playas and Cloverdale), and one in southeastern Arizona (Cochise). In summary, there is evidence for a pre-LGM high-stand at Cochise (>26 Ka), LGM high-stands at Estancia and Cloverdale (>20-16 Ka), deglacial age high-stands at Playas and Cochise (16-13 Ka), and latest Pleistocene-early Holocene still stands of as yet undetermined elevation at Playas and Estancia (13-9K). Further, the absence of high-stands from 11-10 Ka suggests that the Younger Dryas climatic reversal—which is detected in the stable O isotopic composition of speleothems from Cave-of-the-Bells in southeastern Arizona—was marked there by a decrease in mean annual air temperature without a significant increase in precipitation. Alternatively, if a return to glacial precipitation levels did occur, then it was for an interval so short that sedimentological evidence was not preserved. This presentation will cover the afore mentioned chronologies, along with discussion about associated atmospheric circulation patterns in the SBAR and across western North America.

  4. Lithosphere-Asthenosphere Boundary Beneath Regions of Recent Volcanism in the Basin and Range Province and Mojave Desert

    Science.gov (United States)

    Forsyth, D. W.; Rau, C. J.; Plank, T.; Gazel, E.; Bendersky, C.

    2010-12-01

    Melt in the asthenosphere may contribute strongly to the development of the lithosphere-asthenosphere boundary (LAB) in some settings. We have compiled a set of vertical shear-velocity profiles beneath centers of recent (Hill and Amboy in the southern Mojave, the lithospheric lid extends to a depth of ~ 90 km. Minimum velocities in the LVZs beneath the higher velocity lids typically are 4.00-4.05 km/s, similar to that beneath the East Pacific Rise and too low to be caused by temperature alone without unreasonably high attenuation. Beneath other centers, like Big Pine, Lathrop Wells and Tahoe, there is no resolvable lid. The lid is either missing or too thin to resolve, but the absence of the lid/LVZ pattern seems to be due to a combination of lower velocities immediately beneath the Moho and higher velocities in the LVZ. Petrological indicators of temperature and depth of melting from basalt composition are in general agreement with the seismological observations, with the depth of last equilibration typically occurring near the top of the LVZ. Beneath Big Pine, for example, the equilibration temperatures are unusually low and the equilibration depth is 40 to 50 km, just below the Moho, in agreement with the lack of a distinct lid. Beneath Cima, equilibration depths are 60-70 km. Beneath Coso, equilibration depths are only slightly deeper than Big Pine, but the temperatures are higher, in agreement with the more pronounced LVZ and the presence of a thin lid. Beneath the Tabernacle Hill/Black Rock volcanic field in west-central Utah, there is a well-developed lid/LVZ structure, but the "high" velocity lid is only ~ 4.10 km/s while the underlying LVZ reaches as low as 3.90 km/s. This observation points to the importance of melt concentration or distribution controlling the velocities. Lid velocities are often relatively low (4.2-4.4 km/s) in the Basin and Range, indicating high temperatures, but here there is probably melt within the lid as well, with higher

  5. Geochemical Background and Baseline Values Determination and Spatial Distribution of Heavy Metal Pollution in Soils of the Andes Mountain Range (Cajamarca-Huancavelica, Peru)

    Science.gov (United States)

    Santos-Francés, Fernando; Alonso Rojo, Pilar; García Sánchez, Antonio

    2017-01-01

    Concentrations of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and one metalloid (As) as well as various parameters (pH, organic carbon, granulometric analysis and cation exchange capacity) were analyzed in 77 soil samples collected in the mining areas of La Zanja and Colquirrumi (Department of Cajamarca) and Julcani (Department of Huancavelica). Our study proposed geochemical baseline values for heavy metals in a natural region (La Zanja) from samples collected during the period of the environmental impact study (2006), that is, from an earlier period which occurred at the beginning of the exploitation of the current gold mine. The baseline values obtained were as follows: 8.26 mg·kg−1 for Cr; 56.97 mg·kg−1 for Ni; 22, 20 mg·kg−1 for the Cu; 47.42 mg·kg−1 for Zn; 27.50 mg·kg−1 for As; 4.36 mg·kg−1 for Cd; 4.89 mg·kg−1 for Hg, and 44.87 mg·kg−1 for Pb. Through the use of different indices of heavy metal contamination (geo-accumulation index (Igeo), improved Nemerow index (IIN) and potential ecological risk index (RI)), the degree of pollution caused by mining activities in two areas, Colquirrumi and Julcani, which have a high density of mining sites in operation, was determined. The values obtained from these indices indicated that the Colquirrumi region was the most contaminated, followed by Julcani. The area of La Zanja, despite being free of mining operations, presented slight diffuse pollution. Several positive correlations were obtained, with a high level of significance, between pH, organic carbon content, cation exchange capacity, and the Cr, Pb and Ni concentrations of the soils. The spatial distribution of the heavy metals was realized by means of the interpolation method of ordinary kriging. The results obtained and the experience gained in this work were necessary to facilitate the identification of soil contamination processes in high altitude areas of the Andes Western Cordillera (Peru) as a basis for taking appropriate

  6. Geochemical Background and Baseline Values Determination and Spatial Distribution of Heavy Metal Pollution in Soils of the Andes Mountain Range (Cajamarca-Huancavelica, Peru).

    Science.gov (United States)

    Santos-Francés, Fernando; Martinez-Graña, Antonio; Alonso Rojo, Pilar; García Sánchez, Antonio

    2017-07-31

    Concentrations of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and one metalloid (As) as well as various parameters (pH, organic carbon, granulometric analysis and cation exchange capacity) were analyzed in 77 soil samples collected in the mining areas of La Zanja and Colquirrumi (Department of Cajamarca) and Julcani (Department of Huancavelica). Our study proposed geochemical baseline values for heavy metals in a natural region (La Zanja) from samples collected during the period of the environmental impact study (2006), that is, from an earlier period which occurred at the beginning of the exploitation of the current gold mine. The baseline values obtained were as follows: 8.26 mg kg-1 for Cr; 56.97 mg kg-1 for Ni; 22, 20 mg kg-1 for the Cu; 47.42 mg kg-1 for Zn; 27.50 mg kg-1 for As; 4.36 mg kg-1 for Cd; 4.89 mg kg-1 for Hg, and 44.87 mg kg-1 for Pb. Through the use of different indices of heavy metal contamination (geo-accumulation index (Igeo), improved Nemerow index (IIN) and potential ecological risk index (RI)), the degree of pollution caused by mining activities in two areas, Colquirrumi and Julcani, which have a high density of mining sites in operation, was determined. The values obtained from these indices indicated that the Colquirrumi region was the most contaminated, followed by Julcani. The area of La Zanja, despite being free of mining operations, presented slight diffuse pollution. Several positive correlations were obtained, with a high level of significance, between pH, organic carbon content, cation exchange capacity, and the Cr, Pb and Ni concentrations of the soils. The spatial distribution of the heavy metals was realized by means of the interpolation method of ordinary kriging. The results obtained and the experience gained in this work were necessary to facilitate the identification of soil contamination processes in high altitude areas of the Andes Western Cordillera (Peru) as a basis for taking appropriate measures when restoring

  7. National Geochemical Database: Soil

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical analysis of soil samples from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are from the continental US...

  8. National Geochemical Database: Sediment

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical analysis of sediment samples from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are of stream sediment in...

  9. A Fold Province in the Hinterland of the Sevier Orogenic Belt in Eastern Nevada: A Valley and Ridge in the Basin and Range

    Science.gov (United States)

    Long, S. P.

    2014-12-01

    The overprinting effects of Cenozoic extensional tectonism hinder analysis of the style, geometry, and timing of Cordilleran contractional deformation in the hinterland of the Sevier fold-thrust belt in Nevada. To address this problem, a 1:250,000-scale paleogeologic map of eastern Nevada, showing spatial distributions of Paleozoic-Mesozoic rocks exposed beneath a Paleogene unconformity, divided out at the formation scale, is integrated with maps of dip magnitude for Paleozoic-Mesozoic and Tertiary rocks, published sedimentary thickness records, and a published reconstruction of Basin and Range extension, in order to define and regionally-correlate thrust faults and folds, and estimate the pre-extensional amplitude, wavelength, and limb dips of folds. A new structural province, the Eastern Nevada fold belt (ENFB) is defined, and consists of a 100-150 km-wide region containing as many as five 1st-order, N-trending folds that can be traced for map distances between 100-250 km, have amplitudes between 2-4 km, wavelengths between 20-40 km, pre-extensional limb dips typically between 10-30˚, and deform rocks as young as Jurassic and Early Cretaceous. No regional-scale thrust faults or decollemont horizons breach modern exposure levels in the ENFB. ENFB folds are interpreted to have formed above a deep (≥10 km below the Paleogene unconformity), blind decollemont or shear zone, perhaps the westward projection of the master decollemont of the Sevier fold-thrust belt. Two additional structural provinces of the Sevier hinterland, the Central Nevada thrust belt (CNTB) and Western Utah thrust belt (WUTB), represent zones of N-striking, E-vergent thrust faults and folds that each accommodated ca. 10 km of shortening. Both thrust belts branch northward off of the Sevier thrust belt, and are interpreted to represent contemporary, interior components of the Sevier thrust system. The CNTB, WUTB, and the intervening ENFB collectively record low-magnitude (a few 10's of km) upper

  10. Geochemistry of the Kalkarindji Magmas: Insights into the Source of the Oldest Phanerozoic Large Igneous Province

    Science.gov (United States)

    Ware, B. D.; Jourdan, F.; Hodges, K.; Tessalina, S.; Chiaradia, M.; Evins, L.; Gole, M.

    2014-12-01

    The Kalkarindji continental flood basalt province (CFBP) of northern Australia is the oldest Phanerozoic large igneous province (LIP) in the world. The extent of this Middle Cambrian LIP has been estimated to at least 2.1 x 106 km2 with exposures in Western Australia, Northern Territory, Queensland, and South Australia. The research into Kalkarindji is still in its infancy with only a handful of studies published. The rocks of the Kalkarindji province occur as lava flows, sills, dykes, and volcanic tuffs. Kalkarindji has been linked to an extinction event at the Early-Middle Cambrian boundary. The Kalkarindji province displays Low-Ti values and high SiO2 values compared to other large igneous provinces, enriched 87Sr/86Sr values, and low 187Os/188Os. This project presents a large data set of new geochemical analyses of the various constituents of the Kalkarindji CFBP. Source mixing calculations, assimilation and fractionation models, coupled with Monte Carlo simulations were carried out to understand the petrogenesis of the province. The trace element and 87Sr/86Sr values indicate a contribution of enriched crustal-like material into the source region; however, the Os values fall into typical mantle ranges. These geochemical patterns suggest that the mantle source(s) of the Kalkarindji CFBP has been directly enriched at some stage of history, before the emplacement of the province. This study will provide further insights into the magma source and origin processes needed to create one of the world's largest and oldest Phanerozoic large igneous provinces.

  11. Solubility of He, Ne, Ar, Kr and Xe in a basalt melt in the range 1250-1600/sup 0/C. Geochemical implications

    Energy Technology Data Exchange (ETDEWEB)

    Jambon, A.; Weber, H.; Braun, O.

    1986-03-01

    The solubility constant of Henry's law has been experimentally determined in a tholeiitic basalt melt. Equilibrium with air, a noble gas mix, and various mixtures of the two permitted us to assess the validity of Henry's law under 1 bar ambient pressure in the temperature range 1250-1600/sup 0/C. Mass spectrometric analyses of quenched products yield solubilities decreasing with increasing atomic size as: 56(11.), 25(3.), 5.9(0.9), 3.0(0.7) and 1.7(0.4) in units of 10/sup -5/ cm/sup 3/ STP/g-bar (with standard deviation) for He, Ne, Ar, Kr and Xe, respectively (1400/sup 0/C). Partial pressures were varied by factors between 100 and 2 x 10/sup 4/. The data permit calculation of the distribution of noble gases between melt and coexisting vesicles. Comparison with data obtained on MORB glasses shows that He, Ne, and Ar display an equilibrium distribution while Kr and Xe in the vesicle-free glass are probably below analytical detection. The strong fractionation effects implied by the very different solubilities can explain most of the variations observed in MORB-glasses for He/Ne and He/Ar ratios.

  12. Geochemical Trends and Natural Attenuation of RDX, Nitrate, and Perchlorate in the Hazardous Test Area Fractured-Granite Aquifer, White Sands Missile Range, New Mexico, 1996-2006

    Science.gov (United States)

    Langman, Jeff B.; Robertson, Andrew J.; Bynum, Jamar; Gebhardt, Fredrick E.

    2008-01-01

    A fractured-granite aquifer at White Sands Missile Range is contaminated with the explosive compound RDX, nitrate, and perchlorate (oxidizer associated with rocket propellant) from the previous use of the Open Burn/Open Detonation site at the Hazardous Test Area. RDX, nitrate, and perchlorate ground-water concentrations were analyzed to examine source characteristics, spatial and temporal variability, and the influence of the natural attenuation processes of dilution and degradation in the Hazardous Test Area fractured-granite aquifer. Two transects of ground-water wells from the existing monitoring-site network - one perpendicular to ground-water flow (transect A-A') and another parallel to ground-water flow (transect B-B') - were selected to examine source characteristics and the spatial and temporal variability of the contaminant concentrations. Ground-water samples collected in 2005 from a larger sampling of monitoring sites than the two transects were analyzed for various tracers including major ions, trace elements, RDX degradates, dissolved gases, water isotopes, nitrate isotopes, and sulfate isotopes to examine the natural attenuation processes of dilution and degradation. Recharge entrains contaminants at the site and transports them downgradient towards the Tularosa Basin floor through a poorly connected fracture system(s). From 1996 to 2006, RDX, nitrate, and perchlorate concentrations in ground water downgradient from the Open Burn/Open Detonation site have been relatively stable. RDX, nitrate, and perchlorate in ground water from wells near the site indicate dispersed contaminant sources in and near the Open Burn/Open Detonation pits. The sources of RDX and nitrate in the pit area have shifted with time, and the shift correlates with the regrading of the south and east berms of each pit in 2002 and 2003 following closure of the site. The largest RDX concentrations were in ground water about 0.1 mile downgradient from the pits, the largest perchlorate

  13. Reconnaissance Geochemical Study

    African Journals Online (AJOL)

    as means, standard deviation, etc. that allow the calculation of thresholds for individual elements. Geochemical distribution and anomalous-concentration maps were plotted for the elements, so as to have an insight into their distribution patterns. The geochemical distribution maps of the elements reveal that Cu, Pb, Zn, Co, ...

  14. U-Pb ages and geochemistry of zircon from Proterozoic plutons of the Sawatch and Mosquito ranges, Colorado, U.S.A.: Implications for crustal growth of the central Colorado province

    Science.gov (United States)

    Moscati, Richard J.; Premo, Wayne R.; Dewitt, Ed; Wooden, Joseph L.

    2017-01-01

    A broad study of zircons from plutonic rocks of the Sawatch and Mosquito ranges of west-central Colorado (U.S.A.) was undertaken to significantly refine the magmatic chronology and chemistry of this under-studied region of the Colorado province. This region was chosen because it lies just to the north of the suspected arc-related Gunnison-Salida volcano-plutonic terrane, which has been the subject of many recent investigations—and whose origin is still debated. Our new results provide important insights into the processes active during Proterozoic crustal evolution in this region, and they have important ramifications for broader-scope crustal evolution models for southwestern North America.Twenty-four new U-Pb ages and sequentially acquired rare-earth element (REE), U, Th, and Hf contents of zircon have been determined using the sensitive high-resolution ion microprobe-reverse geometry (SHRIMP-RG). These zircon geochemistry data, in conjunction with whole-rock major- and trace-element data, provide important insights into zircon crystallization and melt fractionation, and they help to further constrain the tectonic environment of magma generation.Our detailed zircon and whole-rock data support the following three interpretations:(1) The Roosevelt Granite in the southern Sawatch Range was the oldest rock dated at 1,766 ± 7 Ma, and it intruded various metavolcanic and metasedimentary rocks. Geochemistry of both whole-rock and zircon supports the contention that this granite was produced in a magmatic arc environment and, therefore, is likely an extension of the older Dubois Greenstone Belt of the Gunnison Igneous Complex (GIC) and the Needle Mountains (1,770–1,755 Ma). Rocks of the younger Cochetopa succession of the GIC, the Salida Greenstone Belt, and the Sangre de Cristo Mountains (1,740–1,725 Ma) were not found in the Sawatch and Mosquito ranges. This observation strongly suggests that the northern edge of the Gunnison-Salida arc terrane underlies the

  15. National Geochemical Database: Concentrate

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemistry of concentrates from the National Geochemical Database. Primarily inorganic elemental concentrations, most samples are from the continental US and...

  16. Basin-scale hydrogeological, geophysical, geochemical and isotopic characterization: an essential tool for building a Decision Support System for the sustainable management of alluvial aquifer systems within the provinces of Milan and Monza-Brianza (Northern Italy

    Directory of Open Access Journals (Sweden)

    Maurizio Gorla

    2016-10-01

    Full Text Available CAP Group is a public company, supplying the municipalities within the provinces of Milan and Monza/Brianza (Northern Italy with the integrated water service: 197 municipalities and more than 2 million users served, 887 wells, 154 wall-mounted tanks and hubs, a water supply network of over 7500 km, from which approximately 250 million cubic metres of water per year are withdrawn. The drinking water supply comes exclusively from groundwater resources, circulating in several overlapping aquifer systems. Basin-scale water resource management, as required by the European Water Framework Directive (2000/60/EC, is an extremely complex task. In view of this backdrop, CAP is currently developing a project called Infrastructural Aqueduct Plan that relies on a Decision Support System approach. The paper describes the preliminary steps concerning the design of a prototype Decision Support System aiming at the management of groundwater resources on a basin scale (Ticino and Adda rivers area. CAP Group Decision Support System is intended to be a package allowing for water resource assessment, identification of boundary conditions, climatic driving forces and demographic pressures, simulation and investigation of future forecasts and comparison of alternative policy measures. The project has been designed in steps including Geodatabase building, geographic information system (GIS analysis (including multilayer analysis and numerical modelling. The data collected in the geodatabase were analyzed to design GIS quantitative and qualitative thematic maps in order to perform the multilayer analysis of current and future state and impacts, for providing the decision maker with a comprehensive picture of the water system. The multilayer analysis relies on specific indicators based on some quantitative and qualitative data: hydrogeological, chemical, isotopic, soil use and hazards, climatic and demographic. Each parameter belonging to these macro areas were

  17. Some geochemical considerations in the petrogenesis of Madagali ...

    African Journals Online (AJOL)

    Some geochemical considerations in the petrogenesis of Madagali granitoids, northeastern Nigeria. S Baba. Abstract. Major and trace element geochemical data on granitoids of Madagali area of northeastern Nigeria show a series that ranges from K-calc-alkaline, through granodiorite-monzogranite to granite. They are ...

  18. Geochemical Investigations of Groundwater Stability

    Energy Technology Data Exchange (ETDEWEB)

    Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

    2006-05-15

    groundwaters, and also by stable isotopes and uranium isotopes in secondary minerals. Information on timing of water and solute movements is important because it indicates any correlation with the timing of external events that might have perturbed and destabilised the groundwater system in the past, and allows a timescale to be estimated for the persistence of stable conditions. Data from a number of published site investigation projects and research programmes are reviewed to illustrate the patterns of geochemical data and the relationships between them, and how these are interpreted in terms of hydrodynamic stability. Data from Aespoe and Stripa and from exploratory boreholes at Finnsjoen and other sites in Sweden are compiled and discussed. Preliminary data from SKB's ongoing site investigations at Simpevarp/Laxemar and Forsmark are not considered in detail but their general similarities with Aespoe and Finnsjoen/SFR respectively are introduced into the discussion of geochemical evidence for groundwater stability in inland and coastal areas. Relevant data from Finnish sites including Olkiluoto, from the Whiteshell URL area in Canada, from Sellafield in the UK, and from the Tono area and URL in Japan are also summarised in appendices and discussed because they add further insights into the interpretation of geochemical indicators for a range of geological environments. The compiled data provide only limited scope for comparison of groundwater evolution and stability between inland and coastal areas in Sweden, because of the patchiness of representative data especially from early site studies. The external changes that might have perturbed stable groundwater conditions in the past are glaciation (i.e. melt water, mechanical loading/unloading and permafrost) and varying sea water infiltration at coastal sites due to changes in palaeo-Baltic and isostatic conditions. The present distributions of palaeo-Baltic sea water in groundwaters at coastal sites vary, reflecting

  19. Geochemical modeling: a review

    Energy Technology Data Exchange (ETDEWEB)

    Jenne, E.A.

    1981-06-01

    Two general families of geochemical models presently exist. The ion speciation-solubility group of geochemical models contain submodels to first calculate a distribution of aqueous species and to secondly test the hypothesis that the water is near equilibrium with particular solid phases. These models may or may not calculate the adsorption of dissolved constituents and simulate the dissolution and precipitation (mass transfer) of solid phases. Another family of geochemical models, the reaction path models, simulates the stepwise precipitation of solid phases as a result of reacting specified amounts of water and rock. Reaction path models first perform an aqueous speciation of the dissolved constituents of the water, test solubility hypotheses, then perform the reaction path modeling. Certain improvements in the present versions of these models would enhance their value and usefulness to applications in nuclear-waste isolation, etc. Mass-transfer calculations of limited extent are certainly within the capabilities of state-of-the-art models. However, the reaction path models require an expansion of their thermodynamic data bases and systematic validation before they are generally accepted.

  20. Along-Strike Geochemical Variations in the Late Triassic Nikolai Magmatic System, Wrangellia, Central Alaska

    Science.gov (United States)

    Wypych, A.; Twelker, E.; Lande, L. L.; Newberry, R.

    2015-12-01

    The Nikolai Basalt and related mafic to ultramafic intrusions are one of the world's most complete and best exposed sections of a large igneous province (Amphitheater Mountains, Alaska), and have been explored for magmatic Ni-Cu-Co-PGE mineralization (Wellgreen deposit in the Kluane Ranges, Yukon Territory, and Eureka zone in the Eastern Alaska Range). The full extent of the basalts and the intrusions, as well as along-strike variations in the geochemical and petrological composition and the causes for those variations has yet to be fully established. To better understand the extent and magmatic architecture of this system, the Alaska Division of Geological & Geophysical Surveys conducted mapping and geochemical investigations of the province from 2013 through 2015 field seasons. We present major and trace element data from whole rock, olivine, and chromite from samples of Triassic basalts and intrusives collected over a 250 km along-strike transect. This data is used to answer questions about variations in magma generation, temperature of crystallization, and degree of fractional crystallization required to produce the Nikolai Basalts. Using chalcophile elements, we examine the history of sulfide solubility, further adding to our understanding of the processes of magma evolution and its influence on the formation of economic mineral deposits. Our initial findings corroborate the presence of two phases of magma generation and eruption, as well as along-strike variation in composition of these phases. We propose that the major along-strike variations are due to differences in amount of cumulate olivine and other late-stage processes. This magmatic architecture has important implications for exploration for magmatic sulfide deposits of nickel-copper and strategic and critical platinum group elements (PGEs) as it can help to better understand the occurrences and point to future possible deposits within the system.

  1. A simple method for estimating basin-scale groundwater discharge by vegetation in the basin and range province of Arizona using remote sensing information and geographic information systems

    Science.gov (United States)

    Tillman, F.D.; Callegary, J.B.; Nagler, P.L.; Glenn, E.P.

    2012-01-01

    Groundwater is a vital water resource in the arid to semi-arid southwestern United States. Accurate accounting of inflows to and outflows from the groundwater system is necessary to effectively manage this shared resource, including the important outflow component of groundwater discharge by vegetation. A simple method for estimating basin-scale groundwater discharge by vegetation is presented that uses remote sensing data from satellites, geographic information systems (GIS) land cover and stream location information, and a regression equation developed within the Southern Arizona study area relating the Enhanced Vegetation Index from the MODIS sensors on the Terra satellite to measured evapotranspiration. Results computed for 16-day composited satellite passes over the study area during the 2000 through 2007 time period demonstrate a sinusoidal pattern of annual groundwater discharge by vegetation with median values ranging from around 0.3 mm per day in the cooler winter months to around 1.5 mm per day during summer. Maximum estimated annual volume of groundwater discharge by vegetation was between 1.4 and 1.9 billion m3 per year with an annual average of 1.6 billion m3. A simplified accounting of the contribution of precipitation to vegetation greenness was developed whereby monthly precipitation data were subtracted from computed vegetation discharge values, resulting in estimates of minimum groundwater discharge by vegetation. Basin-scale estimates of minimum and maximum groundwater discharge by vegetation produced by this simple method are useful bounding values for groundwater budgets and groundwater flow models, and the method may be applicable to other areas with similar vegetation types.

  2. Intermittent Volcanism in the S Pacific: Tracking Persistent Geochemical Sources

    Science.gov (United States)

    Konter, J. G.; Koppers, A. A.; Staudigel, H.; Hanan, B. B.; Blichert-Toft, J.

    2004-12-01

    South Pacific ocean intraplate volcanoes (OIV's) have formed relatively short, discontinuous chains over the last 140 Ma, in contrast to classic continuous hot spot chains like Hawaii or Louisville. Moreover, its volcanism stands apart by very diverse and radiogenic mantle source regions, defining the South Pacific Isotopic and Thermal Anomaly (SOPITA). Discontinuous SOPITA OIV's form a complex array of crossing lineaments and isolated seamounts that can be back-tracked in time to the western Pacific. We studied the Hf and Pb isotopic composition of the prominent western Gilbert's and Tokelau chain that mostly correspond to the plate motion stage expressed by the Emperor Seamounts. The Gilbert's chain (to the West of Tokelau) has an age range of 74-65 Ma, and back-tracks to an OIV source origin near Rurutu. Notably, this chain shows an isotopic signature similar to the Rurutu chain, from Burtaritari (176Hf/177Hf: 0.282900, 206Pb/204Pb: 20.582) to Tuba (0.282938, 19.691). The parallel-running Tokelau chain ranges from 76-58 Ma, projecting current activity around Macdonald seamount. Its isotopic composition is also similar to Macdonald seamount, as shown by Howland (0.282951, 20.773) to Polo (0.283050, 19.390). However, both chains also contain seamounts with ages and isotopic signatures that are outliers, inconsistent with their general age range and isotopic trends (e.g. Ava; 0.282641, 17.729 and Sakau; 0.282880, 18.997). Our results show that the discontinuous magmatic provinces within SOPITA can be tracked back in time by geochronology and geochemical fingerprinting. This suggests that the SOPITA OIV's are fed by distinct, long-lived mantle source regions that may turn "on" or "off" for distinct periods during their life-times. This intermittent volcanism is inconsistent with the "standard" fixed hot spot model, since it does not produce continuous chains with linear age progressions. Furthermore, our results demonstrate the utility of geochemical fingerprinting

  3. Geobiochemistry: Placing Biochemistry in Its Geochemical Context

    Science.gov (United States)

    Shock, E.; Boyer, G. M.; Canovas, P. A., III; Prasad, A.; Dick, J. M.

    2014-12-01

    Goals of geobiochemistry include simultaneously evaluating the relative stabilities of microbial cells and minerals, and predicting how the composition of biomolecules can change in response to the progress of geochemical reactions. Recent developments in theoretical geochemistry make it possible to predict standard thermodynamic properties of proteins, nucleotides, lipids, and many metabolites including the constituents of the citric acid cycle, at all temperatures and pressures where life is known to occur, and beyond. Combining these predictions with constraints from geochemical data makes it possible to assess the relative stabilities of biomolecules. Resulting independent predictions of the environmental occurrence of homologous proteins and lipid side-chains can be compared with observations from metagenomic and metalipidomic data to quantify geochemical driving forces that shape the composition of biomolecules. In addition, the energetic costs of generating biomolecules from within a diverse range of habitable environments can be evaluated in terms of prevailing geochemical variables. Comparisons of geochemical bioenergetic calculations across habitats leads to the generalization that the availability of H2 determines the cost of autotrophic biosynthesis relative to the aquatic environment external to microbial cells, and that pH, temperature, pressure, and availability of C, N, P, and S are typically secondary. Increasingly reduced conditions, which are determined by reactions of water with mineral surfaces and mineral assemblages, allow many biosynthetic reactions to shift from costing energy to releasing energy. Protein and lipid synthesis, as well as the reverse citric acid cycle, become energy-releasing processes under these conditions. The resulting energy balances that determine habitability contrast dramatically with assumptions derived from oxic surface conditions, such as those where human biochemistry operates.

  4. [Microbial geochemical calcium cycle].

    Science.gov (United States)

    Zavarzin, G A

    2002-01-01

    The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites.

  5. Geochemical and Rheological Constraints on the Dynamics of the Oceanic Upper Mantle

    Science.gov (United States)

    2007-09-01

    White, W. M., Poreda, R., Bloomer, S. H., Fisher, R. L., Baxter , A. N., 1989. Isotopic and geochemical provinces of the Western Indian Ocean spreading...peridotites are collected. Cannat (1996) argued that incomplete melt extraction (or melt entrapment ) is important during lithosphere formation at lower

  6. The geochemical Phenomenon-Local geochemical fields in a glacier (scientific note)

    OpenAIRE

    V. N., Makarov

    2001-01-01

    Geochemical fields in alpine cold and warm glaciers were studied. Local geochemical fields of typomorphic elements were found to form in the ice and on the surface of glaciers overlying ore bodies and endogenic geochemical haloes. The formation of local cryogenic geochemical fields in the glaciers results from sharp geochemical heterogeneity and geochemical processes in underlying rocks which cause cryogenic migration of chemical elements and compounds in the glacier. The thickness of geochem...

  7. Complexing-precipitating geochemical barriers

    Science.gov (United States)

    Savenko, A. V.

    2017-02-01

    New types of geochemical barriers on which chemical elements are immobilized as a result of combined complex formation and precipitation of barely soluble mineral phases are examined. A significant concentration of major components (Fe, Al) forming more stable complexes than an immobilized component X in the material is a necessary condition for this type of geochemical barriers. Filtration of the solution through a geochemical barrier is accompanied by substitution of X in the complex with a major component. As a result, the activity of X in the free state increases, and one barely soluble mineral phase or another of the component X precipitates when the state of saturation is achieved.

  8. A >100 Ma Mantle Geochemical Record: Retiring Mantle Plumes may be Premature

    Science.gov (United States)

    Konter, J. G.; Hanan, B. B.; Blichert-Toft, J.; Koppers, A. A.; Plank, T.; Staudigel, H.

    2006-12-01

    Hotspot volcanism has long been attributed to mantle plumes, but in recent years suggestions have been made that plate tectonic processes, such as extension, can account for all hotspot tracks. This explanation involves a profoundly less dynamic lower mantle, which justifies a critical evaluation before the plume model is dismissed. Such an evaluation has to involve a wide range of geochemical, geological, and geophysical techniques, broadly investigating the products of volcanism as well as the underlying lithosphere and mantle. We argue here that the combined geological record and geochemistry of intraplate volcanoes holds some important clues that help us decide between models of plume-like upwelling versus passive upwelling with lithospheric extension. The best of these integrated datasets can be obtained from the long seamount chains in the Pacific Ocean. A new combined dataset of trace element and isotopic compositions, along with modern 40Ar/39Ar ages from seamounts in the Gilbert Ridge, Tokelau chain, and West Pacific Seamount Province (WPSP) provides a record of current to Cretaceous volcanism in the South Pacific. We have reconstructed the eruptive locations of the seamounts using a range of absolute plate motion models, including some models with hotspot motion and others that use the Indo-Atlantic hotspot reference frame. Our results show that the backtracked locations consistently form clusters (300km radius) around the active ends of the Macdonald, Rurutu and Rarotonga hotspot chains, while closely matching their distinct C-HIMU and C-EM1 signatures. The oldest WPSP seamounts (older than 100 Ma) form the only exception and backtrack, with larger uncertainty, to north of Rarotonga. Therefore, the mantle currently underlying the Cook-Austral islands has produced volcanoes in three geochemically distinct areas for at least 100 m.y. Furthermore, we find the shortest mantle residence time, 0.6 Ga, for a source of mixed recycled DMM and an EM1-like

  9. Monitoring active volcanoes: The geochemical approach

    Directory of Open Access Journals (Sweden)

    Takeshi Ohba

    2011-06-01

    Full Text Available

    The geochemical surveillance of an active volcano aims to recognize possible signals that are related to changes in volcanic activity. Indeed, as a consequence of the magma rising inside the volcanic "plumbing system" and/or the refilling with new batches of magma, the dissolved volatiles in the magma are progressively released as a function of their relative solubilities. When approaching the surface, these fluids that are discharged during magma degassing can interact with shallow aquifers and/or can be released along the main volcano-tectonic structures. Under these conditions, the following main degassing processes represent strategic sites to be monitored.

    The main purpose of this special volume is to collect papers that cover a wide range of topics in volcanic fluid geochemistry, which include geochemical characterization and geochemical monitoring of active volcanoes using different techniques and at different sites. Moreover, part of this volume has been dedicated to the new geochemistry tools.

  10. Modeling Low-temperature Geochemical Processes

    Science.gov (United States)

    Nordstrom, D. K.

    2003-12-01

    Geochemical modeling has become a popular and useful tool for a wide number of applications from research on the fundamental processes of water-rock interactions to regulatory requirements and decisions regarding permits for industrial and hazardous wastes. In low-temperature environments, generally thought of as those in the temperature range of 0-100 °C and close to atmospheric pressure (1 atm=1.01325 bar=101,325 Pa), complex hydrobiogeochemical reactions participate in an array of interconnected processes that affect us, and that, in turn, we affect. Understanding these complex processes often requires tools that are sufficiently sophisticated to portray multicomponent, multiphase chemical reactions yet transparent enough to reveal the main driving forces. Geochemical models are such tools. The major processes that they are required to model include mineral dissolution and precipitation; aqueous inorganic speciation and complexation; solute adsorption and desorption; ion exchange; oxidation-reduction; or redox; transformations; gas uptake or production; organic matter speciation and complexation; evaporation; dilution; water mixing; reaction during fluid flow; reaction involving biotic interactions; and photoreaction. These processes occur in rain, snow, fog, dry atmosphere, soils, bedrock weathering, streams, rivers, lakes, groundwaters, estuaries, brines, and diagenetic environments. Geochemical modeling attempts to understand the redistribution of elements and compounds, through anthropogenic and natural means, for a large range of scale from nanometer to global. "Aqueous geochemistry" and "environmental geochemistry" are often used interchangeably with "low-temperature geochemistry" to emphasize hydrologic or environmental objectives.Recognition of the strategy or philosophy behind the use of geochemical modeling is not often discussed or explicitly described. Plummer (1984, 1992) and Parkhurst and Plummer (1993) compare and contrast two approaches for

  11. Geochemical water signature in the Bahariya Depression, Western Desert, Egypt

    Science.gov (United States)

    Sciarra, Alessandra; Mazzini, Adriano; Lupi, Matteo; Hammed, Mohammed S.

    2017-04-01

    The Bahariya Oasis is located about 200 km SW of Cairo in the central part of the Western Desert of Egypt. It occupies a sub-elliptic 40 km wide depression stretching NE-SW for approximately 90 km. The Bahariya Oasis has been targeted for numerous geological studies on structural geology, stratigraphy, and iron ore deposits. The oasis was characterized since the Roman times by the presence of natural hydrothermal springs venting water from the relatively shallow Nubia Sandstone formation. Inside the depression are visible numerous circular concentric features that morphologically resemble the hydrothermal vent complexes observed at igneous provinces in other localities of the planet. In order to investigate the origin and the mechanisms of formation of these features, we conducted a fieldwork survey as well as fluids sampling from the available well sites. The aim was to constrain the origin of the fluids that potentially triggered or facilitated the formation of the concentric structures observed on the field. This study presents the geochemical results of groundwaters and soil gas samples. Ten samples were collected from deep wells present in the area. In particular, 8 warm waters were collected by wells between 800 m and 1200 m deep. The measured temperatures at these sites range from 36.5 °C to 52.3°C, while the coldest wells have temperatures ranging from 27.9 °C to 36.5°C. For each sample collected from the wells we analyzed the major, minor and trace elements, dissolved gases (He, Ne, H2, O2, N2, CH4, CO2, Rn), and relative isotopic values. In the areas around the wells we measured CO2 and CH4 fluxes as well as radon activity. Overall, the water showed a high value of dissolved Rn, ranging from 9 to 43 Bq/l, and dissolved CO2 ranging from 5.9 to 17.4 cc/l. The waters show a radiogenic signature of isotopic helium, highlighting very prolonged interaction with local crust enriched in radiogenic elements. The isotopic values of δ18O and δD show a clear

  12. Studies of geology and hydrology in the Basin and Range Province, Southwestern United States, for isolation of high-level radioactive waste - Characterization of the Bonneville region, Utah and Nevada

    Science.gov (United States)

    Bedinger, M.S.; Sargent, K.A.; Langer, William H.

    1990-01-01

    The Bonneville region of the Basin and Range province in westcentral Utah and adjacent Nevada includes several basins lying south of the Great Salt Lake Desert. Physiographically, the region consists of linear, north-trending mountain ranges separated by valleys, many of which are closed basins underlain by thick sequences of fill. Surface drainage of open basins and ground-water flow is to the Great Salt Lake Desert. In structure and composition the ranges are faulted Paleozoic rocks, locally intruded by Mesozoic and Tertiary plugs and stocks. In the southern and northeastern parts of the region, volcanic rocks are widespread and form large parts of some mountain ranges. The Paleozoic sedimentary rocks include great thicknesses of carbonate rocks which compose a significant aquifer in the regionMedia considered to have potential for isolation of high-level radioactive waste in the region include intrusive rocks, such as granite; ash-flow tuff; and basalt and basaltic andesite lava flows. These rock types, basin fill, and possibly other rock types, may have potential as host media in the unsaturated zone. Quaternary tectonism in the region is evidenced by seismic activity, local areas of above-normal geothermal heat flow, Quaternary faulting, late Cenozoic volcanic activity, and active vertical crustal movement. The Bonneville region is part of a large ground-water flow system that is integrated partly through basin-fill deposits, but largely through an underlying carbonate-rock sequence. The region includes: (1) several topographically closed basins with virtually no local surface discharge that are drained by the underlying carbonate-rock aquifer; (2) closed basins with local surface discharge by evapotranspiration; and (3) basins open to the Great Salt Lake Desert that discharge by groundwater underflow and evapotranspiration. The carbonate-rock aquifer discharges to large springs in the Desert and in basins tributary to the Desert. The climate is arid to

  13. Spatial variation of volcanic rock geochemistry in the Virunga Volcanic Province: Statistical analysis of an integrated database

    Science.gov (United States)

    Barette, Florian; Poppe, Sam; Smets, Benoît; Benbakkar, Mhammed; Kervyn, Matthieu

    2017-10-01

    We present an integrated, spatially-explicit database of existing geochemical major-element analyses available from (post-) colonial scientific reports, PhD Theses and international publications for the Virunga Volcanic Province, located in the western branch of the East African Rift System. This volcanic province is characterised by alkaline volcanism, including silica-undersaturated, alkaline and potassic lavas. The database contains a total of 908 geochemical analyses of eruptive rocks for the entire volcanic province with a localisation for most samples. A preliminary analysis of the overall consistency of the database, using statistical techniques on sets of geochemical analyses with contrasted analytical methods or dates, demonstrates that the database is consistent. We applied a principal component analysis and cluster analysis on whole-rock major element compositions included in the database to study the spatial variation of the chemical composition of eruptive products in the Virunga Volcanic Province. These statistical analyses identify spatially distributed clusters of eruptive products. The known geochemical contrasts are highlighted by the spatial analysis, such as the unique geochemical signature of Nyiragongo lavas compared to other Virunga lavas, the geochemical heterogeneity of the Bulengo area, and the trachyte flows of Karisimbi volcano. Most importantly, we identified separate clusters of eruptive products which originate from primitive magmatic sources. These lavas of primitive composition are preferentially located along NE-SW inherited rift structures, often at distance from the central Virunga volcanoes. Our results illustrate the relevance of a spatial analysis on integrated geochemical data for a volcanic province, as a complement to classical petrological investigations. This approach indeed helps to characterise geochemical variations within a complex of magmatic systems and to identify specific petrologic and geochemical investigations

  14. Geochemical and Isotopic Data for Oligocene Ignimbrites, Calderas, and Granitic Plutons, Southern Stillwater Range and Clan Alpine Mountains: Insights into the Volcanic-Plutonic Connection and Crustal Evolution in Western Nevada

    Science.gov (United States)

    John, D. A.; Colgan, J. P.; Watts, K. E.; Henry, C.; Cousens, B.

    2015-12-01

    Oligocene calderas and underlying plutons in the southern Stillwater Range (SSR) and Clan Alpine Mountains (CAM) in western Nevada were tilted (40->90°) by large-magnitude Miocene extension and unconformably overlain by 15-13 Ma intermediate and mafic lava flows. New geologic mapping, geochemistry, and Ar-Ar and U-Pb dating document 2 brief periods of magmatism resulting in 5 nested calderas and related plutons in sections locally ≥9 km thick. Early magmatism at ~29 Ma included the Deep Canyon caldera in CAM, and in the SSR, pre-caldera rhyolites, ~5 km of pre- and post-collapse intermediate lavas and rhyolite tuff that filled Job Canyon caldera (JC, ~29.4 to 28.8 Ma), and the >4-5 km thick IXL pluton (~28.5 Ma) that intruded JC and is compositionally similar to the tuff and lava flows. The second period included 3 ignimbrite units in 3 calderas: small-volume tuff of Louderback Mountains (LM, low-silica rhyolite; ≥600 m thick; ~25.3 Ma); multiple cooling units of tuff of Poco Canyon (PC, high-silica rhyolite; ≤4.5 km thick; ~25.3 Ma); and ≥2500 km3 of tuff of Elevenmile Canyon (EC, trachydacite to rhyolite; ≤4.5 km thick; 25.1 Ma) that covers ~1600 km2 and extends east from SSR to the northern Desatoya Mountains. The composite Freeman Creek pluton (granodiorite, ~25.0 Ma; granite, ~24.8 Ma) and Chalk Mountain rhyolite porphyry (~25.2 Ma) and granite (~24.8 Ma) plutons intruded LM, PC and EC calderas. Radiogenic isotopes in all caldera units are similar (Sri~0.7050, ΕNd~0.0), while oxygen isotope compositions are variable (δ18Oquartz=5.7-8.4‰, δ18Ozircon=4.1-6.3‰), corresponding to a magmatic range of 5.6-7.6‰, including 2-5 km) underlie compositionally and temporally related caldera-filling ignimbrites, (2) caldera-forming cycles are isotopically variable, requiring temporally and spatially distinct magma sources, and (3) caldera magmas have a strong mantle affinity and overlap isotopically (Sr, Nd, and O) with regional Late Cenozoic basalts.

  15. NOAA and MMS Marine Minerals Geochemical Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Minerals Geochemical Database was created by NGDC as a part of a project to construct a comprehensive computerized bibliography and geochemical database...

  16. Leveling data in geochemical mapping: scope of application, pros and cons of existing methods

    Science.gov (United States)

    Pereira, Benoît; Vandeuren, Aubry; Sonnet, Philippe

    2017-04-01

    Geochemical mapping successfully met a range of needs from mineral exploration to environmental management. In Europe and around the world numerous geochemical datasets already exist. These datasets may originate from geochemical mapping projects or from the collection of sample analyses requested by environmental protection regulatory bodies. Combining datasets can be highly beneficial for establishing geochemical maps with increased resolution and/or coverage area. However this practice requires assessing the equivalence between datasets and, if needed, applying data leveling to remove possible biases between datasets. In the literature, several procedures for assessing dataset equivalence and leveling data are proposed. Daneshfar & Cameron (1998) proposed a method for the leveling of two adjacent datasets while Pereira et al. (2016) proposed two methods for the leveling of datasets that contain records located within the same geographical area. Each discussed method requires its own set of assumptions (underlying populations of data, spatial distribution of data, etc.). Here we propose to discuss the scope of application, pros, cons and practical recommendations for each method. This work is illustrated with several case studies in Wallonia (Southern Belgium) and in Europe involving trace element geochemical datasets. References: Daneshfar, B. & Cameron, E. (1998), Leveling geochemical data between map sheets, Journal of Geochemical Exploration 63(3), 189-201. Pereira, B.; Vandeuren, A.; Govaerts, B. B. & Sonnet, P. (2016), Assessing dataset equivalence and leveling data in geochemical mapping, Journal of Geochemical Exploration 168, 36-48.

  17. Geologic history of Siletzia, a large igneous province in the Oregon and Washington Coast Range: correlation to the geomagnetic polarity time scale and implications for a long-lived Yellowstone hotspot

    Science.gov (United States)

    Wells, Ray; Bukry, David; Friedman, Richard; Pyle, Douglas; Duncan, Robert; Haeussler, Peter; Wooden, Joe

    2014-01-01

    Siletzia is a basaltic Paleocene and Eocene large igneous province in coastal Oregon, Washington, and southern Vancouver Island that was accreted to North America in the early Eocene. New U-Pb magmatic, detrital zircon, and 40Ar/39Ar ages constrained by detailed field mapping, global nannoplankton zones, and magnetic polarities allow correlation of the volcanics with the 2012 geologic time scale. The data show that Siletzia was rapidly erupted 56–49 Ma, during the Chron 25–22 plate reorganization in the northeast Pacific basin. Accretion was completed between 51 and 49 Ma in Oregon, based on CP11 (CP—Coccolith Paleogene zone) coccoliths in strata overlying onlapping continental sediments. Magmatism continued in the northern Oregon Coast Range until ca. 46 Ma with the emplacement of a regional sill complex during or shortly after accretion. Isotopic signatures similar to early Columbia River basalts, the great crustal thickness of Siletzia in Oregon, rapid eruption, and timing of accretion are consistent with offshore formation as an oceanic plateau. Approximately 8 m.y. after accretion, margin parallel extension of the forearc, emplacement of regional dike swarms, and renewed magmatism of the Tillamook episode peaked at 41.6 Ma (CP zone 14a; Chron 19r). We examine the origin of Siletzia and consider the possible role of a long-lived Yellowstone hotspot using the reconstruction in GPlates, an open source plate model. In most hotspot reference frames, the Yellowstone hotspot (YHS) is on or near an inferred northeast-striking Kula-Farallon and/or Resurrection-Farallon ridge between 60 and 50 Ma. In this configuration, the YHS could have provided a 56–49 Ma source on the Farallon plate for Siletzia, which accreted to North America by 50 Ma. A sister plateau, the Eocene basalt basement of the Yakutat terrane, now in Alaska, formed contemporaneously on the adjacent Kula (or Resurrection) plate and accreted to coastal British Columbia at about the same time

  18. Morphology and geochemistry of placer gold from Wang River, Lampang Province, Northern Thailand

    Science.gov (United States)

    Lim, D.; Lee, I.

    2011-12-01

    Wang River (Mae Nam Wang) in Lampang Province, Northern Thailand which is surrounded with many lode gold deposits has potential to develop as a placer gold deposit. Gold particles from 10 sites in Wang River range from fine to coarse (electrum or high purity gold with high fineness (1000Au/Au+Ag) levels up to 951 as well as a minor amount of Cu and Hg. Normally, the zoning patterns of Au and Ag are common in placer gold and the high fineness in rim can be explained by either selective extraction of Ag or precipitation of Au. However, there is no significant difference in fineness between core and rim in gold grains in this study even though there are differences in composition among grains. Many cavities are also shown filling with silicate and/or clay mineral in microtextures. These geochemical signatures from microtextures are capable of providing genetic implication. Furthermore, the combination of results such as shape parameter, geochemical signature, and assemblages of heavy minerals can be a useful tool in exploration for gold.

  19. Isotopic, geochemical, and temporal characterization of Proterozoic basement rocks in the Quitovac region, northwestern Sonora, Mexico: Implications for the reconstruction of the southwestern margin of Laurentia

    Science.gov (United States)

    Iriondo, A.; Premo, W.R.; Martínez-Torres, Luis M.; Budahn, J.R.; Atkinson, William W.; Siems, D.F.; Guaras-Gonzalez, B.

    2004-01-01

    A detailed geochemical characterization of 19 representative Proterozoic basement rocks in the Quitovac region in northwestern Sonora, Mexico, has identified two distinct Paleoproterozoic basement blocks that coincide spatially with the previously proposed Caborca and "North America" blocks. New U-Pb zircon geochronology revises their age ranges, the Caborca (1.78-1.69 Ga) and "North America" (1.71-1.66 Ga) blocks at Quitovac, and precludes a simple age differentiation between them. In addition, Grenvillian-age granitoids (ca. 1.1 Ga), spatially associated with the Caborca block have been identified at Quitovac. Nd isotopes and major- and trace-element geochemistry support the distinction of these Paleoproterozoic blocks. Granitoids of the "North America" block are characterized by depleted ??Nd values (3.4-3.9) and younger Nd model ages (1800-1740 Ma) and have lower K2O, Y, Rb, Ba, Th, REE, and Fe/Mg values than coeval rocks of the Caborca block. The Caborca block granitoids are likewise characterized by slightly less depleted ??Nd (0.6-2.6) and older Nd model ages (2070-1880 Ma). Despite the subtle differences, granitoids from both the Caborca and "North America" blocks exhibit island arc-like affinities. We propose that the Proterozoic basement rocks from the Quitovac region are an extension of the Proterozoic crustal provinces in the southwestern United States. Specifically, rocks of the Caborca block exhibit an affinity to rocks of either the Yavapai province or the Mojave-Yavapai transition zone, whereas rocks of the "North America" block have signatures similar to those of the Mazatzal province or possibly the Yavapai province of Arizona. The new isotopic ages and geochemical data do not support the existence of the Late Jurassic Mojave-Sonora megashear at Quitovac, as originally proposed. However, the Quitovac region accounts only for a small fraction of the Proterozoic basement in Sonora, so these findings do not eliminate the possibility of a megashear

  20. Mineralogical, Geochemical and Isotopic Characterisation of the Travertine Formation Associated with the Alicun de las Torres Thermal System (Province of Granada): Palaeoclimatic and Palaeoenvironmental Implications.; Caracterizacion Mineralogica, Geoquimica e Isotopica de los Travertinos Asociados al Sistema Termal de Alicun de las Torres (Provincia de Granada): Implicaciones Paleoclimaticas y Paleoambientales

    Energy Technology Data Exchange (ETDEWEB)

    Prado, A. J.; Delgado, A.; Crespo, M. T.; Martin, A.; Perez del Villar, L.

    2010-12-24

    In the framework of a Singular Strategic Project entitled: Advanced Technologies of Carbon, Capture and Storage (CCS), supported by the MICINN (Spain) and the FEDER founds (EU), specifically in the Carbon Storage Task, a comprehensive study on the CO{sub 2} leakage as DIC (Dissolved Inorganic Carbon) in the Alicun de Las Torres (Prov. of Granada) natural analogue Thermal System was envisaged. This analogous system is characterised by the presence of a very important travertine formation. In order to explain the formation of these travertine mass a detailed mineralogical, petrographic, geochemical and isotopic, including stable and radioactive isotopes, characterisation has been carried out. Based on these data, paleoclimatic and palaeoenvironmental conditions under which this travertine formation was formed, during a period of approximately 230Ky, have also been deduced. (Author) 234 refs.

  1. Validation of the WATEQ4 geochemical model for uranium

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, K.M.; Jenne, E.A.; Deutsch, W.J.

    1983-09-01

    As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite (UO/sub 2/(OH)/sub 2/ . H/sub 2/O), UO/sub 2/(OH)/sub 2/, and rutherfordine ((UO/sub 2/CO/sub 3/) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions.

  2. A geochemical atlas of North Carolina, USA

    Science.gov (United States)

    Reid, J.C.

    1993-01-01

    A geochemical atlas of North Carolina, U.S.A., was prepared using National Uranium Resource Evaluation (NURE) stream-sediment data. Before termination of the NURE program, sampling of nearly the entire state (48,666 square miles of land area) was completed and geochemical analyses were obtained. The NURE data are applicable to mineral exploration, agriculture, waste disposal siting issues, health, and environmental studies. Applications in state government include resource surveys to assist mineral exploration by identifying geochemical anomalies and areas of mineralization. Agriculture seeks to identify areas with favorable (or unfavorable) conditions for plant growth, disease, and crop productivity. Trace elements such as cobalt, copper, chromium, iron, manganese, zinc, and molybdenum must be present within narrow ranges in soils for optimum growth and productivity. Trace elements as a contributing factor to disease are of concern to health professionals. Industry can use pH and conductivity data for water samples to site facilities which require specific water quality. The North Carolina NURE database consists of stream-sediment samples, groundwater samples, and stream-water analyses. The statewide database consists of 6,744 stream-sediment sites, 5,778 groundwater sample sites, and 295 stream-water sites. Neutron activation analyses were provided for U, Br, Cl, F, Mn, Na, Al, V, Dy in groundwater and stream water, and for U, Th, Hf, Ce, Fe, Mn, Na, Sc, Ti, V, Al, Dy, Eu, La, Sm, Yb, and Lu in stream sediments. Supplemental analyses by other techniques were reported on U (extractable), Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, W, Y, and Zn for 4,619 stream-sediment samples. A small subset of 334 stream samples was analyzed for gold. The goal of the atlas was to make available the statewide NURE data with minimal interpretation to enable prospective users to modify and manipulate the data for their end use. The atlas provides only

  3. Riphean hydrocarbon reservoirs of the Yurubchen-Tokhom zone, Lena-Tunguska province, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, V.G. [State Academy of Oil and Gas, Moscow (Russian Federation)

    1997-10-01

    The Siberian Craton covers an area of about 4.5 million sq.km in northern Russia, of which up to 3.5 million sq.km may be prospective for hydrocarbons. The craton was consolidated in the Early Proterozoic, and above the basement granitoids and gneisses is a variable thickness of sedimentary strata ranging in age from Riphean (Middle-Late Proterzoic) to Quaternary. Reservoir rocks are known to occur in the interval between the Middle Riphean and the Upper Cretaceous; those of Riphean age have produced oil commercially since 1973. Geochemical data indicate that the oil within the Riphean reservoir rocks was generated by source rocks of Riphean age, Riphean reservoir rocks include both carbonates and siliciclastics, but commercial volumes of hydrocarbons have only been discovered within the carbonates. Three petroleum-bearing ``provinces`` or megabasins are located on the Siberian Craton; Lena-Tunguska, Lena-Vilyuy and Yenisey-Anabar. The Yurubchen-Tokhom Zone in Lena-Tunguska Province is potentially the most important oil-producing area in the craton, and comprises a number of distinct fields. Reservoir rocks here consist principally of thick Riphean dolomites. Both the development of reservoir characteristics within these dolomites and the formation of stratigraphic traps are related to an episode of emergence and karstification at the end of the Riphean. (author)

  4. Alaska Geochemical Database (AGDB) - Geochemical Data for Rock, Sediment, Soil, Mineral, and Concentrate Sample Media

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Alaska Geochemical Database (AGDB) was created and designed to compile and integrate geochemical data from Alaska in order to facilitate geologic mapping,...

  5. Hydrologic provinces of Michigan

    Science.gov (United States)

    Rheaume, S.J.

    1991-01-01

    This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Michigan Department of Natural Resources, Geological Survey Division, to describe the statewide hydrologic variations in Michigan's water resources. Twelve hydrologic provinces, which are based on similarities in aquifer lithology, yield, recharge, and ground-water- and surface-water-quality data, are described. The definition of statewide hydrologic characteristics and the delineation of hydrologic provinces improves the understanding of Michigan's water resources and provides a firm basis for realistic water-manangement decisions. The 12 provinces identified areas where bedrock aquifers provide most of the potable ground water (five provinces), where glacial-deposit aquifers provide most of the potable ground water (three provinces), and where problems with water quantity and (or) quality have limited the use of ground water as a water supply (four provinces). Subprovinces are defined on the basis of regional surface-water flow directions toward each of the Great Lakes.

  6. Geochemical exploration in the Montseny Mountains (NE Spain)

    OpenAIRE

    Font Cisteró, Xavier; Viladevall Solé, Manuel; Casas i Ponsatí, Albert; Vaquer Navarro, Ramon

    1984-01-01

    A five year program of systematic multi-element geochemical exploration of the Catalonian Coastal Ranges has been initiated by the Geological Survey of Autonomic Government of Catalonia (Generalitat de Catalunya) and the Department of Geological and Geophysical Exploration (University of Barcelona). This paper reports the first stage results of this regional survey, covering an area of 530 km2 in the Montseny Mountains, NE of Barcelona (Spain). Stream sediments for metals and stream waters fo...

  7. Natural Bacterial Communities Serve as Quantitative Geochemical Biosensors

    OpenAIRE

    Smith, Mark B.; Rocha, Andrea M.; Smillie, Chris S.; Olesen, Scott W.; Paradis, Charles; Wu, Liyou; Campbell, James H; Julian L Fortney; Mehlhorn, Tonia L.; Lowe, Kenneth A.; Earles, Jennifer E.; Phillips, Jana; Techtmann, Stephen M.; Joyner, Dominique C.; Elias, Dwayne A.

    2015-01-01

    ABSTRACT Biological sensors can be engineered to measure a wide range of environmental conditions. Here we show that statistical analysis of DNA from natural microbial communities can be used to accurately identify environmental contaminants, including uranium and nitrate at a nuclear waste site. In addition to contamination, sequence data from the 16S rRNA gene alone can quantitatively predict a rich catalogue of 26 geochemical features collected from 93 wells with highly differing geochemis...

  8. Proceedings of the workshop on geochemical modeling

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices.

  9. The pre-Caledonian Large Igneous Province and the North Atlantic Wilson Cycle

    Science.gov (United States)

    Tegner, Christian; Andersen, Torgeir B.; Corfu, Fernando; Planke, Sverre; Jørgen Kjøll, Hans; Torsvik, Trond H.

    2016-04-01

    Magmatism of the first known rifting phase of the North Atlantic Wilson Cycle is surprisingly well preserved in the Caledonian nappes of central Scandinavia. The Särv and Seve Nappes are characterised by spectacular dyke complexes originally emplaced into continental sediments along the rifted margin of Iapetus. The intensity and structure of the pre-Caledonian Dyke Complex is comparable to that of the present passive margins of the North Atlantic large igneous province (NALIP) and U-Pb ages of 610-590 Ma suggest magmatism was short-lived. It can be described as a pre-Caledonian large igneous province (CLIP). To constrain the origin of CLIP magmatism we: (1) re-visited the dyke complexes of the Sarek, Kebnekaise and Tornetrask mountains of North Sweden; (2) compiled new and published geochemical data for the more than 950 km long, magma-rich segment of the Scandinavian Caledonides; and (3) extended reconstructions of the paleo-position of Baltica back to 600 Ma. Although the appearance of the dykes ranges from garnet amphibolite gneiss to pristine magmatic intrusions, all bulk rock compositions largely reflect the original magmatic rock. The compiled dataset includes 584 analyses that essentially forms a coherent suite of tholeiitic ferrobasalt (2-12 wt% MgO, 45-54 wt% SiO2; 6-16 wt% FeOtot; 0.7-4.0 wt% TiO2) akin to LIP basalts such as those of NALIP (61-54 Ma). A few samples (Kebnekaise, Tornetrask). The few available rare earth element data support this distribution of geochemical enrichment. We conclude that the compositions of the pre-Caledonian dykes are similar to LIP basalts dominated by asthenospheric mantle melts in general, and strikingly similar to basalts that erupted at 61-54 Ma (NALIP) in the subsequent rift-phase of the North Atlantic Wilson Cycle. It is also interesting that the paleo-positions of CLIP and NALIP appear to overly the margins of the large low shear-wave velocity provinces mapped today at the core-mantle boundary below the Pacific

  10. The role of mantle plumes in the formation of Large Igneous Provinces: A noble gas isotope study from the Etendeka province of Namibia

    Science.gov (United States)

    Stroncik, Nicole A.; Krienitz, Marc-Sebastian; Niederman, Samuel; Trumbull, Robert B.; Harris, Chris

    2013-04-01

    The magmatic history of the Earth is characterised by the episodic appearance of enormous magmatic events, during which large volumes of mainly mafic magmas are generated and emplaced by processes distinct from seafloor spreading or subduction. The so-called Large Igneous Provinces (LIPs) produced during these events are mainly created within less than 10 Ma, with the bulk of magmatism occurring in the first Ma. The favoured explanation for LIP formation is magmatism resulting from plume head decompressional melting. However, the evidence for this theory is mixed and has been challenged lately. Conventional geochemical tracers (Sr, Nd or Pb isotopes or trace elements) generally used to characterise the mantle sources of a magmatic sample are relatively ambiguous in this context, because (1) various mantle reservoirs can contribute to LIP formation and it is unclear which of them are located in the deep mantle, (2) magmas can be contaminated during their ascent through the lithosphere and crust and (3) trace element patterns are also controlled by the degree and depth of melting. In this respect, the principal advantages of noble gases as geochemical tracers for magmatic processes are related to (1) their chemical inertness - they are only modified by nuclear, melting and degassing processes, (2) the large and indicative isotope variations between the various terrestrial reservoirs and (3) their relatively low abundance in the solid Earth. Here we present He, Ne, and O-isotope data from fresh olivines as well as REE and Sr, Nd, and Pb isotope whole rock data derived from dolerite dykes and related rocks from the southern Etendeka province of Namibia. The He-isotope data show a range from radiogenic values of 0.15 ± 0.01 RAto mantle values of 12.03 ± 0.28 RA. The radiogenic He isotope ratios are indicative of crustal contamination during magmatic evolution, which is generally supported by the Ne and O isotope data. The upper range of the He isotope data is higher

  11. Geochemical Signatures of Potassic to Sodic Adang Volcanics, Western Sulawesi: Implications for Their Tectonic Setting and Origin

    Directory of Open Access Journals (Sweden)

    Godang Shaban

    2016-11-01

    Full Text Available DOI:10.17014/ijog.3.3.195-214The Adang Volcanics represent a series of (ultra potassic to sodic lavas and tuffaceous rocks of predominantly trachytic composition, which forms the part of a sequence of Late Cenozoic high-K volcanic and associated intrusive rocks occurring extensively throughout Western Sulawesi. The tectonic setting and origin of these high-K rocks have been the subject of considerable debates. The Adang Volcanics have mafic to mafitic-intermediate characteristics (SiO2: 46 - 56 wt% and a wide range of high alkaline contents (K2O: 0.80 - 9.08 %; Na2O: 0.90 - 7.21 % with the Total Alkali of 6.67 - 12.60 %. Al2O3 values are relatively low (10.63 - 13.21 % and TiO2 values relatively high (1.27 - 1.91 %. Zr and REE concentrations are also relatively high (Zr: 1154 - 2340 ppm; Total REE (TREY = TRE: 899.20 - 1256.50 ppm; TRExOy: 1079.76 - 1507.97 ppm, with an average Zr/TRE ratio of ~ 1.39. The major rock forming minerals are leucite/pseudoleucite, diopside/aegirine, and high temperature phlogopite. Geochemical plots (major oxides and trace elements using various diagrams suggest the Adang Volcanics formed in a postsubduction, within-plate continental extension/initial rift tectonic setting. It is further suggested magma was generated by minor (< 0.1 % partial melting of depleted MORB mantle material (garnet-lherzolite with the silicate melt having undergone strong metasomatism. Melt enrichment is reflected in the alkaline nature of the rocks and geochemical signatures such as Nb/Zr > 0.0627 and (Hf/SmPM > 1.23. A comparison with the Vulsini ultrapotassic volcanics from the Roman Province in Italy shows both similarities (spidergram pattern indicating affinity with Group III ultrapotassics volcanics and differences (nature of mantle metasomatism.

  12. FREZCHEM: An Aqueous Geochemical Model for Mars

    Science.gov (United States)

    Marion, G. M.; Mironenko, M. V.; Roberts, M. W.

    2006-12-01

    For the past eight years, the NASA PG&G and MFR programs have funded the development of the FREZCHEM model. FREZCHEM is an equilibrium chemical thermodynamic model parameterized for concentrated electrolyte solutions (with 81 solid phases) using the Pitzer equations for the temperature range from 200 to 298 K and the total pressure range from 1 to 1000 bars. This model has been extensively used to explore cold geochemical processes and the limits for life in the Arctic, Antarctica, Europa, and Mars. The FORTRAN code has been made freely available to interested scientists. Despite these wide-spread applications, the continual updating, dissemination, and archiving of the model is problematic. The objectives of this project were to (1) develop a user-friendly FORTRAN code, (2) implement an Internet-accessible working model, and (3) develop an archive for various model versions. In this presentation, we will outline the new computer algorithm that uses the Gibbs energy minimization approach, describe the Internet-accessible working model, and illustrate model applications to Martian geochemistry. This project will make this unique research tool readily and easily available, even to occasional users, now and in the future. Today, such a user-friendly model would be especially helpful in interpreting the exciting data from the new Mars missions.

  13. Geological and geochemical variations in Mid-Tertiary Ethiopian ...

    African Journals Online (AJOL)

    The paper presents the results of a comprehensive major element, trace element, and Sr-Nd-Pb-Hf isotopic study of Mid-Tertiary volcanic sequences from the northwestern flood basalt province in Ethiopia. The volcanic rocks studied range in composition from basanites, alkaline basalts, and ankaramites, which form the 1st ...

  14. Tectonics and metallogenic provinces

    Science.gov (United States)

    Guild, P.W.

    1983-01-01

    Various theories have been advanced to explain the well-known uneven distribution of metals and ore-deposit types in space and time. Primordial differences in the mantle, preferential concentration of elements in the crust, the prevalence of ore-forming processes at certain times and (or) places, and combinations of one or several of these factors have all been called upon to account for the "metallogenic provinces," which can be defined loosely as regions containing similar deposits of one or a group of metals or minerals. Because many, perhaps most, provinces have complex, multistage origins, the relative importance of inheritance vs. process is still controversial. In recent years the geographic relationship of many geologically young provinces to present-day plate-tectonic positions (accreting or consuming margins, intraplate structures, etc.) has been widely recognized, and the presumption is strong that older provinces had similar relationships to former plates. As most ore deposits resulted from a favorable conjunction of geological processes that are no longer operative, elucidation of their genesis requires reconstruction of the geologic history of the province, with particular emphasis on events coeval with mineralization. Tectonic analysis is an important aspect of this reconstruction; data from orbiting satellites have contributed greatly to this analysis, as the voluminous literature of the past decade testifies. Both the synoptic view of large areas and the ability to emphasize faint contrasts have revealed linear, curvilinear, and circular features not previously recognized from field studies. Some of these undoubtedly reflect basement structures that have contributed to the development, or limit the extent, of metallogenic provinces. Their recognition and delineation will be increasingly valuable to the assessment of resources available and as guides to exploration for the ores needed by future generations. ?? 1983.

  15. A record of igneous evolution in Elysium, a major martian volcanic province.

    Science.gov (United States)

    Susko, David; Karunatillake, Suniti; Kodikara, Gayantha; Skok, J R; Wray, James; Heldmann, Jennifer; Cousin, Agnes; Judice, Taylor

    2017-02-24

    A major knowledge gap exists on how eruptive compositions of a single martian volcanic province change over time. Here we seek to fill that gap by assessing the compositional evolution of Elysium, a major martian volcanic province. A unique geochemical signature overlaps with the southeastern flows of this volcano, which provides the context for this study of variability of martian magmatism. The southeastern lava fields of Elysium Planitia show distinct chemistry in the shallow subsurface (down to several decimeters) relative to the rest of the martian mid-to-low latitudes (average crust) and flows in northwest Elysium. By impact crater counting chronology we estimated the age of the southeastern province to be 0.85 ± 0.08 Ga younger than the northwestern fields. This study of the geochemical and temporal differences between the NW and SE Elysium lava fields is the first to demonstrate compositional variation within a single volcanic province on Mars. We interpret the geochemical and temporal differences between the SE and NW lava fields to be consistent with primary magmatic processes, such as mantle heterogeneity or change in depth of melt formation within the martian mantle due to crustal loading.

  16. National Uranium Resource Evaluation program. Uranium geochemical survey in the Crystal City and Beeville Quadrangles, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Nichols, C.E.; Butz, T.R.; Cagle, G.W.; Kane, V.E.

    1977-02-11

    A uranium geochemical survey was conducted in the Crystal City and western half of the Beeville Quadrangles, Texas, an area of approximately 34,000 km/sup 2/. Using the Texas Gulf Coast Uranium Province as a study area, this survey demonstrates the applicability of a 2 phase hierarchical sampling program with multielement analysis of the samples for regional geochemical reconnaissance for uranium. Phase I samples of stream sediment, stream water, and well water were collected from drainage basins with a target drainage of 250 km/sup 2/ to identify uranium province lines which define the area in which closer spaced Phase II sampling should be conducted. Phase II samples of stream sediment, stream water, well water, and tree branches were collected from drainage basins with a target drainage of 25 km/sup 2/ in order to identify uranium district lines. Stream sediment, stream water, well water, and ash of tree branches were analyzed for approximately 25 parameters. The most useful sample type for identifying potential uranium mineralization in the Texas Gulf Coast is well water. Wells were found to accurately distinguish both province lines at Phase I sample spacing and district lines at Phase II sample spacing by several methods of evaluation. Results of the survey indicate that the concept of 2 phase sampling with multielement analyses of samples, developed by the ORGDP Project, may yield good results for the remainder of the area to be surveyed by ORGDP with modifications for different geologic regions.

  17. Geochemical Parameters Required from the SKB Site Characterisation Programme

    Energy Technology Data Exchange (ETDEWEB)

    Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

    2002-01-01

    SKB has described its approach to site characterisation in a number of Technical Reports. One of the scientific topics in which specific information requirements and priorities are set out is geochemistry. This report for SKI examines critically whether the geochemical parameters identified in the SKB programme documents will be adequate for safety and regulatory requirements. It also examines some of the details of parameter requirements and interpretation tools that will be necessary to convert site investigation data into knowledge about chemical conditions and groundwater movements. The SKB strategy for geochemical data focuses on a small number of 'suitability indicators', primarily dissolved oxygen, pH and salinity. Their parameter requirements aim to assess those primary characteristics, as well as to acquire a wider range of data that will support those assessments and provide a broader understanding of candidate areas. An initial observation in this review that, though it is a primary suitability indicator, dissolved oxygen apparently will not be measured and instead will be inferred from other redox indicators. This raises a number of issues about sampling and monitoring measures, analytical data reliability and sensitivity, and the degree of confidence in geochemical understanding. A geochemical programme involves reconnaissance by desk study and acquisition of new data at levels of details that are appropriate to the stage of site investigations. As early as possible, a conceptual model of a candidate area should help to define the objectives of geochemical measurements on both rock and groundwater samples. It is recommended that parameters requirements should be defined and considered not only in terms of isolated measurements but more in terms of addressing broader objectives that relate to safety and also to geoscientific understanding. The safety priorities remain (e.g. dissolved oxygen) but will then be supported by an understanding of

  18. SNOWY RANGE WILDERNESS, WYOMING.

    Science.gov (United States)

    Houston, Robert S.; Bigsby, Philip R.

    1984-01-01

    A mineral survey of the Snowy Range Wilderness in Wyoming was undertaken and was followed up with more detailed geologic and geochemical surveys, culminating in diamond drilling of one hole in the Snowy Range Wilderness. No mineral deposits were identified in the Snowy Range Wilderness, but inasmuch as low-grade uranium and associated gold resources were identified in rocks similar to those of the northern Snowy Range Wilderness in an area about 5 mi northeast of the wilderness boundary, the authors conclude that the northern half of the wilderness has a probable-resource potential for uranium and gold. Closely spaced drilling would be required to completely evaluate this mineral potential. The geologic terrane precludes the occurrence of fossil fuels.

  19. Organic geochemical study of domanik deposits, Tatarstan Republic.

    Science.gov (United States)

    Nosova, F. F.; Pronin, N. V.

    2010-05-01

    High-bituminous argillo-siliceous carbonate deposits of domanik formation (DF) occurring within pale depressions and down warps in the east of the Russian platform are treated by many investigators as a main source of oil and gas in the Volga-Ural province. In this study a special attention was turned to organic-rich rocks DF witch outcrop in the central part (Uratminskaya area 792, 806 boreholes) and in the west part (Sviyagskaya, 423) of the Tatarstan Republic. The aim of the present paper is to characterize the organic matter: origin, depositional environments, thermal maturity and biodegradation-weathering effects. Nowadays the most informative geochemical parameters are some biomarkers which qualitatively and are quantitatively defined from distributions of n-alkanes and branched alkanes. Biomarkers - it's original fingerprints of biomass of organic matter, that reflect molecular hydrocarbonic structure. The bulk, molecular composition of oil is initially a function of the type and maturity of the source rock from which it has been expelled, while the source rock type reflects both the nature of precursor organisms and the conditions of its deposition. Methodology used in this study included sampling, bitumen extraction, liquid-column chromatography and gas chromatography/mass spectrometry analyses. The bitumen was fractionated by column chromatography on silica gel. Non-aromatic or alifatics, aromatics and polar compounds were obtained. Alifatic were analysed by gas chromatography/mass spectrometry Percin Elmer. The hydrocarbons present in the sediments of DF and have a carbon numbers ranging from 12 through 38. The samples contain variably inputs from both terrigenous and non-terrigenous (probably marine algal) organic matter as evident in bimodal GC fingerprints of some samples. Pristane and phytane, also, occur in very high concentration in sample extracts. The relatively low Pr/Ph ratios, CPI and OEP<1 imply that the domanik organic matter was deposited

  20. Collected radiochemical and geochemical procedures

    Energy Technology Data Exchange (ETDEWEB)

    Kleinberg, J [comp.

    1990-05-01

    This revision of LA-1721, 4th Ed., Collected Radiochemical Procedures, reflects the activities of two groups in the Isotope and Nuclear Chemistry Division of the Los Alamos National Laboratory: INC-11, Nuclear and radiochemistry; and INC-7, Isotope Geochemistry. The procedures fall into five categories: I. Separation of Radionuclides from Uranium, Fission-Product Solutions, and Nuclear Debris; II. Separation of Products from Irradiated Targets; III. Preparation of Samples for Mass Spectrometric Analysis; IV. Dissolution Procedures; and V. Geochemical Procedures. With one exception, the first category of procedures is ordered by the positions of the elements in the Periodic Table, with separate parts on the Representative Elements (the A groups); the d-Transition Elements (the B groups and the Transition Triads); and the Lanthanides (Rare Earths) and Actinides (the 4f- and 5f-Transition Elements). The members of Group IIIB-- scandium, yttrium, and lanthanum--are included with the lanthanides, elements they resemble closely in chemistry and with which they occur in nature. The procedures dealing with the isolation of products from irradiated targets are arranged by target element.

  1. Petrographic features, geochemical trends and mass balance ...

    African Journals Online (AJOL)

    Petrographic features, geochemical trends and mass balance computation, in relation to the evolution of anatectic migmatites in the granulite facies terrain of the Manalur area, Tamil Nadu, south India.

  2. The National Geochemical Survey - database and documentation

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The USGS, in collaboration with other federal and state government agencies, industry, and academia, is conducting the National Geochemical Survey (NGS) to produce a...

  3. Geochemical characterization of oceanic basalts using Artificial Neural Network.

    Science.gov (United States)

    Das, Pranab; Iyer, Sridhar D

    2009-12-23

    The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). We have applied Artificial Neural Network (ANN) technique as a supervised Learning Vector Quantisation (LVQ) to identify the inherent geochemical signatures present in the Central Indian Ocean Basin (CIOB) basalts. A range of N-MORB, E-MORB and OIB dataset was used for training and testing of the network. Although the identification of the characters as N-MORB, E-MORB and OIB is completely dependent upon the training data set for the LVQ, but to a significant extent this method is found to be successful in identifying the characters within the CIOB basalts. The study helped to geochemically delineate the CIOB basalts as N-MORB with perceptible imprints of E-MORB and OIB characteristics in the form of moderately enriched rare earth and incompatible elements. Apart from the fact that the magmatic processes are difficult to be deciphered, the architecture performs satisfactorily.

  4. Geochemical characterization of oceanic basalts using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Iyer Sridhar D

    2009-12-01

    Full Text Available Abstract The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB under one class i.e., as mid-oceanic ridge basalts (MORB. Hence, a method is specifically needed to identify the OFB as normal (N-MORB, enriched (E-MORB and ocean island basalts (OIB. We have applied Artificial Neural Network (ANN technique as a supervised Learning Vector Quantisation (LVQ to identify the inherent geochemical signatures present in the Central Indian Ocean Basin (CIOB basalts. A range of N-MORB, E-MORB and OIB dataset was used for training and testing of the network. Although the identification of the characters as N-MORB, E-MORB and OIB is completely dependent upon the training data set for the LVQ, but to a significant extent this method is found to be successful in identifying the characters within the CIOB basalts. The study helped to geochemically delineate the CIOB basalts as N-MORB with perceptible imprints of E-MORB and OIB characteristics in the form of moderately enriched rare earth and incompatible elements. Apart from the fact that the magmatic processes are difficult to be deciphered, the architecture performs satisfactorily.

  5. The role of atomic absorption spectrometry in geochemical exploration

    Science.gov (United States)

    Viets, J.G.; O'Leary, R. M.

    1992-01-01

    In this paper we briefly describe the principles of atomic absorption spectrometry (AAS) and the basic hardware components necessary to make measurements of analyte concentrations. Then we discuss a variety of methods that have been developed for the introduction of analyte atoms into the light path of the spectrophotometer. This section deals with sample digestion, elimination of interferences, and optimum production of ground-state atoms, all critical considerations when choosing an AAS method. Other critical considerations are cost, speed, simplicity, precision, and applicability of the method to the wide range of materials sampled in geochemical exploration. We cannot attempt to review all of the AAS methods developed for geological materials but instead will restrict our discussion to some of those appropriate for geochemical exploration. Our background and familiarity are reflected in the methods we discuss, and we have no doubt overlooked many good methods. Our discussion should therefore be considered a starting point in finding the right method for the problem, rather than the end of the search. Finally, we discuss the future of AAS relative to other instrumental techniques and the promising new directions for AAS in geochemical exploration. ?? 1992.

  6. Geochemical Transformation of Cadmium (Cd) from Creek to Paddy Fields in W Thailand

    Science.gov (United States)

    Kosolsaksakul, Peerapat; Graham, Margaret; Farmer, John

    2013-04-01

    Extensive Cd contamination of paddy soils in Tak Province, western Thailand, a consequence of Zn mining activities, was first established in 2005 and medical studies showed that the health of local communities was being impaired. Mae Tao, Tak Province, comprising many paddy fields and irrigation canals, has been selected for this study of the geochemical transformation of Cd from the contamination source in the mountainous region to the east of the study site through the community irrigation system to the paddy soils. The aim of this research is to (i) investigate the geochemical transformation of Cd as it is transported from the main irrigation creek through the canals and to the paddy fields, (ii) assess the availability of Cd to rice plants, which may be affected by both chemical and physical factors, and (iii) trial some practical treatments to minimise Cd concentrations in rice grains. Soils, irrigation canal sediments and water samples were collected during the dry season and at the onset of the rainy season. Rice samples were collected at harvesting time and samples of soil fertiliser were also obtained. Water samples were filtered, ultrafiltered and analysed by ICP-MS whilst sub-samples of dried, ground soils and sediments were first subjected to micro-wave assisted acid digestion (modified US EPA method 3052). XRD and SEM-EDX methods were used for mineralogical characterisation and selective chemical extractions have assisted in the characterisation of solid phase Cd associations. Soil Cd concentrations were in the range 2.5-87.6 µg g-1, with higher values being obtained for fields furthest from the main creek. Although current irrigation water Cd inputs are low (mean 1.9 μg L-1; flood period), high loads of suspended particles still contribute additional Cd (4.2-9.8 µg L-1) to the paddy fields. For bioavailability assessment by a 3-step BCR sequential extraction, 70-90% Cd was in the exchangeable; HOAc-extractable fraction. That indicated that most of

  7. Comparative analysis of the evaluation of the intrinsic vulnerability in carbonate aquifers (Canete Mountain Range, province of Malaga); Analisis comparativo de la evaluacion de la vulnerabilidad intrinseca de acuiferos carbonaticos (Sierra de Canete, provincia de Malaga)

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Madrid, A.; Carrasco Cantos, F.; Martinez Navarrete, C.

    2009-07-01

    Groundwater of the carbonate aquifers of Canete Mountain Range constitute a basic source for water supply to different populations. Vulnerability intrinsic assesment is one of the most useful tools for the protection of the groundwater bodies, for this reason, this area has been chosen, to realize a comparative analysis, by means of the use of tools of spatial analysis and technical statistics of a Geographical Information System. In this work, Reduced DRASTIC, COP and RISK method have been applied, due to the fact that they are the methods used by Spain, both first ones, to evaluate the vulnerability of the groundwater bodies in the inter communal basins of the whole national territory, and for BRGM of France, the last one, to approach the carbonate aquifers protection. The obtained results show as the COP and RISK methods, specifics of carbonate aquifers, there show results more according to the characteristics of Canete Mountain Range that the obtained ones with Reduced DRASTIC, which unsaturated zone valuation causes an undervaluing the results of vulnerability obtained. (Author) 35 refs.

  8. The effect of scale on the interpretation of geochemical anomalies

    Science.gov (United States)

    Theobald, P.K.; Eppinger, R.G.; Turner, R.L.; Shiquan, S.

    1991-01-01

    The purpose of geochemical surveys changes with scale. Regional surveys identify areas where mineral deposits are most likely to occur, whereas intermediate surveys identify and prioritize specific targets. At detailed scales specific deposit models may be applied and deposits delineated. The interpretation of regional geochemical surveys must take into account scale-dependent difference in the nature and objectives of this type of survey. Overinterpretation of regional data should be resisted, as should recommendations to restrict intermediate or detailed follow-up surveys to the search for specific deposit types or to a too limited suite of elements. Regional surveys identify metallogenic provinces within which a variety of deposit types and metals are most likely to be found. At intermediate scale, these regional provinces often dissipate into discrete clusters of anomalous areas. At detailed scale, individual anomalous areas reflect local conditions of mineralization and may seem unrelated to each other. Four examples from arid environments illustrate the dramatic change in patterns of anomalies between regional and more detailed surveys. On the Arabian Shield, a broad regional anomaly reflects the distribution of highly differentiated anorogenic granites. A particularly prominent part of the regional anomaly includes, in addition to the usual elements related to the granites, the assemblage of Mo, W and Sn. Initial interpretation suggested potential for granite-related, stockwork Mo deposits. Detailed work identified three separate sources for the anomaly: a metal-rich granite, a silicified and stockwork-veined area with scheelite and molybdenite, and scheelite/powellite concentrations in skarn deposits adjacent to a ring-dike complex. Regional geochemical, geophysical and remote-sensing data in the Sonoran Desert, Mexico, define a series of linear features interpreted to reflect fundamental, northeast-trending fractures in the crust that served as the prime

  9. Deep sequencing of subseafloor eukaryotic rRNA reveals active Fungi across marine subsurface provinces.

    Directory of Open Access Journals (Sweden)

    William Orsi

    Full Text Available The deep marine subsurface is a vast habitat for microbial life where cells may live on geologic timescales. Because DNA in sediments may be preserved on long timescales, ribosomal RNA (rRNA is suggested to be a proxy for the active fraction of a microbial community in the subsurface. During an investigation of eukaryotic 18S rRNA by amplicon pyrosequencing, unique profiles of Fungi were found across a range of marine subsurface provinces including ridge flanks, continental margins, and abyssal plains. Subseafloor fungal populations exhibit statistically significant correlations with total organic carbon (TOC, nitrate, sulfide, and dissolved inorganic carbon (DIC. These correlations are supported by terminal restriction length polymorphism (TRFLP analyses of fungal rRNA. Geochemical correlations with fungal pyrosequencing and TRFLP data from this geographically broad sample set suggests environmental selection of active Fungi in the marine subsurface. Within the same dataset, ancient rRNA signatures were recovered from plants and diatoms in marine sediments ranging from 0.03 to 2.7 million years old, suggesting that rRNA from some eukaryotic taxa may be much more stable than previously considered in the marine subsurface.

  10. Organic geochemical constraints on paleoelevation

    Science.gov (United States)

    Polissar, P. J.; Rowley, D. B.; Currie, B. S.; Freeman, K. H.

    2012-12-01

    The elevation history of the land surface is an important factor in the interpretation of past tectonic, climate and ecological processes. However, quantitative estimates of paleoelevation are difficult to produce and new techniques are needed. Organic geochemical approaches to quantifying paleoelevations provide a new perspective on this difficult task. The hydrogen isotopic composition of organic biomarker molecules synthesized by plants and algae is systematically related to the water used for growth. Organic molecules in ancient sediments can provide values for the isotopic composition of this water and thus elevation, provided the relationship between elevation and isotopic values is known. Molecular hydrogen isotope ratios from Cenozoic lake sediments on the Tibetan Plateau demonstrate the utility of a biomarker approach. Terrestrial plant-wax D/H values on Neogene sediments from the Namling-Oiyug Basin provide new paleoelevation estimates that compare well with previous studies. Plant wax D/H ratios paired with lacustrine carbonate oxygen isotope values from the Lunpola and Hoh-Xil basins illustrate how paired isotope systems can unravel the isotopic composition of precipitation from evaporative enrichment of lake waters. A potentially fruitful avenue for future research is illustrated by D/H analyses on older sediments from the Namling-Oiyug Basin. These sediments—like many that could be useful for paleoaltimetry—have experienced significant burial and heating. As temperatures approach the oil window it becomes possible to exchange hydrogen in both the extractable organic molecules (bitumen) and the insoluble organic residue (kerogen). The extent to which this exchange alters the original isotopic composition will determine the usefulness of D/H analyses on thermally mature organic matter. The potential payoff and pitfalls of D/H analyses on heated sediments is illustrated with thermally immature and mature samples from the Namling-Oiyug Basin.

  11. Geochemical and isotopic perspectives on the origin and evolution of the Siletzia Terrane.

    Science.gov (United States)

    Phillips, B. A.; Weis, D.; Mullen, E.; Kerr, A. C.

    2015-12-01

    The Siletzia terrane, located in the Cascadia forearc region of Oregon, Washington and Vancouver Island, consists of a series of accreted basaltic pillow lavas, massive flows and intrusive sheets. It represents a late Paleocene-Eocene oceanic large igneous province (LIP), previously proposed to represent an accreted oceanic plateau, hotspot island chain, backarc basin, island arc, or a sequence of slab window volcanics formed by ridge subduction. A province-wide geochemical reassessment of the terrane, including new high precision Sr-Pb-Nd-Hf isotope data on basaltic samples, has been used to assess the validity of the proposed tectonomagmatic models for Siletzia. The trace element data show REE patterns that are flat to LREE enriched with an absence of any arc signatures. These features are comparable to other oceanic plateaus such as the Ontong Java and the Caribbean and so therefore support a mantle plume origin. Initial isotope ratios range from 206Pb/204Pb = 18.869 - 19.673, 207Pb/204Pb = 15.527 - 15.609, 208Pb/204Pb = 38.551 - 39.220, ɛHf = +9.0 - 14.8, ɛNd = +5.0 - 8.0 and 87Sr/86Sr = 0.70304 - 0.70397. The isotope signatures become more varied southward across the terrane and reveal two trends: i) HIMU-DMM and ii) another extending from DMM towards the Imnaha component, thought to represent the mantle plume source of the Columbia River Basalts and Yellowstone 1,2. The data may support the previously proposed idea that the volcanism of the Siletzia terrane represents initial melting of the mantle plume head of the Yellowstone hotspot 3,4,5. Other evidence indicating a LIP origin includes the relatively rapid eruption/intrusion of an estimated magma volume of 2.6 x 106 km3 6 between ~56-49 Ma 5, which, in conjunction with our new elemental and isotopic data, indicates that the Siletzia terrane most likely represents an accreted oceanic plateau. 1. Wolff et al., (2008) Nature Geoscience 1, 177-180. 2. Jean et al., (2014) EPSL 389, 119-131 3. Duncan (1982

  12. Alaska Geochemical Database - Mineral Exploration Tool for the 21st Century - PDF of presentation

    Science.gov (United States)

    Granitto, Matthew; Schmidt, Jeanine M.; Labay, Keith A.; Shew, Nora B.; Gamble, Bruce M.

    2012-01-01

    The U.S. Geological Survey has created a geochemical database of geologic material samples collected in Alaska. This database is readily accessible to anyone with access to the Internet. Designed as a tool for mineral or environmental assessment, land management, or mineral exploration, the initial version of the Alaska Geochemical Database - U.S. Geological Survey Data Series 637 - contains geochemical, geologic, and geospatial data for 264,158 samples collected from 1962-2009: 108,909 rock samples; 92,701 sediment samples; 48,209 heavy-mineral-concentrate samples; 6,869 soil samples; and 7,470 mineral samples. In addition, the Alaska Geochemical Database contains mineralogic data for 18,138 nonmagnetic-fraction heavy mineral concentrates, making it the first U.S. Geological Survey database of this scope that contains both geochemical and mineralogic data. Examples from the Alaska Range will illustrate potential uses of the Alaska Geochemical Database in mineral exploration. Data from the Alaska Geochemical Database have been extensively checked for accuracy of sample media description, sample site location, and analytical method using U.S. Geological Survey sample-submittal archives and U.S. Geological Survey publications (plus field notebooks and sample site compilation base maps from the Alaska Technical Data Unit in Anchorage, Alaska). The database is also the repository for nearly all previously released U.S. Geological Survey Alaska geochemical datasets. Although the Alaska Geochemical Database is a fully relational database in Microsoft® Access 2003 and 2010 formats, these same data are also provided as a series of spreadsheet files in Microsoft® Excel 2003 and 2010 formats, and as ASCII text files. A DVD version of the Alaska Geochemical Database was released in October 2011, as U.S. Geological Survey Data Series 637, and data downloads are available at http://pubs.usgs.gov/ds/637/. Also, all Alaska Geochemical Database data have been incorporated into

  13. Pillow basalts of the Angayucham terrane: oceanic plateau and island crust accreted to the Brooks Range

    Science.gov (United States)

    Pallister, J.S.; Budahn, J.R.; Murchey, B.L.

    1989-01-01

    The Angayucham Mountains (north margin of the Yukon-Koyukuk province) are made up of an imbricate stack of four to eight east-west trending, steeply dipping, fault slabs composed of Paleozoic, Middle to Late Triassic, and Early Jurassic oceanic upper crustal rocks. Field relations and geochemical characteristics of the basaltic rocks suggest that the fault slabs were derived from an oceanic plateau or island setting and were emplaced onto the Brooks Range continental margin. The basalts are variably metamorphosed to prehnite-pumpellyite and low-greenschist facies. Major element analyses suggest that many are hypersthene-normative olivine tholeiites. The Triassic and Jurassic basalts are geochemically most akin to modern oceanic plateau and island basalts. Field evidence also favors an oceanic plateau or island setting. The great composite thickness of pillow basalt probably resulted from obduction faulting, but the lack of fault slabs of gabbro or peridotite suggests that obduction faults did not penetrate below oceanic layer 2, a likely occurrence if layer 2 were anomalously thick, as in the vicinity of an oceanic island. -from Authors

  14. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates

    Science.gov (United States)

    Atchley, Adam L.; Navarre-Sitchler, Alexis K.; Maxwell, Reed M.

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb2 +) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb2 + concentrations within the plume. Dissimilarities between ensemble Pb2 + concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb2 + concentrations are the same for all three

  15. The effects of physical and geochemical heterogeneities on hydro-geochemical transport and effective reaction rates.

    Science.gov (United States)

    Atchley, Adam L; Navarre-Sitchler, Alexis K; Maxwell, Reed M

    2014-09-01

    The role of coupled physical and geochemical heterogeneities in hydro-geochemical transport is investigated by simulating three-dimensional transport in a heterogeneous system with kinetic mineral reactions. Ensembles of 100 physically heterogeneous realizations were simulated for three geochemical conditions: 1) spatially homogeneous reactive mineral surface area, 2) reactive surface area positively correlated to hydraulic heterogeneity, and 3) reactive surface area negatively correlated to hydraulic heterogeneity. Groundwater chemistry and the corresponding effective reaction rates were calculated at three transverse planes to quantify differences in plume evolution due to heterogeneity in mineral reaction rates and solute residence time (τ). The model is based on a hypothetical CO2 intrusion into groundwater from a carbon capture utilization and storage (CCUS) operation where CO2 dissolution and formation of carbonic acid created geochemical dis-equilibrium between fluids and the mineral galena that resulted in increased aqueous lead (Pb(2+)) concentrations. Calcite dissolution buffered the pH change and created conditions of galena oversaturation, which then reduced lead concentrations along the flow path. Near the leak kinetic geochemical reactions control the release of solutes into the fluid, but further along the flow path mineral solubility controls solute concentrations. Simulation results demonstrate the impact of heterogeneous distribution of geochemical reactive surface area in coordination with physical heterogeneity on the effective reaction rate (Krxn,eff) and Pb(2+) concentrations within the plume. Dissimilarities between ensemble Pb(2+) concentration and Krxn,eff are attributed to how geochemical heterogeneity affects the time (τeq) and therefore advection distance (Leq) required for the system to re-establish geochemical equilibrium. Only after geochemical equilibrium is re-established, Krxn,eff and Pb(2+) concentrations are the same for all

  16. The geochemical atlas of Alaska, 2016

    Science.gov (United States)

    Lee, Gregory K.; Yager, Douglas B.; Mauk, Jeffrey L.; Granitto, Matthew; Denning, Paul D.; Wang, Bronwen; Werdon, Melanie B.

    2016-06-21

    A rich legacy of geochemical data produced since the early 1960s covers the great expanse of Alaska; careful treatment of such data may provide significant and revealing geochemical maps that may be used for landscape geochemistry, mineral resource exploration, and geoenvironmental investigations over large areas. To maximize the spatial density and extent of data coverage for statewide mapping of element distributions, we compiled and integrated analyses of more than 175,000 sediment and soil samples from three major, separate sources: the U.S. Geological Survey, the National Uranium Resource Evaluation program, and the Alaska Division of Geological & Geophysical Surveys geochemical databases. Various types of heterogeneity and deficiencies in these data presented major challenges to our development of coherently integrated datasets for modeling and mapping of element distributions. Researchers from many different organizations and disparate scientific studies collected samples that were analyzed using highly variable methods throughout a time period of more than 50 years, during which many changes in analytical techniques were developed and applied. Despite these challenges, the U.S. Geological Survey has produced a new systematically integrated compilation of sediment and soil geochemical data with an average sample site density of approximately 1 locality per 10 square kilometers (km2) for the entire State of Alaska, although density varies considerably among different areas. From that compilation, we have modeled and mapped the distributions of 68 elements, thus creating an updated geochemical atlas for the State.

  17. Constructing the volcanic architecture of Kalkarindji, an ancient flood basalt province, using a multidisciplinary approach

    Science.gov (United States)

    Marshall, P.; Widdowson, M.; Kelley, S. P.; Mac Niocaill, C.; Murphy, D. T.

    2014-12-01

    The Kalkarindji Continental Flood Basalt Province (CFBP) is the oldest igneous province in the Phanerozoic. Erupted in the mid-Cambrian (505-510 Ma) [1], it is estimated volumes of lava up to 1.5 x 105 km3could have been erupted, making this similar in size to the better known Columbia River Basalts, USA. Relatively little is known about the province, due in part to its remote location, though large swathes remain well preserved (c. 50,000 km2). This study, based on rigorous field investigations, utilises 4 different analytical techniques to construct a volcanic architecture for the Kalkarindji basalts, drawing together these complimentary datasets to generate a series of detailed stratigraphies from around the province. Mineralogy and petrography form the basis while geochemical data aides in defining lava flow stratigraphies and distinguishing individual flow packages in disparate locations around the province. 40Ar/39Ar dating of key stratigraphic marker horizons support stratigraphical correlation across the province whilst the use of palaeomagnetism and magnetostratigraphy has allowed for correlation on a broader scale. Indications from this study point towards an unusual eruption among CFBPs in the Phanerozoic; a lack of tumescence, immediate subsidence of the lava pile following cessation of eruption; and, in the main sub-province, we map a simple volcanic structure thinning to the east from a single source. 1. L. M. Glass, D. Phillips, (2006). Geology. 34, 461-464.

  18. Geochemical evaluation of Niger Delta sedimentary organic rocks: a new insight

    Science.gov (United States)

    Akinlua, Akinsehinwa; Torto, Nelson

    2010-05-01

    A geochemical evaluation of Niger Delta organic matter was carried out using supercritical fluid extraction (SFE) sample preparation procedure. Comparison of geochemical significance of gas chromatographic data of rock extracts of SFE with those of Soxhlet extraction method from previous studies was made in order to establish the usefulness of SFE in geochemical exploration. The assessment of geochemical character of the rock samples from the comparison and interpretation of other geochemical parameters were used to give more insights into understanding the source rocks characteristics of onshore and shelf portions of the Niger Delta Basin. The results of the gas chromatographic (GC) analysis of the rock extracts across the lithostratigraphic units show that Pr/Ph, Pr/nC17, Pr/nC18, CPI and odd/even preference ranged from 0.07 to 12.39, 0.04 to 6.66, 0.05 to 13.80, 0.12 to 8.4 and 0.06 to 8.12, respectively. The Rock-Eval pyrolysis data and geochemical ratios and parameters calculated from the GC data showed that most of the samples are mature and have strong terrestrial provenance while a few samples have strong marine provenance. The few marine source rocks are located in the deeper depth horizon. Pr/Ph and standard geochemical plots indicate that most of samples were derived from organic matter deposited in less reducing conditions, i.e. more of oxidizing conditions while a few samples have predominantly influence of reducing conditions. The results of trace metal analysis of older samples from Agbada Formation also indicate marine and mixed organic matter input deposited in less reducing conditions. The results obtained in this study are comparable with those obtained from previous studies when Soxhlet extraction method was used and also indicated the presence of more than one petroleum systems in the Niger Delta.

  19. Geochemical variability of copper and iron in Oman margin sediments

    Digital Repository Service at National Institute of Oceanography (India)

    Alagarsamy, R.

    An analysis of the geochemical distribution of selected trace metals among various geochemical phases of the sediments in the Oman Margin was carried out using a sequential extraction technique. The present study showed that most Cu in abyssal...

  20. Analyzing legacy U.S. Geological Survey geochemical databases using GIS: applications for a national mineral resource assessment

    Science.gov (United States)

    Yager, Douglas B.; Hofstra, Albert H.; Granitto, Matthew

    2012-01-01

    This report emphasizes geographic information system analysis and the display of data stored in the legacy U.S. Geological Survey National Geochemical Database for use in mineral resource investigations. Geochemical analyses of soils, stream sediments, and rocks that are archived in the National Geochemical Database provide an extensive data source for investigating geochemical anomalies. A study area in the Egan Range of east-central Nevada was used to develop a geographic information system analysis methodology for two different geochemical datasets involving detailed (Bureau of Land Management Wilderness) and reconnaissance-scale (National Uranium Resource Evaluation) investigations. ArcGIS was used to analyze and thematically map geochemical information at point locations. Watershed-boundary datasets served as a geographic reference to relate potentially anomalous sample sites with hydrologic unit codes at varying scales. The National Hydrography Dataset was analyzed with Hydrography Event Management and ArcGIS Utility Network Analyst tools to delineate potential sediment-sample provenance along a stream network. These tools can be used to track potential upstream-sediment-contributing areas to a sample site. This methodology identifies geochemically anomalous sample sites, watersheds, and streams that could help focus mineral resource investigations in the field.

  1. The Mount Pavagadh volcanic suite, Deccan Traps: Geochemical stratigraphy and magmatic evolution

    Science.gov (United States)

    Sheth, Hetu C.; Melluso, Leone

    2008-02-01

    The patterns of eruption and dispersal of flood basalt lavas on the surface, or as magmas in dykes and sills within the crust, determine the volcanological and stratigraphic development of flood basalt provinces. This is a geochemical and Sr-isotopic study of lavas of varied compositions that outcrop around Mount Pavagadh (829 m), Deccan Traps, an important outlier north of the main basalt outcrop. Most of the ˜550-m thick exposed section at Pavagadh is made up of subalkalic basalts rich in the incompatible elements (particularly Nb, Ba, and Sr). Picrite and rhyolite-dacite flows also occur, the latter capping the sequence. The relatively high initial 87Sr/ 86Sr ratios (up to 0.7083) and chemical characteristics of the rhyolitic rocks of Pavagadh are consistent with a small but significant involvement of the granitic basement crust in their genesis. An assimilation-fractional crystallization (AFC) model involving the picrite lava and either a southern Indian or a western Indian granite as the contaminant explains the geochemical and Sr-isotopic variation in the basalts and the rhyolites quite well. A systematic comparison of the basaltic lavas (with binary plots, normalized multielement patterns, and discriminant function analysis) to the well-established lava stratigraphy of the Western Ghats, 400-500 km to the south, precludes any chemical-genetic relationships between the two. Basalts exposed in sections closer to Pavagadh (˜150-200 km), in the Toranmal, Navagam, and Barwani-Mhow areas, have several flows with some similar chemical characteristics. However, the Pavagadh sequence is significantly different from all of these sequences geochemically, petrogenetically, and in magnetic polarity, to be considered independently built. This result is significant in terms of eruptive models for the Deccan Traps, as it is increasingly apparent that there were separate but possibly coeval eruptive centers with their own distinctive chemistries developed in various areas

  2. Heavy Metal Pollution Assessment by Partial Geochemical ...

    African Journals Online (AJOL)

    Mn and Fe oxides are powerful absorbents of heavy metal cations in soils and stream sediments therefore considered in this environmental geochemical investigation. Steam sediment samples were collected from Au-Ag and Pb-Zn-Cu mineralized areas of the Rodalquilar old gold mine, located in the southeastern part of ...

  3. Heavy Metal Pollution Assessment by Partial Geochemical ...

    African Journals Online (AJOL)

    Bheema

    Ni, Mo and P (Thompson, 1983). Table 2. Geochemical analytical procedure for the three leachates. Water extraction (W). Partial extraction (HA). Total extraction (AR). 10 gm,. 1gm. 1gm. Adding 25ml demineralized water. 20 ml of 0.25M hydroxylamine and 0.1M HCl solution. 5ml agua regia and 5ml demineralized water.

  4. Geochemical Investigation of Vertical Migration of Petroleum ...

    African Journals Online (AJOL)

    The investigation comprised bulk geochemical analyses in order to estimate various leakage indicators (S1 & PI). High Extractable Organic Matter (EOM) values of up to 6 mg/g rock were obtained in most of the samples. The high S1 and PI values obtained from the samples suggest oil staining. Furthermore, Iatroscan SARA ...

  5. Alaska Geochemical Database (AGDB)-Geochemical data for rock, sediment, soil, mineral, and concentrate sample media

    Science.gov (United States)

    Granitto, Matthew; Bailey, Elizabeth A.; Schmidt, Jeanine M.; Shew, Nora B.; Gamble, Bruce M.; Labay, Keith A.

    2011-01-01

    The Alaska Geochemical Database (AGDB) was created and designed to compile and integrate geochemical data from Alaska in order to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, environmental impact assessments, and studies in medical geology. This Microsoft Access database serves as a data archive in support of present and future Alaskan geologic and geochemical projects, and contains data tables describing historical and new quantitative and qualitative geochemical analyses. The analytical results were determined by 85 laboratory and field analytical methods on 264,095 rock, sediment, soil, mineral and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed in USGS laboratories or, under contracts, in commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects from 1962 to 2009. In addition, mineralogical data from 18,138 nonmagnetic heavy mineral concentrate samples are included in this database. The AGDB includes historical geochemical data originally archived in the USGS Rock Analysis Storage System (RASS) database, used from the mid-1960s through the late 1980s and the USGS PLUTO database used from the mid-1970s through the mid-1990s. All of these data are currently maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB were used to generate most of the AGDB data set. These data were checked for accuracy regarding sample location, sample media type, and analytical methods used. This arduous process of reviewing, verifying and, where necessary, editing all USGS geochemical data resulted in a significantly improved Alaska geochemical dataset. USGS data that were not previously in the NGDB because the data predate the earliest USGS geochemical databases, or were once excluded for programmatic reasons

  6. Geochemical distribution of trace element concentrations in the vicinity of Boroo gold mine, Selenge Province, Mongolia.

    Science.gov (United States)

    Inam, Edu; Khantotong, Supawan; Kim, Kyoung-Woong; Tumendemberel, Bulgan; Erdenetsetseg, Sugar; Puntsag, Tamir

    2011-01-01

    The environmental impacts of Boroo gold mine project in Mongolia was evaluated by chemical characterization of trace element concentrations in water, soils and tailing dam sediment samples. The results showed that concentrations of B, Cd, Ni and Se in the water samples were within the accepted levels of the Mongolia water quality standard (MNS4586: 1998). However, the concentrations of Al, As, Cu, Mn, Fe, Pb, U and Zn were higher than the maximum allowable concentration especially in the monitoring and heap leach wells. The average concentrations of As, Cd, Cu, Ni, Pb and Zn in the tailing dam sediment were 4419, 58.5, 56.0, 4.8, 20.6 and 25.7 mg/kg, respectively. Generally, arsenic and heavy metals in the soil samples were within the acceptable concentrations of the soil standard of Mongolia (MNS 5850: 2008). The chemical characterization of As solid phase in tailing dam sediment showed that the majority of As were found in the residual fraction comprising about 74% of total As. Assessing the potential risk to humans, simple bioavailability extraction test was used to estimate bioavailability of arsenic and heavy metals, and the concentrations extracted from tailing dam sediment were; 288.2 mg/kg As, 7.2 mg/kg Cd, 41.1 mg/kg Cu, 13.5 mg/kg Pb, 4.7 mg/kg Ni and 23.5 mg/kg Zn, respectively. From these results, the Boroo gold mine project has presently not significantly impacted the environment, but there is a high probability that it may act as a source of future contamination.

  7. Geochemical baseline studies of soil in Finland

    Science.gov (United States)

    Pihlaja, Jouni

    2017-04-01

    The soil element concentrations regionally vary a lot in Finland. Mostly this is caused by the different bedrock types, which are reflected in the soil qualities. Geological Survey of Finland (GTK) is carrying out geochemical baseline studies in Finland. In the previous phase, the research is focusing on urban areas and mine environments. The information can, for example, be used to determine the need for soil remediation, to assess environmental impacts or to measure the natural state of soil in industrial areas or mine districts. The field work is done by taking soil samples, typically at depth between 0-10 cm. Sampling sites are chosen to represent the most vulnerable areas when thinking of human impacts by possible toxic soil element contents: playgrounds, day-care centers, schools, parks and residential areas. In the mine districts the samples are taken from the areas locating outside the airborne dust effected areas. Element contents of the soil samples are then analyzed with ICP-AES and ICP-MS, Hg with CV-AAS. The results of the geochemical baseline studies are published in the Finnish national geochemical baseline database (TAPIR). The geochemical baseline map service is free for all users via internet browser. Through this map service it is possible to calculate regional soil baseline values using geochemical data stored in the map service database. Baseline data for 17 elements in total is provided in the map service and it can be viewed on the GTK's web pages (http://gtkdata.gtk.fi/Tapir/indexEN.html).

  8. Links between environmental geochemistry and rate of birth defects: Shanxi Province, China

    Energy Technology Data Exchange (ETDEWEB)

    Yu Haiying [State Key Laboratory of Earth Surface Processes and Resource Ecology, School of Geography, Beijing Normal University, Beijing 100875 (China); College of Resources and Environmental Sciences, Sichuan Agricultural University, Ya' an, Sichuan 625014 (China); Zhang Keli, E-mail: keli@bnu.edu.cn [State Key Laboratory of Earth Surface Processes and Resource Ecology, School of Geography, Beijing Normal University, Beijing 100875 (China)

    2011-01-01

    The rate of birth defects in Shanxi Province is among the highest worldwide. In order to identify the impacts of geochemical and environmental factors on birth defect risk, samples of soil, water and food were collected from an area with an unusually high rate of birth defects (study area) and an area with a low rate of birth defects (control area) in Shanxi Province, China. Element contents were determined by ICP-OES, and the results were analyzed using a non-parametric test and stepwise regression. Differences in the level and distribution of 14 geochemical elements, namely arsenic (As), selenium (Se), molybdenum (Mo), zinc (Zn), strontium (Sr), iron (Fe), tin (Sn), magnesium (Mg), vanadium (V), calcium (Ca), copper (Cu), aluminum (Al), potassium (K) and sulfur (S) were thus compared between the study and control areas. The results reveal that the geochemical element contents in soil, water and food show a significant difference between the study area and control area, and suggest that the study area was characterized by higher S and lower Sr and Al contents. These findings, based on statistical analysis, may be useful in directing further epidemiological investigations identifying the leading causes of birth defects. - Research Highlights: {yields} Environmental geochemistry has an significant impact on birth defects in the regions with an unusually high rate of birth defects. {yields} An excess of S and deficiency of Sr and Al are the distinctive environmental features associated with the high rate of birth defects in the Shanxi Province of China. {yields} Geochemical anomalies is a non-medical basis for effective prevention and cure of birth defects.

  9. Geochemical engineering problem identification and program description. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crane, C.H.; Kenkeremath, D.C.

    1981-05-01

    The Geochemical Engineering Program has as its goal the improvement of geochemical fluid management techniques. This document presents the strategy and status of the Geochemical Engineering Program. The magnitude and scope of geochemical-related problems constraining geothermal industry productivity are described. The goals and objectives of the DGE Geochemical Engineering Program are defined. The rationale and strategy of the program are described. The structure, priorities, funding, and management of specific elements within the program are delineated, and the status of the overall program is presented.

  10. Silicic magmas from the Emeishan large igneous province, Southwest China: Petrogenesis and their link with the end-Guadalupian biological crisis

    Science.gov (United States)

    Xu, Yi-Gang; Chung, Sun-Lin; Shao, Hui; He, Bin

    2010-09-01

    The Emeishan large igneous province in SW China comprises a bimodal mafic-silicic suite with the silicic rocks occurring at the uppermost part of the thick lava sequence. The silicic rocks have an age of 257-263 Ma, and are thus roughly coeval with the Guadalupian-Loping (G-L) boundary event. Most silicic rocks (trachyte and rhyolite) from the Emeishan province have rather uniform ɛNd values (+ 1 to + 2.9) that are comparable with the uncontaminated high-Ti basalts. This fact and the remarkably narrow ranges of incompatible element ratios (e.g., Zr/Nb) of the basalt-silicic suite indicate a genetic relationship between basalt and silicic members. The significant difference between the Emeishan rocks and the experimental melts of hydrated basaltic crust, suggests the fractional crystallization of basaltic magma, rather than crustal melting, as the major petrogenetic process for the formation of silicic rocks. Indeed, their major and trace element trends can be modeled by fractionation of the observed mineral phases (feldspar, clinopyroxene, Fe-Ti oxide and apatite). In contrast to the virtually closed system differentiation processes associated with trachytes, the rhyolites may have experienced interaction with upper crustal material during ascent. The geochemical characteristics and recent assessment of timing of the Emeishan volcanism suggest the Emeishan rhyolites as the potential source of the widespread clay bed at the G-L boundary in south China. This enhanced the causal link between the Emeishan eruption and the end-Guadalupian biological crisis.

  11. A geochemical examination of humidity cell tests

    Science.gov (United States)

    Maest, Ann; Nordstrom, D. Kirk

    2017-01-01

    Humidity cell tests (HCTs) are long-term (20 to >300 weeks) leach tests that are considered by some to be the among the most reliable geochemical characterization methods for estimating the leachate quality of mined materials. A number of modifications have been added to the original HCT method, but the interpretation of test results varies widely. We suggest that the HCTs represent an underutilized source of geochemical data, with a year-long test generating approximately 2500 individual chemical data points. The HCT concentration peaks and valleys can be thought of as a “chromatogram” of reactions that may occur in the field, whereby peaks in concentrations are associated with different geochemical processes, including sulfate salt dissolution, sulfide oxidation, and dissolution of rock-forming minerals, some of which can neutralize acid. Some of these reactions occur simultaneously, some do not, and geochemical modeling can be used to help distinguish the dominant processes. Our detailed examination, including speciation and inverse modeling, of HCTs from three projects with different geology and mineralization shows that rapid sulfide oxidation dominates over a limited period of time that starts between 40 and 200 weeks of testing. The applicability of laboratory tests results to predicting field leachate concentrations, loads, or rates of reaction has not been adequately demonstrated, although early flush releases and rapid sulfide oxidation rates in HCTs should have some relevance to field conditions. Knowledge of possible maximum solute concentrations is needed to design effective treatment and mitigation approaches. Early flush and maximum sulfide oxidation results from HCTs should be retained and used in environmental models. Factors that complicate the use of HCTs include: sample representation, time for microbial oxidizers to grow, sample storage before testing, geochemical reactions that add or remove constituents, and the HCT results chosen for use

  12. Geochemical characterization of critical dust source regions in the American West

    Science.gov (United States)

    Aarons, Sarah M.; Blakowski, Molly A.; Aciego, Sarah M.; Stevenson, Emily I.; Sims, Kenneth W. W.; Scott, Sean R.; Aarons, Charles

    2017-10-01

    The generation, transport, and deposition of mineral dust are detectable in paleoclimate records from land, ocean, and ice, providing valuable insight into earth surface conditions and cycles on a range of timescales. Dust deposited in marine and terrestrial ecosystems can provide critical nutrients to nutrient-limited ecosystems, and variations in dust provenance can indicate changes in dust production, sources and transport pathways as a function of climate variability and land use change. Thus, temporal changes in locations of dust source areas and transport pathways have implications for understanding interactions between mineral dust, global climate, and biogeochemical cycles. This work characterizes dust from areas in the American West known for dust events and/or affected by increasing human settlement and livestock grazing during the last 150 years. Dust generation and uplift from these dust source areas depends on climate and land use practices, and the relative contribution of dust has likely changed since the expansion of industrialization and agriculture into the western United States. We present elemental and isotopic analysis of 28 potential dust source area samples analyzed using Thermal Ionization Mass Spectrometry (TIMS) for 87Sr/86Sr and 143Nd/144Nd composition and Multi-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) for 176Hf/177Hf composition, and ICPMS for major and trace element concentrations. We find significant variability in the Sr, Nd, and Hf isotope compositions of potential source areas of dust throughout western North America, ranging from 87Sr/86Sr = 0.703699 to 0.740236, εNd = -26.6 to 2.4, and εHf = -21.7 to -0.1. We also report differences in the trace metal and phosphorus concentrations in the geologic provinces sampled. This research provides an important resource for the geochemical tracing of dust sources and sinks in western North America, and will aid in modeling the biogeochemical impacts of increased

  13. Geochemical origins of sedimentary benzoporphyrins and tetrahydrobenzoporphyrins

    Energy Technology Data Exchange (ETDEWEB)

    Lash, T.D. (Illinois State University, Normal, IL (USA). Dept. of Chemistry)

    Complex mixtures of metalloporphyrins are associated with organic-rich sediments. Although some of these petroporphyrins have been correlated with known biological pigments, the origins of certain structures are obscure. Benzoporphyrins and tetrahydrobenzoporphyrins, two minor families of geological tetrapyrroles, have been isolated from numerous oil shales and petroleums but the origins of these molecular fossils are poorly understood. A number of possible pathways for the geochemical formation of benzo- and tetrahydrobenzoporphyrins are discussed. The data presently available favours a Diels-Alder cycloaddition mechanism between putative divinylchlorophyll and quinone precursors for the formation of these compounds. As an aid to these duties, total syntheses of benzo- and naphthoporphyrins have been carried out and the spectroscopic properties of these extended chromophores are discussed. Further studies are proposed to help distinguish between the various possible pathways for the geochemical genesis of tetrahydrobenzo- and benzoporphyrins. 62 refs., 2 figs.

  14. Geochemical signature of columbite-tantalite and environmental impact of radioactive pegmatite mining in the Parelhas region, Rio Grande do Norte, Northeast Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Jorge Costa de; Cruz, Paulo R.; Pereira, Valmir, E-mail: jcmoura@cnen.gov.br, E-mail: pcruz@cnen.gov.br, E-mail: vpereira@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN-RJ), Rio de Janeiro, RJ (Brazil); Ludka, Isabel P.; Mendes, Julio C., E-mail: ludka@geologia.ufrj.br, E-mail: julio@geologia.ufrj.br [Universidade Federal de Rio do Janeiro (CCMN/UFRJ), Rio de Janeiro, RJ (Brazil). Centro de Ciencias Matematicas e da Natureza. Dept. de Geologia

    2013-07-01

    This article comprises geochemical, structural and radiometric investigations on radioactive pegmatites of the Borborema Pegmatitic Province in Northeast Brazil. The studied area is located in the surroundings of the city of Parelhas, in the geotectonic Province of Borborema. It is well known for its thousands of pegmatitic bodies exploited in primitive mines called garimpos. The main goal was to find an efficient, cheap and routine inspection procedure to identify the origin of commercialized radioactive columbite-tantalite (coltan) ore. The Brazilian Nuclear Energy Agency (CNEN) controls uranium commerce and nuclear activity in Brazil. Without an effective method to characterize coltan ores from different localities it is impossible to control the trade. The here presented new method was developed by correlating structural features of these pegmatites with the geochemical behavior of their coltan samples. It was found that the variation of U/Th vs. Nb{sub 2}O{sub 5}/Ta{sub 2}O{sub 5} provides geochemical signatures (analytical fingerprints) for the source location of such ore. The new method was tested with coltan samples of commercial batches from the Brazilian states of Amapa and Rondonia and also generated distinct geochemical signatures. A radiometric survey (CPS) to study the environmental impact of gamma radiation was also carried out in several mines and pegmatites. It included in situ measurements of pegmatite walls, enclosing rocks, soil, and accumulated water and revealed that gamma emitters are hardly solubilized and therefore environmental gamma radiation generally is not enhanced to a dangerous level. (author)

  15. Magmatic systems of large continental igneous provinces

    Directory of Open Access Journals (Sweden)

    E. Sharkov

    2017-07-01

    Full Text Available Large igneous provinces (LIPs formed by mantle superplume events have irreversibly changed their composition in the geological evolution of the Earth from high-Mg melts (during Archean and early Paleoproterozoic to Phanerozoic-type geochemically enriched Fe-Ti basalts and picrites at 2.3 Ga. We propose that this upheaval could be related to the change in the source and nature of the mantle superplumes of different generations. The first generation plumes were derived from the depleted mantle, whereas the second generation (thermochemical originated from the core-mantle boundary (CMB. This study mainly focuses on the second (Phanerozoic type of LIPs, as exemplified by the mid-Paleoproterozoic Jatulian–Ludicovian LIP in the Fennoscandian Shield, the Permian–Triassic Siberian LIP, and the late Cenozoic flood basalts of Syria. The latter LIP contains mantle xenoliths represented by green and black series. These xenoliths are fragments of cooled upper margins of the mantle plume heads, above zones of adiabatic melting, and provide information about composition of the plume material and processes in the plume head. Based on the previous studies on the composition of the mantle xenoliths in within-plate basalts around the world, it is inferred that the heads of the mantle (thermochemical plumes are made up of moderately depleted spinel peridotites (mainly lherzolites and geochemically-enriched intergranular fluid/melt. Further, it is presumed that the plume heads intrude the mafic lower crust and reach up to the bottom of the upper crust at depths ∼20 km. The generation of two major types of mantle-derived magmas (alkali and tholeiitic basalts was previously attributed to the processes related to different PT-parameters in the adiabatic melting zone whereas this study relates to the fluid regime in the plume heads. It is also suggested that a newly-formed melt can occur on different sides of a critical plane of silica undersaturation and can

  16. Geochemical and isotopic characteristics of groundwater from Velenje Basin, Slovenia

    Science.gov (United States)

    Kanduč, Tjaša; Grassa, Fausto; Mori, Nataša; Verbovšek, Timotej

    2016-04-01

    The Velenje Basin in Slovenia is one of the largest actively mined coal basins in central Europe, producing around 4 million tons of lignite per year. Large amounts of groundwater are extracted from aquifers to facilitate underground mining of coal, and coal seam gas outbursts are a serious mine safety concern. This study analyses the geochemical and isotopic composition of groundwater to provide a general understanding of hydrogeological and geochemical processes in groundwater. Thirty-eight groundwater samples were taken from dewatering objects in the mine and at the surface in years 2014-2015. Groundwater in the Triassic aquifer is dominated by hydrogen carbonate, calcium, magnesium and isotopic composition of dissolved inorganic carbon in the range from -19.3 to -2.8‰ indicating degradation of soil organic matter and dissolution of carbonate minerals. In contrast, groundwater in the Pliocene aquifers is enriched in magnesium, sodium, calcium, potassium, and silicon, and has high alkalinity, with isotopic composition of dissolved inorganic carbon in the range of -14.4 to +4.6‰ . Based on isotopic composition of dissolved inorganic carbon values in all aquifers (Pliocene and Triassic), influencing processes are the dissolution of carbonate minerals and dissolution of organic matter, and additionally methanogenesis in the Pliocene aquifers. Based on the Principal Component Analysis (PCA) we can conclude that following different types of groundwater in Velenje Basin could be distinguished based on geochemical and isotopic data: Triassic aquifers with higher pH and lower conductivity and chloride, Pliocene, Pliocene 1 and Pliocene 2 aquifers with lower pH and higher conductivity and chloride contents, and Pliocene 3 and Pliocene 2, 3 aquifers with the highest pH and lowest conductivity and chloride contents. Major dissolved gas component in groundwater are carbon dioxide, nitrogen and methane. Concentrations of dissolved gases dewatering Triassic strata are low

  17. Geochemical patterns in the soils of Cyprus.

    Science.gov (United States)

    Cohen, David R; Rutherford, Neil F; Morisseau, Eleni; Zissimos, Andreas M

    2012-03-15

    The soil geochemical atlas of Cyprus is a recent addition to the series of national to continental-scale geochemical mapping programmes implemented over the last two decades for environmental and resource applications. The study has been conducted at the high sampling density of 1 site per 1km(2), with multi-element and multi-method analysis performed on samples of top soil (0-25cm) and sub soil (50-75cm) from a grid of over 5350 sites across a major portion of Cyprus. Major and most trace elements display sharp concentration changes across the main geological boundaries but a high degree of spatial continuity and consistency of values within those boundaries. Some elements display one to two orders of magnitude difference in median concentrations between the soils developed over ultramafic or mafic units and those developed over sedimentary rocks or alluvial units. The ratio of aqua regia-extractable to total metal contents provides an indication of the general mineralogical host for a number of trace elements. The majority of soils are near-neutral to alkaline with the small proportion of areas with soil pHmapping local to regional-scale features of the geochemical landscape. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Entrepreneur achievement. Liaoning province.

    Science.gov (United States)

    Zhao, R

    1994-03-01

    This paper reports the successful entrepreneurial endeavors of members of a 20-person women's group in Liaoning Province, China. Jing Yuhong, a member of the Family Planning Association at Shileizi Village, Dalian City, provided the basis for their achievements by first building an entertainment/study room in her home to encourage married women to learn family planning. Once stocked with books, magazines, pamphlets, and other materials on family planning and agricultural technology, dozens of married women in the neighborhood flocked voluntarily to the room. Yuhong also set out to give these women a way to earn their own income as a means of helping then gain greater equality with their husbands and exert greater control over their personal reproductive and social lives. She gave a section of her farming land to the women's group, loaned approximately US$5200 to group members to help them generate income from small business initiatives, built a livestock shed in her garden for the group to raise marmots, and erected an awning behind her house under which mushrooms could be grown. The investment yielded $12,000 in the first year, allowing each woman to keep more than $520 in dividends. Members then soon began going to fairs in the capital and other places to learn about the outside world, and have successfully ventured out on their own to generate individual incomes. Ten out of twenty women engaged in these income-generating activities asked for and got the one-child certificate.

  19. Colorectal cancer trends in Kerman province, the largest province in Iran, with forecasting until 2016.

    Science.gov (United States)

    Roya, Nikbakht; Abbas, Bahrampour

    2013-01-01

    Colorectal cancer is one of the most common cancers. The aim of this study is determination its trends in Kerman province and individual cities separately until year 2016. This analytical and modeling study was based of cancer registry data of Kerman University of Medical Sciences, collected during 2001-2010. Among 20,351 cancer case, 792 were colorectal cancer cases in age group 18-93 years with a mean of 59.4 and standard deviation of 15.1. By applying time series and data trends, incidences were predicted until 2016 for the province and each city, with adjustment for population size. In colorectal cases, 413 (52%) were male, and 379 (48%) were female. The annual increasing rate in Kerman province overall was and can be expected to be 6%, and in the cities of the province Rafsanjan, Bardsir, Bam, Kerman, Baft, Sirjan, Jiroft, Kahnuj and Manujan had an increasing range from 5 to 14% by the year 2016. But in Ravar, Zarand and Shahrbabak reduction in rates of at least 2% could be predicted. The time series showed that the trend of colorectal cancer in female will increase 15% and in male 7% by year 2016. Given the trend of this cancer is increasing so that resources will be consumed in the treatment of the patients, efforts shoudlbe focused on prevention and early diagnosis of the disease. Screening could have an important role leading to improved survival.

  20. Geochemical translocation of thallium in the sediments from the North River, China

    Science.gov (United States)

    Liu, J.

    2016-12-01

    Thallium (Tl) is a highly toxic rare heavy metal. As a sulphophile element, it usually occurs in numerous sulphide minerals (such as pyrite, galena, sphlerite). Guangdong north region, known as the hometown of nonferrous metals, has abundant containing Tl mineral resources. Numerous industrial activities, such as mining, smelting, and electroplating are also flourishing. In 2010, a serious Tl pollution in the North River (a major river in the Northern Guangdong Province) shocked the society. The Tl pollution in water appeared to be under control after that incident. But in fact, even if the wastewater discharge of pollution sources has been controlled, the potential risk of heavy metal pollution in the sediments of the North River still exists, for the metals are easy to precipitate and accumulate into sediment from water. So far, Tl pollution in sediments has been studied to a very limited extent. In this paper, we investigated the content and vertical distribution characteristics of Tl and some other related heavy metals in a typical sediment profile from the North River by using inductively coupled plasma mass spectrometry (ICP-MS). Then the Pb isotopic compositions in the sediments were measured by using multi-inductively coupled plasma mass spectrometry (MC-ICP-MS). Several sediments from typical layers were also subjected to sequential extraction procedure for investigating the geochemical fractions of Tl. The risk of Tl and other metal pollution was finally assessed by calculating geo-accumulation indexes (Igeo) and potential ecological risk. The results showed that: (1) Tl concentrations range 1.03 mg/kg to 3.13 mg/kg with a mean of 1.89 mg/kg, three times higher than that in local background soil; (2) Tl content generally increased with depth with some fluctuations and significant correlations were found between Tl and Pb, Zn, Cd, Cu, and Ni; (3) About 46 % to 70 % in sediment cores were resided in the residual fraction; (4) Igeo showed that the studied

  1. Concentration of heavy metal As, Pb, Mn, Ni, Sn, Zn, Cr, Fe and radon gas in bottom sediment from abandoned tin mines in the Phuket Province

    Directory of Open Access Journals (Sweden)

    Suteerasak, T.

    2006-05-01

    Full Text Available This research is aimed at analyzing the heavy metals: As, Pb, Mn, Ni, Sn, Zn, Cr, Fe, and radon gas emission in bottom sediment from six abandoned tin mines in Phuket Province. Fe, Mn, and Sn were found in higher concentrations (but non-polluting than Cr and Ni. As, Pb, and Zn were polluting at lower levels. The concentration ranges for As, Pb, and Zn were 75.3-169, 98.6-547.5, and 120.4-323.3 mg/kg respectively. The activity of radon gas emission from bottom sediment from an abandoned tin mine in Amphur Muang was in the range of 162-212 Bq/kg., in the Amphur Katoo mine the range was 122-266 Bq/kg. and in the Amphur Talang mine the range was 180-263 Bq/kg. All these sites have higher concentrations of radon gas emissions than other similar sites. The heavy metals and radon gas come from geochemical materials such as soil and granite rock, found around the abandoned tin mines.

  2. Geochemical Modeling of ILAW Lysimeter Water Extracts

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-22

    Geochemical modeling results of water extracts from simulated immobilized low-activity waste (ILAW) glasses, placed in lysimeters for eight years suggest that the secondary phase reaction network developed using product consistency test (PCT) results at 90°C may need to be modified for field conditions. For sediment samples that had been collected from near the glass samples, the impact of glass corrosion could be readily observed based upon the pH of their water extracts. For unimpacted sediments the pH ranged from 7.88 to 8.11 with an average of 8.04. Sediments that had observable impacts from glass corrosion exhibited elevated pH values (as high as 9.97). For lysimeter sediment samples that appear to have been impacted by glass corrosion to the greatest extent, saturation indices determined for analcime, calcite, and chalcedony in the 1:1 water extracts were near equilibrium and were consistent with the secondary phase reaction network developed using PCT results at 90°C. Fe(OH)3(s) also appears to be essentially at equilibrium in extracts impacted by glass corrosion, but with a solubility product (log Ksp) that is approximately 2.13 units lower than that used in the secondary phase reaction network developed using PCT results at 90°C. The solubilities of TiO2(am) and ZrO2(am) also appear to be much lower than that assumed in the secondary phase reaction network developed using PCT results at 90°C. The extent that the solubility of TiO2(am) and ZrO2(am) were reduced relative to that assumed in the secondary phase reaction network developed using PCT results at 90°C could not be quantified because the concentrations of Ti and Zr in the extracts were below the estimated quantification limit. Gibbsite was consistently highly oversaturated in the extract while dawsonite was at or near equilibrium. This suggests that dawsonite might be a more suitable phase for the secondary phase reaction network

  3. Mixing and speciation algorithms for geochemical and reactive transport problems

    OpenAIRE

    De Gaspari, Francesca

    2015-01-01

    Geochemical and reactive transport modelling are essential tools in hydrogeology. They help to identify and assess geochemical processes occurring in applications such as groundwater contamination, water-rock interactions and geologic carbon sequestration. In this thesis we present methods for mixing and speciation calculations to be used for both interpretation of hydrochemical data and numerical modelling. The first method presented allows solving geochemical speciation using redundant i...

  4. DNA-based methods of geochemical prospecting

    Science.gov (United States)

    Ashby, Matthew [Mill Valley, CA

    2011-12-06

    The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

  5. Kriging - a challenge in geochemical mapping

    Science.gov (United States)

    Stojdl, Jiri; Matys Grygar, Tomas; Elznicova, Jitka; Popelka, Jan; Vachova, Tatina; Hosek, Michal

    2017-04-01

    Geochemists can easily provide datasets for contamination mapping thanks to recent advances in geographical information systems (GIS) and portable chemical-analytical instrumentation. Kriging is commonly used to visualise the results of such mapping. It is understandable, as kriging is a well-established method of spatial interpolation. It was created in 1950's for geochemical data processing to estimate the most likely distribution of gold based on samples from a few boreholes. However, kriging is based on the assumption of continuous spatial distribution of numeric data that is not realistic in environmental geochemistry. The use of kriging is correct when the data density is sufficient with respect to heterogeneity of the spatial distribution of the geochemical parameters. However, if anomalous geochemical values are focused in hotspots of which boundaries are insufficiently densely sampled, kriging could provide misleading maps with the real contours of hotspots blurred by data smoothing and levelling out individual (isolated) but relevant anomalous values. The data smoothing can thus it results in underestimation of geochemical extremes, which may in fact be of the greatest importance in mapping projects. In our study we characterised hotspots of contamination by uranium and zinc in the floodplain of the Ploučnice River. The first objective of our study was to compare three methods of sampling: random (based on stochastic generation of sampling points), systematic (square grid) and judgemental sampling (based on judgement stemming from principles of fluvial deposition) as the basis for pollution maps. The first detected problem in production of the maps was the reduction of the smoothing effect of kriging using appropriate function of empirical semivariogram and setting the variation of at microscales smaller than the sampling distances to minimum (the "nugget" parameter of semivariogram). Exact interpolators such as Inverse Distance Weighting (IDW) or Radial

  6. Hygienic assessment of microelementosis in primary school children living on geochemical territory

    Directory of Open Access Journals (Sweden)

    Kuzminov B.P.

    2015-03-01

    Full Text Available In this work we consider methods of solving urgent issues of prevention of violations of children’s health those who live in technologically contaminated areas. Content of pollutants in environmental objects of Sosnivka town as geochemical province was conducted. We made a comparative analysis of pre-pathological health indicators of children living on this territory, as well as "conditionally clean territory" by the elemental composition of children’s hair and blood content, intensity of lipid peroxidation and activity of antioxidant enzymes, parameters of physical development and condition of their actual nutrition. Correlations between exposure to toxicants of the environment and changes in the health of children was revealed. There was developed integrated scheme of measures for the prevention of technogenic microelementosis among children.

  7. Geochemical Investigation of Clay Minerals in Marte, Borno State, Nigeria

    Directory of Open Access Journals (Sweden)

    F. D. Adams

    2017-10-01

    Full Text Available Clay deposit collected from various locations in Marte (Northern Borno, were studied to determine their physical and chemical characteristics in order to evaluate their suitability for industrial uses. Major and trace element analyses were carried out on clay samples using Inductively Couple Plasma-Optical Emission Spectrometry (ICP-OES and X- Ray Fluorescence (XRF. The result of the chemical analysis of the ten (10 samples collected showed significant amounts of SiO2 and Al2O3. Silica content ranges from 51.48 to 62.44 % while alumina varies from 12.49 to 19.00 %. The calcium oxide ranges from 1.17 to 3.39 %, Na2O ranges from 1.1 to 8.61 %, K2O from 1.54 to 3.66 %, MgO varies from 0.04 to0.14 %, Fe2O3 varies from 0.3 to 2.7 % and MnO ranges from 0.01 to 1.03 %. The result showed that the clays are mainly smectite with quartz and felspar as the main non-clay minerals. Generally, the geochemical results of the samples do not meet the standard for industrial utilization when compared to the Industrial specifications. However, for industrial utilization, some of the clay samples may be used after necessary beneficiations.

  8. Estimation of Supraglacial Dust and Debris Geochemical Composition via Satellite Reflectance and Emissivity

    Science.gov (United States)

    Casey, Kimberly Ann; Kaab, Andreas

    2012-01-01

    We demonstrate spectral estimation of supraglacial dust, debris, ash and tephra geochemical composition from glaciers and ice fields in Iceland, Nepal, New Zealand and Switzerland. Surface glacier material was collected and analyzed via X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD) for geochemical composition and mineralogy. In situ data was used as ground truth for comparison with satellite derived geochemical results. Supraglacial debris spectral response patterns and emissivity-derived silica weight percent are presented. Qualitative spectral response patterns agreed well with XRF elemental abundances. Quantitative emissivity estimates of supraglacial SiO2 in continental areas were 67% (Switzerland) and 68% (Nepal), while volcanic supraglacial SiO2 averages were 58% (Iceland) and 56% (New Zealand), yielding general agreement. Ablation season supraglacial temperature variation due to differing dust and debris type and coverage was also investigated, with surface debris temperatures ranging from 5.9 to 26.6 C in the study regions. Applications of the supraglacial geochemical reflective and emissive characterization methods include glacier areal extent mapping, debris source identification, glacier kinematics and glacier energy balance considerations.

  9. Estimation of Supraglacial Dust and Debris Geochemical Composition via Satellite Reflectance and Emissivity

    Directory of Open Access Journals (Sweden)

    Kimberly Casey

    2012-09-01

    Full Text Available We demonstrate spectral estimation of supraglacial dust, debris, ash and tephra geochemical composition from glaciers and ice fields in Iceland, Nepal, New Zealand and Switzerland. Surface glacier material was collected and analyzed via X-ray fluorescence spectroscopy (XRF and X-ray diffraction (XRD for geochemical composition and mineralogy. In situ data was used as ground truth for comparison with satellite derived geochemical results. Supraglacial debris spectral response patterns and emissivity-derived silica weight percent are presented. Qualitative spectral response patterns agreed well with XRF elemental abundances. Quantitative emissivity estimates of supraglacial SiO2 in continental areas were 67% (Switzerland and 68% (Nepal, while volcanic supraglacial SiO2 averages were 58% (Iceland and 56% (New Zealand, yielding general agreement. Ablation season supraglacial temperature variation due to differing dust and debris type and coverage was also investigated, with surface debris temperatures ranging from 5.9 to 26.6 C in the study regions. Applications of the supraglacial geochemical reflective and emissive characterization methods include glacier areal extent mapping, debris source identification, glacier kinematics and glacier energy balance considerations.

  10. Electrical resistivity tomography determines the spatial distribution of clay layer thickness and aquifer vulnerability, Kandal Province, Cambodia

    Science.gov (United States)

    Uhlemann, Sebastian; Kuras, Oliver; Richards, Laura A.; Naden, Emma; Polya, David A.

    2017-10-01

    Despite being rich in water resources, many areas of South East Asia face difficulties in securing clean water supply. This is particularly problematic in regions with a rapidly growing population. In this study, the spatial variability of the thickness of a clay layer, controlling surface - groundwater interactions that affect aquifer vulnerability, was investigated using electrical resistivity tomography (ERT). Data were acquired along two transects, showing significant differences in the imaged resistivities. Borehole samples were analyzed regarding particle density and composition, and linked to their resistivity. The obtained relationships were used to translate the field electrical resistivities into lithologies. Those revealed considerable variations in the thickness of the clay layer, ranging from 0 m up to 25 m. Geochemical data, highlighting zones of increased ingress of surface water into the groundwater, confirmed areas of discontinuities in the clay layer, which act as preferential flow paths. The results may guide urban planning of the Phnom Penh city expansion, in order to supply the growing population with safe water. The presented approach of using geophysics to estimate groundwater availability, accessibility, and vulnerability is not only applicable to Kandal Province, Cambodia, but also to many other areas of fast urbanization in South East Asia and beyond.

  11. Geochemical Proxies for Enhanced Process Control of Underground Coal Gasification

    Science.gov (United States)

    Kronimus, A.; Koenen, M.; David, P.; Veld, H.; van Dijk, A.; van Bergen, F.

    2009-04-01

    Underground coal gasification (UCG) represents a strategy targeting at syngas production for fuel or power generation from in-situ coal seams. It is a promising technique for exploiting coal deposits as an energy source at locations not allowing conventional mining under economic conditions. Although the underlying concept has already been suggested in 1868 and has been later on implemented in a number of field trials and even at a commercial scale, UCG is still facing technological barriers, impeding its widespread application. Field UCG operations rely on injection wells enabling the ignition of the target seam and the supply with oxidants (air, O2) inducing combustion (oxidative conditions). The combustion process delivers the enthalpy required for endothermic hydrogen production under reduction prone conditions in some distance to the injection point. The produced hydrogen - usually accompanied by organic and inorganic carbon species, e.g. CH4, CO, and CO2 - can then be retrieved through a production well. In contrast to gasification of mined coal in furnaces, it is difficult to measure the combustion temperature directly during UCG operations. It is already known that geochemical parameters such as the relative production gas composition as well as its stable isotope signature are related to the combustion temperature and, consequently, can be used as temperature proxies. However, so far the general applicability of such relations has not been proven. In order to get corresponding insights with respect to coals of significantly different rank and origin, four powdered coal samples covering maturities ranging from Ro= 0.43% (lignite) to Ro= 3.39% (anthracite) have been gasified in laboratory experiments. The combustion temperature has been varied between 350 and 900 ˚ C, respectively. During gasification, the generated gas has been captured in a cryo-trap, dried and the carbon containing gas components have been catalytically oxidized to CO2. Thereafter, the

  12. Geochemical signature of radioactive waste: oil NORM

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Gilberto T. de Paula; Costa-de-Moura, Jorge; Gomes, Carlos de Almeida; Sampaio, Emidio A. Lopes, E-mail: gilberto.costa@cnen.gov.br, E-mail: jcmoura@cnen.gov.br, E-mail: cgomes@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Div. de Controle de Rejeitos e Transporte de Materiais Radioativos

    2017-07-01

    The Brazilian Nuclear Agency (CNEN) rules all nuclear activity in Brazil as demanded by the Federal Constitution, articles 21, XXIII, and 177, V, and by the Federal Acts 4.118/62 and 10.308/2001. Therefore, the CNEN is responsible for any radioactive waste disposal in the country. Oil Naturally Occurring Radioactive Materials (Oil NORM) in this paper refers to waste coming from oil exploration. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for each oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is a specific geochemical modeling of oil sludge NORM samples which are analyzed for radioisotopes normally present in oil pipes, such as {sup 228}Ac, {sup 214}Bi and {sup 214}Pb. The activity ratios are plotted in scatter diagrams. This method was successfully tested with data of different sources obtained from analysis reports from the Campos Basin/Brazil and from literature. (author)

  13. Forensic Analysis using Geological and Geochemical Techniques

    Science.gov (United States)

    Hoogewerff, J.

    2009-04-01

    Due to the globalisation of legal (and illegal) trade there is an increasing demand for techniques which can verify the geographical origin and transfer routes of many legal and illegal commodities and products. Although geological techniques have been used in forensic investigations since the emergence of forensics as a science in the late eighteen hundreds, the last decade has seen a marked increase in geo-scientists initiating concept studies using the latest analytical techniques, including studying natural abundance isotope variations, micro analysis with laser ablation ICPMS and geochemical mapping. Most of the concept studies have shown a good potential but uptake by the law enforcement and legal community has been limited due to concerns about the admissibility of the new methods. As an introduction to the UGU2009 session "Forensic Provenancing using Geological and Geochemical Techniques" I will give an overview of the state of the art of forensic geology and the issues that concern the admissibility of geological forensic evidence. I will use examples from the NITECRIME and FIRMS networks, the EU TRACE project and other projects and literature to illustrate the important issues at hand.

  14. Anotaciones sobre la enfermedad de Chagas en Panamá. Frecuencia y distribución de Trypanosoma cruzi y Trypanosoma rangeli

    OpenAIRE

    Sousa, Octavio E.

    2016-01-01

    In Panama Chagas' disease occurs primarily in the provinces of Panama and Colon, near the Canal Zone. Trypanosoma cruzi infections appear to be of moderate parasitemia and short patency, without inducement of megaviscera. In Panama province the prevalence in the rural population was 2.8% and 1.9% in the province of Colon. In both provinces T. rangeli is 6 to 10 times more frequent than T. cruzi. Positive serologic reactions (complement fixation) were found in almost all the provinces, ranging...

  15. Experimental study on neptunium migration under in situ geochemical conditions

    Science.gov (United States)

    Kumata, M.; Vandergraaf, T. T.

    1998-12-01

    Results are reported for migration experiments performed with Np under in situ geochemical conditions over a range of groundwater flow rates in columns of crushed rock in a specially designed facility at the 240-level of the Underground Research Laboratory (URL) near Pinawa, Manitoba, Canada. This laboratory is situated in an intrusive granitic rock formation, the Lac du Bonnet batholith. Highly altered granitic rock and groundwater were obtained from a major subhorizontal fracture zone at a depth of 250 m in the URL. The granite was wet-crushed and wet-sieved with groundwater from this fracture zone. The 180-850-μm size fraction was selected and packed in 20-cm long, 2.54-cm in diameter Teflon™-lined stainless steel columns. Approximately 30-ml vols of groundwater containing 3HHO and 237Np were injected into the columns at flow rates of 0.3, 1, and 3 ml/h, followed by elution with groundwater, obtained from the subhorizontal fracture, at the same flow rates, for a period of 95 days. Elution profiles for 3HHO were obtained, but no 237Np was detected in the eluted groundwater. After terminating the migration experiments, the columns were frozen, the column material was removed and cut into twenty 1-cm thick sections and each section was analyzed by gamma spectrometry. Profiles of 237Np were obtained for the three columns. A one-dimensional transport model was fitted to the 3HHO breakthrough curves to obtain flow parameters for this experiment. These flow parameters were in turn applied to the 237Np concentration profiles in the columns to produce sorption and dispersion coefficients for Np. The results show a strong dependence of retardation factors ( Rf) on flow rate. The decrease in the retarded velocity of the neptunium ( Vn) varied over one order of magnitude under the geochemical conditions for these experiments.

  16. Geochemical study of volcanic and associated granitic rocks from ...

    Indian Academy of Sciences (India)

    Geochemical studies and modelling show that both volcanic and granitic magmas from the western part of the Johor National Park, Endau Rompin are different and probably have different sources. The geochemical plot suggests that both dacite/rhyolite and andesite probably have a common origin as in many of the ...

  17. Late Permian basalts in the Yanghe area, eastern Sichuan Province, SW China: Implications for the geodynamics of the Emeishan flood basalt province and Permian global mass extinction

    Science.gov (United States)

    Li, Hongbo; Zhang, Zhaochong; Santosh, M.; Lü, Linsu; Han, Liu; Liu, Wei

    2017-02-01

    We report the finding of a ∼20 m thick sequence of massive pyroxene-plagioclase-phyric basalt lava flows in the Yanghe area of the northeastern Sichuan Basin, within the Yangtze craton of SW China, which were previously considered to be located outside the Emeishan flood basalt province. This basaltic sequence above the middle Permian Maokou Formation (Fm.) is overlain by the late Permian Longtan Fm. Thus, the Yanghe basalts should be stratigraphically correlated with the Emeishan flood basalts. The Yanghe basalts show typical oceanic island basalt (OIB) affinity, and geochemically resemble Emeishan basalts, especially in the case of high-Ti (HT) basalts from the eastern domain of the Emeishan flood basalt province. The rocks have low age-corrected (87Sr/86Sr)t (t = 260 Ma) ratios (0.704158-0.704929) and Pb isotopic ratios [206Pb/204Pb(t) (18.264-18.524), 207Pb/204Pb(t) (15.543-15.58), and 208Pb/204Pb(t) (38.147-38.519)], and positive εNd(t) values (+3.15 to +3.61), suggesting that the lavas have not undergone any significant crustal contamination. The crystallization temperature of clinopyroxene is estimated to be 1368-1420 °C, suggesting anomalously thermal inputs from a mantle source and a possible plume-head origin. The fractionation of middle rare earth elements (MREE) to heavy REE (HREE) suggests that these rocks were produced by small degrees of partial melting of mantle peridotite within the garnet-spinel transition region. The stratigraphic relationships and similar geochemical signatures with the Emeishan flood basalts suggest that the Yanghe basalts are part of the Emeishan flood basalt province and can be considered as the northeastern limit of the Emeishan flood basalt province. Our finding extends the diameter of the Emeishan flood basalt province to ∼1200-1400 km, covering an area of up to ∼7 × 105 km2, two times more than previously estimated. The larger areal extent and giant eruption volume, incorporating the Sichuan Basin, lend support

  18. Mesozoic rift magmatism in the North Sea region: 40Ar/39Ar geochronology of Scanian basalts and geochemical constraints

    Science.gov (United States)

    Bergelin, Ingemar; Obst, Karsten; Söderlund, Ulf; Larsson, Kent; Johansson, Leif

    2011-06-01

    More than 100 volcanic necks composed of basanites and melanephelinites occur in Scania, southern Sweden, at the junction of two major tectonic lineaments, the Phanerozoic Sorgenfrei-Tornquist Zone (STZ) and the Proterozoic Protogine Zone. New 40Ar/39Ar isotope analyses of whole rock fragments of nine selected basalt necks suggest that the Mesozoic alkaline volcanism in the Scanian province commenced earlier than previously reported and comprised three separate volcanic episodes that span a total period of ca. 80 Myr: a first Jurassic (191-178 Ma), a second at the Jurassic/Cretaceous boundary (ca. 145 Ma), and a final middle Cretaceous episode (ca. 110 Ma). The new results allow for precise time correlations between eruption events in the Scanian and those in the North Sea volcanic provinces. The older, early Jurassic event in Scania is largely synchronous with that in the Egersund Basin and the Forties field whereas the event at ca. 145 Ma is correlated with activity in the Central Graben. These volcanic episodes also correlate in age with Kimmerian tectonic activity. Volcanic activity in the middle Cretaceous period has also been dated in the triple junction in the North Sea and offshore in the Netherland Sector. The correlation of basalt volcanism in Scania with the Egersund nephelinites strongly suggest that volcanism was triggered by repeated tectonic activity along the STZ. Geochemical data of alkaline mafic rocks in the Scanian and the North Sea volcanic provinces imply that different provinces have largely unique geochemical signatures in favour of a heterogeneous mantle in the North Sea volcanic region. However, basalts of different generations in one and the same province cannot be readily separated on the basis of geochemistry, suggesting that the same lithospheric mantle was the source of repeated volcanism over time in each province. The data suggest a low degree of melting of a volatile-bearing mantle lherzolite enriched in incompatible elements with

  19. Post-Delamination Magmatism at the Hasandag Cinder Cone Province, Central Anatolia

    Science.gov (United States)

    Gall, H. D.; Pickard, M.; Sayit, K.; Hanan, B. B.; Kürkçüoğlu, B.; Furman, T.

    2016-12-01

    Central Anatolian mafic lavas record both closure of the Tethyan Ocean and post-Miocene extension. Regional-scale delamination of the horizontally-subducted Neotethyan slab beneath Central Anatolia 9-14 Ma is inferred on the basis of >1 km of uplift of the Central Anatolian Plateau and the onset of widespread volcanism induced by melting of ascending asthenosphere (Bartol and Govers, 2014). Geochemical data from the Quaternary Hasandağ Cinder Cone Province suggest a more complicated story and require melting of both asthenosphere and lithosphere. Hasandağ cinder cones produce basalt, trachybasalt and basaltic trachyandesite (7.2-10.3 wt. % MgO; 48.9-51.8 wt. % SiO2). Systematic trends in key element ratios indicate a significant contribution from the lithosphere with metasomatic phases including rutile and sodic amphibole. Tb/YbN (1.2-1.7) values restrict depth of melting to the spinel stability field, 30-90 km. Sr-Nd-Hf isotopic values fall within published ranges of post-Miocene Central Anatolian mafic lavas and suggest binary mixing between geographically-constrained enriched and depleted endmembers. In contrast, ternary Pb isotopic abundances are nearly uniform and lack psuedobinary trends indicative of ordered mixing observed elsewhere in Anatolia and in other young extensional provinces. This difference suggests that Hasandağ lavas do not undergo progressive crustal contamination in an evolving extensional environment. Rather, Hasandağ primitive lavas document an increase in degree of melting with depth, a signature associated with drip magmatism (Elkins-Tanton, 2007; Holbig and Grove, 2008).Together, these data argue for a two-part lithospheric foundering process: Miocene microplate-scale delamination of the subducted African slab and the subsequent influx of warm asthenosphere stimulated localized Quaternary drip melting of the remaining Anatolian lithosphere. These distinct mechanisms and scales of lithospheric removal provide a consistent explanation

  20. Geochemical Evidence for a Terrestrial Magma Ocean

    Science.gov (United States)

    Agee, Carl B.

    1999-01-01

    The aftermath of phase separation and crystal-liquid fractionation in a magma ocean should leave a planet geochemically differentiated. Subsequent convective and other mixing processes may operate over time to obscure geochemical evidence of magma ocean differentiation. On the other hand, core formation is probably the most permanent, irreversible part of planetary differentiation. Hence the geochemical traces of core separation should be the most distinct remnants left behind in the mantle and crust, In the case of the Earth, core formation apparently coincided with a magma ocean that extended to a depth of approximately 1000 km. Evidence for this is found in high pressure element partitioning behavior of Ni and Co between liquid silicate and liquid iron alloy, and with the Ni-Co ratio and the abundance of Ni and Co in the Earth's upper mantle. A terrestrial magma ocean with a depth of 1000 km will solidify from the bottom up and first crystallize in the perovskite stability field. The largest effect of perovskite fractionation on major element distribution is to decrease the Si-Mg ratio in the silicate liquid and increase the Si-Mg ratio in the crystalline cumulate. Therefore, if a magma ocean with perovskite fractionation existed, then one could expect to observe an upper mantle with a lower than chondritic Si-Mg ratio. This is indeed observed in modern upper mantle peridotites. Although more experimental work is needed to fully understand the high-pressure behavior of trace element partitioning, it is likely that Hf is more compatible than Lu in perovskite-silicate liquid pairs. Thus, perovskite fractionation produces a molten mantle with a higher than chondritic Lu-Hf ratio. Arndt and Blichert-Toft measured Hf isotope compositions of Barberton komatiites that seem to require a source region with a long-lived, high Lu-Hf ratio. It is plausible that that these Barberton komatiites were generated within the majorite stability field by remelting a perovskite

  1. Geochemical variations in the Quaternary Andean back-arc volcanism, southern Mendoza, Argentina

    Science.gov (United States)

    Espanon, Venera R.; Chivas, Allan R.; Kinsley, Leslie P. J.; Dosseto, Anthony

    2014-11-01

    The Payenia Basaltic Province (PBP) is located 450 km east of the Chile-Peru trench in central west Argentina, behind the Andean arc front, constituting the back-arc. In order to evaluate the influence of the subducting slab as well as the magmatic source of this region, two volcanic fields located at comparable distance to the trench, having abundant basaltic products and similar eruptive timeframes were chosen. The Llancanelo (LLVF) and the Payún Matrú (PMVF) volcanic fields are part of the PBP and exhibit abundant basaltic activity during the Pleistocene. The geochemical data suggest that the LLVF has some arc signatures which have been described as weak as they are not as pronounced as in the Andean arc. The weak arc signature is not derived from slab dehydration as high Th enrichment relative to U cannot be explained by this process. We relate the Th enrichment as well as the lack of large residual garnet signatures, to slab sediments in the source. In the case of the PMVF, no arc signature has been inferred despite being only 30 km south of the LLVF. However the PMVF has a composition similar to that of the local intraplate end member, represented by the Rio Colorado volcanic field. The two volcanic fields, LLVF and PMVF, show indications of lower crustal assimilation as they trend towards the lower continental crust end member in Nb/U vs Ce/Pb and Nb/Yb vs Th/Yb diagrams. The geochemical differences between the LLVF and the PMVF as well as between several volcanic fields are illustrated using spatial distribution maps of geochemical ratios. Using this new approach, the decrease in arc signature can be traced in the back-arc and the higher enrichment in high field strength elements (HFSE) relative to large ion lithophile elements (LILE) in the PMVF compared to the LLVF is explicitly shown. These geospatial maps provide a graphical manner to illustrate the presence of two distinct types of volcanism (OIB-like and arc-like) occurring in the same Quaternary

  2. Quaternary stratigraphy and developmental history of the Central Russian Periglacial-Loessal Province

    Science.gov (United States)

    Agadjanian, A. K.; Glushankova, N. I.

    2017-07-01

    As a result of complex investigation in the Central Russian Loessal Province, detailed lithologic, geochemical, paleopedological, and paleontological characteristics of the young deposits of the stratotype section Mikhailovka are obtained. They provide the basis for facies genetic differentiation, stratification, and correlation of particular horizons chronologically coordinated by paleopedological and paleontological data with the geological scale of the Neopleistocene. The loess-soil sequences corresponding to climatolites of the Lower, Middle, and Upper Neopleistocene are established and characterized. In dynamical history of the Central Russian Periglacial Loessal Province, thirteen paleogeographical stages of natural-climatic changes (seven warm interglacial and interstadial epochs, six cold epochs alternating with them) are revealed. A rhythmic climatic substantiation for the stratigraphical division of recent sediments in the investigated region is provided.

  3. Geochemical and isotopic constraints on the genesis of the Jueluotage native copper mineralized basalt, Eastern Tianshan, Northwest China

    Science.gov (United States)

    Zhang, Dayu; Zhou, Taofa; Yuan, Feng; Fiorentini, Marco L.; Said, Nuru; Lu, Yongjun; Pirajno, Franco

    2013-09-01

    The Jueluotage native copper mineralized basalt is located in the Jueluotage Volcanic-sedimentary Belt, Eastern Tianshan, Xinjiang Uygur Autonomous region. The basalt, amygdaloidal basalt and tuff, which host native copper mineralization, were erupted in the lower strata of the Late Carboniferous Matoutan Formation. Whole-rock geochemistry shows that the basaltic occurrences at Shilipo, Heilongfeng, Changchengshan and Dongjianfeng have fractionated chondrite-normalized REE distributions and distinctly negative primitive mantle-normalized Nb, Ta and Ti anomalies. The whole-rock strontium, neodymium and lead isotopic data indicate low εSr(t) (-7.9 to +23.6), high εNd(t) (+2.5 to +7.1), with restricted 206Pb/204Pb (18.152-18.491), 207Pb/204Pb (15.521-15.562) and 208Pb/204Pb (37.978-38.251) ranges. On the basis of these data, we report that the Cu-bearing basalt is associated with high-iron tholeiitic basalts that were sourced from depleted continental lithosphere mantle garnet-bearing peridotite. The primary magma of the Cu-bearing basalt was: (1) relatively low in silica and magnesium; and (2) underwent only slight olivine and clinopyroxene crystal fractionation during the magmatic evolution process. In the Jueluotage belt, the Shilipo basalt lavas display significant geochemical similarities to numerous mafic intrusions that are present throughout the Jueluotage belt. Those mafic lavas and intrusions probably represent successive pulses of mafic magmatism, which lasted between ca. 310 and 270 Ma. A crucial empirical observation is that the Jueluotage volcanic-sedimentary belt is a well-known metallogenic province that contains a wide range of copper, nickel, gold, and iron mineral deposits. These mineral systems were formed at different times and are associated with radically different ore-forming processes. However, they are all within the Jueluotage belt, which is interpreted to be a suture zone between the Junggar and Tarim plates, northwestern China. We

  4. The geochemical record in rock glaciers

    Science.gov (United States)

    Steig, E.J.; Fitzpatrick, J.J.; Potter, N.; Clark, D.H.

    1998-01-01

    A 9.5 m ice core was extracted from beneath the surficial debris cover of a rock glacier at Galena Creek, northwestern Wyoming. The core contains clean, bubble-rich ice with silty debris layers spaced at roughly 20 cm intervals. The debris layers are similar in appearance to those in typical alpine glaciers, reflecting concentration of debris by melting at the surface during the summer ablation season. Profiles of stable isotope concentrations and electrical conductivity measurements provide independent evidence for melting in association with debris layers. These observations are consistent with a glacial origin for the ice, substantiating the glacigenic model for rock glacier formation. The deuterium excess profile in the ice indicates that the total depth of meltwater infiltration is less than the thickness of one annual layer, suggesting that isotope values and other geochemical signatures are preserved at annual resolution. This finding demonstrates the potential for obtaining useful paleoclimate information from rock glacier ice.

  5. A stream sediment geochemical survey of the Ganga River headwaters in the Garhwal Himalaya

    Science.gov (United States)

    Mukherjee, P.K.; Purohit, K.K.; Saini, N.K.; Khanna, P.P.; Rathi, M.S.; Grosz, A.E.

    2007-01-01

    This study models geochemical and adjunct geologic data to define provinces that are favorable for radioactive-mineral exploration. A multi-element bed-sediment geochemical survey of streams was carried out in the headwaters region of the Ganga River in northern India. Overall median values for uranium and thorium (3.6 and 13.8 ppm; maxima of 4.8 and 19.0 ppm and minima of 3.1 and 12.3 ppm respectively) exceed average upper crustal abundances (2.8 and 10.7 ppm) for these radioactive elements. Anomalously high values reach up to 8.3 and 30.1 ppm in thrust zone rocks, and 11.4 and 22.5 ppm in porphyroids. At their maxima, these abundances are nearly four- and three-fold (respectively) enriched in comparison to average crustal abundances for these rock types. Deformed, metamorphosed and sheared rocks are characteristic of the main central thrust zone (MCTZ). These intensively mylonitized rocks override and juxtapose porphyritic (PH) and proterozoic metasedimentary rock sequences (PMS) to the south. Granitoid rocks, the major protoliths for mylonites, as well as metamorphosed rocks in the MCT zone are naturally enriched in radioelements; high values associated with sheared and mylonitized zones are coincident with reports of radioelement mineralization and with anomalous radon concentrations in soils. The radioelement abundance as well as REE abundance shows a northward enrichment trend consistent with increasing grade of metamorphism indicating deformation-induced remobilization of these elements. U and Th illustrate good correlation with REEs but not with Zr. This implies that zircon is not a principal carrier of U and Th within the granitoid-dominant thrust zone and that other radioelement-rich secondary minerals are present in considerable amounts. Thus, the relatively flat, less fractionated, HREE trend is also not entirely controlled by zircon. The spatial correlation of geologic boundary zones (faults, sheared zones) with geochemical and with geophysical (Rn

  6. National Assessment of Oil and Gas Project - Uinta-Piceance Province (020) Maturation Contours

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The maturation contours show vitrinite reflectance trends and ranges for five key petroleum system horizons within the Uinta-Piceance Province. The horizons are the...

  7. Calymmian magmatism in the basement of the Jauru Terrain (Rondonian - San Ignacio Province), Amazon Craton: U-Pb and Sm-Nd geochemistry and geochronology

    Energy Technology Data Exchange (ETDEWEB)

    Fachetti, Frankie James Serrano; Costa, Ana Claudia Dantas da; Silva, Carlos Humberto da, E-mail: frankiefachetti@hotmail.com, E-mail: acdcosta@ufmt.br, E-mail: chsilva@ufmt.br [Universidade Federal de Mato Grosso (UFMT), Cuiaba, MT (Brazil). Instituto de Ciencias Exatas e da Terra

    2016-11-01

    The Taquarussu Orthogneiss and the Guadalupe Granodiorite, part of the Rondonian-San Ignacio Province basement, southwest of the Amazonian Craton, correspond to oriented bodies with a NW trend. The rocks show granodiorite composition with minor occurrences of coarse grained monzogranites consisting essentially of plagioclase, quartz, microcline, orthoclase and biotite. The accessory minerals are amphibole, titanite, garnet, apatite, epidote, zircon and opaque. The geochemical data indicate that the rocks are classified as granodiorites and monzogranites, with an intermediate to acid magmatism, sub-alkaline character, from the calc-alkaline to the high-K calc-alkaline series, with alumina ratios ranging from metaluminous to lightly peraluminous. The rocks were classified as generated in volcanic islands arc environment and the U-Pb data (SHRIMP zircon) show a concord age 1575 ± 6 Ma. The Sm-Nd model age (T{sub DM}) is 1.63 Ga with εNd (t = 1.57 Ga) ranging from -1.52 to +0.78. These data indicate that these rocks are probably a juvenile crust with a possible contamination of crustal rocks. (author)

  8. The IUGS/IAGC Task Group on Global Geochemical Baselines

    Science.gov (United States)

    Smith, David B.; Wang, Xueqiu; Reeder, Shaun; Demetriades, Alecos

    2012-01-01

    The Task Group on Global Geochemical Baselines, operating under the auspices of both the International Union of Geological Sciences (IUGS) and the International Association of Geochemistry (IAGC), has the long-term goal of establishing a global geochemical database to document the concentration and distribution of chemical elements in the Earth’s surface or near-surface environment. The database and accompanying element distribution maps represent a geochemical baseline against which future human-induced or natural changes to the chemistry of the land surface may be recognized and quantified. In order to accomplish this long-term goal, the activities of the Task Group include: (1) developing partnerships with countries conducting broad-scale geochemical mapping studies; (2) providing consultation and training in the form of workshops and short courses; (3) organizing periodic international symposia to foster communication among the geochemical mapping community; (4) developing criteria for certifying those projects whose data are acceptable in a global geochemical database; (5) acting as a repository for data collected by those projects meeting the criteria for standardization; (6) preparing complete metadata for the certified projects; and (7) preparing, ultimately, a global geochemical database. This paper summarizes the history and accomplishments of the Task Group since its first predecessor project was established in 1988.

  9. Major- and Trace-Element Concentrations in Soils from Northern California: Results from the Geochemical Landscapes Project Pilot Study

    Science.gov (United States)

    Morrison, Jean M.; Goldhaber, Martin B.; Holloway, JoAnn M.; Smith, David B.

    2008-01-01

    In 2004, the U.S. Geological Survey (USGS), the Geological Survey of Canada (GSC), and the Mexican Geological Survey (Servicio Geologico Mexicano, or SGM) initiated pilot studies in preparation for a soil geochemical survey of North America called the Geochemical Landscapes Project. The purpose of this project is to provide a better understanding of the variability in chemical composition of soils in North America. The data produced by this survey will be used to construct baseline geochemical maps for regions within the continent. Two initial pilot studies were conducted: (1) a continental-scale study involving a north-south and east-west transect across North America and (2) a regional-scale study. The pilot studies were intended to test and refine sample design, sampling protocols, and field logistics for the full continental soils geochemical survey. Smith and others (2005) reported the results from the continental-scale pilot study. The regional-scale California study was designed to represent more detailed, higher resolution geochemical investigations in a region of particular interest that was identified from the low-sample-density continental-scale survey. A 20,000-km2 area of northern California (fig. 1), representing a wide variety of topography, climate, and ecoregions, was chosen for the regional-scale pilot study. This study area also contains diverse geology and soil types and supports a wide range of land uses including agriculture in the Sacramento Valley, forested areas in portions of the Sierra Nevada, and urban/suburban centers such as Sacramento, Davis, and Stockton. Also of interest are potential effects on soil geochemistry from historical hard rock and placer gold mining in the foothills of the Sierra Nevada, historical mercury mining in the Coast Range, and mining of base-metal sulfide deposits in the Klamath Mountains to the north. This report presents the major- and trace-element concentrations from the regional-scale soil geochemical

  10. Mercury content in agricultural soils (Vojvodina Province, Serbia).

    Science.gov (United States)

    Ninkov, Jordana; Marković, Slobodan; Banjac, Dušana; Vasin, Jovica; Milić, Stanko; Banjac, Borislav; Mihailović, Aleksandra

    2017-04-01

    The Vojvodina Province in northern Serbia is well known for its intensive field crops production. Over 90 % of total arable land, which represents more than 1500.000 ha, is used for field or vegetable crop production. A grid superimposed on Vojvodina land by means of a GIS tool (GIS ArcView 10) has divided land into 4 × 4 km units, each representing an area of 1600 ha. Total number of 1370 bulked soil samples were taken (0-30 cm depth) from agricultural land and analysed for total mercury content THg. The samples were analysed using Direct Mercury Analyzer DMA 80 Milestone. Quality control was carried out with IRMM BCR reference materials 143R. The aim of this study was to determine the total content of Hg in agricultural soils and its spatial distributions in different parts of Vojvodina Province. The obtained results were within interval 0.008-0.974 mg kg -1 . The average concentration of Hg was 0.068, with median 0.048 mg kg -1 . The correlation was determined between Hg concentration and organic matter content in the soil. Content of Hg coincides with main geomorphological units of Vojvodina Province. Average values of Hg concentrations for soils formatted on different geomorphological units were 0.031 for sandy area with dune fields, 0.048 for alluvial terraces, 0.055 for upper Pleistocene terraces, 0.058 for loess plateaus, 0.083 for mountains and 0.092 mg kg -1 for alluvial plains. Hg spatial distribution confirmed that most of Vojvodina Province area has geochemical origin of Hg. Higher concentration of Hg on alluvial plains indicated that the origin of Hg near rivers could be from anthropogenic source. The main rivers in Vojvodina have been dammed more than a century ago. Thus, higher concentrations of Hg in their alluvial plains out of narrow dammed zone around the rivers must be related to natural and anthropogenic sources located in their huge catchments. Higher content of Hg in mountain region can be explained by high clay content in

  11. Using multifractal modeling as a standard tool in geochemical exploration for predicting mineralized areas

    Science.gov (United States)

    Gonçalves, Mario A.

    2015-04-01

    scattered geochemical data sets that have been accumulating for decades of mining exploration in Southern Portugal. The studied zones include: the tectonic controlled quartz-vein Au-Sb mineralizations, the gabbroic and ultramafic complex of the southern border of the Ossa-Morena Zone, and the rocks belonging to the World-class massive sulfide province, the Iberian Pyrite Belt (IPB). The methodology used the CA method but also variogram analysis and modelling to outline and classify different sets of mineral deposits before confirmation in the field. This diversity of geologic contexts serves to show how effective and powerful the CA method can be, since it not only enhances already known mineralizations, it allowed the screening and identification of several new mineralized spots that have been previously overlooked. This has been of particularly economic importance because a major re-analysis of data and new exploration campaigns are currently under way for the next years in the IPB, with the potential for opening a new paradigm in the exploration for massive sulfide deposits in the region. Cheng et al, 1994, J. Geochem. Explor., 51, 109.

  12. Zinc and mercury in soils and plants of technogenic pollution territories (on example yavoriv military range and the factory "radical"

    Directory of Open Access Journals (Sweden)

    Наталия Олеговна Крюченко

    2015-07-01

    Full Text Available The results of geochemical studies of anthropogenic heavy metal pollution of surface sediments and vegetation from a variety of sources: zinc - for example Yavorоv military range Lviv region and mercury - the former plant "Radical" Kyiv. Geochemical anomalies identified elements in soils are installed depending on their behavior in the system "soil-plant".

  13. The peculiar case of Marosticano xenoliths: a cratonic mantle fragment affected by carbonatite metasomatism in the Veneto Volcanic Province (Northern Italy)

    Science.gov (United States)

    Brombin, Valentina; Bonadiman, Costanza; Coltorti, Massimo; Florencia Fahnestock, M.; Bryce, Julia G.; Marzoli, Andrea

    2017-04-01

    The Tertiary Magmatic Province of Veneto, known as Veneto Volcanic Province (VVP), in the Northern Italy, represents one of the most important volcanic provinces of the Adria Plate. It is composed by five volcanic districts: Val d'Adige, Marosticano, Mts. Lessini, Berici Hills and Euganean Hills. Most of the volcanic products are relatively undifferentiated lavas, from nephelinites to tholeiites in composition. Commonly VVP nephelinites and basanites carry mantle xenoliths. This study presents a petrological characterization of the new xenolith occurrence of Marosticano and comparison with previously studied VVP xenolith populations (i.e. from the Lessinean and Val d'Adige areas), which represent off-craton lithospheric mantle fragment affected by Na-alkaline silicate metasomatism (Siena & Coltorti 1989; Beccaluva et al., 2001; Gasperini et al., 2006). Marosticano (MA) peridotites are anhydrous spinel-bearing lherzolites and harzburgites, which are geochemically well distinguishible from the other VVP mantle xenoliths. Primary minerals record the "most restitic" composition of the VVP sampled mantle, even calling the geochemical features of a sub-cratonic mantle. Olivines in both lherzolites and harzburgites show high Ni contents compared with the Fo values (Ni→ lherzolite: 2600-3620 ppm; harzburgite: 2600-3540 ppm; Fo → lh: 91-92; hz: 90-93) that follow the trend of olivine from a cratonic area (Kelemen, 1998). Orthopyroxenes have mg# values with 1:1 ratio with coexisting olivines and Al2O3 contents always 0.5 wt%) contents are also the chemical characteristics of the clinopyroxenes. On the whole both MA pyroxenes show major element contents that recall the characteristics of those from cratonic (sp-bearing) peridotites (e.g. from Greenland, South Africa and Tanzania; Downes et al., 2004). In addition, the relationship between the high Fo content of olivine and the high chromium contents (cr#=(Cr/(Cr+Al)X100); lh: 30-53; hz: 38-67) in coexisting spinel, out of

  14. The Geochemical Earth Reference Model (GERM)

    Energy Technology Data Exchange (ETDEWEB)

    Staudigel, H. [Vrije Univ., Amsterdam (Netherlands); Albarede, F. [Ecole Normale Superieure, Lyon (France); Shaw, H. [Lawrence Livermore National Lab., CA (United States); McDonough, B. [Harvard Univ., Cambridge, MA (United States). Dept. of Earth and Planetary Sciences; White, W. [Cornell Univ., Ithaca, NY (United States). Dept. of Geology

    1996-12-01

    The Geochemical Earth Reference Model (GERM) initiative is a grass- roots effort with the goal of establishing a community consensus on a chemical characterization of the Earth, its major reservoirs, and the fluxes between them. Long term goal of GERM is a chemical reservoir characterization analogous to the geophysical effort of the Preliminary Reference Earth Model (PREM). Chemical fluxes between reservoirs are included into GERM to illuminate the long-term chemical evolution of the Earth and to characterize the Earth as a dynamic chemical system. In turn, these fluxes control geological processes and influence hydrosphere-atmosphere-climate dynamics. While these long-term goals are clearly the focus of GERM, the process of establishing GERM itself is just as important as its ultimate goal. The GERM initiative is developed in an open community discussion on the World Wide Web (GERM home page is at http://www-ep.es.llnl. gov/germ/germ-home.html) that is mediated by a series of editors with responsibilities for distinct reservoirs and fluxes. Beginning with the original workshop in Lyons (March 1996) GERM is continued to be developed on the Internet, punctuated by workshops and special sessions at professional meetings. It is planned to complete the first model by mid-1997, followed by a call for papers for a February 1998 GERM conference in La Jolla, California.

  15. Geochemical modeling of magmatic gas scrubbing

    Directory of Open Access Journals (Sweden)

    B. Gambardella

    2005-06-01

    Full Text Available The EQ3/6 software package, version 7.2 was successfully used to model scrubbing of magmatic gas by pure water at 0.1 MPa, in the liquid and liquid-plus-gas regions. Some post-calculations were necessary to account for gas separation effects. In these post-calculations, redox potential was considered to be fixed by precipitation of crystalline a-sulfur, a ubiquitous and precocious process. As geochemical modeling is constrained by conservation of enthalpy upon water-gas mixing, the enthalpies of the gas species of interest were reviewed, adopting as reference state the liquid phase at the triple point. Our results confirm that significant emissions of highly acidic gas species (SO2(g, HCl(g, and HF(g are prevented by scrubbing, until dry conditions are established, at least locally. Nevertheless important outgassing of HCl(g can take place from acid, HCl-rich brines. Moreover, these findings support the rule of thumb which is generally used to distinguish SO2-, HCl-, and HF-bearing magmatic gases from SO2-, HCl-, and HF-free hydrothermal gases.

  16. National Geochemical Survey Locations and Results for Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — The United States Geological Survey (USGS), in collaboration with other state and federal agencies, industry, and academia, is conducting a National Geochemical...

  17. Geochemical barriers of manganese distribution in edaphotopes of Dnieper Prysamarye

    National Research Council Canada - National Science Library

    N. N. Tsvetkova; Y. O. Tagunova

    2015-01-01

    ...’ health and stability of the biosphere as a whole. Geochemical barriers are local zones where the conditions of elemental migration are significantly different, resulting in accumulation of some chemical elements...

  18. Chlorine isotopes potential as geo-chemical tracers

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Pradhan, U.K.; Banerjee, R.

    The potential of chlorine isotopes as tracers of geo-chemical processes of earth and the oceans is highlighted based on systematic studies carried out in understanding the chlorine isotope fractionation mechanism, its constancy in seawater and its...

  19. Geochemical characteristics of the Jos-Plateau Basalts, North ...

    African Journals Online (AJOL)

    phenocrysts of both olivine, plagioclase (bytwonite-labradorite) and rarely pyroxene (diopside-augite) set in a groundmass of labradorite laths, magnetite, ilmenite, biotite, minor k-feldpars, nepheline and volcanic glass. Geochemical data show ...

  20. Geochemical characterization of the siliciclastic rocks of Chitravati ...

    Indian Academy of Sciences (India)

    59

    feldspar. 15 and plagioclase), mica, rock fragments, heavy minerals, with minor proportion of the matrix. 16 and cement. Based on major element geochemical classification diagram, Pulivendla. 17. Quartzite is considered as quartz-arenite and ...

  1. Geochemistry of rock samples from the National Geochemical Database

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set contains geochemical data for rock samples collected by U.S. Geological Survey (USGS) personnel and analyzed either in the analytical laboratories of...

  2. The geochemical chararateristics of the marble deposits east of ...

    African Journals Online (AJOL)

    ), marbles were investigated with the view to establishing marble occurrences and their geochemical characteristics. Crystalline rocks of the Nigerian Basement Complex (migmatite – gneiss complex) underlie the area. Ten marble bodies were ...

  3. Geochemical production of reactive oxygen species from biogeochemically reduced Fe.

    Science.gov (United States)

    Murphy, Sarah A; Solomon, Benson M; Meng, Shengnan; Copeland, Justin M; Shaw, Timothy J; Ferry, John L

    2014-04-01

    The photochemical reduction of Fe(III) complexes to Fe(II) is a well-known initiation step for the production of reactive oxygen species (ROS) in sunlit waters. Here we show a geochemical mechanism for the same in dark environments based on the tidally driven, episodic movement of anoxic groundwaters through oxidized, Fe(III) rich sediments. Sediment samples were collected from the top 5 cm of sediment in a saline tidal creek in the estuary at Murrell's Inlet, South Carolina and characterized with respect to total Fe, acid volatile sulfides, and organic carbon content. These sediments were air-dried, resuspended in aerated solution, then exposed to aqueous sulfide at a range of concentrations chosen to replicate the conditions characteristic of a tidal cycle, beginning with low tide. No detectable ROS production occurred from this process in the dark until sulfide was added. Sulfide addition resulted in the rapid production of hydrogen peroxide, with maximum concentrations of 3.85 μM. The mechanism of hydrogen peroxide production was tested using a simplified three factor representation of the system based on hydrogen sulfide, Fe(II) and Fe(III). The resulting predictive model for maximum hydrogen peroxide agreed with measured hydrogen peroxide in field-derived samples at the 95% level of confidence, although with a persistent negative bias suggesting a minor undiscovered peroxide source in sediments.

  4. Origin of the Late Jurassic to Early Cretaceous peraluminous granitoids in the northeastern Hunan province (middle Yangtze region), South China: Geodynamic implications for the Paleo-Pacific subduction

    Science.gov (United States)

    Ji, Wenbin; Lin, Wei; Faure, Michel; Chen, Yan; Chu, Yang; Xue, Zhenhua

    2017-06-01

    The Late Mesozoic granitic belt in the northeastern Hunan province (situated in the south of the middle Yangtze region) represents the western front of the large magmatic province of SE China. In order to determine their ages and petrogenesis, we carried out zircon U-Pb dating, Hf isotope and whole-rock geochemical analyses for four granitic plutons, namely Taohuashan, Dayunshan-Mufushan, Wangxiang and Lianyunshan. Our SIMS zircon U-Pb ages, together with previously published data, reveal that the magmatic activities in this area can be roughly subdivided into three phases at 151-146 Ma, 132-127 Ma and ca. 117 Ma, and the Dayunshan-Mufushan batholith therein is a composite pluton. These four plutons are mainly composed of weakly to strongly peraluminous biotite or two-mica monzogranites, with a minor amount of biotite granodiorites. Their geochemical features are similar to S-type as well as fractionated S-type granites, with enrichment in LREEs and negative Ba, Sr, Nb, P and Ti anomalies. All samples show negative zircon εHf(t) values ranging from -12.5 to -3.6, corresponding to crustal Hf model (TDMC) ages of 1.4-2.0 Ga. It is inferred that these granitoids were derived from partial melting of metasedimentary rocks analogous to the Neoproterozoic Lengjiaxi Group, predominantly with psammitic component. Fractional crystallization probably played an important role in the magma evolution, while input of mantle-derived magma was insignificant. Combined with other geological evidence, our new data allow us to propose that the Cretaceous (132-127 Ma and ca. 117 Ma) magmatism might be response to episodic slab rollback of the Paleo-Pacific plate, while the early-stage (151-146 Ma) magmatism that overlapped the epilogue of Jurassic magmatic flare-up and subsequent magmatic quiescence probably foreshadowed the transformation from foundering of a subducted flat-slab to slab rollback. Alternatively, slab foundering after a SE-directed intracontinental subduction in the

  5. GEOCHEM-EZ: a chemical speciation program with greater power and flexibility

    Science.gov (United States)

    GEOCHEM –EZ is a multi-functional chemical speciation program, which was designed to replace the existing GEOCHEM-PC, a program that can only be used on DOS consoles. Chemical speciation programs, such as GEOCHEM (Sposito and Mattigod, 1980) and GEOCHEM-PC (Parker et al., 1995), have been excellent ...

  6. Identification of Sediment Sources to Calumet River through Geochemical Fingerprinting

    Science.gov (United States)

    2017-04-01

    historic geochemical fingerprint for sediments within this reach of the river. Geochemical measurements and advanced multivariate statistics were...depositional fluxes of stable Pb, 210Pb, and 7Be into Chesapeake Bay. Journal of Atmospheric Chemistry 36(1):65–79. Kirchner, G. 2011. 210Pb as a tool for...Jackson, M. Roy-Barman, S. Schmidt, and M. Elskens. 2006. 234Th sorption and export models in the water column: A review. Marine Chemistry 100(3– 4

  7. Assessment of diagenetic alteration of dinosaur eggshells through petrography and geochemical analysis

    Science.gov (United States)

    Enriquez, M. V.; Eagle, R.; Eiler, J. M.; Tripati, A. K.; Ramirez, P. C.; Loyd, S. J.; Chiappe, L.; Montanari, S.; Norell, M.; Tuetken, T.

    2012-12-01

    Carbonate clumped isotope analysis of fossil eggshells has the potential to constrain both the physiology of extinct animals and, potentially, paleoenvironmental conditions, especially when coupled with isotopic measurements of co-occurring soil carbonates. Eggshell samples from both modern vertebrates and Cretaceous Hadrosaurid, Oviraptorid, Titanosaur, Hypselosaurus, Faveoolithus, dinosaur fossils have been collected from Auca Mahuevo, Argentina and Rousett, France, amongst other locations, for geochemical analysis to determine if isotopic signatures could be used to indicate warm- or cold-bloodedness. In some locations soil carbonates were also analyzed to constrain environmental temperatures. In order to test the validity of the geochemical results, an extensive study was undertaken to establish degree of diagenetic alteration. Petrographic and cathodoluminescence characterization of the eggshells were used to assess diagenetic alteration. An empirical 1-5 point scale was used to assign each sample an alteration level, and the observations were then compared with the geochemical results. Specimens displayed a wide range of alteration states. Some of which were well preserved and others highly altered. Another group seemed to be structural intact and only under cathodoluminescence was alteration clearly observed. In the majority of samples, alteration level was found to be predictably related to geochemical results. From specimens with little evidence for diagenesis, carbonate clumped isotope signatures support high (37-40°C) body temperature for Titanosaurid dinosaurs, but potentially lower body temperatures for other taxa. If these data do, in fact, represent original eggshell growth temperatures, these results support variability in body temperature amongst Cretaceous dinosaurs and potentially are consistent with variations between adult body temperature and size — a characteristic of 'gigantothermy'.

  8. Temperature Range for Metasomatism at the Bakalskoe Siderite Deposits with Use of Geochemical Data

    OpenAIRE

    M. T. Krupenin

    2017-01-01

    The data obtained with the quantitative microprobe ankerite–siderite composition analysis of seven samples from the different parts of Bakalskoe field showed that the wallrock ankerites in the western and central parts of the ore field differ in average concentrations of FeCO 3 (respectively 14.21 and 20.84 wt.%). However, there is no significant difference in composition of siderites. The calculation of the Mg-Fe metasomatism temperatures based on ankerite-siderite and ankerite-breinerite ge...

  9. ELECTRE III: A knowledge-driven method for integration of geophysical data with geological and geochemical data in mineral prospectivity mapping

    Science.gov (United States)

    Abedi, Maysam; Torabi, Seyed Ali; Norouzi, Gholam-Hossain; Hamzeh, Mohammad

    2012-12-01

    This paper describes the application of a multicriteria decision-making (MCDM) technique called ELECTRE III, which is well-known in operations research, to mineral prospectivity mapping (MPM), which involves representation and integration of evidential map layers derived from geological, geophysical, and geochemical geo-data sets. In a case study, thirteen evidential map layers are used for MPM in the area containing the Now Chun copper prospect in the Kerman province of Iran. The ELECTRE III technique was applied for MPM, and the outputs are validated using 3D models of Cu and Mo concentrations from 21 drill hole data. This proposed method shows high performance for MPM.

  10. Alaska Geochemical Database Version 2.0 (AGDB2) - Including "Best Value" Data Compilations for Geochemical Data for Rock, Sediment, Soil, Mineral, and Concentrate Sample Media

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Alaska Geochemical Database Version 2.0 (AGDB2) contains new geochemical data compilations in which each geologic material sample has one "best value"...

  11. Malaria Epidemiology in Mersin Province, Turkey from 2002 to 2011

    Directory of Open Access Journals (Sweden)

    M F AYDIN

    2013-06-01

    Full Text Available Background: Malaria is an infectious disease caused by Plasmodium spp. with high morbidity and mortality in human in tropical and subtropical regions. In recent years, number of malaria cases has been significantly reduced because of fight with the disease in Turkey. This study intended to investigate the malaria epidemiology in Mersin Province from 2002 to 2011 using data from the provincial Public Health Directorate.Methods: Over ten years, 303573 blood samples were taken from the people by active and passive surveillance methods and blood smears were prepared. Smears were stained with Giemsa and examined under the microscope.Results: Totally, 73 people including 44 male and 29 female were positive in terms of Plasmodium spp. It was determined that P. vivax observed in 67 cases while P. falciparum in 6 cases. Cases were mainly observed in 15 to 44 years old range, showed an increase between June-September periods and a significant decrease after 2006. Out of the 73 malaria cases, 54 cases were from Mersin Province and 13 cases were imported from another province of Turkey. Six cases were transmitted from abroad.Conclusion: These results provide information about malaria epidemiology in an endemic area in Turkey and contribute its prevention in Mersin Province

  12. Development of thermodynamic databases for geochemical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.C. [Monitor Scientific, L.L.C., Denver, Colorado (United States); Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan); Neyama, Atsushi [Computer Software Development Corp., Tokyo (Japan)

    1999-09-01

    Two thermodynamic databases for geochemical calculations supporting research and development on geological disposal concepts for high level radioactive waste are described in this report. One, SPRONS.JNC, is compatible with thermodynamic relations comprising the SUPCRT model and software, which permits calculation of the standard molal and partial molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to 1000degC. This database includes standard molal Gibbs free energies and enthalpies of formation, standard molal entropies and volumes, and Maier-Kelly heat capacity coefficients at the reference pressure (1 bar) and temperature (25degC) for 195 minerals and 16 gases. It also includes standard partial molal Gibbs free energies and enthalpies of formation, standard partial molal entropies, and Helgeson, Kirkham and Flowers (HKF) equation-of-state coefficients at the reference pressure and temperature for 1147 inorganic and organic aqueous ions and complexes. SPRONS.JNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQE.JNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25degC and l bar for mineral-dissolution, gas-solubility, aqueous-association and oxidation-reduction reactions. Reaction enthalpies, or coefficients in an empirical log K(T) function, are also included in this database, which permits calculation of equilibrium constants between 0 and 100degC at 1 bar. All equilibrium constants, reaction enthalpies, and log K(T) coefficients in PHREEQE.JNC are calculated using SUPCRT and SPRONS.JNC, which ensures that these two databases are mutually consistent. They are also internally consistent insofar as all the data are compatible with basic thermodynamic definitions and functional relations in the SUPCRT model, and because primary

  13. Compilation of kinetic data for geochemical calculations

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.C. [Monitor Scientific, LLC., Denver, Colorado (United States); Savage, D. [Quintessa, Ltd., Nottingham (United Kingdom); Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works

    2000-01-01

    Kinetic data, including rate constants, reaction orders and activation energies, are compiled for 34 hydrolysis reactions involving feldspars, sheet silicates, zeolites, oxides, pyroxenes and amphiboles, and for similar reactions involving calcite and pyrite. The data are compatible with a rate law consistent with surface reaction control and transition-state theory, which is incorporated in the geochemical software package EQ3/6 and GWB. Kinetic data for the reactions noted above are strictly compatible with the transition-state rate law only under far-from-equilibrium conditions. It is possible that the data are conceptually consistent with this rate law under both far-from-equilibrium and near-to-equilibrium conditions, but this should be confirmed whenever possible through analysis of original experimental results. Due to limitations in the availability of kinetic data for mine-water reactions, and in order to simplify evaluations of geochemical models of groundwater evolution, it is convenient to assume local-equilibrium in such models whenever possible. To assess whether this assumption is reasonable, a modeling approach accounting for couple fluid flow and water-rock interaction is described that can be use to estimate spatial and temporal scale of local equilibrium. The approach is demonstrated for conditions involving groundwater flow in fractures at JNC's Kamaishi in-situ tests site, and is also used to estimate the travel time necessary for oxidizing surface waters to migrate to the level of a HLW repository in crystalline rock. The question of whether local equilibrium is a reasonable assumption must be addressed using an appropriate modeling approach. To be appropriate for conditions at the Kamaishi site using the modeling approach noted above, the fracture fill must closely approximate a porous mine, groundwater flow must be purely advective and diffusion of solutes across the fracture-host rock boundary must not occur. Moreover, the

  14. Geochemical Treasure Hunt for Primary School Children

    Science.gov (United States)

    Tesmer, Maja; Frick, Daniel; Gerrits, Ruben; des GFZ-GeoWunderWerkstatt, Schülerlabor

    2017-04-01

    How can you inspire school children for geochemistry, and scientific exploratory urge? The key is to raise their curiosity and make learning new things a hands-on experience. The Fellows of the European Marie Curie Initial Training Network IsoNose designed and established a "Geochemical Treasure Hunt" to excite children for scientific investigations. This workshop explains primary school children the research and scientific methods of isotopic geochemistry, and their use to understand processes on the Earth's surface. From obtaining 'samples', performing various experiments, the school children gather clues leading them to the hidden treasure on the Telegrafenberg (campus of the GFZ Potsdam). The course was designed for school children to learn hands-on the meaning of elements, atoms and isotopes. In small groups the children conduct experiments of simplified methods being indispensable to any isotope geochemist. However, prior to working in any laboratory environment, a security briefing is necessary. For the course, two stages were implemented; firstly the use of harmful substances and dangerous equipment was minimised, and secondly children were equipped with size-matched personal protective equipment (lab coats, gloves, and safety googles). The purification of elements prior to isotopic analysis was visualised using colour chromatography. However, instead of using delicate mass spectrometers for the isotope ratio measurements, the pupils applied flame spectroscopy to analyse their dissolved and purified mineral solutions. Depending on the specific element present, a different colour was observed in the flame. The children plotted their colours of the flame spectroscopy onto a map and by interpreting the emerging colour patterns they localized the treasure on the map. In small teams they swarmed out on the Telegrafenberg to recover the hidden treasure. The project leading to this outreach activity has received funding from the People Programme (Marie Curie

  15. Geochemical fate of arsenic in swine litter

    Science.gov (United States)

    Quazi, S.; Makris, K.; Sarkar, D.; Datta, R.; Punamiya, P.

    2007-12-01

    Swine diet is often supplemented by organoarsenicals, such as roxarsone to treat diseases and to promote growth. Recent data reported roxarsone degradation under anaerobic conditions in poultry litter, but no such data exist for swine wastes typically stored in unprotected lagoons in concentrated animal feeding operations (CAFOs). However, serious environmental health risk may arise upon significant arsenic (As) release into solution. The problem may be exacerbated under certain environmental conditions where organoarsenicals, such as roxarsone transform into the more toxic inorganic As, posing serious health risk to the surrounding ecosystem. The objective of this study were to analyze swine wastes collected from 19 randomly selected CAFOs in the USA for As concentrations, and to determine the geochemical fate of As in the swine waste suspensions. Swine wastes were analyzed for total-recoverable, total soluble, and water-extractable As, which were measured by ICP-MS. Speciation of As was performed following a well-established hyphenated technique using HPLC- ICPMS. Swine waste suspensions differed in solids contents; thus, the particulate matters with varying As concentrations were spiked with roxarsone and incubated under dark/light and aerobic/anaerobic conditions. Findings show the prevalence of inorganic As [As(V)] in swine waste suspension solutions. Roxarsone underwent degradation to both organoarsenicals, such as p-ASA, as well as inorganic arsenate and to a number of unidentified metabolites. Roxarsone degradation kinetics was influenced by the solids content and the air conditions (anaerobic/aerobic) of the swine waste suspensions. Maximum degradation rates were observed under anaerobic conditions, in suspensions which were low in solids content. Roxarsone degradation was primarily microbially-mediated, but in certain cases abiotic degradation was also observed, which were significantly slower.

  16. Geochemical Energy for Catabolism and Anabolism in Hydrothermal Systems

    Science.gov (United States)

    Amend, J. P.; McCollom, T. M.; Bach, W.

    2008-12-01

    Chemically reduced deep-sea vent fluids mixed with oxidized seawater can generate redox disequilibria that serve as energy sources for chemolithoautotrophic (catabolism) and biomass synthesis (anabolism) reactions. Numerical models can be used to evaluate Gibbs energies of such processes on the early Earth and in present-day systems. Here, geochemical data from compositionally diverse vent fluids (Lost City, Rainbow, Logatchev, TAG, 21 °N EPR) are combined with several seawater chemistries to yield a wide range of mixed hydrothermal solutions; this is the starting point for our thermodynamic calculations. In ultramafic-hosted hydrothermal systems, such as Rainbow or Lost City, aerobic chemolithotrophic catabolisms (oxidation of H2, FeII, CH4) are the most energy-yielding at low temperatures (<25 °C); at elevated temperatures, the anaerobic counterparts (e.g., sulfate reduction, methanogenesis) dominate. In basalt-hosed systems, such as TAG and 21 °N EPR, aerobic sulfide oxidation appears to dominate over much of the microbially-relevant temperature range. Such catabolic reaction energetics can then be used to put constraints on the amount of primary biomass production. Under putative early Earth conditions, for example, the net chemoautotrophic synthesis of cellular building blocks is thermodynamically most favorable at moderate temperatures (~50°C), where the energy contributions from HCO3- and H+ in cool seawater coupled to the reducing power in hot vent fluid are optimized. At these conditions, and counter to conventional wisdom, the synthesis of amino acids may even yield small amounts of energy.

  17. Geochemical Data for Samples Collected in 2007 Near the Concealed Pebble Porphyry Cu-Au-Mo Deposit, Southwest Alaska

    Science.gov (United States)

    Fey, David L.; Granitto, Matthew; Giles, Stuart A.; Smith, Steven M.; Eppinger, Robert G.; Kelley, Karen D.

    2008-01-01

    In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molydenum (Cu-Au-Mo) deposit in southwest Alaska. The Pebble deposit is extremely large and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic and volcaniclastic rocks. The deposit is presently being explored by Northern Dynasty Minerals, Ltd., and Anglo-American LLC. The USGS undertakes unbiased, broad-scale mineral resource assessments of government lands to provide Congress and citizens with information on national mineral endowment. Research on known deposits is also done to refine and better constrain methods and deposit models for the mineral resource assessments. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, it is relatively undisturbed (except for exploration company drill holes), it is a large mineral system, and it is fairly well constrained at depth by the drill hole geology and geochemistry. The goals of the USGS study are (1) to determine whether the concealed deposit can be detected with surface samples, (2) to better understand the processes of metal migration from the deposit to the surface, and (3) to test and develop methods for assessing mineral resources in similar concealed terrains. This report presents analytical results for geochemical samples collected in 2007 from the Pebble deposit and surrounding environs. The analytical data are presented digitally both as an integrated Microsoft 2003 Access? database and as Microsoft 2003 Excel? files. The Pebble deposit is located in southwestern Alaska on state lands about 30 km (18 mi) northwest of the village of Illiamna and 320 km (200 mi) southwest of Anchorage (fig. 1). Elevations in the Pebble area range from 287 m (940 ft) at Frying Pan Lake just south of the deposit to 1146 m (3760 ft) on Kaskanak Mountain about 5 km (5 mi) to the west. The deposit is in an area of

  18. Pediatric burns in Khuzestan Province, Iran.

    Science.gov (United States)

    Houshyarikhah, Hojjat; Shayestehfard, Marzieh; Javaherizadeh, Hazhir; Cheraghian, Bahman; Latifzadeh, Shila; Madari, Zahra

    2012-04-01

    Burn injuries are the most frequently occurring injuries among pediatric populations worldwide, and they are significant pediatric injuries in Iran. This study was conducted to analyze the pattern of pediatric burns in Khuzestan province in the south-west of Iran from April 2006 to March 2007. The location of the study was Taleghani Hospital, a sole center for burn patients in Khuzestan province. The number of patients with burns admitted to the center in 1 year (from April 2006 to March 2007) was 211. Data were obtained by reviewing the medical records of patients hospitalized at the center. Of the patients, 85 (40.3%) were female and 126 (59.7%) were male. Of the 85 female patients, 50 were from urban areas and 35 were from rural areas. Of the 126 male patients, 68 (54%) were from urban areas and 58 (46%) were from rural areas. The mean ± SE age of the children ranging between 0 and 11 years was 3.20 ± 0.188. Scalding was the predominant cause of burns and caused 86.7% of the burns. The age of the patients with scald injuries (2.95 ± 2.56 years) was significantly lower than that of patients with flame injuries (4.28 ± 3.3 years) (P=0.007). Correlation analysis showed that younger children and urban residents are more vulnerable to scald injuries. The mean body surface area of burns was 20.5 ± 10.26 cm in all patients. Scalding was the most common cause of burns. Age burn accidents in children in Khuzestan. An appropriate burn prevention program, with focus on education, is needed to prevent this injury.

  19. AN INVESTIGATION OF MULTIDIMENSIONAL ENERGY POVERTY IN PAKISTAN: A PROVINCE LEVEL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Falak Sher

    2014-01-01

    Full Text Available Present study employs Alkire and Foster’s (2007 methodology to measure Multidimensional Energy Poverty (MEP at provincial level in Pakistan. MEP Headcount has been calculated using PSLM data. Indoor pollution is found to be the largest contributor to MEP Headcount in all four provinces of Pakistan while cooking fuel is the second largest contributor. Results of MEP Headcount show that 47%, 51%, 69% and 66% of the households residing in Punjab, Sindh, Khyber Pakhtoon Khaw (KPK and Baluchistan provinces of Pakistan respectively are energy poor. Households of all the four provinces are most deprived in the dimension of indoor pollution i.e. in the range of 49% to 63% followed by cooking fuel i.e. in the range of 35% to 59%. Deprivation is least in the dimension of home appliances for all provinces except Baluchistan which is least deprived in entertainment appliances dimension.

  20. Petrological, geochemical and isotopic characteristics of lignite and calcified lignite from mining area Pesje, Velenje Basin, Slovenia

    Science.gov (United States)

    Vrabec, Mirijam; Markič, Miloš; Vrabec, Marko; Jaćimović, Radojko; Kanduč, Tjaša

    2014-05-01

    energy dispersive X-ray spectroscopy at the Department of Ceramics at the Jožef Stefan Institute. Geochemical characteristics of major and trace elements indicate that the values of major and trace elements are comparable to world average coal (Zhang et al., 2004). Isotopic composition of carbon and isotopic composition of nitrogen of investigated samples indicate values from to -29.4o to -23.7o and 1.8o to 5.9o respectively. Lower value of isotopic composition of carbon indicates higher gelification (values up to -29.4) and higher value of isotopic composition of nitrogen (values up to 5.9) indicate higher mineralization. The results of SEM/EDXS microscopy revealed that in calcified lignite chemical composition of calcite prevails. Traces of diagenetic pyrite were also found, indicating localized anoxic conditions during sedimentation. Values of isotopic composition of CCaCO3 range from -2 to +13 and indicate temperature of precipitation from 17.3 to 35 deg C, which is similar to results obtained in previous studies (Kanduč et al., 2012). References Krantz, D.E., Williams, D.F., Jones, D.S., 1987: Ecological and paleoenvironmental information using stable isotope profiles from living and fossil mollusks. Palaeogeography, Palaeoclimatology, Palaeoecology 58, 249-266. Kanduč T., Markič M., Zavšek S., McIntosh J. 2012: carbon cycling in the Pliocene Velenje Coal Basin, Slovenia, inferred from stable carbon isotopes. International Journal of Coal Geology 89, 70-83. Jaćimović, R., Lazaru, A., Mihajlović, D., Ilić, R., Stafilov, T., 2002: Determination of major and trace elements in some minerals by k0-instrumental neutron activation analysis. Journal of Radioanalytical Nuclear Chemistry, 253, 427-434. McCrea, JM., 1950. On the isotopic chemistry of carbonates and a paleotemperature scale. Journal of Chemical Physics 18, 849. Ward C.R. (Ed.), 1984: Coal Geology and Coal Technology. Black-well, Oxford, 345 pp. Zhang J.Y., Zheng C.G., Ren D.Y., Chou C.L., Zheng R

  1. A regional soil and sediment geochemical study in northern California

    Science.gov (United States)

    Goldhaber, M.B.; Morrison, J.M.; Holloway, J.M.; Wanty, R.B.; Helsel, D.R.; Smith, D.B.

    2009-01-01

    Regional-scale variations in soil geochemistry were investigated in a 20,000-km2 study area in northern California that includes the western slope of the Sierra Nevada, the southern Sacramento Valley and the northern Coast Ranges. Over 1300 archival soil samples collected from the late 1970s to 1980 in El Dorado, Placer, Sutter, Sacramento, Yolo and Solano counties were analyzed for 42 elements by inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry following a near-total dissolution. These data were supplemented by analysis of more than 500 stream-sediment samples from higher elevations in the Sierra Nevada from the same study site. The relatively high-density data (1 sample per 15 km2 for much of the study area) allows the delineation of regional geochemical patterns and the identification of processes that produced these patterns. The geochemical results segregate broadly into distinct element groupings whose distribution reflects the interplay of geologic, hydrologic, geomorphic and anthropogenic factors. One such group includes elements associated with mafic and ultramafic rocks including Cr, Ni, V, Co, Cu and Mg. Using Cr as an example, elevated concentrations occur in soils overlying ultramafic rocks in the foothills of the Sierra Nevada (median Cr = 160 mg/kg) as well as in the northern Coast Ranges. Low concentrations of these elements occur in soils located further upslope in the Sierra Nevada overlying Tertiary volcanic, metasedimentary and plutonic rocks (granodiorite and diorite). Eastern Sacramento Valley soil samples, defined as those located east of the Sacramento River, are lower in Cr (median Cr = 84 mg/kg), and are systematically lower in this suite compared to soils from the west side of the Sacramento Valley (median Cr = 130 mg/kg). A second group of elements showing a coherent pattern, including Ca, K, Sr and REE, is derived from relatively silicic rocks types. This group occurs at elevated

  2. Ongoing mumps outbreak in Novi Sad, the autonomous province of Vojvodina, Serbia, January to April 2012.

    Science.gov (United States)

    Rajčević, S; Seguljev, Z; Petrovic, V; Medić, S; Nedelijković, J; Milosević, V; Turo, L; Ristić, M

    2012-05-10

    From 16 January to 30 April 2012, a total of 119 cases of mumps were notified in Novi Sad, Serbia. Of these cases, 89 (75%), were among students. The average age of cases was 22 years-old (range 3-37). The outbreak is still ongoing in Novi Sad and is spreading to other parts of the Vojvodina province. As of 30 April, 209 cases have been notified in the province among those 119 from Novi Sad.

  3. Flora of soil fungi in Khuzestan province\\\\\\'s oil regions

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    vida dawoodi

    2014-07-01

    Full Text Available   Introduction: Many Species of fungi with ability to metabolize of petroleum hydrocarbons are known so far. These fungi are resistant in oil contaminated sites.This investigation aims at studying fungal population diversity in oil contaminated soils of Khuzestan province and identifying fungal flora in these regions .   Materials and methods: Crude oil contaminated soil samples were collected from different regions of Khuzestan province. For isolation and enumeration of total heterotrophic fungi, Potato Dextrose Agar medium supplemented with streptomycine was used. The isolated fungi were identified via morphological studies, staining by lactophenol cotton blue, observation with a light microscope and comparing with descriptive and canonizative refereces .   Results: Total fungal counts ranged from 0.41 × 102 to 3333.33 × 102 CFU/g. Isolated fungi belong to Aspergillus, Penicillium, Fusarium, Candida, Rhodotorula, Aureobasidium, Mucor, Rhizopus and Acremonium. Most dominant genera were Aspergillus and Penicillium .   Discussion and conclusion : Studies on isolation of fungi in oil containing environments showed that, abundance and fungal diversity in different stations significantly were different. The increase in the number of fungi in crude oil soils showes the probability of degradation and consumption of oil contaminated by fungi. Diversity and distribution of soil microbial population are determined by a number of environmental factors such as pH, electrical conductivity and soil organic matter .  

  4. Hydrologic Regulation of Global Geochemical Cycles

    Science.gov (United States)

    Maher, K.

    2015-12-01

    understand the processes controlling marine isotopic weathering processes, the need to integrate solute and solid transport into Earth system models, and the need to understand the role of extreme physical and temporal heterogeneities in moderating geochemical fluxes.

  5. Thermodynamic Data for Geochemical Modeling of Carbonate Reactions Associated with CO2 Sequestration – Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, Kenneth M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McGrail, B. Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2010-09-01

    Permanent storage of anthropogenic CO2 in deep geologic formations is being considered as a means to reduce the concentration of atmospheric CO2 and thus its contribution to global climate change. To ensure safe and effective geologic sequestration, numerous studies have been completed of the extent to which the CO2 migrates within geologic formations and what physical and geochemical changes occur in these formations when CO2 is injected. Sophisticated, computerized reservoir simulations are used as part of field site and laboratory CO2 sequestration studies. These simulations use coupled multiphase flow-reactive chemical transport models and/or standalone (i.e., no coupled fluid transport) geochemical models to calculate gas solubility, aqueous complexation, reduction/oxidation (redox), and/or mineral solubility reactions related to CO2 injection and sequestration. Thermodynamic data are critical inputs to modeling geochemical processes. The adequacy of thermodynamic data for carbonate compounds has been identified as an important data requirement for the successful application of these geochemical reaction models to CO2 sequestration. A review of thermodynamic data for CO2 gas and carbonate aqueous species and minerals present in published data compilations and databases used in geochemical reaction models was therefore completed. Published studies that describe mineralogical analyses from CO2 sequestration field and natural analogue sites and laboratory studies were also reviewed to identify specific carbonate minerals that are important to CO2 sequestration reactions and therefore require thermodynamic data. The results of the literature review indicated that an extensive thermodynamic database exists for CO2 and CH4 gases, carbonate aqueous species, and carbonate minerals. Values of ΔfG298° and/or log Kr,298° are available for essentially all of these compounds. However, log Kr,T° or heat capacity values at temperatures above 298 K exist for less than

  6. Geochemical studies, magmatic evolution, microstructures and replacement mechanisms in Jebale-Barez granitoid Complex (East and Southeast Jiroft

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    Jamal Rasouli

    2017-08-01

    Full Text Available Introduction The Jebale-Barez Plutonic Complex (JBPC is composed of many intrusive bodies and is located in the southeastern province of Kerman on the longitude of the 57◦ 45 ' east to 58◦ 00' and Northern latitudes 28◦ 30' to 29◦ 00'. The petrologic composition is composed of granodiorite, quartzdiorite, granite, alkali-granite, and trace amounts of tonalite with dominant granodiorite composition. Previously, the JBPC was separated into three plutonic phases by Ghorbani (2014. The first plutonic phase is the main body of the complex with composition of quartz-diorite to granodiorite. After differentiation of magma in the magmatic chamber, the porphyritic and not fully consolidated magmas have intruded into the main body. Their compositions were dominantly granodiorite and granite that are defined as the second plutonic phase. Finally, the last phase was started by an intrusion of the holo- leucogranite into the previous bodies. This plutonic activity was pursued by the minor Quaternary basaltic volcanism that shows metamorphic haloes in the contacts. They are dominantly porphyric leucogranites. However, some bodies show dendritic texture that may imply the existence of silicic fluids in the latest crystallization stages. Materials and methods In this article different analysis methods were used. For example, we used a total of two hundred samples of the various granitoids that were selected for common thin section study. Forty four representative samples from the different granitic rocks were selected for whole rock chemical analyses. The analyses of both major and trace elements were performed at the Department of Earth Sciences, the University of Perugia, Italy. The analysis for all major elements was carried out by an X-ray fluorescence spectrometry (XRF using a tube completed with a Rn and W anode under conditions with acceleration voltage of 40-45 kV and electric current ranging from I=30-35 mA. After calcination of powdered

  7. Geochemical variability in MORB controlled by concurrent mixing and crystallisation

    Science.gov (United States)

    Shorttle, Oliver

    2015-08-01

    The isotopic and elemental diversity in mid-ocean ridge basalts (MORB) traces the history of mantle differentiation, recycling and convective stirring. However, to interpret this record it is critical to account for the magma transport and storage processes modifying the primary geochemical variability of mantle derived melts. Magma mixing during low pressure differentiation is a key petrological process that controls the chemical variability of basalts throughout the global mid-ocean ridge system. Mixing occurs concurrent with crystallisation and must in general be dominant over any assimilatory processes in controlling the chemical evolution of basalts with MgO concentrations >5 wt% MgO. The effect of this mixing is to collapse the diversity of melt compositions leaving the mantle into the narrow range expressed in most mid-ocean ridge settings. In this context magma mixing can be viewed as contaminating the variance structure of primitive mantle melts, which leads to irreversible information loss on the sources and processes involved in melt generation unless primitive, unmixed, liquids and crystal phases are erupted. However, where we can track magma mixing, the homogenisation itself offers the potential to be an important petrological tool, which constrains the storage and transport processes magma experiences during its ascent through the mantle and crust. In the global dataset interrogated here systematic mixing trends are visible up to the length scales of first order ridge segmentation (∼300 km), indicating the possible links between surface tectonics and the record of mantle heterogeneity in basalts. The importance of magma mixing at mid-ocean ridges hints at the need to reevaluate the MORB-ocean island basalt chemical dichotomy, given the poorly understood mixing processes operating during intraplate magma transport from mantle to surface.

  8. Barnacles - recorders of environmental conditions with unique geochemical signatures

    Science.gov (United States)

    Vinzenz Ullmann, Clemens; Gale, Andy; Korte, Christoph; Frei, Robert; Huggett, Jenny; Wray, Dave

    2017-04-01

    Barnacles are calcite-forming arthropods that occur in a wide range of habitats in modern times and are found in sedimentary successions reaching back to the Paleozoic. Despite potential use of their mostly low-Mg calcite hard parts for palaeoenvironmental reconstructions, their geochemical composition has been little studied. Here, we present the first comprehensive overview of barnacle geochemistry, with C and O isotope, as well as Mg/Ca, Sr/Ca, Mn/Ca and Fe/Ca data for multiple samples of 42 species covering the orders Sessilia, Scalpelliformes, and Lepadiformes. XRD analyses confirm calcite as the only significant carbonate mineral of the studied barnacle shell material. Apart from one species, median Mg/Ca ratios fall below 50 mmol/mol, the approximate limit for low-Mg-calcite. In the order Sessilia, the scuta and terga are on average enriched in Mg by 36 % over the unmoveable plates. Amongst the calcite-forming marine animals, barnacles have very high Sr/Ca ratios of 2.6 to 5.9 mmol/mol, amongst the highest known for calcite secreting animals. Mn/Ca and Fe/Ca ratios are commonly low and compatible with other modern shell calcite, but can be strongly enriched to > 1 mmol/mol in proximal habitats, particularly close to areas strongly affected by human activity. Carbon and oxygen isotope data indicate formation of the calcite in or near isotopic equilibrium with ambient water conditions. Apart from species showing δ18O values below 0 ‰ V-PDB, a negative correlation of oxygen isotope ratios with Sr/Ca ratios is observed, which may be related to metabolic activity. Compositional patterns in barnacle shell material, particularly high Sr concentrations and Mg distribution in shell plates of the Sessilia, point to a great potential of barnacles for high fidelity reconstruction of past seawater chemistry and environmental conditions complementary to other archives.

  9. Human geography of New Orleans' high-lead geochemical setting.

    Science.gov (United States)

    Campanella, Richard; Mielke, Howard W

    2008-12-01

    Previous soil lead studies in New Orleans focused on the geochemical footprint and its health impacts. This study examines the human geography of race, income, and age in pre-Katrina metropolitan New Orleans within the context of lead accumulation in soils. Sample points of soil lead data (n = 5,467) collected in 1998-2000 were mapped in a geographic information system (GIS), binned into 9 ranges, and queried by (1) 2000 Census racial demographic data, (2) 1999 median household income, and (3) 2000 age data. The absolute population generally declines as lead levels increase except at lead levels from 200-400 to 400-1,000 mg/kg when population increases; the African-American population comprises a disproportionate share of this cohort. The high-lead areas occur in the inner city, home to the largest populations of African-Americans in New Orleans. The mean household income curve indicates that lower economic groups are at risk to higher levels of lead. A total of 44,701 children under the age of 5 years, plus 123,579 children aged 5-17, lived in census block groups containing at least one sample point with over 100 mg/kg lead, and these include 23,124 and 64,064 young people, respectively, who live near at least one point over 400 mg/kg. Lead exposure affects a panoply of outcomes that influence the health and welfare of the community. Unless corrected, children are likely to return to the same or, because of lack of lead-safe practices during renovation, even higher exposure risks than before the flooding of New Orleans.

  10. Natural bacterial communities serve as quantitative geochemical biosensors.

    Science.gov (United States)

    Smith, Mark B; Rocha, Andrea M; Smillie, Chris S; Olesen, Scott W; Paradis, Charles; Wu, Liyou; Campbell, James H; Fortney, Julian L; Mehlhorn, Tonia L; Lowe, Kenneth A; Earles, Jennifer E; Phillips, Jana; Techtmann, Steve M; Joyner, Dominique C; Elias, Dwayne A; Bailey, Kathryn L; Hurt, Richard A; Preheim, Sarah P; Sanders, Matthew C; Yang, Joy; Mueller, Marcella A; Brooks, Scott; Watson, David B; Zhang, Ping; He, Zhili; Dubinsky, Eric A; Adams, Paul D; Arkin, Adam P; Fields, Matthew W; Zhou, Jizhong; Alm, Eric J; Hazen, Terry C

    2015-05-12

    Biological sensors can be engineered to measure a wide range of environmental conditions. Here we show that statistical analysis of DNA from natural microbial communities can be used to accurately identify environmental contaminants, including uranium and nitrate at a nuclear waste site. In addition to contamination, sequence data from the 16S rRNA gene alone can quantitatively predict a rich catalogue of 26 geochemical features collected from 93 wells with highly differing geochemistry characteristics. We extend this approach to identify sites contaminated with hydrocarbons from the Deepwater Horizon oil spill, finding that altered bacterial communities encode a memory of prior contamination, even after the contaminants themselves have been fully degraded. We show that the bacterial strains that are most useful for detecting oil and uranium are known to interact with these substrates, indicating that this statistical approach uncovers ecologically meaningful interactions consistent with previous experimental observations. Future efforts should focus on evaluating the geographical generalizability of these associations. Taken as a whole, these results indicate that ubiquitous, natural bacterial communities can be used as in situ environmental sensors that respond to and capture perturbations caused by human impacts. These in situ biosensors rely on environmental selection rather than directed engineering, and so this approach could be rapidly deployed and scaled as sequencing technology continues to become faster, simpler, and less expensive. Here we show that DNA from natural bacterial communities can be used as a quantitative biosensor to accurately distinguish unpolluted sites from those contaminated with uranium, nitrate, or oil. These results indicate that bacterial communities can be used as environmental sensors that respond to and capture perturbations caused by human impacts. Copyright © 2015 Smith et al.

  11. Aves, province of Guizhou, China.

    Directory of Open Access Journals (Sweden)

    Chen, G.

    2008-01-01

    Full Text Available We report our inventories of birds observed and collected at three field sites from the province of Guizhou,southeastern China. Our findings detailed herein complement our previous ornithological surveys from Guangxiprovince, as part of a comprehensive biotic survey of the region. Of 153 total bird species recorded, 17 were new for theprovince, among which several taxa of conservational importance, such as: Golden Pheasant Crysolophus pictus,Tawny Fish-Owl Ketupa flavipes, Black-breasted Thrush Turdus dissimilis, Fujian Flycatcher Niltava davidii, RedtailedLaughingthrush Garrulax milnei, and Slaty Bunting Latoucheornis siemsseni. These records provide the mostrecent insight into the current status of the habitats and the avian biodiversity of an important, yet sparsely surveyed andreported biogeographic region.

  12. Natural Gamma Radiation in Primary Schools of Zanjan Province

    Directory of Open Access Journals (Sweden)

    Faranak Saghatchi

    2016-06-01

    Full Text Available Background: Environmental gamma ray refers to the gamma radiation from terrestrial sources and building materials. In enclosed spaces radiation can become a health hazard leading to potential increase in the rates of lung cancer. The goal of this study is to assess the exposure to natural gamma radiation of children in the schools of Zanjan province. Method: The natural gamma radiation was assessed in 46 primary schools of Zanjan province. A total number of 75 classrooms were studied. The measurements were performed in classrooms and schoolyards using a Geiger–Muller detector (RDS-110. Alongside radiation measurements, all the data corresponding to the characteristics of each school building were collected. Results: The results showed that the outdoor dose rate ranged from 82 to 106nSv h-1 while gamma dose rate due to inside classrooms ranged from 106 to 137nSvh-1. The findings represented that the highest indoor gamma dose rate belonged to the buildings of more than 30 years and metal frame and brick (P<0.05. Conclusion: We concluded that the effective dose due to gamma radiation from terrestrial sources and building materials for students of primary schools in Zanjan province (0.83 mSv was higher than worldwide average of the annual effective dose (0.48 mSv.

  13. Uranium provinces of North America; their definition, distribution, and models

    Science.gov (United States)

    Finch, Warren Irvin

    1996-01-01

    Uranium resources in North America are principally in unconformity-related, quartz-pebble conglomerate, sandstone, volcanic, and phosphorite types of uranium deposits. Most are concentrated in separate, well-defined metallogenic provinces. Proterozoic quartz-pebble conglomerate and unconformity-related deposits are, respectively, in the Blind River–Elliot Lake (BRELUP) and the Athabasca Basin (ABUP) Uranium Provinces in Canada. Sandstone uranium deposits are of two principal subtypes, tabular and roll-front. Tabular sandstone uranium deposits are mainly in upper Paleozoic and Mesozoic rocks in the Colorado Plateau Uranium Province (CPUP). Roll-front sandstone uranium deposits are in Tertiary rocks of the Rocky Mountain and Intermontane Basins Uranium Province (RMIBUP), and in a narrow belt of Tertiary rocks that form the Gulf Coastal Uranium Province (GCUP) in south Texas and adjacent Mexico. Volcanic uranium deposits are concentrated in the Basin and Range Uranium Province (BRUP) stretching from the McDermitt caldera at the Oregon-Nevada border through the Marysvale district of Utah and Date Creek Basin in Arizona and south into the Sierra de Peña Blanca District, Chihuahua, Mexico. Uraniferous phosphorite occurs in Tertiary sediments in Florida, Georgia, and North and South Carolina and in the Lower Permian Phosphoria Formation in Idaho and adjacent States, but only in Florida has economic recovery been successful. The Florida Phosphorite Uranium Province (FPUP) has yielded large quantities of uranium as a byproduct of the production of phosphoric acid fertilizer. Economically recoverable quantities of copper, gold, molybdenum, nickel, silver, thorium, and vanadium occur with the uranium deposits in some provinces.Many major epochs of uranium mineralization occurred in North America. In the BRELUP, uranium minerals were concentrated in placers during the Early Proterozoic (2,500–2,250 Ma). In the ABUP, the unconformity-related deposits were most likely

  14. Geochemical perspectives from a new aerosol chemical mass closure

    Directory of Open Access Journals (Sweden)

    B. Guinot

    2007-01-01

    Full Text Available The aerosol chemical mass closure is revisited and a simple and inexpensive methodology is proposed. This methodology relies on data obtained for aerosol mass, and concentration of the major ions and the two main carbon components, the organic carbon (OC and the black carbon (BC. Atmospheric particles are separated into coarse (AD>2 μm and fine (AD<2 μm fractions and are treated separately. For the coarse fraction the carbonaceous component is minor and assumption is made for the conversion factor k of OC-to-POM (Particulate Organic Matter which is fixed to the value of 1.8 accounting for secondary species. The coarse soluble calcium is shown to display a correlation (regression coefficient f, y axis intercept b with the missing mass. Conversely, the fine fraction is dominated by organic species and assumption is made for dust which is assumed to have the same f factor as the coarse mode dust. The fine mode mass obtained from chemical analyses is then adjusted to the actual weighed mass by tuning the k conversion factor. The k coefficient is kept different in the two modes due to the expected different origins of the organic particles. Using the f and k coefficient obtained from the data set, the mass closure is reached for each individual sample with an undetermined fraction less than 10%. The procedure has been applied to different urban and peri-urban environments in Europe and in Beijing and its efficiency and uncertainties on f and k values are discussed. The f and k coefficients are shown to offer consistent geochemical indications on aerosol origin and transformations. f allows to retrieve dust mass and its value accounting for Ca abundance in dust at the site of investigation may serve as an indicator of dust origin and aerosol interactions with anthropogenic acids. f values were found to vary in the 0.08–0.12 range in European urban areas, and a broader range in Beijing (0.01–0.16. As expected, k appears to be a relevant proxy for

  15. Stratigraphical framework of basaltic lavas in Torres Syncline main valley, southern Parana-Etendeka Volcanic Province

    Science.gov (United States)

    Rossetti, Lucas M.; Lima, Evandro F.; Waichel, Breno L.; Scherer, Claiton M.; Barreto, Carla J.

    2014-12-01

    The Paraná-Etendeka Volcanic Province records the volcanism of the Early Cretaceous that precedes the fragmentation of the South-Gondwana supercontinent. Traditionally, investigations of these rocks prioritized the acquisition of geochemical and isotopic data, considering the volcanic stack as a monotonous succession of tabular flows. Torres Syncline is a tectonic structure located in southern Brazil and where the Parana-Etendeka basalts are well preserved. This work provides a detailed analysis of lithofacies and facies architecture, integrated to petrographic and geochemical data. We identified seven distinct lithofacies grouped into four facies associations related to different flow morphologies. The basaltic lava flows in the area can be divided into two contrasting units: Unit I - pahoehoe flow fields; and Unit II - simple rubbly flows. The first unit is build up by innumerous pahoehoe lava flows that cover the sandstones of Botucatu Formation. These flows occur as sheet pahoehoe, compound pahoehoe, and ponded lavas morphologies. Compound lavas are olivine-phyric basalts with intergranular pyroxenes. In ponded lavas and cores of sheet flows coarse plagioclase-phyric basalts are common. The first pahoehoe lavas are more primitive with higher contents of MgO. The emplacement of compound pahoehoe flows is related to low volume eruptions, while sheet lavas were emplaced during sustained eruptions. In contrast, Unit II is formed by thick simple rubbly lavas, characterized by a massive core and a brecciated/rubbly top. Petrographically these flows are characterized by plagioclase-phyric to aphyric basalts with high density of plagioclase crystals in the matrix. Chemically they are more differentiated lavas, and the emplacement is related to sustained high effusion rate eruptions. Both units are low TiO2 and have geochemical characteristics of Gramado magma type. The Torres Syncline main valley has a similar evolution when compared to other Large Igneous Provinces

  16. Supervolcanoes Within an Ancient Volcanic Province in Arabia Terra, Mars

    Science.gov (United States)

    Michalski, Joseph. R.; Bleacher, Jacob E.

    2014-01-01

    Several irregularly shaped craters located within Arabia Terra, Mars represent a new type of highland volcanic construct and together constitute a previously unrecognized martian igneous province. Similar to terrestrial supervolcanoes, these low-relief paterae display a range of geomorphic features related to structural collapse, effusive volcanism, and explosive eruptions. Extruded lavas contributed to the formation of enigmatic highland ridged plains in Arabia Terra. Outgassed sulfur and erupted fine-grained pyroclastics from these calderas likely fed the formation of altered, layered sedimentary rocks and fretted terrain found throughout the equatorial region. Discovery of a new type of volcanic construct in the Arabia volcanic province fundamentally changes the picture of ancient volcanism and climate evolution on Mars. Other eroded topographic basins in the ancient Martian highlands that have been dismissed as degraded impact craters should be reconsidered as possible volcanic constructs formed in an early phase of widespread, disseminated magmatism on Mars.

  17. Benthic foraminifera of the Panamanian Province: distribution and origins.

    Science.gov (United States)

    Crouch, R.W.; Poag, C.W.

    1987-01-01

    Two hundred twenty-nine species of benthic foraminifera have been identified from 96 stations representing 33 localities on the eastern Pacific inner continental shelf, ranging from southern Peru to northern Baja California. Their distributions mark nearshore provincial boundaries that are nearly identical with those previously documented from the distribution of ostracodes and molluscs. Thirteen species are characteristic of the Panamanian Province, one is characteristic of the Chilean-Peruvian Province, and one is characteristic of the newly proposed Sonoran Subprovince. Seventeen species (7%) appear to be endemic to the eastern Pacific. Fifty-eight (25%) of the species recognized are disjunct from population centers in the western Pacific, 134 species (59%) are disjunct from modern assemblages of the Atlanto-Carribean region, and 40 species (17%) are disjunct from both the western Pacific and the Atlanto-Caribbean. The distribution of the remaining 57 species (25%) is poorly documented; we classify them as of unknown origin. -Authors

  18. Granitoids of different geodynamic settings of Baikal region (Russia) their geochemical evolution and origin

    Science.gov (United States)

    Antipin, Viktor; Sheptyakova, Natalia

    2016-04-01

    In the southern folded framing of the Siberian craton the granitoid magmatism of different ages involves batholiths, small low-depth intrusions and intrusion-dyke belts with diverse mineral and geochemical characteristics of rocks. Granitoid formation could be related to the Early Paleozoic collision stage and intra-plate magmatism of the Late Paleozoic age of the geologic development of Baikal area. The Early Paleozoic granitoids of Khamar-Daban Ridge and Olkhon region revealed their closeness in age and composition. They were referred to syncollision S-type formations derived from gneiss-schistose substratum of metamorphic sequences. The magmatic rocks were classified into various geochemical types comprising formations of normal Na-alkalinity (migmatites and plagiogranites), calc-alkaline and subalkaline (K-Na granitoids, granosyenites and quartz syenites) series. It is significant, that plagiomigmatites and plagiogranites in all elements repeat the shape of the chart of normalized contents marked for trend of K-Na granitoids, but at considerably lower level of concentrations of all elements. This general pattern of element distribution might indicate similar anatectic origin of both granitoid types, but from crustal substrata distinguished by composition and geochemical features. Comparative geochemical analysis pointed out that the source of melts of the Early Paleozoic granitoids of the Olkhon (505-477 Ma) and Khamar-Daban (516-490 Ma) complexes of the Baikal region could be the crustal substratum, which is obviously the criterion for their formation in the collisional geodynamic setting. Using the Late Paleozoic subalkaline magmatism proceeding at the Khamar-Daban Range (Khonzurtay pluton, 331 Ma) as an example, it was found that the formation of monzodiorite-syenite-leucogranite series was considerably contributed by the processes of hybridism and assimilation through mixing of the upper mantle basaltoid magma derived melts of granitic composition. The

  19. Mineralization study on Dehbid magnetite deposit, Fars; using mineralogical and geochemical data

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Rajabzadeh

    2011-11-01

    Full Text Available The Dehbid magnetite deposit is located in northeastern part of Fars province, in the southern border of Sanandaj-Sirjan metamorphic zone. The mineralization occurred as veins and lenses along NW-SE faults. The ores are mainly hosted in silicified dolomite of early Mesozoic (Triassic. Mineralogical studies show that the ores are dominated by magnetite and minor hematite with massive texture occurring as cement of angular remnants of silicified host dolomite. According to geochemical data, Fe2O3 content in the mineralized zones show extensive variation between 34 to 75 wt %. The P, Ti, Cr and V contents of the iron ores are remarkably low and Co/Ni, Cr/V and LREE/HREE ratios, positive Eu anomalies, negative Ce anomalies, Eu/Sm = 1, along with field and textural observations of Dehbid ores indicate that the deposit belongs to the class of hydrothermal iron ores. At Dehbid, the magnetite ores are formed as open space fillings. The sparse rhyolites and basalts in the area may be regarded as the origin of iron and heat in the hydrothermal system. A decrease in temperature and likely pressure due to fluid mixing are the major causes of iron oxide deposition.

  20. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors

  1. National Assessment of Oil and Gas Project - Uinta-Piceance Province (020) Depth to the top of the Dakota Sandstone

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset shows depth ranges to the top of the Dakota Sandstone within the Uinta-Piceance Province, northwestern Colorado and northeastern Utah.

  2. New Insights to the Mid Miocene Calc-alkaline Lavas of the Strawberry Volcanics, NE Oregon Surrounded by the Coeval Tholeiitic Columbia River Basalt Province

    Science.gov (United States)

    Steiner, A. R.; Streck, M. J.

    2013-12-01

    The Strawberry Volcanics (SV) of NE Oregon were distributed over 3,400 km2 during the mid-Miocene and comprise a diverse volcanic suite, which span the range of compositions from basalt to rhyolite. The predominant composition of this volcanic suite is calc-alkaline (CA) basaltic andesite and andesite, although tholeiitic (TH) lavas of basalt to andesite occur as well. The coeval flood basalts of the Columbia River province surround the SV. Here we will discuss new ages and geochemical data, and present a new geologic map and stratigraphy of the SV. The SV are emplaced on top of pre-Tertiary accreted terranes of the Blue Mountain Province, Mesozoic plutonic rocks, and older Tertiary volcanic rocks thought to be mostly Oligocene of age. Massive rhyolites (~300 m thick) are exposed mainly along the western flank and underlie the intermediate composition lavas. In the southern portion of this study area, alkali basaltic lavas, thought to be late Miocene to early Pliocene in age, erupted and overlie the SV. In addition, several regional ignimbrites reach into the area. The 9.7 Ma Devine Canyon Tuff and the 7.1 Ma Rattlesnake Tuff also overlie the SV. The 15.9-15.4 Ma Dinner Creek Tuff is mid-Miocene, and clear stratigraphic relationships are found in areas where the tuff is intercalated between thick SV lava flows. All of the basalts of the SV are TH and are dominated by phenocryst-poor (≤2%) lithologies. These basalts have an ophitic texture dominated by plagioclase, clinopyroxene and olivine (often weathered to iddingsite). Basalts and basaltic andesites have olivine Fo #'s ranging from 44 at the rims (where weathered to iddingsite) and as high as 88 at cores. Pyroxene Mg #'s range from 65 to 85. Andesites of the SV are sub-alkaline, and like the basalts, are exceedingly phenocryst-poor (≤3%) with microphenocrysts of plagioclase and lesser pyroxene and olivine, which occasionally occur as crystal clots of ~1-3 mm instead of single crystals. In addition, minimal

  3. Mechanisms and Magnitude of Cenozoic Crustal Extension in the Vicinity of Lake Mead, Nevada and the Beaver Dam Mountains, Utah: Geochemical, Geochronological,Thermochronological and Geophysical Constraints

    Science.gov (United States)

    Almeida, Rafael V.

    The central Basin and Range Province of Nevada and Utah was one of the first areas in which the existence of widespread low-angle normal faults or detachments was first recognized. The magnitude of associated crustal extension is estimated by some to be large, in places increasing original line lengths by as much as a factor of four. However, rock mechanics experiments and seismological data cast doubt on whether these structures slipped at low inclination in the manner generally assumed. In this dissertation, I review the evidence for the presence of detachment faults in the Lake Mead and Beaver Dam Mountains areas and place constraints on the amount of extension that has occurred there since the Miocene. Chapter 1 deals with the source-provenance relationship between Miocene breccias cropping out close to Las Vegas, Nevada and their interpreted source at Gold Butte, currently located 65 km to the east. Geochemical, geochronological and thermochronological data provide support for that long-accepted correlation, though with unexpected mismatches requiring modification of the original hypothesis. In Chapter 2, the same data are used to propose a refinement of the timing of ~1.45 Ga anorogenic magmatism, and the distribution of Proterozoic crustal boundaries. Chapter 3 uses geophysical methods to address the subsurface geometry of faults along the west flank of the Beaver Dam Mountains of southwestern Utah. The data suggest that the range is bounded by steeply inclined normal faults rather than a regional-scale detachment fault. Footwall folding formerly ascribed to Miocene deformation is reinterpreted as an expression of Cretaceous crustal shortening. Fission track data presented in Chapter 4 are consistent with mid-Miocene exhumation adjacent to high-angle normal faults. They also reveal a protracted history dating back to the Pennsylvanian-Permian time, with implications for the interpretation of other basement-cored uplifts in the region. A key finding of this

  4. An integrated geochemical and geoelectrical Investigation of an ...

    African Journals Online (AJOL)

    Geochemical analysis of borehole soil samples for Total Petroleum Hydrocarbon (TPH), geoelectrical imaging and geotechnical sieve analysis were used to assess the intensity and extent of hydrocarbon contamination at an ancient oil spill site near Ejama-Ebubu community in Eleme, near Port Harcourt. The subsurface ...

  5. Geochemical and isotopic signatures for the identification of ...

    Indian Academy of Sciences (India)

    The objective of this study is to identify the extent of seawater intruded area by major geochemical and isotopic signatures. A total of 102 groundwater samples were collected and analysed for major and minor ions. Groundwater samples with electrical conductivity (EC) greater than 5000 S/cm and a river mouth sample ...

  6. phosphorus sorption in relation to soil grain size and geochemical ...

    African Journals Online (AJOL)

    Mgina

    Agriculture (Morogoro) for determination of. P sorption capacity, pH and soil grain size distribution. Sub-samples were also taken to. Southern and Eastern Africa Mineral Centre. - SEAMIC (Dar es Salaam) where soil geochemical compositions were determined. Particle size distribution was determined by the hydrometer ...

  7. Geochemical study of volcanic and associated granitic rocks from ...

    Indian Academy of Sciences (India)

    Geochemical studies and modelling show that both volcanic and granitic magmas from the western part of the Johor National Park, Endau Rompin are different and probably have different sources. The geo- chemical plot suggests that both dacite/rhyolite and andesite probably have a common origin as in many.

  8. Geochemical behaviour of vanadium in iron—titanium oxides

    NARCIS (Netherlands)

    Schuiling, R.D.; Feenstra, A.

    The following geochemical rules-of-thumb seem to hold for vanadium: 1. (1) Magnetites as a group have higher V contents than either hematites or ilmenites. 2. (2) In magnetite—hematite pairs, however, the hematite has the higher V content. 3. (3) In magnetite—ilmenite pairs, the magnetite

  9. Reconnaissance geochemical study of a part of Igarra Schist Belt ...

    African Journals Online (AJOL)

    Geochemical exploration of Orle district within the Igarra schist belt in southwestern Nigeria was carried out using reconnaissance stream-sediment survey. A total of 56 samples were collected and chemically analysed for 22 trace elements including Au, Ag, As, Pb, Zn, Cu, Co, Mo, Hg, Sb, Tl, Sc, Cr, Ni, La, W, V, U, Th, ...

  10. mineralogical and geochemical trends in lateritic weathering profiles ...

    African Journals Online (AJOL)

    Three soil profiles on the basement rocks in Awa-Oru-Ijebu Igbo area of southwestern Nigeria were investigated for the formation secondary minerals and the comparison of the mineralogical and geochemical patterns in the weathering profiles overlying the rocks during the humid tropical weathering. X-ray data showed that ...

  11. Geochemical characteristics and organic carbon sources within the ...

    Indian Academy of Sciences (India)

    Carbon (POC, DOC) and carbon isotopes (δ13C) within two headwater tributaries to the Xi River Basin, southwest China were analyzed to document the geochemical characteristics and sources of organic carbon (C) within basins characterized by a monsoonal climate and karst landforms. δ¹³CPOC value and C/N ratio ...

  12. Adaptive processing of geochemical analysis by means of spline model

    Directory of Open Access Journals (Sweden)

    А. Я. Білецький

    2000-09-01

    Full Text Available Proposed is adaptive algorithm of geochemical analysis processing by means of spline model. Demonstrated is the possibility of splines to reveal heterogeneous fields in the composition of iron ore which, because of considerable dispersion of random component, is practically impossible to reveal

  13. Use of thermal springs for geochemical exploration in Ethiopia ...

    African Journals Online (AJOL)

    Hence, hot spring water anomalous in Au, Mn, Zn, Pb, Cu, Co and Ag could be a proxy for precious metal searching in epithermal systems associated with thermal springs. Keywords: Epithermal system, Ethiopian Rift Valley, geochemical exploration, thermal springs. Ethiopian Journal of Environmental Studies and ...

  14. Highlights from Johannesburg, Gauteng Province, South Africa

    Science.gov (United States)

    2002-01-01

    Although the extraction of mineral wealth has been the major influence in the history of Johannesburg and the surrounding Witwatersrand regions (with about 45% of all gold ever mined coming from there), the discovery of now-famous hominid fossils at the Sterkfontein Caves, and the convening of the world's largest-ever conference on environment and development, are setting a new stage for the future. The United Nations began the second Development and Environment Conference in Johannesburg on August 26, 2002. This meeting addresses the implementation of international goals to fight poverty and protect the global environment that were established at the first such conference held in Rio de Janeiro in 1992. The Johannesburg summit involves about forty thousand participants, and perhaps 100 world leaders. One of several official opening ceremonies for the conference was held at the Sterkfontein Caves to recognize the outstanding universal value of the paleo-anthropological fossils found there.These views from the Multi-angle Imaging SpectroRadiometer (MISR) highlight a number of the land use, vegetation, and geological features found within Gauteng Province (including the urban center of Johannesburg and the capital city Pretoria) and parts of the North West and Free State Provinces. The image on the right displays vegetation in red hues and is a false-color view utilizing data from MISR's near-infrared, red and blue bands. Both the natural-color view (left) and the false-color version were acquired by MISR's nadir camera on June 16, 2002. The urban areas appear as gray-colored pixels in the natural-color view, and exhibit colors corresponding with the relative abundance of vegetation found in the urban parts of this arid region.The mountains trending east-west near the center of the images extend from Pretoria in the east to Rustenberg in the west. These ranges, the Magaliesberg and Witwatersberg, separate the low-lying, hotter bushveld to the north from the cooler

  15. Soil Geochemical Control Over Nematode Populations in Bull Pass, McMurdo Dry Valleys, Antarctica

    Science.gov (United States)

    Poage, M. A.; Barrett, J. E.; Virginia, R. A.; Wall, D. H.

    2005-12-01

    The McMurdo Dry Valleys occupy the largest ice-free region of Antarctica and are characterized by climatic conditions among the most extreme on Earth. Despite the harsh environmental conditions, some soils of the dry valleys host simple low-diversity ecosystems dominated by microbes and several taxa of metazoans, predominantly nematodes. Distributions, abundance, and diversity of these biota appear to be related to the highly variable soil geochemistry (pH, conductivity, nitrate, sulfate, chloride) of the dry valleys. Bull Pass is a glacially carved valley within the dry valleys. An ancient lake margin near the valley floor creates a continuous gradient spanning the full range of geochemical parameters found across the entire McMurdo Dry Valleys system. This unique setting provides the opportunity to systematically investigate the soil geochemical control on local biodiversity and establish, on the spatial scale of hundreds of meters, correlations between nematode populations and individual geochemical parameters that have application at the regional scale. We measured soil geochemistry and nematode population data from a 1500-meter transect across this ancient lake margin. There were significant negative correlations between live nematode abundance and concentrations of soil nitrate, sulfate and chloride as well as total soil salinity, consistent with recent laboratory experiments showing strong salinity inhibition of nematode survival. A logistical regression analysis based on a compilation of published datasets from across the dry valleys was designed to calculate the probably of live nematode populations occurring given a particular soil chemistry, using the dataset from the Bull Pass transect as a case study to field-test the model. Small-scale chemical and biological gradients can provide insights on the distribution of soil biota at much larger regional scales.

  16. Assessment of groundwater quality: a fusion of geochemical and geophysical information via Bayesian neural networks.

    Science.gov (United States)

    Maiti, Saumen; Erram, V C; Gupta, Gautam; Tiwari, Ram Krishna; Kulkarni, U D; Sangpal, R R

    2013-04-01

    Deplorable quality of groundwater arising from saltwater intrusion, natural leaching and anthropogenic activities is one of the major concerns for the society. Assessment of groundwater quality is, therefore, a primary objective of scientific research. Here, we propose an artificial neural network-based method set in a Bayesian neural network (BNN) framework and employ it to assess groundwater quality. The approach is based on analyzing 36 water samples and inverting up to 85 Schlumberger vertical electrical sounding data. We constructed a priori model by suitably parameterizing geochemical and geophysical data collected from the western part of India. The posterior model (post-inversion) was estimated using the BNN learning procedure and global hybrid Monte Carlo/Markov Chain Monte Carlo optimization scheme. By suitable parameterization of geochemical and geophysical parameters, we simulated 1,500 training samples, out of which 50 % samples were used for training and remaining 50 % were used for validation and testing. We show that the trained model is able to classify validation and test samples with 85 % and 80 % accuracy respectively. Based on cross-correlation analysis and Gibb's diagram of geochemical attributes, the groundwater qualities of the study area were classified into following three categories: "Very good", "Good", and "Unsuitable". The BNN model-based results suggest that groundwater quality falls mostly in the range of "Good" to "Very good" except for some places near the Arabian Sea. The new modeling results powered by uncertainty and statistical analyses would provide useful constrain, which could be utilized in monitoring and assessment of the groundwater quality.

  17. Forensic Assessment of Metal Contaminated Rivers in the 21st Century Using Geochemical and Isotopic Tracers

    Directory of Open Access Journals (Sweden)

    Jerry R. Miller

    2013-05-01

    Full Text Available Documentation of contaminant source and dispersal pathways in riverine environments is essential to mitigate the potentially harmful effects of contaminants on human and ecosystem health, and is required from a legal perspective (particularly where the polluter pays principle is in effect in assessing site liability. Where multiple natural and/or anthropogenic sources exist, identification of contaminant provenance has proven problematic, and estimated contributions from a specific source are often the subject of judicial debate. The past, current, and future use of geochemical and isotopic tracers in environmental forensic investigations of contaminant provenance, transport, and fate are analyzed herein for sediment-associated trace metals in riverine environments, particularly trace metals derived from mining and refining operations. The utilized methods have evolved significantly over the past four decades. Of primary significance has been the growing integration of geomorphic and stratigraphic techniques with the use of an increasing number of geochemical tracers including stable isotopes. The isotopes of Pb have been particularly well studied, and have been applied to a wide range of environmental media. Advances in analytical chemistry since the early 1990s have allowed for the precise characterization of other non-traditional stable isotopic systems within geological materials. The potential for using these non-traditional isotopes as tracers in river systems has yet to be adequately explored, but a number of these isotopes (e.g., Cd, Cu, Cr, Hg, Sb, and Zn show considerable promise. Moreover, some of these isotopes (e.g., those of Cu, Cr, and Hg may provide important insights into biogeochemical cycling processes within aquatic environments. This review suggests that future environmental forensic investigations will be characterized by an interdisciplinary approach that combines the use of multiple geochemical tracers with detailed

  18. PhreeqcRM: A reaction module for transport simulators based on the geochemical model PHREEQC

    Science.gov (United States)

    Parkhurst, David L.; Wissmeier, Laurin

    2015-01-01

    PhreeqcRM is a geochemical reaction module designed specifically to perform equilibrium and kinetic reaction calculations for reactive transport simulators that use an operator-splitting approach. The basic function of the reaction module is to take component concentrations from the model cells of the transport simulator, run geochemical reactions, and return updated component concentrations to the transport simulator. If multicomponent diffusion is modeled (e.g., Nernst–Planck equation), then aqueous species concentrations can be used instead of component concentrations. The reaction capabilities are a complete implementation of the reaction capabilities of PHREEQC. In each cell, the reaction module maintains the composition of all of the reactants, which may include minerals, exchangers, surface complexers, gas phases, solid solutions, and user-defined kinetic reactants.PhreeqcRM assigns initial and boundary conditions for model cells based on standard PHREEQC input definitions (files or strings) of chemical compositions of solutions and reactants. Additional PhreeqcRM capabilities include methods to eliminate reaction calculations for inactive parts of a model domain, transfer concentrations and other model properties, and retrieve selected results. The module demonstrates good scalability for parallel processing by using multiprocessing with MPI (message passing interface) on distributed memory systems, and limited scalability using multithreading with OpenMP on shared memory systems. PhreeqcRM is written in C++, but interfaces allow methods to be called from C or Fortran. By using the PhreeqcRM reaction module, an existing multicomponent transport simulator can be extended to simulate a wide range of geochemical reactions. Results of the implementation of PhreeqcRM as the reaction engine for transport simulators PHAST and FEFLOW are shown by using an analytical solution and the reactive transport benchmark of MoMaS.

  19. Modules based on the geochemical model PHREEQC for use in scripting and programming languages

    Science.gov (United States)

    Charlton, Scott R.; Parkhurst, David L.

    2011-01-01

    The geochemical model PHREEQC is capable of simulating a wide range of equilibrium reactions between water and minerals, ion exchangers, surface complexes, solid solutions, and gases. It also has a general kinetic formulation that allows modeling of nonequilibrium mineral dissolution and precipitation, microbial reactions, decomposition of organic compounds, and other kinetic reactions. To facilitate use of these reaction capabilities in scripting languages and other models, PHREEQC has been implemented in modules that easily interface with other software. A Microsoft COM (component object model) has been implemented, which allows PHREEQC to be used by any software that can interface with a COM server—for example, Excel®, Visual Basic®, Python, or MATLAB". PHREEQC has been converted to a C++ class, which can be included in programs written in C++. The class also has been compiled in libraries for Linux and Windows that allow PHREEQC to be called from C++, C, and Fortran. A limited set of methods implements the full reaction capabilities of PHREEQC for each module. Input methods use strings or files to define reaction calculations in exactly the same formats used by PHREEQC. Output methods provide a table of user-selected model results, such as concentrations, activities, saturation indices, and densities. The PHREEQC module can add geochemical reaction capabilities to surface-water, groundwater, and watershed transport models. It is possible to store and manipulate solution compositions and reaction information for many cells within the module. In addition, the object-oriented nature of the PHREEQC modules simplifies implementation of parallel processing for reactive-transport models. The PHREEQC COM module may be used in scripting languages to fit parameters; to plot PHREEQC results for field, laboratory, or theoretical investigations; or to develop new models that include simple or complex geochemical calculations.

  20. GEOBASI: The geochemical Database of Tuscany Region (Italy

    Directory of Open Access Journals (Sweden)

    Brunella Raco

    2015-03-01

    Full Text Available In this study the new Regional Geochemical Database (RGDB, called GEOBASI, is presented and illustrated in the framework of a joint collaboration among the three Tuscan universities (Florence, Pisa and Siena, CNR-IGG (Institute of Geosciences and Earth Resources of Pisa, ARPAT (Regional Agency for the Environmental Protection, LAMMA (Environmental Modelling and Monitoring Laboratory for Sustainable Development Consortium and S.I.R.A. (Territorial and Environmental Informative System of Tuscany. The database has permitted the construction of a repository where the geochemical information (compositional and isotopic has been stored in a structured way so that it can be available for different groups of users (e.g. institutional, public and private companies. The information contained in the database can in fact be downloaded freely and queried to correlate geochemistry to other non compositional variables. The first phase of the project was aimed at promoting the use of the geochemical data already available from previous investigations through a powerful Web-GIS interface to implement the exploratory statistics graphical-numerical tools used to: 1 analyse the spatial variability of the investigated context, 2 highlight the geographic location of data pertaining to classes of values or single cases, 3 compare the results of different analytical methodologies applied to the determination of the same element and/or chemical species, 4 extract the geochemical data related to specific monitoring plans and/or geographical areas, and finally 5 recover information about data below the detection limit to understand their impact on the behaviour of the investigated variable. Developments of this project will be focused on the definition of rules and standardized methods in a way that external users could also interactively pursue the RGDB. Furthermore, a detailed investigation of the Scarlino-Follonica plain will permit the improvement and test of

  1. Geologic Provinces of the Arctic, 2000 (prvarcst)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage includes arcs, polygons and polygon labels that describe Arctic portion of the U.S. Geological Survey defined geologic provinces of the World in 2000.

  2. [Epidemiology of caprine and ovine brucellosis in Formosa province, Argentina].

    Science.gov (United States)

    Russo, Ana M; Mancebo, Orlando A; Monzón, Carlos M; Gait, Juan J; Casco, Rubén D; Torioni de Echaide, Susana M

    2016-01-01

    An epidemiological study of brucellosis was carried out in 516 goats and mixed flocks (goat/sheep) from the three agro-ecological regions of Formosa province, Argentina. Serum samples from a total of 25401 goats and 2453 sheeps were analyzed using buffered plate agglutination test (BPAT) and complement fixation test (CFT). Bacteriological and PCR analyses on milk samples from goats in three flocks with a history of brucellosis and recent abortions were also performed. Brucellosis was detected in four of the nine departments of the province with an overall prevalence of 2% and an intra-flock prevalence ranging between 1% and 40%. The proportion of infected flocks was 3.6%, 12% and 36% for the eastern, central and western regions, respectively. Brucella melitensis bv. 1 was isolated efrom goats for the first time in the province. The expected fragments of 827bp from the omp2ab gene (Brucella spp.) and 731bp from the insert IS711 (B. melitensis) were amplified by PCR. Detection of antibodies by BPAT and FCT in sheep cohabiting with goats suggests that infections could have been caused by B. melitensis, posing an additional risk to public health. Control and eradication programs for brucellosis should consider mixed flocks as a single epidemiological unit. The results indicate that brucellosis by B. melitensis bv1 is highly endemic in the central and western regions of Formosa province. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  3. Study on Banana Cooperatives in Hainan Province

    OpenAIRE

    HUANG, Huide; Zhang, Wanzhen; Liu, Enping; Zhang, Xizhu

    2013-01-01

    This paper gives an overview of the distribution, member scale, production and operation of banana cooperatives in Hainan Province, and points out the market risk and natural risk faced by the production of banana cooperatives in Hainan Province. In order to promote the banana cooperatives to form new agricultural management system integrating organization and intensification, this paper puts forth the production and operation recommendations, such as joint production of banana cooperatives, ...

  4. CURCULIONOIDEA FROM GOLESTAN PROVINCE, NORTHERN IRAN (Coleoptera)

    OpenAIRE

    Hassan Ghahari; Enzo Colonnelli

    2012-01-01

    The 195 species of Curculionoidea (Coleoptera) thus far indicated from Golestan province (northern Iran) according to both literature and original records are listed in this paper. New data for 61 species belonging to 18 genera collected during this research are also given. Besides the 42 species newly reported for the Golestan province, the following additional 15 species are newly recorded from Iran: Brachypera lunata, Ceutorhynchus anatolicus, Datonychus urticae, Hypera contaminata, Hypera...

  5. The age of Kondyor massif dunites (Aldan Province, Russia): First U-Pb isotopic data

    Science.gov (United States)

    Malitch, K. N.; Efimov, A. A.; Badanina, I. Yu.

    2012-09-01

    The material and isotope-geochemical peculiarities of zircons from dunites of the Kondyor massif (Aldan Province, Southeast Siberian Craton) have been described for the first time. This massif is associated with an economic platinum placer deposit. On the basis of detailed study of the morphology, internal structure, and geochemical characteristics, zircons have been subdivided into two types. The first type is represented by crystals of oval and rounded shapes, characterized by a bimodal distribution of "ancient" (2477 ± 18 and 1885 ± 52 Ma) U-Pb (SHRIMP-II) ages. The second type of zircons forms idiomorphic crystals and aggregates of prismatic habitus, forming two "young" age clusters (176 ± 1.2 and 143 ± 2.0 Ma). The obtained results allow us to make a conclusion about the long evolution of platinum-bearing dunites. The first type of zircons formed by metamictic cores and homogeneous peripheral rims indicates the time of metamorphism at the Archean-Proterozoic boundary (˜2.5 Ga), implying an older age of porous zircon cores. Such zircons characterize the minimal age of the initial mantle substance or a close time when the platinum-bearing dunite was generated. Based on their formation time, the second type of zircons can be referred to the epoch of tectonic-magmatic activation of the Aldan Shield. The new geochronological data, along with the material identity of dunites from the Urals and the Aldan Province, argue for a common genetic origin of platinum-bearing dunites of the fold belts and ancient cratons.

  6. The U.S. geological survey rass-statpac system for management and statistical reduction of geochemical data

    Science.gov (United States)

    VanTrump, G.; Miesch, A.T.

    1977-01-01

    RASS is an acronym for Rock Analysis Storage System and STATPAC, for Statistical Package. The RASS and STATPAC computer programs are integrated into the RASS-STATPAC system for the management and statistical reduction of geochemical data. The system, in its present form, has been in use for more than 9 yr by scores of U.S. Geological Survey geologists, geochemists, and other scientists engaged in a broad range of geologic and geochemical investigations. The principal advantage of the system is the flexibility afforded the user both in data searches and retrievals and in the manner of statistical treatment of data. The statistical programs provide for most types of statistical reduction normally used in geochemistry and petrology, but also contain bridges to other program systems for statistical processing and automatic plotting. ?? 1977.

  7. Determination of Mineralization Zones Using Interpretation of IP and RS Data in The GarmabCopper Deposit (South Khorasan province

    Directory of Open Access Journals (Sweden)

    Mansour Adelpour

    2016-07-01

    Full Text Available Introduction The Garmab copper deposit is located northeast of Qaen (South Khorasan province in the1:100,000 scale map of Abiz in the eastern tectonic zone of Iran. It is hosted by Late Paleocene-Eocene lava flows consisting mainly of andesite, trachy¬andesite, andesite-basalt and basalt lavas, as well as pyroclastic rocks, including tuffs and ignimbrites. The Lut Block has undergone intense magmatic activitywith a variety of geochemical characteristics due to changing tectonic conditions (e.g., compression during subduction followed by tensional conditions; Karimpour et al., 2012; Zarrinkoub et al., 2012. The Lut Block has a great potential for the discovery of new mineral deposits, like the Mahrabad and Khonik porphyry copper-gold deposits (Malekzadeh shafarodi, 2009, the Dehsalam porphyry copper deposit (Arjmandzadeh, 2011, high sulfidation epithermal gold deposits such as Chah Shalghami (Karimpour, 2005 and IOCG deposits such as Kuh-E-Zar and Qaleh Zari (Mazlomi et al., 2008. Materials and methods After field studies of the Garmab area, 32 thin sections and 21 polished sections were prepared for petrological and mineralogical studies.In addition, 10 least-altered and fractured samples of volcanic rocks were selected for geochemical studies. Major oxides were determined using XRF analyses at the Zarazma laboratory. Induced polarization and resistivity geophysical data were collected and correlated with geological and alteration maps. The geophysical datawere collectedfrom 420 individual points, using a dipole-dipole arrangement along five profiles separated 60m apart.This covered the study area entirely. After a change in the mineralization trend was observed,additional profileswere designed, twoon bearings of 25º and three on 75º. Results The Garmab volcanic rocks exhibit typical geochemical characteristics of subduction zone magmas including strong enrichment in LILE and depletion in HFSE. Based on the discrimination plot of Irvine and

  8. An ethnobotanical survey on hormozgan province, Iran

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    Omid Safa

    2012-12-01

    Full Text Available Objective: The present study is based on an ethnobotanical research project conducted in Hormozgan province that is located in south of Iran, bordering waters of the Persian Gulf and Oman Sea. This survey was carried out in order to recover the ethnobotanical and ethnomedicinal knowledge of the residents of this province. They are using medicinal and functional plants for treating or preventing several diseases. Materials and Methods: Ethnobotanical data sheets were run with the native inhabitants and people of the province by arranging frequent field trips to different parts of the province and direct interviews with them especially those who were more familiar with the plants and their usage.Results: A total of 150 plant species belonging to 53 families were recorded for their ethnobotanical and ethnomedicinal uses among the people of province. The records were developed by scientific names, family names, local names, medicinal parts used, different ways of their application, and traditional uses of the plants. There was high compliance in the use of plants in painful disorders, gastrointestinal, and dermatological diseases.Conclusion: This study revealed that the people of Hormozgan province have a rich knowledge of natural resources. The use and consumption of medicinal plants are still important parts of their life. Rational use of native medicinal plants may benefit and improve their living standards and quality of life. The results of this study can be used as a basis for selecting herbs for further pharmacological, phytochemical, and pharmacognostical studies.

  9. Raman Imagery: A New Approach to Assess the Geochemical Maturity and Biogenicity of Permineralized Precambrian Fossils

    Science.gov (United States)

    Schopf, J. William; Kudryavtsev, Anatoliy B.; Agresti, David G.; Czaja, Andrew D.; Wdowiak, Thomas J.

    2005-06-01

    Laser-Raman imagery is a non-intrusive, non-destructive analytical technique, recently introduced to Precambrian paleobiology, that can be used to demonstrate a one-to-one spatial correlation between the optically discernible morphology and kerogenous composition of permineralized fossil microorganisms. Made possible by the submicron-scale resolution of the technique and its high sensitivity to the Raman signal of carbonaceous matter, such analyses can be used to determine the chemical-structural characteristics of organic-walled microfossils and associated sapropelic carbonaceous matter in acid-resistant residues and petrographic thin sections. Here we use this technique to analyze kerogenous microscopic fossils and associated carbonaceous sapropel permineralized in 22 unmetamorphosed or little-metamorphosed fine-grained chert units ranging from ~400 to ~2,100 Ma old. The lineshapes of the Raman spectra acquired vary systematically with five indices of organic geochemical maturation: (1) the mineral-based metamorphic grade of the fossil-bearing units; (2) the fidelity of preservation of the fossils studied; (3) the color of the organic matter analyzed; and both the (4) H/C and (5) N/C ratios measured in particulate kerogens isolated from bulk samples of the fossil-bearing cherts. Deconvolution of relevant spectra shows that those of relatively well-preserved permineralized kerogens analyzed in situ exhibit a distinctive set of Raman bands that are identifiable also in hydrated organic-walled microfossils and particulate carbonaceous matter freed from the cherts by acid maceration. These distinctive Raman bands, however, become indeterminate upon dehydration of such specimens. To compare quantitatively the variations observed among the spectra measured, we introduce the Raman Index of Preservation, an approximate measure of the geochemical maturity of the kerogens studied that is consistent both with the five indices of organic geochemical alteration and with

  10. Quantifying inorganic sources of geochemical energy in hydrothermal ecosystems, Yellowstone National Park, USA

    Science.gov (United States)

    Shock, Everett L.; Holland, Melanie; Meyer-Dombard, D.'Arcy; Amend, Jan P.; Osburn, G. R.; Fischer, Tobias P.

    2010-07-01

    Combining analytical data from hot spring samples with thermodynamic calculations permits a quantitative assessment of the availability and ranking of various potential sources of inorganic chemical energy that may support microbial life in hydrothermal ecosystems. Yellowstone hot springs of diverse geochemical composition, ranging in pH from 9 were chosen for this study, and dozens of samples were collected during three field seasons. Field measurements of dissolved oxygen, nitrate, nitrite, total ammonia, total sulfide, alkalinity, and ferrous iron were combined with laboratory analyses of sulfate and other major ions from water samples, and carbon dioxide, hydrogen, methane, and carbon monoxide in gas samples to evaluate activity products for ˜300 coupled oxidation-reduction reactions. Comparison of activity products and independently calculated equilibrium constants leads to values of the chemical affinity for each of the reactions, which quantifies how far each reaction is from equilibrium. Affinities, in turn, show systematic behavior that is independent of temperature but can be correlated with pH of the hot springs as a proxy for the full spectrum of geochemical variability. Many affinities are slightly to somewhat dependent on pH, while others are dramatically influenced by changes in chemical composition. All reactions involving dissolved oxygen as the electron acceptor are potential energy sources in all hot spring samples collected, but the ranking of dominant electron donors changes from ferrous iron, and sulfur at high pH to carbon monoxide, hydrogen, and magnetite as pH decreases. There is a general trend of decreasing energy yields depending on electron acceptors that follows the sequence: O 2(aq) > NO 3- ≈ NO 2- ≈ S > pyrite ≈ SO 4-2 ≈ CO(g) ≈ CO 2(g) at high pH, and O 2(aq) ≈ magnetite > hematite ≈ goethite > NO 3- ≈ NO 2- ≈ S ≈ pyrite ≈ SO 4-2 at low pH. Many reactions that are favorable sources of chemical energy at one

  11. Geochemical barriers of manganese distribution in edaphotopes of Dnieper Prysamarye

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    N. N. Tsvetkova

    2015-01-01

    Full Text Available Microelement composition is an important condition of edaphotopes as the major, summarizing parts of any biogeocenosis. Microelements in ultra-microquantity are necessary for vital functions of all organisms, but their anthropogenic accumulation and transformation in soil environment represents a real threat for living organisms’ health and stability of the biosphere as a whole. Geochemical barriers are local zones where the conditions of elemental migration are significantly different, resulting in accumulation of some chemical elements. The relevance of geochemical barriers’ study consists in the prospective possibility of artificial limitation of the migration of polluting elements in the environment. The aim of this research is to determine the role of geochemical barriers in distribution and migration of manganese in edaphotopes of Dnieper Prysamarye. Content of manganese in soils, regularity of its distribution and relationship between a number of physical and chemical properties of soils were considered in the course of investigation. Besides, this paper summarizes the main features and regularities of the different geochemical barriers’ formation. Manganese content in soils was analyzed by atomic absorption spectrophotometry. The objects of the research are edaphotopes of the biogeocenoses of Dnieper Prisamarye situated in steppe zone of Ukraine, subzone of forb-fescue-stipa steppe. According to our data, the average concentrations of manganese in the horizons of 0–50 cm of ordinary chernozem, alkaline-saline meadow-forest soil, floodplain meadow-forest and sod upland soils are 495 ± 24, 610 ± 223, 810 ± 220, 51 ± 11 mg/kg of ovendry weight soil, respectively. Furthermore, the authors investigated the correlation between the content of manganese and absorption capacity, humus content, composition of exchange cations, pH and dry residue of soils under study. The results obtained demonstrate that specific soil horizons can be

  12. Geochemical and geophysical investigations, and fluid inclusion studies in the exploration area of Zafarghand (Northeast Isfahan, Iran

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    Zahra Alaminia

    2017-11-01

    concentration should also be combined with other exploration methods to identify mineralization in the Zafarghand district. Quartz veins are classified as V1 and V2 (Fig. 3G. Based on the properties of quartz hydrothermal fluids in the Zafarghand district, they are interpreted to have evolved in two-types of fluid fields (Fig. 7: - Stage 1 fluid inclusion: This inclusion included 32 to 43 wt percent NaCl eqv (high salinity and homogenizing between 328° and 550°C. Primary quartz in stage 1 veins (V1 is poor inclusion and associated with sulfide minerals. It can be represented by fluids trapped during aporphyry- system episode. - Stage 2 fluid inclusion. This inclusion typically contains <5 wt percent NaCl eqv (low salinity and homogenizing between 123° and 391°C. Quartz in stage 2 veins (V2 is characterized by milky color and inclusion rich. Low temperature, low salinity fluid inclusions demonstrate the last hydrothermal event. A possible origin for vapor-liquid inclusions in quartz veins (V2 could be explained by mixing of magma-related fluids with ground water. References Aitchison, J., 1986. The Statistical Analysis of Compositional Data. Chapman and Hall, London, 416 pp. Bodnar, R.J., 1993. Revised equation and table for determining the freezing point depression of H2O-NaCl solutions. Geochimica et Cosmochimica Acta, 57(3: 683–684. Chen, J., Chen, R., Mao, Z., Yang, H., Zhang, Ch. and Han, R., 2016. Regional mineral resources assessment based on rasterized geochemical. Ore Geology Reviews, 74: 15–25. Cheng, Q., 2007. Mapping singularities with stream sediment geochemical data for prediction of undiscovered mineral deposits in Gejiu, Yunnan Province, China. Ore Geology Reviews, 32(1-2: 314–324. Goldstein, R.H. and Reynolds, T.J., 1994. Systematics of fluid inclusions in diagenetic minerals: SEPM Short Course 31. Society for sedimentary geology, United states of America, 213 pp. Sun, X., Deng, J., Gong, Q., Wang, Q., Yang, L. and Zhao, Z., 2009. Kohonen neural

  13. Geologic influences on the distribution of potentially hazardous trace elements in lignites, Gulf Coast Province, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, P.D.; Crowley, S.S.; San Filipo, J.R. [Geological Survey, Reston, VA (United States)

    1997-12-31

    As a part of the National Coal Assessment Project of the US Geological Survey (USGS), the authors are characterizing the quantity and quality of coals expected to be mined during the next quarter century in the Gulf Coast Province (Gulf of Mexico coastal plain area) of the US. The primary areas of interest are within the states of Texas, Louisiana, and Mississippi. However, a recently compiled map of the Gulf Province shows that the coal-bearing rocks in the region extend into the adjoining states of Arkansas, Tennessee, and Alabama. The major interval of study is the Wilcox Group (Paleocene-Eocene); other selected coal-producing intervals (such as Upper Cretaceous rocks, and the Eocene Jackson and Claiborne Groups) that are producing or have potential for producing coal will also be investigated. In the National Coal Assessment Project, the authors are particularly interested in the distribution of potentially hazardous air pollutant elements (As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) that were cited by the US Clean Air Act Amendments of 1990. The goal is to produce a regional stratigraphic and geochemical database that is accessible through Geographic Information Systems and the World Wide Web. Most of the coal in the Gulf Province is lignite produced from the Wilcox Group and is used as fuel for mine-mouth electric-power generating plants. Gulf Coast coal quality is generally below that of other major coal-producing regions of the US; mean values (on an as-received basis) for the mined Gulf Province coals are: ash yield, 16%; sulfur content, 1 %; and calorific value of 15 MJ/kg. The province produces about 60 million short tons of coal annually from the states of Texas and Louisiana. Coal production is expected to expand to other states in the province in the near future. Geochemical data (about 250 samples) have been obtained from the coal mining industry, and the archives of USGS National Coal Resource Data System (NCRDS), which contains data

  14. A geochemical study of the Rio Pantanos area, Department of Antioquia, Colombia preliminary report

    Science.gov (United States)

    Alminas, Henry V.; Mosier, Elwin L.

    1972-01-01

    Geochemical sampling in the Western Cordillera has delineated an 18 km 2 area anomalous in copper, molybdenum, and silver. Highly anomalous metal contents are found in stream sediment, soil, and outcrop samples collected within this area. The area is underlain by intrusive granodiorite to quartz diorite that has porphyritic and granitoid phases. Most of the outcrop samples contain disseminated pyrite, chalcopyrite, and bornite. A geochemical reconnaissance sampling program in the Western Cordillera, formulated by Andros Jimeno V., Director, Instituto National de Investigaciones Geologico-Mineras (INGEOMINAS), and Earl M. Irving, U. S. Geological Survey (USGS) Chief of Party in Colombia, was carried out from 1969 to 1971 by geologists of the INGEOMINAS office in Medellin. This work was part of a cooperative program of INGEOMINAS and the USGS sponsored by the Government of Colombia and the Agency for International Development, U. S. Department of State. Seventeen generally east-trending traverses were completed across the Western Cordillera. These traverses, generally paralleling major drainages, cross the range at intervals of 10 to 30 km.

  15. Multi-element geochemical mapping in Southern China.

    Science.gov (United States)

    Cheng, Zhizhong; Xie, Xuejing; Yao, Wensheng; Feng, Jizhou; Zhang, Qin; Fang, Jindong

    2014-04-01

    The 76-element Geochemical Mapping (76 GEM) Project was undertaken in southwestern China in 2000 and in southeastern China in 2008. In this project, 5244 composite samples of stream sediment at a density of one composite sample for each 1:50,000-scale map sheet were prepared from sample archives of the China Regional Geochemistry-National Reconnaissance (RGNR) Project, which have been available since 1978. The 76 elements were analyzed by using inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). In the present study, a new quality-control method known as the visualized standard map method was applied to the results of the 76 GEM project. Mean value and background value, which indicate the average concentration of the 76 elements in southern China, were derived from statistical data. Moreover, geochemical maps were compiled to demonstrate the distribution of the 76 elements in southern China.

  16. Geochemical barriers for environment protection and recovery of nonferrous metals.

    Science.gov (United States)

    Chanturiya, Valentine; Masloboev, Vladimir; Makarov, Dmitriy; Nesterov, Dmitriy; Bajurova, Julia; Svetlov, Anton; Men'shikov, Yuriy

    2014-01-01

    A study of natural minerals, ore tailings and their products as materials for artificial geochemical barriers is presented. In particular, it focuses on interaction between calcite and dolomite and sulfate solutions containing nickel, copper and iron under static conditions. Calcite of -0.1 mm fraction has been shown to perform well as a barrier when added to water phases of tailing dumps and natural reservoirs. Experiments under dynamic conditions have revealed a high potential of thermally activated copper-nickel tailings as barriers. After a 500-day precipitating period on a geochemical barrier, the contents of nickel and copper in ore dressing tailings were found to increase 12- and 28-fold, respectively. An effective sorbent of copper, iron and nickel ions is a brucite-based product of hydrochloric acid treatment of vermiculite ore tailings. Its sorption capacity can be essentially increased through thermal activation.

  17. Petrogenesis and tectonic setting of the Roman Volcanic Province, Italy

    Science.gov (United States)

    Beccaluva, L.; Di Girolamo, P.; Serri, G.

    1991-01-01

    The volcanism in the Roman Province of Italy can be modelled by the partial melting of heterogeneously enriched mantle sources. The heterogeneity was created by materials derived from a subducted slab which can still be traced geophysically beneath the central Apennines. New petrographical and chemical data are presented for the high-K calc-alkaline and the shoshonitic volcanics of the Campania region. Primary magmas are present only locally. The existence of spatial zonation in the volcanism of Campania is documented for the first time. The shoshonitic, leucite-basanitic and leucititic volcanics of the Phlegraean Fields-Procida-Ischia and the Somma-Vesuvius areas are, at similar degrees of evolution, about two times richer in Nb and Ba than those of northwestern Campania and the Latium part of the Roman Province. Accordingly, distinct north-western and south-eastern subprovinces can be defined. The evaluation of enrichment factors, that is the abundance ratio between the average contents of each element in the relatively primitive lavas of the low K- and the high K suites, shows that the mantle sources prior to K-metasomatism were different in the two sub-provinces of the Roman Province. In the north-western one, they resembled the sources of ocean-island tholeiites and moderately enriched MOR-basalts. In the south-east they were similar to those of ocean island alkaline lavas and enriched MORB's. Modelling based on K, P, Ce, Sr, Rb, Ba, Th, Sm, Eu, Gd, Y, Nb and {87 Sr}/{86 Sr} was carried out. It indicates that the range of mantle sources of the volcanics in northwestern Campania and Latium can be modelled by the addition of 3 to 20% of materials derived by partial melting of carbonaceous pelites to a Sr-enriched mantle wedge comparable to the Honolulu mantle source least enriched in Nb. The production of Sr-enriched mantle wedge requires either the action of fluids produced by dehydration of subducted oceanic crust, or a small amount of metasomatism caused by

  18. Geochemistry and petrogenesis of mafic-ultramafic suites of the Irindina Province, Northern Territory, Australia: Implications for the Neoproterozoic to Devonian evolution of central Australia

    Science.gov (United States)

    Wallace, Madeline L.; Jowitt, Simon M.; Saleem, Ahmad

    2015-10-01

    Petrological and geochemical data for magmatic mafic-ultramafic suites of the Irindina and Aileron provinces of the Eastern Arunta region, Northern Territory, Australia constrain the petrogenesis and tectonic setting of magmatic events covering ~ 500 million years. Six geochemically distinct magmatic suites, here named A-F, have been identified and provide evidence of the tectonic history of this region and also are linked to two mineralisation-related magmatic events: the Lloyd Gabbro (Ni-Cu-PGE mineralisation) and the Riddoch Amphibolite (Cyprus-style Cu-Co volcanogenic massive sulphide mineralisation). The whole-rock geochemistry of Suites A and F is indicative of melts derived from a range of mantle depths (garnet to spinel lherzolite) and source enrichment. Suite D is likely related to the ~ 1070 Ma Warakurna/Giles event of central Australia, including the Alcurra (Musgrave) and Stuart (Arunta) dyke swarms, and likely formed through either: a) melting of subduction modified, sub-continental lithospheric mantle (SCLM) by an upwelling mantle plume; or b) a combination of intra-plate tectonic processes involving a long-lived thermal anomaly, lithospheric-scale architecture that focussed magmatism, and large-scale tectonism. Suite F represents more alkaline magmas, derived from a deeper source, but most likely formed during the same Warakurna LIP event (possibly contemporaneously) as Suite D. Suite E (the Riddoch Amphibolite) was most likely emplaced in a back-arc basin (BAB) setting at ~ 600 Ma, coincident with Delamerian subduction and BAB formation along the eastern Proterozoic margin of Australia from Queensland to the eastern Arunta and possibly further south. Subsequent destabilisation of the SCLM underneath the North Australian Craton generated the ~ 510 Ma Kalkarindji LIP in the form of Suite B intrusions that assimilated some of the older Suite E (Riddoch) material. This event is locally known as the ~ 506 Ma Stanovos Igneous Suite and represents the most

  19. Epidemiology of Ectopic Pregnancy in Hamadan Province

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    Fatemeh Shobeiri

    2012-04-01

    Full Text Available Background: The blastocyst implantation in any place other than uterus cavity endometrium is called ectopic pregnancy. The prevalence of ectopic pregnancy is different in various countries. This study has been conducted to investigate the epidemiology of ectopic pregnancy in Hamadan province during 2000-2010.Materials and Methods: The present study is a retrospective descriptive study. The data on 872 ectopic pregnancies were extracted by questionnaires from the files in the records department of hospitals and delivery centers in Hamadan province during 2000-2010. Data were analyzed using descriptive statistics and the obtained data were analyzed using SPSS-16 software.Results: The frequency of ectopic pregnancy in Hamadan province during 2000-2010 was averagely 2.6 per 1000 pregnancies. Tubal pregnancy with 95.2% is the most prevalent type of ectopic pregnancy most of which had occurred in the right tube (52.4%. Most ectopic pregnancies (52.2% were in the age group of 25-34.Conclusion: The prevalence of ectopic pregnancy in Hamadan province during the mentioned years has been 2.6 in 1000 pregnancies, which is lower compared to many existing data. However, the prevalence of ectopic pregnancy in this province has increased over time, so that it has become 3.3 times as much from 2000-2010.

  20. A Cenozoic diffuse alkaline magmatic province (DAMP) in the southwest Pacific without rift or plume origin

    Science.gov (United States)

    Finn, Carol A.; Müller, R. Dietmar; Panter, Kurt S.

    2005-02-01

    Common geological, geochemical, and geophysical characteristics of continental fragments of East Gondwana and adjacent oceanic lithosphere define a long-lived, low-volume, diffuse alkaline magmatic province (DAMP) encompassing the easternmost part of the Indo-Australian Plate, West Antarctica, and the southwest portion of the Pacific Plate. A key to generating the Cenozoic magmatism is the combination of metasomatized lithosphere underlain by mantle at only slightly elevated temperatures, in contrast to large igneous provinces where mantle temperatures are presumed to be high. The SW Pacific DAMP magmatism has been conjecturally linked to rifting, strike-slip faulting, mantle plumes, or hundreds of hot spots, but all of these associations have flaws. We suggest instead that sudden detachment and sinking of subducted slabs in the late Cretaceous induced Rayleigh-Taylor instabilities along the former Gondwana margin that in turn triggered lateral and vertical flow of warm Pacific mantle. The interaction of the warm mantle with metasomatized subcontinental lithosphere that characterizes much of the SW Pacific DAMP concentrates magmatism along zones of weakness. The model may also provide a mechanism for warming south Pacific mantle and resulting Cenozoic alkaline magmatism, where the oceanic areas are characterized primarily, but not exclusively, by short-lived hot spot tracks not readily explained by conventional mantle plume theory. This proposed south Pacific DAMP is much larger and longer-lived than previously considered.

  1. Trace elements assessment in agricultural and desert soils of Aswan area, south Egypt: Geochemical characteristics and environmental impacts

    Science.gov (United States)

    Darwish, Mohamed Abdallah Gad; Pöllmann, Hebert

    2015-12-01

    Determination of chemical elements, Al, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, Sc, Sr, Ti, Y, and Zn have been performed in agricultural and desert soils and alfalfa (Medicago sativa) at Aswan area. Consequently, the pollution indices, univariate and multivariate statistical methods have been applied, in order to assess the geochemical characteristics of these elements and their impact on soil environmental quality and plant, and to reach for their potential input sources. The investigation revealed that the mean and range values of all element concentrations in agricultural soil are higher than those in desert soil. Furthermore, the agricultural soil displayed various degrees of enrichment and pollution of Cd, Zn, Mo, Co, P, Ti, Pb. The geochemical pattern of integrated pollution indices gave a clear image of extreme and strong pollution in the agricultural soil stations, their poor quality with high risk to human health and considered as a tocsin for an alert. In contrast, the desert soil is the good environmental quality and safe for plant, animal and human health. Alfalfa is tolerant plant and considered as a biomarker for P and Mo in polluted agricultural soil. Four geochemical associations of analyzing elements in agricultural soil and three ones in desert soil have been generated, and their enhancements were essentially caused by various anthropogenic activities and geogenic sources. The investigation also revealed that the broad extended desert soil is fruitful and promising as cultivable lands for agricultural processes in the futures.

  2. Geochemical and geophysical approach to the Tenerife (Canary Islands) anomalous seismic swarm on the 2nd October 2016

    Science.gov (United States)

    Luengo-Oroz, Natividad; Torres-González, Pedro; Domíguez Cerdeña, Itahiza; Moure, David; Villasante-Marcos, Víctor; Jiménez-Mejías, María; del Fresno, Carmen; García-Cañada, Laura

    2017-04-01

    On the 2nd October 2016, anomalous seismic activity took place in the volcanic island of Tenerife. During 5 hours, 96 low magnitude earthquakes (manually detected showing a high correlation between their waveforms. Relocation by double differences shows all hypocenters situated in a small cluster with a radius of a few hundred meters. Magnitudes ranged between 0 and 0.9 but the time evolution shows a variation in narrow bands of ±0.2 magnitudes. In order to better understand the origin and main causes of such anomalous behavior in the volcanic island, data obtained from different volcano monitoring techniques were analyzed. GPS deformation data did not show anomalous changes related to the studied phenomena. In the aim of this interdisciplinary interpretation, available geochemical data from the IGN volcano monitoring network were also revised. Values of several geochemical parameters previous to the seismic swarm have been studied. Chemical and isotopic analysis from fumaroles and soil gases, groundwater physicochemical parameters, CO2 diffuse emissions from the soil, Rn and CO2 concentrations inside a gallery and soil temperature in the summit of Teide volcano did not revealed significant geochemical changes clearly related to the seismic activity on the 2thOctober 2016. However, this conclusion could be reconsidered in the future since upcoming events may show new insights into past circumstances.

  3. Geochemical Gradients and the Supply Side of Habitability

    Science.gov (United States)

    Shock, E. L.

    2005-12-01

    One way to quantify habitability is to evaluate the ratio of the power supply from an environment to the power demand of the organisms that live there. Conditions at which this ratio is maximized provide ample power for growth and reproduction, and can be considered to be highly habitable. In contrast, conditions at which this ratio approaches one qualify as extreme. Characteristics of extreme environments that meet this definition include a variety of stresses that can be assessed by studying the response of organisms to the factors that determine the power supply. It follows that quantifying habitability in chemosynthetic communities awaits the development of a geochemically-derived analysis of physiology. Meanwhile, it is presently possible to evaluate the supply side of the habitability ratio, which may help to identify those conditions where habitability can ultimately be quantified. Guidance may be provided by the hypothesis that there is likely to be a close positive correlation between the presence of strong gradients in an environment and the magnitude and variance of habitability. Microbial communities in ecosystems supported by hot springs undergo dramatic population changes as boiling water flows, cools, spreads out, becomes capable of supporting photosynthesis, and ultimately hosts grazers of photosynthetic mats and their predators. In the high temperature portions of these systems, where photosynthesis is inhibited, power supplies can be assessed from thermodynamic analysis of compositional data. In this analysis, power supply is evaluated by factoring the energy per mole of electrons transferred in metabolic reactions with the concentrations of the limiting constituents of those reactions and fluid flow rates. Chemical power supplies in hydrothermal ecosystems that are tapped by microbial communities at Yellowstone National Park tend to fall in the range of 0.1 to 100 watts. In general, reactions in which O2 is the electron acceptor fall at the upper

  4. Adaptive Multiscale Modeling of Geochemical Impacts on Fracture Evolution

    Science.gov (United States)

    Molins, S.; Trebotich, D.; Steefel, C. I.; Deng, H.

    2016-12-01

    Understanding fracture evolution is essential for many subsurface energy applications, including subsurface storage, shale gas production, fracking, CO2 sequestration, and geothermal energy extraction. Geochemical processes in particular play a significant role in the evolution of fractures through dissolution-driven widening, fines migration, and/or fracture sealing due to precipitation. One obstacle to understanding and exploiting geochemical fracture evolution is that it is a multiscale process. However, current geochemical modeling of fractures cannot capture this multi-scale nature of geochemical and mechanical impacts on fracture evolution, and is limited to either a continuum or pore-scale representation. Conventional continuum-scale models treat fractures as preferential flow paths, with their permeability evolving as a function (often, a cubic law) of the fracture aperture. This approach has the limitation that it oversimplifies flow within the fracture in its omission of pore scale effects while also assuming well-mixed conditions. More recently, pore-scale models along with advanced characterization techniques have allowed for accurate simulations of flow and reactive transport within the pore space (Molins et al., 2014, 2015). However, these models, even with high performance computing, are currently limited in their ability to treat tractable domain sizes (Steefel et al., 2013). Thus, there is a critical need to develop an adaptive modeling capability that can account for separate properties and processes, emergent and otherwise, in the fracture and the rock matrix at different spatial scales. Here we present an adaptive modeling capability that treats geochemical impacts on fracture evolution within a single multiscale framework. Model development makes use of the high performance simulation capability, Chombo-Crunch, leveraged by high resolution characterization and experiments. The modeling framework is based on the adaptive capability in Chombo

  5. Geochemical and geophysical monitoring activities in Campo de Calatrava Volcanic Field (Spain)

    Science.gov (United States)

    Luengo-Oroz, Natividad; Villasante-Marcos, Víctor; López-Díaz, Rubén; Calvo, Marta; Albert, Helena; Domínguez Cerdeña, Itahiza

    2017-04-01

    The Campo de Calatrava Volcanic Field (CCVF) or Spanish Central Volcanic Zone is located in central continental Spain (Ciudad Real province) and covers about 5000 km2. It includes around 240 eruptive centers, mainly monogenetic basaltic cones but also explosive maar structures. According to K-Ar geochronology, its main activity phase occurred during Pliocene and Pleistocene epochs (between 5 and 1.7 Ma) and involved alkaline to ultraalkaline magmas, although an older ultrapotassic phase is dated around 8.7-6.4 Ma. However, some recent works have proposed Holocene ages for some of the volcanic products, opening the possibility of considering the CCVF "active" according to international standards. Responding to this situation, the Instituto Geográfico Nacional (IGN) has initiated geochemical and geophysical monitoring activities in the CCVF. Here, we describe these ongoing efforts and we report results about groundwater geochemistry at several natural highly-gaseous springs in the area (hervideros), as well as soil temperature, CO2 diffuse flux from the soil and electrical self-potential data mapped on a small degassing structure called La Sima. In order to analyze microseismicity or any seismic anomaly in the CCVF, a seismic station has also been installed close to this degassing structure. Physicochemical parameters (temperature, pH, Eh and electric conductivity) were measured in situ in four springs and samples were taken in order to analyze major ions and trace elements. Total composition of dissolved gases and helium isotopic ratios were also determined. To complete soil temperature, self-potential and gas prospections performed in La Sima, soil gases were sampled at the bottom of the structure at a depth of 20 cm. Analysis of the total gas composition found 957400 ppm of CO2. Low values of O2 and N2 were also detected (5600 and 24800 ppm respectively).

  6. Experiences of mothers of sexually abused children in North-West province, post disclosure

    National Research Council Canada - National Science Library

    Masilo, Gaboipolelwe M; Davhana-Maselesele, Mashudu

    2016-01-01

    ... of mothers of sexually abused children post disclosure of the abuse. Method: The research design was qualitative, exploratory, descriptive and contextual. Purposive sampling was used to select mothers of sexually abused children aged 23 to 59 years whose children ranged from 0 to 16 years. Permission to conduct the study was sought from the Provinc...

  7. CURCULIONOIDEA FROM GOLESTAN PROVINCE, NORTHERN IRAN (Coleoptera

    Directory of Open Access Journals (Sweden)

    Hassan Ghahari

    2012-04-01

    Full Text Available The 195 species of Curculionoidea (Coleoptera thus far indicated from Golestan province (northern Iran according to both literature and original records are listed in this paper. New data for 61 species belonging to 18 genera collected during this research are also given. Besides the 42 species newly reported for the Golestan province, the following additional 15 species are newly recorded from Iran: Brachypera lunata, Ceutorhynchus anatolicus, Datonychus urticae, Hypera contaminata, Hypera viciae, Larinus canescens, L. adspersus, Lixus ascanii, Microplontus rugulosus, Neoglocianus smyrnensis, Otiorhynchus tetrarchus, O. scitus, Tychius cuprifer, T. picirostris, T. thoracicus.

  8. PHAST Version 2-A Program for Simulating Groundwater Flow, Solute Transport, and Multicomponent Geochemical Reactions

    Science.gov (United States)

    Parkhurst, David L.; Kipp, Kenneth L.; Charlton, Scott R.

    2010-01-01

    The computer program PHAST (PHREEQC And HST3D) simulates multicomponent, reactive solute transport in three-dimensional saturated groundwater flow systems. PHAST is a versatile groundwater flow and solute-transport simulator with capabilities to model a wide range of equilibrium and kinetic geochemical reactions. The flow and transport calculations are based on a modified version of HST3D that is restricted to constant fluid density and constant temperature. The geochemical reactions are simulated with the geochemical model PHREEQC, which is embedded in PHAST. Major enhancements in PHAST Version 2 allow spatial data to be defined in a combination of map and grid coordinate systems, independent of a specific model grid (without node-by-node input). At run time, aquifer properties are interpolated from the spatial data to the model grid; regridding requires only redefinition of the grid without modification of the spatial data. PHAST is applicable to the study of natural and contaminated groundwater systems at a variety of scales ranging from laboratory experiments to local and regional field scales. PHAST can be used in studies of migration of nutrients, inorganic and organic contaminants, and radionuclides; in projects such as aquifer storage and recovery or engineered remediation; and in investigations of the natural rock/water interactions in aquifers. PHAST is not appropriate for unsaturated-zone flow, multiphase flow, or density-dependent flow. A variety of boundary conditions are available in PHAST to simulate flow and transport, including specified-head, flux (specified-flux), and leaky (head-dependent) conditions, as well as the special cases of rivers, drains, and wells. Chemical reactions in PHAST include (1) homogeneous equilibria using an ion-association or Pitzer specific interaction thermodynamic model; (2) heterogeneous equilibria between the aqueous solution and minerals, ion exchange sites, surface complexation sites, solid solutions, and gases; and

  9. Tectonic setting and metallogenesis of volcanogenic massive sulfide deposits in the Bonnifield Mining District, Northern Alaska Range: Chapter B in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Aleinikoff, John N.; Premo, Wayne R.; Paradis, Suzanne; Lohr-Schmidt, Ilana; Gough, Larry P.; Day, Warren C.

    2007-01-01

    This paper summarizes the results of field and laboratory investigations, including whole-rock geochemistry and radiogenic isotopes, of outcrop and drill core samples from volcanogenic massive sulfide (VMS) deposits and associated metaigneous rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range (see fig. 1 of Editors’ Preface and Overview). U-Pb zircon igneous crystallization ages from felsic rocks indicate a prolonged period of Late Devonian to Early Mississippian (373±3 to 357±4 million years before present, or Ma) magmatism. This magmatism occurred in a basinal setting along the ancient Pacific margin of North America. The siliceous and carbonaceous compositions of metasedimentary rocks, Precambrian model ages based on U-Pb dating of zircon and neodymium ages, and for some units, radiogenic neodymium isotopic compositions and whole-rock trace-element ratios similar to those of continental crust are evidence for this setting. Red Mountain (also known as Dry Creek) and WTF, two of the largest VMS deposits, are hosted in peralkaline metarhyolite of the Mystic Creek Member of the Totatlanika Schist. The Mystic Creek Member is distinctive in having high concentrations of high-field-strength elements (HFSE) and rare-earth elements (REE), indicative of formation in a within-plate (extensional) setting. Mystic Creek metarhyolite is associated with alkalic, within-plate basalt of the Chute Creek Member; neodymium isotopic data indicate an enriched mantle component for both members of this bimodal (rhyolite-basalt) suite. Anderson Mountain, the other significant VMS deposit, is hosted by the Wood River assemblage. Metaigneous rocks in the Wood River assemblage span a wide compositional range, including andesitic rocks, which are characteristic of arc volcanism. Our data suggest that the Mystic Creek Member likely formed in an extensional, back-arc basin that was associated with an outboard continental-margin volcanic arc that included

  10. Interface Induced Carbonate Mineralization: A Fundamental Geochemical Process Relevant to Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Teng, H. Henry [PI, The George Washington University; Xu, Huifang [Co-PI, University of Wisconsin-Madison

    2013-07-17

    We have approached the long-standing geochemical question why anhydrous high-Mg carbonate minerals (i.e., magnesite and dolomite) cannot be formed at ambient conditions from a new perspective by exploring the formation of MgCO{sub 3} and Mg{sub x}Ca{sub (1-x)}CO{sub 3} in non-aqueous solutions. Data collected from our experiments in this funding period suggest that a fundamental barrier, other than cation hydration, exists that prevents Mg{sup 2+} and CO{sub 3}{sup 2-} ions from forming long-range ordered structures. We propose that this barrier mainly stems from the lattice limitation on the spatial configuration of CO{sub 3} groups in magnesite crystals. On the other hand, the measured higher distribution coefficients of Mg between magnesian calcites formed in the absence and presence of water give us a first direct proof to support and quantify the cation hydration effect.

  11. Influence of ammonia on leaching behaviors of incineration fly ash and its geochemical modeling

    DEFF Research Database (Denmark)

    Astrup, Thomas Fruergaard; Guan, Zhen Zhen; Chen, De Zhen

    2013-01-01

    Incineration fly ash could be contaminated with NH3 that was slipped from the ammonia-based selective non-catalytic reduction(SNCR) process and from evaporation of municipal solid wastes' leachate involved in the wastes. This research was conducted to investigate the impacts of ammonia on leaching...... of dissolved organic carbon (DOC) and metals from incineration fly ash in the pH range of 3.66-12.44 with an active ammonia spike. A geochemical modeling software Visual MINTEQ was adopted to calculate the chemical speciation of metals under the leaching conditions to reveal the mechanism behind the impacts...... by precipitation/dissolution and surface complexation/precipitation processes; Visual MINTEQ modeling could well describe the leaching behaviors of Al, Cu, Pb and Zn from incineration fly ash....

  12. PRELIMINARY GEOID MODEL IN SAN JUAN PROVINCE: A CASE STUDY IN THE ANDES

    DEFF Research Database (Denmark)

    Tocho, Claudia; Miranda, Silvia; Pacino, Maria Cristina

    2008-01-01

    A high-resolution and high-precision detailed gravimetric geoid has been computed for San Juan province in Argentina, ranging from 27 degrees S to 34 degrees S in latitude and 72 degrees W to 65 degrees W in longitude. The gravimetric geoid was calculated using the RTM method, a multiband spherical...... Stokes Fast Fourier Transformation, and the removerestore technique for the spherical harmonic reference field and the terrain. As an external evaluation, the gravimetric quasigeoid/geoid was compared to the geoid heights obtained from 90 GPS/levelling points available for the province. Finally, a GPS...

  13. Evaluating soil mineral and geochemical variations in Alaska using a geo-tectonic framework

    Science.gov (United States)

    Wang, B.; Hults, C.; Woodruff, L. G.; Cannon, W.; Gough, L.

    2016-12-01

    A geo-tectonic framework for Alaska provides context for understanding mineral and geochemical variability along a 1400 km-long soil transect across the state. Soils in Alaska are typically poorly developed, suggesting that bulk mineralogy and geochemistry characteristics will reflect primary minerals inherited from the parent material. Most of the parent material along the transect is alluvial, glacial, or eolian unconsolidated sediment derived from a variety of source rocks. The diversity of potential parent-material source rocks necessitates a regional geologic framework for understanding the minerology and geochemical variability because the transect crosses major structural features and distinct lithotectonic domains. We parsed sites into five tectonic affinities. When the soil mineralogy is plotted on a quartz (Q) - plagioclase feldspar (P) - K-feldspar (K) diagram all samples are displaced toward the quartz-plagioclase axis. Soil mineralogy in samples from the Arctic Coastal Plain, Arctic foothills, and the Brooks Range are typically dominated by quartz (>90%) and have a chemical index of alteration (CIA) of 70 to 80. Low quartz (< 40%) and low CIA values (40 - 50) are typical in samples from the Alaska Range and the Copper River plateau. When the Q-P-K diagram is compared to one of Q-alkali feldspar- CaP it becomes evident that Na-plagioclase minerals are the dominant plagioclase feldspar minerals in soils from the Chugach Mountains while the Copper River plateau has a greater proportion of Ca-plagioclase among all plagioclase minerals. Sample mineralogy is consistent with known lithotectonic assemblages in the suspected source region of the soil parent-material, suggesting the differing CIA indexes reflect an inherited signature that reflects the geologic history of the source rocks. This framework aided interpretation and illustrates the well-established principle that parent-material composition must be considered when evaluating soil processes.

  14. Mafic dikes at Kahel Tabelbala (Daoura, Ougarta Range, south-western Algeria): New insights into the petrology, geochemistry and mantle source characteristics

    Science.gov (United States)

    Mekkaoui, Abderrahmane; Remaci-Bénaouda, Nacéra; Graïne-Tazerout, Khadidja

    2017-09-01

    New petrological, geochemical and Sr-Nd isotopic data of the Late Triassic and Early Jurassic Kahel Tabelbala (KT) mafic dikes (south-western Algeria) offer a unique opportunity to examine the nature of their mantle sources and their geodynamic significance. An alkaline potassic Group 1 of basaltic dikes displaying relatively high MgO, TiO2, Cr and Ni, La/YbN ∼ 15, coupled with low 87Sr/86Sri ∼ 0.7037 and relatively high ɛNd(t) ∼ +3, indicates minor olivine and clinopyroxene fractionation and the existence of a depleted mantle OIB source. Their parental magma was generated from partial melting in the garnet-lherzolite stability field. A tholeiitic Group 2 of doleritic dikes displaying low MgO, Cr and Ni contents, La/YbN ∼ 5, positive Ba, Sr and Pb anomalies, the absence of a negative Nb anomaly coupled with moderate 87Sr/86Sri ∼ 0.7044 and low ɛNd(t) ∼ 0 (BSE-like), indicates a contamination of a mantle-derived magma that experienced crystal fractionation of plagioclase and clinopyroxene. This second group, similar to the low-Ti tholeiitic basalts of the Central Atlantic Magmatic Province (CAMP), was derived from partial melting in the peridotite source within the spinel stability field. Lower Mesozoic continental rifting could have been initiated by a heterogeneous mantle plume that supplied source components beneath Daoura, in the Ougarta Range.

  15. Midwifery workforce profile in Limpopo Province referral hospitals

    Directory of Open Access Journals (Sweden)

    Sam T. Ntuli

    2014-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Background: In sub-Saharan Africa including South Africa, maternal mortality rates remain unacceptably high due to a shortage of registered nurses with advanced midwifery diplomas.Objective: To determine the profile of registered nurses (RNs involved in maternity care in public referral hospitals of the Limpopo Province, South Africa.Method: A cross-sectional descriptive study was conducted in all maternity units of Limpopo’s public referral hospitals. The study population comprised of 210 registered nurses, who became the study sample. Data on their educational profile and work experience in midwifery was analysed using STATA version 9.0.Results: The mean age of the 210 registered nurses was 44.5 ± 9.1 years (range 21 to 62. The majority (152/210; 70% were 40 years and older, 56% (117/210 had been working for more than 10 years, and 63/210 (30% were due to retire within 10 years. Only 22% (46/210 had advanced midwifery diplomas, i.e. after their basic undergraduate training. Only six (2.9% of the RNs providing maternity care in these referral hospitals were studying for advanced midwifery diplomas at the time of the study.Conclusion: This study demonstrated a shortage of registered nurses with advanced midwifery training/diplomas in referral hospitals of the Limpopo Province. This has a potentially negative effect in reducing the high maternal mortality rate in the province.

  16. Syrian Refugees in Turkey and Their Reflections in Gaziantep Province

    Directory of Open Access Journals (Sweden)

    Ersin Kaya SANDAL

    2016-12-01

    Full Text Available The wave of democracy the Arab Spring Caused got started in 18 December 2010, after a university graduate stallholder's stall has been taken hold of and his burning himself to protest government led to o range of event in Tunisia deeply affected Syria by causing populations to pay for this. The Syrian Civil War started in March 2011 and it was seen as a result of Arab Spring, that noteworthy affects this region. But, although it had been a few years the Arab Spring hasn't come to Syria yet. While Syrian people,neighbor countries and the people in the region were all waiting for the spring to come, the rising of the Civil Wars and the affects of military, political and the economics sports of the countries that Syrian Regime politically, economically and commercially aligned with, had been turned into a humanitarian tragedy. As a result of the civil attacks of the Regime of Syrian to his people, around 300.000 people did,around 6.5 million people have been displaced, the numbers of the people need help increased to 10 million and so the number of the Syrian refugees in the neighbor countries reached to 3.795.284. As a result of this civil war in Syria 1.679.963 Syrian Arab Republic citizens have come to our country as refuges since 2011. The number of Syrian refugees reached 326 333 in Gaziantep Province. In this study, distribution by province of Syrian refugees in Turkey, and reflections of refugees in Gaziantep province are analyzed

  17. pplication of Fractal Technique for Analysis of Geophysical - Geochemical Databases in Tekieh Pb-Zn Ore Deposit (SE of Arak

    Directory of Open Access Journals (Sweden)

    Seyed Reza Mehrnia

    2017-02-01

    should emphasize on self-organized distribution of Pb-Zn anomalies to introduce a new set of nonlinear distributions in order to find the confidence regression coefficients between the variables. As the final results, fractal analysis of available databases represented new target areas with better mineralization aggregations than linear analysis of the anomalous regions according to micrographs. It means that surficial mineralization processes could be extended in depth and enriched next to altered host units because of a nonlinear but self-organized distribution of geochemical- geophysical anomalies in Tekieh ore deposit region. References Annells, R.N., Arthurton, R.S., Bazley, R.A.B., Davies, R.G., Hamedi, M.A.R. and Rahimzadeh, F.R., 1985. Geological Map of Shazand- Khomein. Scale: 1:100000, Cartographic Department of Geological Survey of Iran. Calagari, A.A., 2010. Principles of geophysical explorations. University of Tabriz, Tabriz, 485 pp. Jafari, H., 2007. Using geoelectrical techniques for Zn-Pb explorations in Haft-Emarat district, Tekieh region (South East of Arak. Kimya Kavan Tosee Novin Company, Tehran, 206 pp. Mandelbrot, B., 2005. Fractal Geometry of Nature. W.H Freeman & Company, New York, 468 pp. Mehrnia, S.R.,2013. Application of fractal geometry for recognizing the pattern of textural zoning in epithermal deposits: (case study: Shikhdarabad Au-Cu indices East- Azerbaijan province. Journal of Economic Geology, 5(1: 23-36. (in Persian Momenzadeh, M. and Ziseman, H., 1981. Lead – Zinc re mineralization potentials in Malayer – Esfahan district. Journal of Ore Deposit, 3(1: 88-101. Salehi, L., 2004. Geochemistry of REE content in Tekieh Pb-Zn ore deposit. M.Sc. Thesis, Shahid Beheshti University, Tehran, Iran, 181 pp. Torkashvand, S., Mehrnia, S.R. and Moghaddasi, S.J., 2009. Co-Processing of the geophysical parameters for Tekieh Zn-Pb ore deposits (south east of Arak. 4th PNU Geological National Conference, Payam Noor University of Mashhad, Mashhad

  18. Source implications for the different geochemical features of recent basaltic rocks from the northernmost part of the Cappadocian region, Turkey

    Science.gov (United States)

    Kurkcuoglu, Biltan; Yurur, Tekin

    2017-04-01

    Extensive magmatic activities developed since middle-Miocene, in the Cappadocian Region of Central Anatolia in Turkey. The nature and the sources of the magmatism were well-constrained by previous studies. Even though the sources of Strato-volcanoes and monogenetic vents were briefly explained, extremely young basalts (1.22 - 0.094 Ka) situated in northernmost part of Cappadocian Region and erupted between the two extentional faults, are not deeply investigated. Karaburna and Gülşehir lavas (1.22, 0.094 Ka, respectively, Dogan, 2011) are considered as a part of the Central Anatolian Volcanic Province, with extremely young ages, generated either at the final or after the final stage of the Cappadocian systems. These lavas have similar LIL and HFS elements patterns with each other, however, Karaburna samples are more enriched in HFS elements. These basalts also display approximately similar trends in LIL elements ( except Rb) and reflect HFS depletion relative to the OIB signature, moreover, HFS are more enriched compared to the Hasandag basaltic rocks, all these features suggesting, basaltic rocks are originated from the modified mantle source. Karaburna and Gülşehir basalts have low Nb/La (0.45-0.5 ; 0.35-0.42), Nb/Y( 0.33-.39; 0.27-0.44 Nb/Th (2.75-4.6; 1.26-1.68) and high Ba/Nb (22-32; 38-43) ratios suggesting the contributions from the crustal sources, moreoever, Gülşehir basaltic rocks differ from the Karaburna lavas with relatively low Nb/U ( 4.5-6.4) and high Ba/La ( 14.67-17.20) Th/La (0.22-0.27), whereas Karaburna samples are represented by low Ba/La (10.04-14.90) and Th/La (0.09-0.16) ratios, these geochemical features reveal that these differences are originated either from the different degrees of crustal involvement or change in the nature of the source in a short time interval. Of all the most recent basaltic products generated in central Anatolia are alkaline in nature, besides, the trace element content, multi-element patterns and HFS/LIL and

  19. Human rabies in Zhejiang Province, China

    Directory of Open Access Journals (Sweden)

    Jiangping Ren

    2015-09-01

    Conclusions: The majority of rabies cases occurred among 40–65-year-old male residents of northern, mid-west, and southeast Zhejiang Province. Further health education is needed to increase the coverage of post-exposure prophylaxis (PEP in people exposed to possible rabid animals and rabies vaccine use in household animals.

  20. [Factors influencing infant mortality. Havana Province, 1983].

    Science.gov (United States)

    Castell-florit Serrate, P; Portuondo Dustet, N; Suarez Rosas, L; Ovies Garcia, A; Alvarez Fernandez, R; Lima Perez, M T

    1986-01-01

    Questionnaires intended to determine the factors involved in deaths in infants under 1 year have been completed in the province of Havana, Cuba, since 1980. The questionnaires are completed by obstetricians and pediatricians of the municipal health areas and analyzed at the secondary care level. This work examines the factors present in the 133 infant deaths occurring in Havana Province in 1983. The infant mortality rate in the province in 1983 was 14.1/1000 live births, the lowest ever recorded in the province. 74 of the deaths occurred in the early neonatal period, 13 in the late neonatal, and 46 in the postneonatal period. 22 of the early neonatal deaths were due to intrapartum anoxia, 15 to hyaline membrane disease, 10 to prematurity, 7 to bronchoaspiration, 3 to sepsis, 1 to bronchial pneumonia, and 13 to malformations. In the late neonatal and postneonatal periods, 11 deaths were attributed to acute diarrheal disease, 6 to meningitis, and 5 to accidents. 8 of the mothers were under 17 years old, 30 were 18-20, 57 were 21-30, and 16 were 31 or over. Maternal age was unknown for 22. 22 of the mothers were overweight, 29 were malnourished, 55 were of normal nutritional status, and the status of 27 was unknown. 67.7% of the early neonatal deaths were in low birth weight babies. Low educational level and rural residence were social factors in infant mortality.

  1. (Francolinus francolinus) in Khouzestan Province, Southwestern Iran

    African Journals Online (AJOL)

    STORAGESEVER

    2010-06-21

    Jun 21, 2010 ... Habitat destruction and indiscriminate hunting as well as agricultural pesticides are among the most crucial factors threatening the populations of these birds in Khouzestan Province, southwestern Iran. Using plot sampling, this study aims to investigate different vegetative factors including plant species,.

  2. Plume-Lithosphere Interaction in the Ethiopian CFB Province: Breaking up Gondwana

    Science.gov (United States)

    Plummer, C. L.; Furman, T.

    2006-12-01

    The Ethiopia-Yemen continental flood basalt (CFB) province formed 30 Ma and today covers some 600,000 sq. km with an approximate total volume of 350,000 sq. km of basalt and associated rhyolite. The majority of lavas were extruded over about 1 my (Baker et al. 1996; Pik et al. 1998) and have not been subject to tectonism, making this area ideal for study of processes associated with continental break-up, mantle plume impacts and CFB magmatism. The Ethiopian province is the youngest of the Mesozoic CFB occurrences associated with break-up of Gondwana, following the Karoo and Ferrar (180-175 Ma), Parana-Etendeka (134- 132 Ma) and Deccan (67-65 Ma) events. In Ethiopia, as with other Gondwana CFB provinces, basalts have been separated into high titanium (HT) and low titanium (LT) series (Pik et al. 1998). Stratigraphic studies indicate HT and LT units erupted contemporaneously so temporal control cannot explain the chemical variations; Pik et al (1998) drew a NE-SW trending line separating the region into HT and LT sub-provinces. Detailed investigation of new study sites along the SW margin of the flood basalt province (Tesfaye 2006) found interlayered LT and HT units indicating more complex spatial controls. Our investigation of Ethiopian CFBs evaluates source and process heterogeneities that could produce voluminous mafic magmatism in these two distinctive series. To first order the mildly alkalic HT lavas have higher incompatible trace element abundances than the tholeiitic LT basalts (Pik et al. 1998, 1999; Keiffer et al. 2004), suggesting derivation of the former by lower degrees of partial melting at greater pressures (Furman et al. 2006). Sr-Nd-Pb isotopic signatures of the LT and HT series largely overlap with one another and with the modern Afar plume; in detail the highest Ti-lavas (HT2 of Pik et al. 1998) are isotopically and geochemically distinct from LT and HT1 basalts, which form a broad continuum in all representations of data. HT2 basalts have mantle

  3. Occurrence of canine parvovirus in dogs from Henan province of China in 2009-2014.

    Science.gov (United States)

    Zhao, Zhanqin; Liu, Huisheng; Ding, Ke; Peng, Chunping; Xue, Qiao; Yu, Zuhua; Xue, Yun

    2016-07-04

    There is no information concerning the genotype of Canine parvovirus (CPV) currently circulating in Henan province, China. Therefore, the aim of the present study was to provide insights into the epidemiology and molecular characterization of CPV circulating in Henan province from 2009 to 2014. Nineteen thousand nine hundred seven dogs from pet hospitals in the cities of Luoyang, Anyang, Jiaozuo, Sanmenxia, Xinxiang, Zhengzhou in Henan province between 2009 and 2014 were investigated. Over the 6-year period, 1169 CPV-positive cases were identified and the morbidity of CPV infection ranged from 4.16 to 8.06 %, although morbidity was not significant (P > 0.05) between 2009 and 2014. Factors associated with morbidity included sampling season, dog age, breed, vaccination status, and sex. CPV co-infection with coccidium (10.00 %), canine distemper virus (4.79 %), hookworm (2.40 %), canine coronavirus (1.11 %), roundworm (1.03 %), tapeworm (0.17 %) and Babesia spp. (0.09 %) were observed. The new CPV-2a variant was more prevalent than the new CPV-2b variant in Henan province. CPV 2c was not observed in this study. The epidemiology of CPV infection and identification of the circulating genotypes in Henan province, China from 2009 to 2014 determined that the new CPV-2a variant was more prevalent.

  4. Petrological and Geochemical Features of the Neogene Volcanites of the Osogovo Mountains, Eastern Macedonia

    OpenAIRE

    Serafimovski, Todor; Tasev, Goran; DOLENEC, TADEJ

    2006-01-01

    The subject of the presented study was the petrological and geochemical characterization of the Neogene volcanic rocks from the Osogovo Mountains. In this paper we present new results of petrological and geochemical analyses of igneous rocks, mostly from Sasa, Toranica and Ruen. The mineralogical and geochemical characteristics of the studied rocks confirmed the results of some previous investigations that indicated that the exposed lithologies are mostly dacites, quartzlatites, trachyandesit...

  5. Geologic Provinces of the Caribbean Region, 2004 (prv6bg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset includes a modified subset of polygon features that describe U.S. Geological Survey's defined geologic provinces of the World. Each province has a set...

  6. A carbonate-silicate aqueous geochemical cycle model for Mars

    Science.gov (United States)

    Schaefer, M. W.; Leidecker, H.

    1992-01-01

    A model for the carbonate-silicate geochemical cycle of an early, wet Mars is under development. The results of this study will be used to constrain models of the geochemical history of Mars and the likely mineralogy of its present surface. Although Mars today is a cold, dry planet, it may once have been much warmer and wetter. Values of total outgassed CO2 from several to about 10 bars are consistent with present knowledge (Pollack et al. 1987), and this amount of CO2 implies an amount of water outgassed at least equal to an equivalent depth of 500-1000 meters (Carr 1986). Pollack et al. (1987), in addition, estimate that a thick CO2 atmosphere may have existed for an extended period of time, perhaps as long as a billion years. The greenhouse effect of such an atmosphere would permit the presence of liquid water on the surface, most likely in the form of a shallow sea in the lowest regions of the planet, such as the northern plains (Schaefer 1990). The treatment of geochemical cycles as complex kinetic chemical reactions has been undertaken for terrestrial systems in recent years with much success (Lasaga 1980, 1981; Berner et al. 1983; Lasaga et al. 1985). Although the Martian system is vastly less well understood, and hence less well-constrained, it is also a much simpler system, due to the lack of biogenic reactions that make the terrestrial system so complex. It should be possible, therefore, to use the same techniques to model the Martian system as have been used for terrestrial systems, and to produce useful results. A diagram of the carbonate-silicate cycle for Mars (simplified from the terrestrial system) is given.

  7. This year`s model: Geochemical modeling and groundwater quality

    Energy Technology Data Exchange (ETDEWEB)

    Tuchfeld, H.A.; Simmons, S.P.; Jesionek, K.S. [GeoSyntec Consultants, Walnut Creek, CA (United States)]|[GeoSyntec Consultants, Atlanta, GA (United States); Romito, A.A. [Browning-Ferris Industries, Inc., Houston, TX (United States)

    1998-07-01

    It has been determined that landfill gas migration is a source of volatile organic compounds (VOCs) in groundwater. This can occur through: direct partitioning of migrating gas constituents into the groundwater; alteration of the physiochemical properties of the groundwater; and by indirect means (such as migration of landfill gas condensate and vadose zone water contaminated by landfill gas). This article examines the use of geochemical modeling as a useful tool for differentiating the effects of municipal solid waste (MSW) landfill gas versus leachate on groundwater quality at MSW landfill sites.

  8. Review of geochemical measurement techniques for a nuclear waste repository in bedded salt

    Energy Technology Data Exchange (ETDEWEB)

    Knauss, K.G.; Steinborn, T.L.

    1980-05-22

    A broad, general review is presented of geochemical measurement techniques that can provide data necessary for site selection and repository effectiveness assessment for a radioactive waste repository in bedded salt. The available measurement techniques are organized according to the parameter measured. The list of geochemical parameters include all those measurable geochemical properties of a sample whole values determine the geochemical characteristics or behavior of the system. For each technique, remarks are made pertaining to the operating principles of the measurement instrument and the purpose for which the technique is used. Attention is drawn to areas where further research and development are needed.

  9. The Geologic and Geochemical Setting of Lago Fagnano, Tierra del Fuego, Argentina

    Science.gov (United States)

    Tingle, D.; Odle, K.; Knettel, P.; Redding, S.; Perry, E.; Ellins, K.; Ormiston, C.; Dovzak, N.; Anderson, S.

    2005-12-01

    Lago Fagnano, Tierra del Fuego, Argentina is the largest and southernmost ice-free lake on Earth. The isolated lake is unique because the geographic and geologic context provides information relating to the westerly wind patterns, interaction of multiple water sources (hot springs, glacial meltwater, precipitation, groundwater), and tectonic dynamics along a major transform fault. In March, 2005, four students and three teachers from Boerne High School, south-central Texas joined scientists from the United States, Argentina and Switzerland engaged in a geophysical survey of this lake. Lago Fagnano potentially contains within its sediments an undisturbed record of the geotectonic and global climate variability of past 20,000 years. The science team imaged the lake floor with a boat specially equipped to collect both high resolution data (high frequency), imaging the upper 10-15 meters of the sediment, and long range data (low frequency), penetrating 100 or more meters into the sediment. The group conducted field research of existing tectonic features at the eastern end of Tierra del Fuego, an activity directly tied to the research objectives of the science team. They also collected water and soil samples to assess chemical and isotopic trends in the Lago Fagnano region. The research performed can help to characterize the modern geochemical setting of the lake. Analyses of dissolved oxygen, NH4+, PO42-, pH (water) and N, P, and pH (soils) demonstrate a link between low nutrient levels and low biodiversity (which was confirmed by observation) in Tierra del Fuego. Water and soil data are incorporated into a database to facilitate comparisons to North American samples collected and analyzed during the Boerne High School summer field courses. Twenty-three ^18O and ^D analyses yielded a south-north isotopic trend across the Lago Fagnano region. ^18O and ^D transition from -11.92 to -3.53% and -87.81 to -40.26%, respectively, moving south to the Beagle Channel. These

  10. National Assessment of Oil and Gas Project - Uinta-Piceance Province (020) Estimated Depth to the Base of the Mesaverde Total Petroleum System

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset shows estimated depth ranges to stratigraphic horizons near the base of the Mesaverde Total Petroleum System, Uinta-Piceance Province, northwestern...

  11. PHAST--a program for simulating ground-water flow, solute transport, and multicomponent geochemical reactions

    Science.gov (United States)

    Parkhurst, David L.; Kipp, Kenneth L.; Engesgaard, Peter; Charlton, Scott R.

    2004-01-01

    The computer program PHAST simulates multi-component, reactive solute transport in three-dimensional saturated ground-water flow systems. PHAST is a versatile ground-water flow and solute-transport simulator with capabilities to model a wide range of equilibrium and kinetic geochemical reactions. The flow and transport calculations are based on a modified version of HST3D that is restricted to constant fluid density and constant temperature. The geochemical reactions are simulated with the geochemical model PHREEQC, which is embedded in PHAST. PHAST is applicable to the study of natural and contaminated ground-water systems at a variety of scales ranging from laboratory experiments to local and regional field scales. PHAST can be used in studies of migration of nutrients, inorganic and organic contaminants, and radionuclides; in projects such as aquifer storage and recovery or engineered remediation; and in investigations of the natural rock-water interactions in aquifers. PHAST is not appropriate for unsaturated-zone flow, multiphase flow, density-dependent flow, or waters with high ionic strengths. A variety of boundary conditions are available in PHAST to simulate flow and transport, including specified-head, flux, and leaky conditions, as well as the special cases of rivers and wells. Chemical reactions in PHAST include (1) homogeneous equilibria using an ion-association thermodynamic model; (2) heterogeneous equilibria between the aqueous solution and minerals, gases, surface complexation sites, ion exchange sites, and solid solutions; and (3) kinetic reactions with rates that are a function of solution composition. The aqueous model (elements, chemical reactions, and equilibrium constants), minerals, gases, exchangers, surfaces, and rate expressions may be defined or modified by the user. A number of options are available to save results of simulations to output files. The data may be saved in three formats: a format suitable for viewing with a text editor; a

  12. Assessment of Wind Energy Potential in Golestan Province of Iran

    Directory of Open Access Journals (Sweden)

    Mehdi Hashemi-Tilehnoee

    2016-02-01

    Full Text Available Renewable energy sources are estimated to have a thriving future in many countries as well as Iran. The aim of this work is the evaluation of wind energy potentiality for the five counties of Golestan province in the northern region of Iran. A long term data source, consisting of  30 years in Gorgan, 22 years in Gonbade-e Qabus, 21 years in Maraveh Tappeh, 9 years in Aliabad, and 7 years in Bandar-e Turkaman of eight-hourly mean wind data, was adopted and analyzed. Mean wind power based on quantified data, Weibull distribution function, the relative percentage error (RPE and wind direction between obtaining values of wind power has been considered. According to these data, it was found that the numerical values of the shape parameter and scale parameter for Golestan varied a tight range. Annual values of ‘‘k’’ ranged from 2.7 to 4.7 where it is constant in different elevation because of better performance of this method in estimating wind energy potential, while annual values of ‘‘c’’ were in the range of 2.6 m/s in 10 m and 7.6 m/s in 40 m. Wind power densities have been estimated and relatively low for large wind turbines. The consequences indicate that in some months Maraveh Tappeh and Bandar-e Turkaman has best wind energy potential, as class 2, in order to establish some small wind turbine models for the sustainable development of Golestan province. Article History: Received Sept 13, 2015; Received in revised form Dec 27, 2015; Accepted January 17, 2016; Available online How to Cite This Article: Babayani, D., Khaleghi, M. and Hashemi-Tilehnoee, M. (2016 Assessment of Wind Energy Potential in Golestan Province of Iran. Int. Journal of Renewable Energy Development, 5(1, 25-31. http://dx.doi.org/10.14710/ijred.5.1.25-31 

  13. Impact of geochemical stressors on shallow groundwater quality

    Science.gov (United States)

    An, Y.-J.; Kampbell, D.H.; Jeong, S.-W.; Jewell, K.P.; Masoner, J.R.

    2005-01-01

    Groundwater monitoring wells (about 70 wells) were extensively installed in 28 sites surrounding Lake Texoma, located on the border of Oklahoma and Texas, to assess the impact of geochemical stressors to shallow groundwater quality. The monitoring wells were classified into three groups (residential area, agricultural area, and oil field area) depending on their land uses. During a 2-year period from 1999 to 2001 the monitoring wells were sampled every 3 months on a seasonal basis. Water quality assay consisted of 25 parameters including field parameters, nutrients, major ions, and trace elements. Occurrence and level of inorganics in groundwater samples were related to the land use and temporal change. Groundwater of the agricultural area showed lower levels of ferrous iron and nitrate than the residential area. The summer season data revealed more distinct differences in inorganic profiles of the two land use groundwater samples. There is a possible trend that nitrate concentrations in groundwater increased as the proportions of cultivated area increased. Water-soluble ferrous iron occurred primarily in water samples with a low dissolved oxygen concentration and/or a negative redox potential. The presence of brine waste in shallow groundwater was detected by chloride and conductivity in oil field area. Dissolved trace metals and volatile organic carbons were not in a form of concentration to be stressors. This study showed that the quality of shallow ground water could be related to regional geochemical stressors surrounding the lake. ?? 2005 Elsevier B.V. All rights reserved.

  14. Multivariate analysis relating oil shale geochemical properties to NMR relaxometry

    Science.gov (United States)

    Birdwell, Justin E.; Washburn, Kathryn E.

    2015-01-01

    Low-field nuclear magnetic resonance (NMR) relaxometry has been used to provide insight into shale composition by separating relaxation responses from the various hydrogen-bearing phases present in shales in a noninvasive way. Previous low-field NMR work using solid-echo methods provided qualitative information on organic constituents associated with raw and pyrolyzed oil shale samples, but uncertainty in the interpretation of longitudinal-transverse (T1–T2) relaxometry correlation results indicated further study was required. Qualitative confirmation of peaks attributed to kerogen in oil shale was achieved by comparing T1–T2 correlation measurements made on oil shale samples to measurements made on kerogen isolated from those shales. Quantitative relationships between T1–T2 correlation data and organic geochemical properties of raw and pyrolyzed oil shales were determined using partial least-squares regression (PLSR). Relaxometry results were also compared to infrared spectra, and the results not only provided further confidence in the organic matter peak interpretations but also confirmed attribution of T1–T2 peaks to clay hydroxyls. In addition, PLSR analysis was applied to correlate relaxometry data to trace element concentrations with good success. The results of this work show that NMR relaxometry measurements using the solid-echo approach produce T1–T2 peak distributions that correlate well with geochemical properties of raw and pyrolyzed oil shales.

  15. Geochemical response to hydrologic change along land-sea interfaces

    Science.gov (United States)

    Michael, H. A.; Yu, X.; LeMonte, J. J.; Sparks, D. L.; Kim, K. H.; Heiss, J.; Ullman, W. J.; Guimond, J. A.; Seyfferth, A.

    2016-12-01

    Coastal groundwater-surface water interfaces are hotspots of geochemical activity, where reactants contributed by different sources come in contact. Reactions that occur along these land-sea boundaries have important effects on fluxes and cycling of carbon, nutrients, and contaminants. Hydrologic perturbations can alter interactions by promoting mixing, changing redox state, and altering subsurface residence times during which reactions may occur. We present examples from field and modeling investigations along the Delaware coastline that illustrate the impacts of hydrologic fluctuations on geochemical conditions and fluxes in different coastal environments. Along the highly populated Wilmington coastline, soils are contaminated with heavy metals from legacy industrial practices. We show with continuous redox monitoring and sampling over tidal to seasonal timescales that arsenic is mobilized and immobilized in response to hydrologic change. Along a beach, modeling and long-term monitoring show the influence of tidal to seasonal changes in the mixing zone between discharging fresh groundwater and seawater in the intertidal beach aquifer and associated impacts on biogeochemical reactivity and denitrification. In a saltmarsh, hydrologic changes alter carbon dynamics, with implications for the discharge of dissolved organic carbon to the ocean and export of carbon dioxide and methane to the atmosphere. Understanding the impacts of hydrologic changes on both long and short timescales is essential for improving our ability to predict the global biogeochemical impacts of a changing climate.

  16. Soil Lysimeter Excavation for Coupled Hydrological, Geochemical, and Microbiological Investigations.

    Science.gov (United States)

    Sengupta, Aditi; Wang, Yadi; Meira Neto, Antonio A; Matos, Katarena A; Dontsova, Katerina; Root, Rob; Neilson, Julie W; Maier, Raina M; Chorover, Jon; Troch, Peter A

    2016-09-11

    Studying co-evolution of hydrological and biogeochemical processes in the subsurface of natural landscapes can enhance the understanding of coupled Earth-system processes. Such knowledge is imperative in improving predictions of hydro-biogeochemical cycles, especially under climate change scenarios. We present an experimental method, designed to capture sub-surface heterogeneity of an initially homogeneous soil system. This method is based on destructive sampling of a soil lysimeter designed to simulate a small-scale hillslope. A weighing lysimeter of one cubic meter capacity was divided into sections (voxels) and was excavated layer-by-layer, with sub samples being collected from each voxel. The excavation procedure was aimed at detecting the incipient heterogeneity of the system by focusing on the spatial assessment of hydrological, geochemical, and microbiological properties of the soil. Representative results of a few physicochemical variables tested show the development of heterogeneity. Additional work to test interactions between hydrological, geochemical, and microbiological signatures is planned to interpret the observed patterns. Our study also demonstrates the possibility of carrying out similar excavations in order to observe and quantify different aspects of soil-development under varying environmental conditions and scale.

  17. Evolution of geochemical conditions in SFL 3-5

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Fred [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Lindgren, M.; Skagius, K.; Wiborgh, M. [Kemakta Konsult AB, Stockholm (Sweden); Engkvist, I. [Barsebaeck Kraft AB (Sweden)

    1999-12-01

    The evolution of geochemical conditions in the repository for long-lived low- and intermediate-level waste, SFL 3-5, and in the vicinity of the repository are important when predicting the retention of radionuclides and the long-term stability of engineered barriers. In this study the initial conditions at different repository sites at 300 - 400 m depth, the influence of repository construction and operation, the expected conditions after repository closure and saturation, and the evolution in a long-term perspective are discussed. Groundwaters that are found at these depths have near-neutral pH and are reducing in character, but the composition can vary from saline to non-saline water. The water chemistry in the near-field will mainly be influenced by the composition of the groundwater and by the large amounts of cementitious material that can be found in the repository. Disturbances caused during construction and operation are not expected to be permanent. Studies of old concrete indicate that leaching of concrete is a slow process. The geochemical conditions in the repository are therefore expected to be stable and prevail for hundreds of thousand years. However, the evolution of the surrounding environment may influence the conditions in long-term perspective.

  18. Stream sediment detailed geochemical survey for Date Creek Basin, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    Butz, T.R.; Tieman, D.J.; Grimes, J.G.; Bard, C.S.; Helgerson, R.N.; Pritz, P.M.

    1980-06-30

    Results of the Date Creek Basin detailed geochemical survey are reported. Field and laboratory data are reported for 239 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Based on stream sediment geochemical data, significant concentrations of uranium are restricted to the Anderson Mine area. The 84th percentile concentrations of U-FL, U-NT, and U-FL/U-NT combined with low thorium/U-NT values reflect increased mobility and enrichment of uranium in the carbonate host rocks of that area. Elements characteristically associated with the uranium mineralization include lithium and arsenic. No well defined diffusion halos suggesting outliers of similar uranium mineralization were observed from the stream sediment data in other areas of the Date Creek Basin. Significant concentrations of U-FL or U-NT found outside the mine area are generally coincident with low U-FL/U-NT values and high concentrations of zirconium, titanium, and phosphorus. This suggests that the uranium is related to a resistate mineral assemblage derived from surrounding crystalline igneous and metamorphic rocks.

  19. Metagenomes from High-Temperature Chemotrophic Systems Reveal Geochemical Controls on Microbial Community Structure and Function

    Science.gov (United States)

    Inskeep, William P.; Rusch, Douglas B.; Jay, Zackary J.; Herrgard, Markus J.; Kozubal, Mark A.; Richardson, Toby H.; Macur, Richard E.; Hamamura, Natsuko; Jennings, Ryan deM.; Fouke, Bruce W.; Reysenbach, Anna-Louise; Roberto, Frank; Young, Mark; Schwartz, Ariel; Boyd, Eric S.; Badger, Jonathan H.; Mathur, Eric J.; Ortmann, Alice C.; Bateson, Mary; Geesey, Gill; Frazier, Marvin

    2010-01-01

    The Yellowstone caldera contains the most numerous and diverse geothermal systems on Earth, yielding an extensive array of unique high-temperature environments that host a variety of deeply-rooted and understudied Archaea, Bacteria and Eukarya. The combination of extreme temperature and chemical conditions encountered in geothermal environments often results in considerably less microbial diversity than other terrestrial habitats and offers a tremendous opportunity for studying the structure and function of indigenous microbial communities and for establishing linkages between putative metabolisms and element cycling. Metagenome sequence (14–15,000 Sanger reads per site) was obtained for five high-temperature (>65°C) chemotrophic microbial communities sampled from geothermal springs (or pools) in Yellowstone National Park (YNP) that exhibit a wide range in geochemistry including pH, dissolved sulfide, dissolved oxygen and ferrous iron. Metagenome data revealed significant differences in the predominant phyla associated with each of these geochemical environments. Novel members of the Sulfolobales are dominant in low pH environments, while other Crenarchaeota including distantly-related Thermoproteales and Desulfurococcales populations dominate in suboxic sulfidic sediments. Several novel archaeal groups are well represented in an acidic (pH 3) Fe-oxyhydroxide mat, where a higher O2 influx is accompanied with an increase in archaeal diversity. The presence or absence of genes and pathways important in S oxidation-reduction, H2-oxidation, and aerobic respiration (terminal oxidation) provide insight regarding the metabolic strategies of indigenous organisms present in geothermal systems. Multiple-pathway and protein-specific functional analysis of metagenome sequence data corroborated results from phylogenetic analyses and clearly demonstrate major differences in metabolic potential across sites. The distribution of functional genes involved in electron transport

  20. Trace element mapping by LA-ICP-MS: assessing geochemical mobility in garnet

    Science.gov (United States)

    Raimondo, Tom; Payne, Justin; Wade, Benjamin; Lanari, Pierre; Clark, Chris; Hand, Martin

    2017-04-01

    A persistent problem in the study of garnet geochemistry is that the consideration of major elements alone excludes a wealth of information preserved by trace elements, particularly the rare-earth elements (REEs). This is despite the fact that trace elements are generally less vulnerable to diffusive resetting, and are sensitive to a broader spectrum of geochemical interactions involving the entire mineral assemblage, including the growth and/or dissolution of accessory minerals. We outline a technique for the routine acquisition of high-resolution 2D trace element maps by LA-ICP-MS, and introduce an extension of the software package XMapTools for rapid processing of LA-ICP-MS data to visualise and interpret compositional zoning patterns. These methods form the basis for investigating the mechanisms controlling geochemical mobility in garnet, which are argued to be largely dependent on the interplay between element fractionation, mineral reactions and partitioning, and the length scales of intergranular transport. Samples from the Peaked Hill shear zone, Reynolds Range, central Australia, exhibit contrasting trace element distributions that can be linked to a detailed sequence of growth and dissolution events. Trace element mapping is thus employed to place garnet evolution in a specific paragenetic context and derive absolute age information by integration with existing U-Pb monazite and Sm-Nd garnet geochronology. Ultimately, the remarkable preservation of original growth zoning and its subtle modification by subsequent re-equilibration is used to `see through' multiple superimposed events, thereby revealing a previously obscure petrological and temporal record of metamorphism, metasomatism, and deformation.

  1. A comparative review of petrogenetic processes beneath the Cameroon Volcanic Line: Geochemical constraints

    Directory of Open Access Journals (Sweden)

    Asobo N.E. Asaah

    2015-07-01

    Full Text Available The origin and petrogenesis of the Cameroon Volcanic Line (CVL, composed of volcanoes that form on both the ocean floor and the continental crust, are difficult to understand because of the diversity, heterogeneity, and nature of available data. Major and trace elements, and Sr-Nd-Pb isotope data of volcanic rocks of the CVL spanning four decades have been compiled to reinterpret their origin and petrogenesis. Volcanic rocks range from nephelinite, basanite and alkali basalts to phonolite, trachyte and rhyolite with the presence of a compositional gap between SiO2 58–64 wt.%. Similarities in geochemical characteristics, modeled results for two component mixing, and the existence of mantle xenoliths in most mafic rocks argue against significant crustal contamination. Major and trace element evidences indicate that the melting of mantle rocks to generate the CVL magma occurred dominantly in the garnet lherzolite stability field. Melting models suggest small degree (<3% partial melting of mantle bearing (6–10% garnet for Mt. Etinde, the Ngaoundere Plateau and the Biu Plateau, and <5% of garnet for the oceanic sector of the CVL, Mt. Cameroon, Mt. Bambouto, Mt. Manengouba and the Oku Volcanic Group. The Sr-Nd-Pb isotope systematics suggest that mixing in various proportions of Depleted MORB Mantle (DMM with enriched mantle 1 and 2 (EM1 and EM2 could account for the complex isotopic characteristics of the CVL lavas. Low Mg number (Mg# = 100 × MgO/(MgO + FeO and Ni, Cr and Co contents of the CVL mafic lavas reveal their crystallization from fractionated melts. The absence of systematic variation in Nb/Ta and Zr/Hf ratios, and Sr-Nd isotope compositions between the mafic and felsic lavas indicates progressive evolution of magmas by fractional crystallization. Trace element ratios and their plots corroborate mantle heterogeneity and reveal distinct geochemical signatures for individual the CVL volcanoes.

  2. Petrological and geochemical characteristics related to early rifting of Iapetus Ocean, Quebec Appalachians

    Energy Technology Data Exchange (ETDEWEB)

    Vermette, D.R.; Hebert, R. (Universite Laval, Ste-Foy, Quebec (Canada)); Bergeron, M. (INRS-Georessources, Ste-Foy, Quebec (Canada))

    1993-02-01

    A detailed petrological and geochemical study was conducted on Lower Cambrian volcanic rocks associated with the Chaudiere River Nappe (C.R.N.) Drummondville Olisotostrome (D.O.) in the Quebec Southern Appalachians. These volcanic rocks are interpreted as products of igneous events related to the break-up of continental crust and the opening of the Iapetus Ocean. Three major volcanic rock assemblages were identified that correspond to very low-grade metamorphosed basalts, andesites, and rhyolites. The basaltic flows can be subdivided into four geochemical groups: subalkaline, transitional-subalkaline, transitional-alkaline, and alkali basalts. The first three groups consist of olivine- and plagioclase-phyric basalts erupted as pillows, massive flows, flows breccias and blocky lavas. Alkali basalts represent massive flows characterized by kaersutite-Ti-augite-biotite-and apatite-phenocrysts. Groups 2 and 4 basalts show affinities with intraplate basalts. The geodynamic model proposed for the generation of these volcanic rocks involves, for groups 2, 3, and 4 basalts, partial melting of a previously metasomatized spinel lherzolite source and diapiric upwelling of an enriched melt. Only group 1 basalts could have been generated by an unmetasomatized depleted lherzolite source. Estimated degrees of partial melting range from 22 percent for subalkaline basalts to 5 percent for alkali basalts. Andesites may be generated by 85 percent fractional crystallization of basalts from group 3. Rhyolite could be produced by melting of continental crust. Sedimentary units in contact with or observed in proximity to the volcanic outcrops suggest that groups 1 and 2 basalts were erupted in a relatively deep and low-energy environment whereas groups 3 and 4 were erupted on or close to a continental margin. Both sedimentary and volcanic events are compatible with pregressive opening of a continental rift leading to formation of a mature oceanic basin. 44 refs., 9 figs., 3 tabs.

  3. Hydrogeologic and geochemical characteristics of the Ogallala and White River aquifers, Cheyenne, Wyoming

    Science.gov (United States)

    Ogle, K.M.; Hallberg, L.L.

    2000-01-01

    The Ogallala aquifer and the underlying White River aquifer are important ground-water resources of public and private drinking water in the Cheyenne, Wyoming area. In 1997, as part of a cooperative project between the Cheyenne Board of Public Utilities and the U.S. Geological Survey, a well was installed to develop information for those two aquifers. Information provided for the Ogallala aquifer included core descriptions, geophysical logs, water levels, aquifer transmissivity, water quality, isotopic analysis, and geochemical modeling. Information for the White River aquifer was limited to core descriptions and geophysical logs.Evaluation of the core obtained from the drill hole showed the sediments to be primarily sands, silts, and clays. The thickness of the Ogallala Formation at the well site was estimated to be 246 feet. Water levels and precipitation from October 1, 1998 to September 30, 1999 indicated that water levels responded to precipitation. During that time, water levels ranged from 6,002.41 feet to 6,004.27 feet above mean sea level. The transmissivity was estimated to be 1.1 feet squared/day. The temperature differences between the municipal water and the Ogallala aquifer water were examined in relation to selected hydraulic conductivities and it was found that the warmer municipal water would slightly increase the hydraulic conductivity if the water were injected into the Ogallala aquifer.The water quality of a sample from the Ogallala 1 well indicated the predominant major ions were calcium, magnesium, and bicarbonate. Isotopic analyses of hydrogen-2, tritium, chlorine-36, carbon-14, and carbon-13 indicated the water was a mixture of pre- and post-1953 recharge. A simple geochemical mixing model indicated there was the potential for dissolution of anhydrite, calcite, gypsum, and dolomite and precipitation of goethite, hematite, pyrolusite, and amorphous ferric hydroxide if municipal and Ogallala aquifer waters were mixed.

  4. Integrating Geochemical and Geodynamic Numerical Models of Mantle Evolution and Plate Tectonics

    Science.gov (United States)

    Tackley, P. J.; Xie, S.

    2001-12-01

    The thermal and chemical evolution of Earth's mantle and plates are inextricably coupled by the plate tectonic - mantle convective system. Convection causes chemical differentiation, recycling and mixing, while chemical variations affect the convection through physical properties such as density and viscosity which depend on composition. It is now possible to construct numerical mantle convection models that track the thermo-chemical evolution of major and minor elements, and which can be used to test prospective models and hypotheses regarding Earth's chemical and thermal evolution. Model thermal and chemical structures can be compared to results from seismic tomography, while geochemical signatures (e.g., trace element ratios) can be compared to geochemical observations. The presented, two-dimensional model combines a simplified 2-component major element model with tracking of the most important trace elements, using a tracer method. Melting is self-consistently treated using a solidus, with melt placed on the surface as crust. Partitioning of trace elements occurs between melt and residue. Decaying heat-producing elements and secular cooling of the mantle and core provide the driving heat sources. Pseudo-plastic yielding of the lithosphere gives a first-order approximation of plate tectonics, and also allows planets with a rigid lid or intermittent plate tectonics to be modeled simply by increasing the yield strength. Preliminary models with an initially homogeneous mantle show that regions with a HIMU-like signature can be generated by crustal recycling, and regions with high 3He/4He ratios can be generated by residuum recycling. Outgassing of Argon is within the observed range. Models with initially layered mantles will also be investigated. In future it will be important to include a more realistic bulk compositional model that allows continental crust as well as oceanic crust to form, and to extend the model to three dimensions since toroidal flow may alter

  5. Geochemical variables as plausible aetiological cofactors in the incidence of some common environmental diseases in Africa

    Science.gov (United States)

    Davies, T. C.

    2013-03-01

    Over the last two decades, there has been a rapid growth in research in the field of medical geology around the world, and we continue to encounter “new” and important correlations between certain environmental health conditions and factors related to our interactions with geological materials and processes. A review of the possible role of geochemical factors such as the circulation of Mg, Se and F and the physico-chemical composition of volcanic soil particles, on the aetiology of some common diseases in Africa, is presented. Such studies till now, have tended to emphasise only the deleterious health impacts due to geoenvironmental factors. This is justifiable, since a proper understanding of the negative health impacts has contributed significantly towards improvement in diagnosis and therapy. But there are also beneficial effects accrued from judiciously exploiting geological materials and processes, exemplified in this review, by the several important medical applications of African clays, the therapeutic gains associated with hot springs, and balneology of peat deposits. The criticality of the “optimal range” of intake for the nutrient elements Mg, Se and F in metabolic processes is also emphasised, and illustrations given of illnesses such as cardiovascular disorders and various cancers (all major causes of mortality in Africa) that can possibly occur on either side of this range. It is hoped that this review would help generate ideas for the formulation of experimental studies that take into account the role of the geochemical environment, in an attempt to establish precisely the obscure aetiology of some of the diseases treated, and uncover new pathways in their pathogenesis.

  6. Investigation of the geochemical evolution of groundwater under agricultural land: A case study in northeastern Mexico

    Science.gov (United States)

    Ledesma-Ruiz, Rogelio; Pastén-Zapata, Ernesto; Parra, Roberto; Harter, Thomas; Mahlknecht, Jürgen

    2015-02-01

    Zona Citrícola is an important area for Mexico due to its citriculture activity. Situated in a sub-humid to humid climate adjacent to the Sierra Madre Oriental, this valley hosts an aquifer system that represents sequences of shales, marls, conglomerates, and alluvial deposits. Groundwater flows from mountainous recharge areas to the basin-fill deposits and provides base flows to supply drinking water to the adjacent metropolitan area of Monterrey. Recent studies examining the groundwater quality of the study area urge the mitigation of groundwater pollution. The objective of this study was to characterize the physical and chemical properties of the groundwater and to assess the processes controlling the groundwater's chemistry. Correlation was used to identify associations among various geochemical constituents. Factor analysis was applied to identify the water's chemical characteristics that were responsible for generating most of the variability within the dataset. Hierarchical cluster analysis was employed in combination with a post-hoc analysis of variance to partition the water samples into hydrochemical water groups: recharge waters (Ca-HCO3), transition zone waters (Ca-HCO3-SO4 to Ca-SO4-HCO3) and discharge waters (Ca-SO4). Inverse geochemical models of these groups were developed and constrained using PHREEQC to elucidate the chemical reactions controlling the water's chemistry between an initial (recharge) and final water. The primary reactions contributing to salinity were the following: (1) water-rock interactions, including the weathering of evaporitic rocks and dedolomitization; (2) dissolution of soil gas carbon dioxide; and (3) input from animal/human wastewater and manure in combination with by denitrification processes. Contributions from silicate weathering to salinity ranged from less important to insignificant. The findings suggest that it may not be cost-effective to regulate manure application to mitigate groundwater pollution.

  7. Metagenomes from high-temperature chemotrophic systems reveal geochemical controls on microbial community structure and function

    Energy Technology Data Exchange (ETDEWEB)

    Frank Roberto

    2010-03-01

    The Yellowstone caldera contains the most numerous and diverse geothermal systems on Earth, yielding an extensive array of unique high-temperature environments that host numerous deeply-rooted and understudied Archaea, Bacteria and Eukarya. The combination of extreme temperature and chemical conditions encountered in geothermal environments often results in considerably less microbial diversity than other terrestrial habitats and offers a tremendous opportunity for studying the structure and function of indigenous microbial communities and for establishing linkages between putative metabolisms and element cycling. Metagenome sequence (14-15,000 Sanger reads per site) was obtained for five high-temperature (> 65 oC) chemotrophic microbial communities sampled from geothermal springs (or pools) in Yellowstone National Park (YNP) that exhibit a wide range in geochemistry including pH, dissolved sulfide, dissolved O2 and ferrous Fe. Metagenome data revealed significant differences in the predominant phyla associated with each of these geochemical environments. Novel members of the Sulfolobales are dominant in low pH environments, while other Crenarchaeota including distantly-related Thermoproteales and Desulfurococcales populations dominate in suboxic sulfidic sediments. Several novel archaeal groups are well represented in an acidic (pH 3) Fe-oxyhydroxide mat, where a higher O2 influx is accompanied with an increase in archaeal diversity. The presence or absence of genes and pathways important in S oxidation-reduction, H2-oxidation, and aerobic respiration (terminal oxidation) provide insight regarding the metabolic strategies of indigenous organisms present in geothermal systems. Multiple-pathway and protein-specific functional analysis of metagenome sequence data corroborated results from phylogenetic analyses and clearly demonstrate major differences in metabolic potential across sites. The distribution of functional genes involved in electron transport is

  8. Metagenomes from high-temperature chemotrophic systems reveal geochemical controls on microbial community structure and function.

    Directory of Open Access Journals (Sweden)

    William P Inskeep

    Full Text Available The Yellowstone caldera contains the most numerous and diverse geothermal systems on Earth, yielding an extensive array of unique high-temperature environments that host a variety of deeply-rooted and understudied Archaea, Bacteria and Eukarya. The combination of extreme temperature and chemical conditions encountered in geothermal environments often results in considerably less microbial diversity than other terrestrial habitats and offers a tremendous opportunity for studying the structure and function of indigenous microbial communities and for establishing linkages between putative metabolisms and element cycling. Metagenome sequence (14-15,000 Sanger reads per site was obtained for five high-temperature (>65 degrees C chemotrophic microbial communities sampled from geothermal springs (or pools in Yellowstone National Park (YNP that exhibit a wide range in geochemistry including pH, dissolved sulfide, dissolved oxygen and ferrous iron. Metagenome data revealed significant differences in the predominant phyla associated with each of these geochemical environments. Novel members of the Sulfolobales are dominant in low pH environments, while other Crenarchaeota including distantly-related Thermoproteales and Desulfurococcales populations dominate in suboxic sulfidic sediments. Several novel archaeal groups are well represented in an acidic (pH 3 Fe-oxyhydroxide mat, where a higher O2 influx is accompanied with an increase in archaeal diversity. The presence or absence of genes and pathways important in S oxidation-reduction, H2-oxidation, and aerobic respiration (terminal oxidation provide insight regarding the metabolic strategies of indigenous organisms present in geothermal systems. Multiple-pathway and protein-specific functional analysis of metagenome sequence data corroborated results from phylogenetic analyses and clearly demonstrate major differences in metabolic potential across sites. The distribution of functional genes involved in

  9. Analysis on the inbound tourist source market in Fujian Province

    Science.gov (United States)

    YU, Tong

    2017-06-01

    The paper analyzes the development and structure of inbound tourism in Fujian Province by Excel software and conducts the cluster analysis on the inbound tourism market by SPSS 23.0 software based on the inbound tourism data of Fujian Province from 2006 to 2015. The results show: the rapid development of inbound tourism in Fujian Province and the diversified inbound tourist source countries indicate the stability of inbound tourism market; the inbound tourist source market in Fujian Province can be divided into four categories according to the cluster analysis, and tourists from the United States, Japan, Malaysia, and Singapore are the key of inbound tourism in Fujian Province.

  10. MINERALOGICAL AND GEOCHEMICAL EVIDENCE FOR MULTI-STAGE FORMATION OF THE CHERTOVO KORYTO DEPOSIT

    Directory of Open Access Journals (Sweden)

    Yu. I. Tarasova

    2016-01-01

    Full Text Available Introduction. The Lena gold province is one of the largest known gold resources in the world. The history of its exploration is long, but the genesis of gold mineralization hosted in black shales in the Bodaibo synclinorium still remains unclear. The studies face the challenge of discovering sources for the useful component and mechanisms of its redistribution and concentration. This study aims to clarify the time sequence of the ore mineralization in the Chertovo Koryto deposit on the basis of detailed mineralogical and geochemical characteristics of the ore, wallrock metasomatites and the Early Proterozoic host black shales, and to assess the applicability of the Sukhoi Log model for clarifying the Chertovo Koryto origin.Geological setting. The Lena gold province is located in the junction area of the Siberian platform and the Baikal mountain region (Fig. 1. The main element of its geological structure is the Chuya-Tonoda-Nechera anticline. Its axial segment is marked by horsts composed of the Early Proterozoic rocks with abundant granitoid massifs. The Chertovo Koryto deposit is located within the Kevakta ore complex at the Tonoda uplift, the largest tectonically disturbed block between the Kevakta and Amandrak granitoids massifs. The 150 m thick and 1.5 km long ore zone of the Chertovo Koryto deposit is confined to the hanging wall of the fold-fault zone feathering the Amandrak deep fault (Fig. 2.Composition. In the ore zone, rocks of the Mikhailovsk Formation include carbonaceous shales of the feldspar-chlorite-sericite-quartz composition with nest-shaped ore accumulations of the pyrite-quartz composition and quartz veinlets. In our study, we distinguish five mineral associations resulting from heterochronous processes that sequentially replaced each other:- The earliest association related with the quartz-muscovite-sericite metasomatism and the removal of REE and other elements from the rocks and their partial redeposition;- Metamorphic

  11. Spatial and Geochemical Spatial and Geochemical Heterogeneity Impacts on Iron Biomineralization and Uranium Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott Fendorf; Shawn Benner; Jim Neiss; Colleen Hansel; Peter Nico; Chris Francis; Phil Jardine

    2004-03-17

    Bioreductive transformations of iron (hydr)oxides are a critically important processes controlling the fate and transport of contaminants in soil and aquifer systems. Heterogeneity arising from both chemical and physical conditions will lead to various biomineralization products of iron oxides and will additionally alter reactions controlling the partitioning of hazardous elements such as uranium. We are presently exploring chemical and mineralogical transformations within physically complex material having a range of pore-size distribution and chemical environments. Here we discuss the impact of calcium on the reactive transport of uranium and the spatial heterogeneity in iron hydroxide mineralization and concomitant uranium reduction along a diffusive flow path.

  12. Sequential extraction techniques applied to a porphyry copper deposit in the basin and range province

    Science.gov (United States)

    Filipek, L.H.; Theobald, P.K.

    1981-01-01

    Samples of minus-80-mesh (weathering processes. However, the relative proportions of elements dissolved in each step of the jarosite and chrysocolla extractions could be used as a "fingerprint" for recognition of the presence of these two minerals in the stream-sediment and rock samples. The relative abundance of hydrous Fe oxide and jarosite and the alteration zoning could be mapped using data from jarosite and chrysocolla extractions. Manganese oxides were also found to have a greater influence on Zn than on Cu or Pb during supergene alteration. The rapid change in relative importance of the first (1M-acetic acid) extraction for Cu, Zn, and Pb near the mineralized zone suggested the occurrence of minor hydromorphic processes within the stream sediments. Thus, the acetic acid extraction proved the most effective for pinpointing mineralization in sediments. In contrast, the residual fraction had the longest dispersion train, suggesting that total metal concentrations are most effective in arid environments for reconnaissance surveys. ?? 1981.

  13. Geochemical Atlas of the San Jose and Golfito quadrangles, Costa Rica. Atlas Geoquimico de los cuadrangulos de San Jose y Golfito, Costa Rica

    Energy Technology Data Exchange (ETDEWEB)

    1987-07-01

    The Geochemical Atlas of the San Jose and Golfito 1:200,000-scale quadrangles, Costa Rica, was produced to help stimulate the growth of the Costa Rican mining industry and, thus, to benefit the economy of the country. As a result of the geochemical data presented in the Atlas, future exploration for metallic minerals in Costa Rica can be focused on specific areas that have the highest potential for mineralization. Stream-sediment samples were collected from drainage basins within the two quadrangles. These samples were analyzed for 50 elements and the results were displayed as computer-generated color maps. Each map shows the variation in abundance of a single element within the quadrangle. Basic statistics, geological and cultural data are included as insets in each map to assist in interpretation. In the Golfito quadrangle, the geochemical data do not clearly indicate undiscovered gold mineralization. The areas known to contain placer (alluvial) gold are heavily affected by mining activity. Statistical treatment of the geochemical data is necessary before it will be possible to determine the gold potential of this quadrangle. In San Jose quadrangle, gold and the pathfinder elements, arsenic and antimony, are indicators of the gold mineralization characteristic of the Costa Rican gold district located in the Tilaran-Montes del Aguacate Range. This work shows that high concentrations of these elements occur in samples collected downstream from active gold mines. More importantly, the high concentrations of gold, arsenic, and antimony in sediment samples from an area southeast of the known gold district suggest a previously unknown extension of the district. This postulated extension underlain by Tertiary volcanic rocks which host the gold deposits within the gold district. The geochemical data, displayed herein, also indicate that drainage basins north of Ciudad Quesada on the flanks of Volcan Platanar have high gold potential.

  14. An ethnobotanical survey on hormozgan province, Iran

    Directory of Open Access Journals (Sweden)

    Omid Safa

    2012-12-01

    Conclusion: This study revealed that the people of Hormozgan province have a rich knowledge of natural resources. The use and consumption of medicinal plants are still important parts of their life.Rational use of native medicinal plants may benefit and improve their living standards and quality of life. The results of this study can be used as a basis for selecting herbs for further pharmacological, phytochemical, and pharmacognostical studies.

  15. USMC Rethinking Coin in Helmand Province Afghanistan

    Science.gov (United States)

    2015-04-01

    security and stability. This is much harder than it sounds in a fragmented rural population such as Helmand province. The demands placed on leaders in...AH-1 “ Cobra ” and UH-1”Huey” helicopters to support ground operations commanders were able to deliver precision fires while retaining visible...them. Much will be asked of leaders in COIN operations in the future, but with a flexible organization, sound intelligence, the will to fight when

  16. Pt content of Cu-Ni deposits and ore occurrences in the Stanovoi Ni-bearing province (Far East, Russia)

    Science.gov (United States)

    Melnikov, A. V.; Strikha, V. E.; Moiseenko, V. G.

    2017-12-01

    Data on the Pt content in Cu-Ni deposits and ore occurrences of the Stanovoi Ni-bearing province of the Upper Amur Region are reported. Description and comparative analysis of the deposits and ore occurrences of the Pt-bearing Cu-Ni ores have been carried out taking into account new data on the ore geology, geochemistry, and material composition. We have described the formation prerequisites, forecast, and search criteria for large deposits of Pt-bearing Cu-Ni ores in the Upper Amur Region: the geotectonic and structural position, deep structure, formational features, magmatism of the mineralization period, hydrothermal alterations of the rocks, mineral and geochemical assemblages, PGM typomorphism, etc. This paper emphasizes the considerable potential of the Upper Amur Cu-Ni ores in relation to the complex of useful mineral resources such as gold, PGEs, sulfur, and cobalt.

  17. Geochemical Distribution of Lead and Chromium in River Getsi-Kano

    African Journals Online (AJOL)

    Geochemical forms of lead (Pb) and Chromium (Cr) from the sediment of River Getsi Kano-Nigeria were determined using Atomic Absorption spectrometer for eighteen months. Apart from determination of the metals in water, geochemical forms of the metals were also evaluated into five fractions. Exchangeable, bound to ...

  18. Geochemical and Isotopic Interpretations of Groundwater Flow in the Oasis Valley Flow System, Southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Thomas; F.C. Benedict, Jr.; T.P. Rose; R.L. Hershey; J.B. Paces; Z.E. Peterman; I.M. Farnham; K.H. Johannesson; A.K. Singh; K.J. Stetzenbach; G.B. Hudson; J.M. Kenneally; G.F. Eaton; D.K. Smith

    2003-01-08

    This report summarizes the findings of a geochemical investigation of the Pahute Mesa-Oasis Valley groundwater flow system in southwestern Nevada. It is intended to provide geochemical data and interpretations in support of flow and contaminant transport modeling for the Western and Central Pahute Mesa Corrective Action Units.

  19. Geochemistry of aquifer sediments and arsenic-rich groundwaters from Kandal Province, Cambodia

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, Helen A.L.; Gault, Andrew G.; Lythgoe, Paul [School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL (United Kingdom); Polya, David A. [School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester M13 9PL (United Kingdom)], E-mail: david.polya@manchester.ac.uk

    2008-11-15

    Elevated As is well known to be present in aquifers utilised for drinking water and irrigation in West Bengal and Bangladesh. This problem has also more recently been discovered in other parts of Asia, including Vietnam, Cambodia, Inner Mongolia and the Middle Ganges Plain. Analysis of groundwaters in Kandal Province of Cambodia found waters with comparable geochemistry to the As-rich groundwaters of the West Bengali Delta. Similarities included high but heterogeneous As distributions, predominantly in the form As(III), high Fe, moderate to high HCO{sub 3}{sup -}, circumneutral pH, low SO{sub 4}{sup 2-} and geochemical components indicative of reducing conditions. Good positive correlations between As, Fe, HCO{sub 3}{sup -} and NH{sub 4}{sup +}, and dissolved organic C is consistent with As release predominantly via microbially mediated reductive dissolution of As bearing Fe(III) oxides. Further evidence for such a process is found from correlations between As, Fe and organic matter from analysis of aquifer sediments, by the presence of goethite in the finer fractions and from the association of As with amorphous, poorly crystalline and well crystallised hydrous Fe oxides. The presence of several high As, but low Fe, wells implies that microbes could have a more direct role in mediating As release via the direct utilisation of Fe(III) or As(V) as electron acceptors. The presence of elevated As in waters with short aquifer residence times (as indicated by their geochemical signature) highlights the possible vulnerability of these aquifers to the influx of surface derived waters, providing an additional source of labile organic C that could exacerbate As release by stimulating microbial activity.

  20. Cluster Analysis of Indonesian Province Based on Household Primary Cooking Fuel Using K-Means

    Science.gov (United States)

    Huda, S. N.

    2017-03-01

    Each household definitely provides installations for cooking. Kerosene, which is refined from petroleum products once dominated types of primary fuel for cooking in Indonesia, whereas kerosene has an expensive cost and small efficiency. Other household use LPG as their primary cooking fuel. However, LPG supply is also limited. In addition, with a very diverse environments and cultures in Indonesia led to diversity of the installation type of cooking, such as wood-burning stove brazier. The government is also promoting alternative fuels, such as charcoal briquettes, and fuel from biomass. The use of other fuels is part of the diversification of energy that is expected to reduce community dependence on petroleum-based fuels. The use of various fuels in cooking that vary from one region to another reflects the distribution of fuel basic use by household. By knowing the characteristics of each province, the government can take appropriate policies to each province according each character. Therefore, it would be very good if there exist a cluster analysis of all provinces in Indonesia based on the type of primary cooking fuel in household. Cluster analysis is done using K-Means method with K ranging from 2-5. Cluster results are validated using Silhouette Coefficient (SC). The results show that the highest SC achieved from K = 2 with SC value 0.39135818388151. Two clusters reflect provinces in Indonesia, one is a cluster of more traditional provinces and the other is a cluster of more modern provinces. The cluster results are then shown in a map using Google Map API.

  1. Natural gas and energy revolution: A case study of Sichuan–Chongqing gas province

    Directory of Open Access Journals (Sweden)

    Xinhua Ma

    2017-03-01

    Full Text Available For a full and accurate understanding of the position and role of natural gas in China's energy revolution and providing a decision-making reference for the scientific establishment of natural gas development strategies and the deepening of the energy revolution, this paper analyzed the role of natural gas in guiding the energy revolution in China and points out the main direction of natural gas utilization in the Sichuan–Chongqing gas province which takes the lead in China's natural gas industry. The study provides the following findings. First, with a huge space for development, natural gas will play an important role in China's third energy revolution. Second, natural gas resources are abundant and have a huge potential for development in China. Third, natural gas can be used for a large range of purposes in the Sichuan–Chongqing gas province. In addition to be used as city gas, natural gas can also be used for industrial fuel mainly as a substitute for coal, transportation, distributed energy, peak-shaving power generation, and high-end natural gas chemical raw materials. Some conclusions are made. First, as the cleanest fossil energy and the best fuel, natural gas will play an irreplaceable role in China's third energy revolution in the 21st century. Second, the Sichuan–Chongqing gas province is rich in natural gas, hydropower and other renewable resources. By 2020, it will become the largest gas production province in China, with natural gas production over 550 × 108 m3. By 2030, driven by the rapid development of shale gas, gas production in the province is expected to exceed 800 × 108 m3. Third, the Sichuan–Chongqing gas province is likely to become the leader in China's third energy revolution.

  2. Calculation of individual isotope equilibrium constants for geochemical reactions

    Science.gov (United States)

    Thorstenson, D.C.; Parkhurst, D.L.

    2004-01-01

    Theory is derived from the work of Urey (Urey H. C. [1947] The thermodynamic properties of isotopic substances. J. Chem. Soc. 562-581) to calculate equilibrium constants commonly used in geochemical equilibrium and reaction-transport models for reactions of individual isotopic species. Urey showed that equilibrium constants of isotope exchange reactions for molecules that contain two or more atoms of the same element in equivalent positions are related to isotope fractionation factors by ?? = (Kex)1/n, where n is the number of atoms exchanged. This relation is extended to include species containing multiple isotopes, for example 13C16O18O and 1H2H18O. The equilibrium constants of the isotope exchange reactions can be expressed as ratios of individual isotope equilibrium constants for geochemical reactions. Knowledge of the equilibrium constant for the dominant isotopic species can then be used to calculate the individual isotope equilibrium constants. Individual isotope equilibrium constants are calculated for the reaction CO2g = CO2aq for all species that can be formed from 12C, 13C, 16O, and 18O; for the reaction between 12C18 O2aq and 1H218Ol; and among the various 1H, 2H, 16O, and 18O species of H2O. This is a subset of a larger number of equilibrium constants calculated elsewhere (Thorstenson D. C. and Parkhurst D. L. [2002] Calculation of individual isotope equilibrium constants for implementation in geochemical models. Water-Resources Investigation Report 02-4172. U.S. Geological Survey). Activity coefficients, activity-concentration conventions for the isotopic variants of H2O in the solvent 1H216Ol, and salt effects on isotope fractionation have been included in the derivations. The effects of nonideality are small because of the chemical similarity of different isotopic species of the same molecule or ion. The temperature dependence of the individual isotope equilibrium constants can be calculated from the temperature dependence of the fractionation

  3. Range management visual impacts

    Science.gov (United States)

    Bruce R. Brown; David Kissel

    1979-01-01

    Historical overgrazing of western public rangelands has resulted in the passage of the Public Rangeland Improvement Act of 1978. The main purpose of this Act is to improve unsatisfactory range conditions. A contributing factor to unfavorable range conditions is adverse visual impacts. These visual impacts can be identified in three categories of range management: range...

  4. PRASYARAT KEBERHASILAN KERJA SAMA SISTER PROVINCE : STUDI KASUS SISTER PROVINCE ANTARA JAWA TENGAH DENGAN PROVINSI FUJIAN-CINA

    Directory of Open Access Journals (Sweden)

    Hermini S.

    2016-02-01

    Full Text Available The implementation of Indonesian local government autonomy gives many consequences. One of it is the augmentation of cooperation with foreign countries conducted by local government. One type of the cooperation is sister province. This cooperation still bring lack of success story and best practices. Rather brings clear profits, mostly sister province cooperation has no clear benefits. By using the case of sister province cooperation between Central Java province and Fujian, this research providing the answer why central java wants to cooperate with Fujian under the scheme sister province due to the massive criticism of Free Trade Area with China. By using Scholte’s Globalization approach, and Botenbal’s lowered politics issue this paper argue that the sister province cooperation between Central Java and Fujian is being conduct for the cause of spillover effect and due to long road historical demographic background between these two provinces.

  5. Shale gas characterization based on geochemical and geophysical analysis: Case study of Brown shale, Pematang formation, Central Sumatra Basin

    Science.gov (United States)

    Haris, A.; Nastria, N.; Soebandrio, D.; Riyanto, A.

    2017-07-01

    Geochemical and geophysical analyses of shale gas have been carried out in Brown Shale, Middle Pematang Formation, Central Sumatra Basin. The paper is aimed at delineating the sweet spot distribution of potential shale gas reservoir, which is based on Total Organic Carbon (TOC), Maturity level data, and combined with TOC modeling that refers to Passey and Regression Multi Linear method. We used 4 well data, side wall core and 3D pre-stack seismic data. Our analysis of geochemical properties is based on well log and core data and its distribution are constrained by a framework of 3D seismic data, which is transformed into acoustic impedance. Further, the sweet spot of organic-rich shale is delineated by mapping TOC, which is extracted from inverted acoustic impedance. Our experiment analysis shows that organic materials contained in the formation of Middle Pematang Brown Shale members have TOC range from 0.15 to 2.71 wt.%, which is classified in the quality of poor to very good. In addition, the maturity level of organic material is ranging from 373°C to 432°C, which is indicated by vitrinite reflectance (Ro) of 0.58. In term of kerogen type, this Brown shale formation is categorized as kerogen type of II I III, which has the potential to generate a mixture of gasIoil on the environment.

  6. Geochemical characteristics of the Church Rock 1 and 1 East uranium deposits, Grants uranium region, New Mexico

    Science.gov (United States)

    Fishman, Neil S.; Reynolds, Richard L.

    1983-01-01

    In the Church Rock 1 and 1 East mines, Grants uranium region (GUR), New Mexico, uranium orebodies occur within three sandstone units in the upper part of the Westwater Canyon Member of the late Jurassic Morrison Formation. Geochemical analyses reveal that organic carbon contents in ore samples from all three sand units are uniformly low (most are less than 0.01 percent). Vanadium (ranging from 0.0002 to 0.19 percent) and sulfur (ranging from carbon and greater amounts of vanadium and sulfur. These differences and radiometric age determinations strongly suggest that the Church Rock ores formed as a result of the redistribution of uranium from preexisting uranium deposits within the last 1 m.y. However, the Church Rock deposits differ geochemically from redistributed orebodies in the Westwater Canyon Member elsewhere in the GUR. Specifically, redistributed orebodies in the Ambrosia Lake district, which are comparable in contents of uranium and organic carbon with the Church Rock deposits, are characterized by vanadium contents typically higher than those of uranium. Similarly, sulfur contents in the redistributed deposits of the Ambrosia Lake district are greater than those found in the Church Rock ores. In addition, anomalously high concentrations of molybdenum have rarely been found in other redistributed orebodies of the GUR.

  7. Influence of black shales on soils and edible plants in the Ankang Area, Shanxi Province, P.R. of China

    Energy Technology Data Exchange (ETDEWEB)

    Fang, W.; Hu, R.; Wu, P. [Institute of Geochemistry, Chinese Academy of Sciences, Guiyang (China). Lab. of Ore Deposit Geochemistry (LODG)

    2002-03-01

    The Ankang black shales in China provides an important example of natural geological materials containing toxic elements. This paper presents the results of environmental geochemical research on black shales, soils, waters and edible plants in the Ankang areas, Shanxi Province of China. The study area lies in the northern margin of the Yangtze Platform; there are black shales which contains black shale, carbonaceous rocks and coal in the Cambrian Donghe Formation throughout the area. Mean trace element concentrations of the coal were high. Soils derived from these rocks tends to reflect their extreme geochemical composition. Chemical analysis of common plant species in the Ankang area showed a heterogeneous distribution of Se, Mo and V within the single and among plant species. Selenium was more concentrated in radish than in legumes, and in potato more than in green vegetable. High V concentrations were found in two kinds of Chinese tea. Legume had more Mo in the seed than potato, although Mo concentrations in radish vary. Higher concentrations of Se and Mo are present in the leaf of radish. 26 refs., 3 figs., 5 tabs.

  8. Geological Controls on Mineralogy and Geochemistry of an Early Permian Coal from the Songshao Mine, Yunnan Province, Southwestern China

    Directory of Open Access Journals (Sweden)

    Ruixue Wang

    2016-07-01

    Full Text Available This paper discusses the content, distribution, modes of occurrence, and enrichment mechanism of mineral matter and trace elements of an Early Permian coal from Songshao (Yunnan Province, China by means of coal-petrological, mineralogical, and geochemical techniques. The results show that the Songshao coal is characterized by high total and organic sulfur contents (3.61% and 3.87%, respectively. Lithium (170.39 μg/g and Zr (184.55 μg/g are significantly enriched in the Songshao coal, and, to a lesser extent, elements such as Hg, La, Ce, Nd, Th, Sr, Nb, Sn, Hf, V, and Cr are also enriched. In addition to Hg and Se that are enriched in the roof and floor strata of the coal seam, Li, La, Ce, Pr, Nd, Sm, Gd, Y, Cd, and Sb are slightly enriched in these host rocks. Compared to the upper continental crust, rare earth elements and yttrium in the host rocks and coal samples are characterized by a light-REE enrichment type and have negative Eu, positive Ce and Gd anomalies. Major minerals in the samples of coal, roof, and floor are boehmite, clay minerals (kaolinite, illite, and mixed layer illite-smectite, pyrite, and anatase. Geochemical and mineralogical anomalies of the Songshao coal are attributed to hydrothermal fluids, seawater, and sediment-source rocks.

  9. The Earth's heterogeneous mantle a geophysical, geodynamical, and geochemical perspective

    CERN Document Server

    Khan, Amir

    2015-01-01

    This book highlights and discusses recent developments that have contributed to an improved understanding of observed mantle heterogeneities and their relation to the thermo-chemical state of Earth's mantle, which ultimately holds the key to unlocking the secrets of the evolution of our planet. This series of topical reviews and original contributions address 4 themes. Theme 1 covers topics in geophysics, including global and regional seismic tomography, electrical conductivity and seismic imaging of mantle discontinuities and heterogeneities in the upper mantle, transition zone and lower mantle. Theme 2 addresses geochemical views of the mantle including lithospheric evolution from analysis of mantle xenoliths, composition of the deep Earth and the effect of water on subduction-zone processes. Theme 3 discusses geodynamical perspectives on the global thermo-chemical structure of the deep mantle. Theme 4 covers application of mineral physics data and phase equilibrium computations to infer the regional-scale ...

  10. Geochemical signatures in Late Triassic brachiopods from New Caledonia

    DEFF Research Database (Denmark)

    Ullmann, C. V.; Campbell, H. J.; Frei, R.

    2014-01-01

    .7065, and light δ13C values of c.-20‰, suggesting major contributions by oxidized organic matter. Diagenetic equilibrium was reached at δ18O values of c.-12‰, very low Sr/Ca ratios of ...Brachiopod fossils from the sedimentary sequences of the Téremba Terrane (New Caledonia) provide a unique opportunity to study the environmental parameters of the Late Triassic. 87Sr/86Sr ratios, δ13C and δ18O values, and Sr/Ca, Mg/Ca and Mn/Ca ratios were measured on brachiopods from Oretian...... to Otapirian (Norian to Rhaetian) fossil localities of the Baie de St.-Vincent area. Post-depositional impacts on the geochemical proxies were investigated by analysing calcite cements and partly recrystallized shell material. Diagenetic fluids carried strontium with a low 87Sr/86Sr ratio of c. 0...

  11. Geochemical characterisation of arsenic in uranium tailings pore fluids

    Energy Technology Data Exchange (ETDEWEB)

    Moldovan, B.; Hendry, M.J. [Univ. of Saskatchewan, Dept. of Geological Sciences, Saskatoon, Saskatchewan (Canada); Landine, P. [Cameco Corp., Saskatoon, Saskatchewan (Canada)

    2000-07-01

    Geochemical characterisation of uranium tailings porewater and solids is required to determine the long-term source contaminant potential of arsenic in the tailings. The Rabbit Lake In-pit Tailings Management Facility in Northern Saskatchewan was investigated with the objective of obtaining representative tailings porewater samples from a detailed depth profile. Methods of extracting porewater, including centrifugation and hydraulic squeezing were compared to drive-point piezometer data. Field measurements of Eh, pH and temperature were taken as the core samples were recovered. Pore fluid samples were analysed for arsenic speciation. Analytical results were compared to the previous sampling event in the same location. Tailings produced from several ore bodies were also compared in terms of pore fluid contaminant concentrations. (author)

  12. The Emeishan large igneous province: A synthesis

    Directory of Open Access Journals (Sweden)

    J. Gregory Shellnutt

    2014-05-01

    Full Text Available The late Permian Emeishan large igneous province (ELIP covers ∼0.3 × 106 km2 of the western margin of the Yangtze Block and Tibetan Plateau with displaced, correlative units in northern Vietnam (Song Da zone. The ELIP is of particular interest because it contains numerous world-class base metal deposits and is contemporaneous with the late Capitanian (∼260 Ma mass extinction. The flood basalts are the signature feature of the ELIP but there are also ultramafic and silicic volcanic rocks and layered mafic-ultramafic and silicic plutonic rocks exposed. The ELIP is divided into three nearly concentric zones (i.e. inner, middle and outer which correspond to progressively thicker crust from the inner to the outer zone. The eruptive age of the ELIP is constrained by geological, paleomagnetic and geochronological evidence to an interval of ≤3 Ma. The presence of picritic rocks and thick piles of flood basalts testifies to high temperature thermal regime however there is uncertainty as to whether these magmas were derived from the subcontinental lithospheric mantle or sub-lithospheric mantle (i.e. asthenosphere or mantle plume sources or both. The range of Sr (ISr ≈ 0.7040–0.7132, Nd (ɛNd(t ≈ −14 to +8, Pb (206Pb/204Pb1 ≈ 17.9–20.6 and Os (γOs ≈ −5 to +11 isotope values of the ultramafic and mafic rocks does not permit a conclusive answer to ultimate source origin of the primitive rocks but it is clear that some rocks were affected by crustal contamination and the presence of near-depleted isotope compositions suggests that there is a sub-lithospheric mantle component in the system. The silicic rocks are derived by basaltic magmas/rocks through fractional crystallization or partial melting, crustal melting or by interactions between mafic and crustal melts. The formation of the Fe-Ti-V oxide-ore deposits is probably due to a combination of fractional crystallization of Ti-rich basalt and fluxing of CO2-rich fluids

  13. Geochemical behavior of uranium mill tailings leachate in the subsurface

    Energy Technology Data Exchange (ETDEWEB)

    Brookins, D.G. (New Mexico Univ., Albuquerque, NM (United States). Dept. of Geology); Thomson, B.M. (New Mexico Univ., Albuquerque, NM (United States). Dept. of Civil Engineering); Longmire, P.; Eller, P.G. (Los Alamos National Lab., Isotope and Nuclear Chemistry Div., Los Alamos (United States))

    1993-01-01

    Leachate generated from surface disposal of acidic uranium mill tailings at Maybell, CO has impacted groundwater quality within the underlying mineralized Browns Park Formation. The extent of groundwater contamination, however, is located directly beneath the tailings impoundment. The milling process consisted of sulfuric acid extraction of uranium from the feed ore by a complex chemical leaching and precipitation process. Tailings leachate at the site contains elevated concentrations of Al, As, Cd, Mo, Ni, NO[sub 3], Se, U, and other solutes. From column leach tests, the concentrations of contaminants within tailings pore fluid are SO[sub 4]>NH[sub 4]>NO[sub 3]>U>Se>Ni>As>Cd at pH 4.0. The carbonate buffering capacity of the tailings subsoil has decreased because of calcite dissolution in the presence of acidic leachate. Groundwater quality data, mineralogical and microbiological studies, and geochemical modeling suggest that As, NO[sub 3], Se, U and other solutes are being removed from solution through precipitation, adsorption, and denitrification processes under reducing conditions. Presence of hydrogen sulfide, liquid and gaseous hydrocarbons, dissolved organic, and abundant pyrite within the Browns Park Formations have maintained reducing conditions subjacent to the tailings impoundment. Groundwater is in close equilibrium with coffinite and uraninite, the primary U(IV) minerals extracted from the Browns Parks Formation. Denitrifying bacteria identified in this study catalyze redox reactions involving NO[sub 3]. Subsequently, contaminant distributions of NO[sub 3] decrease 1000 times beneath the tailings impoundment. Applying geochemical and biochemical processes occurring at Maybell provides an excellent model for in situ aquifer restoration programs considered at other uranium tailings and heavy-metal-mixed waste contaminated sites. (author) 4 figs., 4 tabs., 27 refs.

  14. Geophysical and geochemical signatures of Gulf of Mexico seafloor brines

    Directory of Open Access Journals (Sweden)

    S. B. Joye

    2005-01-01

    Full Text Available Geophysical, temperature, and discrete depth-stratified geochemical data illustrate differences between an actively venting mud volcano and a relatively quiescent brine pool in the Gulf of Mexico along the continental slope. Geophysical data, including laser-line scan mosaics and sub-bottom profiles, document the dynamic nature of both environments. Temperature profiles, obtained by lowering a CTD into the brine fluid, show that the venting brine was at least 10°C warmer than the bottom water. At the brine pool, thermal stratification was observed and only small differences in stratification were documented between three sampling times (1991, 1997 and 1998. In contrast, at the mud volcano, substantial temperature variability was observed, with the core brine temperature being slightly higher than bottom water (by 2°C in 1997 but substantially higher than bottom water (by 19°C in 1998. Detailed geochemical samples were obtained in 2002 using a device called the 'brine trapper' and concentrations of dissolved gases, major ions and nutrients were determined. Both brines contained about four times as much salt as seawater and steep concentration gradients of dissolved ions and nutrients versus brine depth were apparent. Differences in the concentrations of calcium, magnesium and potassium between the two brine fluids suggest that the fluids are derived from different sources, have different dilution/mixing histories, or that brine-sediment reactions are more important at the mud volcano. Substantial concentrations of methane, ammonium, and silicate were observed in both brines, suggesting that fluids expelled from deep ocean brines are important sources of these constituents to the surrounding environment.

  15. Arsenic: geochemical distribution and health risk in Italy

    Science.gov (United States)

    Zuzolo, Daniela; Cicchella, Domenico; Albanese, Stefano; Catani, Vittorio; Dinelli, Enrico; Lima, Annamaria; Valera, Paolo; De Vivo, Benedetto

    2017-04-01

    Characterization of risks to human health is determinant for risk management and population surveillance. This study represent the first work at national scale for Italy about arsenic occurrence, distribution and health impact. We analyzed the As geochemical distribution in different environmental matrices on the whole Italian territory, and assessed both carcinogenic and non-carcinogenic risks for different exposure routes and age groups. The results demonstrate that, in Italy, arsenic is present in significant concentrations both in water (up to 27.2 µg/L) and soils (up to 70 mg/kg). Its presence is mainly controlled by geological processes and locally reflects the industrial history of the Country. The population of the Central Italy, where high content of arsenic in the analyzed samples is due to the presence of alkaline volcanics, are the most exposed to the health risk. Based on the results of our work, it is clear that the consumption of tap water for potable use is the most impactful route for As daily exposure and play an important role in governing potential cancer and non-cancer risks for the considered population. It is interesting to observe that the Incremental Life Cancer Risk through water ingestion show that almost 80% of data falls above the internationally accepted benchmark value of 1 x 10-5. Moreover it was demonstrated that childhood is the most susceptible age stage to As exposure. Geochemical mapping provided a useful tool to spatially analyze and represent data and to highlight the most critic areas and the most exposed population to arsenic at national scale. In conclusion, this study improve knowledge about As occurrence for an entire Country, recognizing an health emerging problem. It might be a good starting point to support the urgently needed policy actions, in order to prevent and reduce the health risk. Moreover, the performed method in this case study research is potentially generalizable and applicable in other countries.

  16. WATEQ3 geochemical model: thermodynamic data for several additional solids

    Energy Technology Data Exchange (ETDEWEB)

    Krupka, K.M.; Jenne, E.A.

    1982-09-01

    Geochemical models such as WATEQ3 can be used to model the concentrations of water-soluble pollutants that may result from the disposal of nuclear waste and retorted oil shale. However, for a model to competently deal with these water-soluble pollutants, an adequate thermodynamic data base must be provided that includes elements identified as important in modeling these pollutants. To this end, several minerals and related solid phases were identified that were absent from the thermodynamic data base of WATEQ3. In this study, the thermodynamic data for the identified solids were compiled and selected from several published tabulations of thermodynamic data. For these solids, an accepted Gibbs free energy of formation, ..delta..G/sup 0//sub f,298/, was selected for each solid phase based on the recentness of the tabulated data and on considerations of internal consistency with respect to both the published tabulations and the existing data in WATEQ3. For those solids not included in these published tabulations, Gibbs free energies of formation were calculated from published solubility data (e.g., lepidocrocite), or were estimated (e.g., nontronite) using a free-energy summation method described by Mattigod and Sposito (1978). The accepted or estimated free energies were then combined with internally consistent, ancillary thermodynamic data to calculate equilibrium constants for the hydrolysis reactions of these minerals and related solid phases. Including these values in the WATEQ3 data base increased the competency of this geochemical model in applications associated with the disposal of nuclear waste and retorted oil shale. Additional minerals and related solid phases that need to be added to the solubility submodel will be identified as modeling applications continue in these two programs.

  17. Trend in cataract surgical rate in iran provinces.

    Science.gov (United States)

    Hashemi, Hassan; Rezvan, Farhad; Khabazkhoob, Mehdi; Gilasi, Hamidreza; Etemad, Koroush; Mahdavi, Alireza; Asgari, Soheila

    2014-07-01

    The aim of this study was to determine the trend of changes in Cataract Surgical Rate (CSR) in the provinces of Iran during 2006 to 2010 and identify high risk areas. This report is part of the national Iranian CSR Study. The percentage change in CSR in 2010 compared to 2006 was conducted in each province, retrospectively. One hundred and ten centers were chosen from all provinces, to determine CSR in each, the weight of major (>3,000 annual surgeries) and minor (3,000 annual surgeries or less) centers was calculated based on the number of selected centers, and multiplied by the number of surgeries in each province. In eight provinces, CSR was decreased by 1-60%. One province (Booshehr) showed no change. Eighteen provinces had 2-79% increase. No 2006 data was available in three provinces. North Khorasan had the most decrease while Kerman had the most increase in CSR. Six of these 8 provinces had CSR>3,000 despite a decrease in 2010, but North Khorasan had CSRCSR had a gap from 3,000 despite an ascending trend, and in two, the gap was quite considerable. Although CSR has an improving trend in most provinces in Iran, it is decreasing in some provinces, and despite an already low CSR, the exacerbation continues. The growing population of over 50 year olds calls for prompt measures in such provinces. Even in improving provinces, some lag behind the minimum recommended by WHO, and the growth rate of the over 50 population reveals the necessity of immediate planning.

  18. Petrogenesis of Jurassic tungsten-bearing granites in the Nanling Range, South China: Evidence from whole-rock geochemistry and zircon U-Pb and Hf-O isotopes

    Science.gov (United States)

    Zhang, Yang; Yang, Jin-Hui; Chen, Jing-Yuan; Wang, Hao; Xiang, Yuan-Xin

    2017-05-01

    The Nanling Range (NLR) is the largest tungsten metallogenic province in China and perhaps in the world. The tungsten mineralization is believed to be related to Jurassic granitic magmatism. However, the petrogenesis of these granites and their relation to the tungsten mineralization are still debated. Whole-rock geochemical and Sr-Nd-Hf isotopic data and zircon in situ U-Pb ages and Hf-O isotopes are reported for W-bearing granitic intrusions from the southern Jiangxi Province in the NLR, in order to constrain their magmatic sources and petrogenesis. The NLR granites include biotite granites, two-mica granites and garnet muscovite granites. SIMS and LA-ICPMS U-Pb dating of zircons and monazites give emplacement ages of 161-154 Ma for these rocks. The granites are metaluminous to strongly peraluminous with high SiO2 (> 72.3 wt.%) and high K2O (> 3.7 wt.%). Petrographic and geochemical features show that they are highly fractionated I-type granites. The biotite granites are enriched in light rare earth elements (LREEs) relative to heavy REEs, have weakly negative Eu anomalies and are depleted in Nb, Ba, P and Ti. In contrast, the two-mica and garnet-bearing muscovite granites have tetrad-type REE patterns with strongly negative Eu anomalies and are extremely depleted in Ba, Nb, Sr, P and Ti. Magmatic garnets are mainly almandine and spessartine, and have low-Mn cores and high-Mn rims. Their (Y + HREE) contents are high and generally decrease from core (1.2 wt.%) to rim (average = 4955 ppm). All of these granites are characterized by variable whole-rock initial 87Sr/86Sr (0.7053-0.8000), εNd(t) (- 12.6 to - 9.4) and εHf(t) (- 12.3 to - 8.5), as well as variable zircon εHf(t) and δ18O, with values of - 16.3 to - 7.4 and 7.6 to 10.0‰, respectively. They contain abundant zircon xenocrysts and xenoliths of micaceous schist. All of these features are consistent with a process of crystal fractionation of crustally-derived magmas coupled with strong assimilation of

  19. Sampling designs for geochemical baseline studies in the Colorado oil shale region: a manual for practical application

    Energy Technology Data Exchange (ETDEWEB)

    Klusman, R. W.; Ringrose, C. D.; Candito, R. J.; Zuccaro, B.; Rutherford, D. W.; Dean, W. E.

    1980-06-01

    This manual presents a rationale for sampling designs, and results of geochemical baseline studies in the Colorado portion of the oil-shale region. The program consists of a systematic trace element study of soils, stream sediments, and plants carried out in a way to be conservative of human and financial resources and yield maximum information. Extension of this approach to other parameters, other locations, and to environmental baseline studies in general is a primary objective. A baseline for any geochemical parameter can be defined as the concentration of that parameter in a given medium such as soil, the range of its concentration, and the geographic scale of variability. In air quality studies, and to a lesser extent for plants, the temporal scale of variability must also be considered. In studies of soil, the temporal variablility does not become a factor until such time that a study is deemed necessary to evaluate whether or not there have been changes in baseline levels as a result of development. The manual is divided into five major parts. The first is a suggested sampling protocol which is presented in an outline form for guiding baseline studies in this area. The second section is background information on the physical features of the area of study, trace elements of significance occurring in oil shale, and the sample media used in these studies. The third section is concerned primarily with sampling design and its application to the geochemical studies of the oil shale region. The last sections, in the form of appendices, provide actual data and illustrate in a systematic manner, the calculations performed to obtain the various summary data. The last segment of the appendices is a more academic discussion of the geochemistry of trace elements and the parameters of importance influencing their behavior in natural systems.

  20. Ecological and geochemical impacts of exotic earthworm dispersal in forest ecosystems of Eastern Canada

    Science.gov (United States)

    Drouin, Melanie; Fugere, Martine; Lapointe, Line; Vellend, Mark; Bradley, Robert L.

    2016-04-01

    In Eastern Canada, native earthworm species did not survive the Wisconsin glaciation, which ended over 11,000 years ago. Accordingly, the 17 known Lumbricidae species in the province of Québec were introduced in recent centuries by European settlers. Given that natural migration rates are no more than 5-10 m yr-1, exotic earthworm dispersal across the landscape is presumed to be mediated by human activities, although this assertion needs further validation. In agroecosystems, earthworms have traditionally been considered beneficial soil organisms that facilitate litter decomposition, increase nutrient availability and improve soil structure. However, earthworm activities could also increase soil nutrient leaching and CO2 emissions. Furthermore, in natural forest ecosystems, exotic earthworms may reduce organic forest floors provoking changes in watershed hydrology and loss of habitat for some faunal species. Over the past decade, studies have also suggested a negative effect of exotic earthworms on understory plant diversity, but the underlying mechanisms remain elusive. Finally, there are no studies to our knowledge that have tested the effects of Lumbricidae species on the production of N2O (an important greenhouse gas) in forest ecosystems. We report on a series of field, greenhouse and laboratory studies on the human activities responsible for the dispersal of exotic earthworms, and on their ecological / geochemical impacts in natural forest ecosystems. Our results show: (1) Car tire treads and bait discarded by fishermen are important human vectors driving the dispersal of earthworms into northern temperate forests; (2) Exotic earthworms significantly modify soil physicochemical properties, nutrient cycling, microbial community structure and biomass; (3) Earthworm abundances in the field correlate with a decrease in understory plant diversity; (4) Lumbricus terrestris, an anecic earthworm species and favorite bait of fishermen, reduces seed germination and

  1. Geochemical and Textural Investigation of an Archean Paleosol, South Roberts Pit, Steep Rock Area, Ontario, Canada

    Science.gov (United States)

    Stafford, S. L.; Capo, R. C.; Stewart, B. W.; MacPherson, G.

    2005-12-01

    Micromorphologic, geochemical and isotopic analysis of an apparent Archean paleosol exposed at South Roberts Pit, Steep Rock area, Superior Province, Canada are consistent with in situ, subaerial weathering followed by potassium metasomatism and greenschist metamorphism. The profile formed on tonalite of the 3.0 Ga Marmion Complex and is unconformably overlain by the basal conglomerates of the >2.7 Ga Steep Rock greenstone series. Only the lowermost part of the soil profile is preserved. Weathering of plagioclase, biotite, ilmenite, titanite, epidote, and apatite likely produced clays such as kaolinite and smectite (now altered to sericite and paragonite) and leucoxene. Micromorphologic evidence of soil-forming processes includes intertexic and agglomeroplasmic fabric, spalling quartz grains, and clay cutans. With increased weathering, quartz and plagioclase decrease and the sericite matrix increases. Rip-up clasts are present at and above the unconformity. Base cations (Ca, Mg, Na, P), Fe and Mn are depleted relative to parent material, while K is enriched. Chondrite-normalized rare earth element (REE) plots for the paleosol show light-REE enrichment, whereas heavy-REE patterns are mostly flat. Parent-normalized patterns indicate some REE mobilization and fractionation during pedogenesis. The low K-corrected chemical index of alteration and modest changes in the overall REE budget indicate that either the profile was not well developed or that the most heavily weathered sections were eroded away. Laser ablation-ICP-MS examination shows that the REE budget is largely controlled by titanite, which is generally LREE-depleted relative to its igneous parent. Eu anomalies (Eu/Eu*) in the paleosol are more negative than that of average parent, consistent with plagioclase weathering. Significant iron loss (>40%), Fe(III)/Fe(II) ratio of >1, and lack of strong Ce anomalies suggest that the paleosol could have formed under conditions sufficient to oxidize Fe, but not Ce

  2. Geochemical data package for the Hanford immobilized low-activity tank waste performance assessment (ILAW PA)

    Energy Technology Data Exchange (ETDEWEB)

    DI Kaplan; RJ Serne

    2000-02-24

    , called the solution concentration limit, a constant value. In future geochemical data packages, they will determine whether a more rigorous measure of solubility is necessary or warranted based on the dose predictions emanating from the ILAW 2001 PA and reviewers' comments. The K{sub d}s and solution concentration limits for each contaminant are direct inputs to subsurface flow and transport codes used to predict the performance of the ILAW system. In addition to the best-estimate K{sub d}s, a reasonable conservative value and a range are provided. They assume that K{sub d} values are log normally distributed over the cited ranges. Currently, they do not give estimates for the range in solubility limits or their uncertainty. However, they supply different values for both the K{sub d}s and solution concentration limits for different spatial zones in the ILAW system and supply time-varying K{sub d}s for the concrete zone, should the final repository design include concrete vaults or cement amendments to buffer the system pH.

  3. Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database

    Science.gov (United States)

    Clegg, Samuel M.; Wiens, Roger C.; Anderson, Ryan; Forni, Olivier; Frydenvang, Jens; Lasue, Jeremie; Cousin, Agnes; Payré, Valérie; Boucher, Tommy; Dyar, M. Darby; McLennan, Scott M.; Morris, Richard V.; Graff, Trevor G.; Mertzman, Stanley A.; Ehlmann, Bethany L.; Belgacem, Ines; Newsom, Horton; Clark, Ben C.; Melikechi, Noureddine; Mezzacappa, Alissa; McInroy, Rhonda E.; Martinez, Ronald; Gasda, Patrick; Gasnault, Olivier; Maurice, Sylvestre

    2017-03-01

    The ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity has obtained > 300,000 spectra of rock and soil analysis targets since landing at Gale Crater in 2012, and the spectra represent perhaps the largest publicly-available LIBS datasets. The compositions of the major elements, reported as oxides (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, K2O), have been re-calibrated using a laboratory LIBS instrument, Mars-like atmospheric conditions, and a much larger set of standards (408) that span a wider compositional range than previously employed. The new calibration uses a combination of partial least squares (PLS1) and Independent Component Analysis (ICA) algorithms, together with a calibration transfer matrix to minimize differences between the conditions under which the standards were analyzed in the laboratory and the conditions on Mars. While the previous model provided good results in the compositional range near the average Mars surface composition, the new model fits the extreme compositions far better. Examples are given for plagioclase feldspars, where silicon was significantly over-estimated by the previous model, and for calcium-sulfate veins, where silicon compositions near zero were inaccurate. The uncertainties of major element abundances are described as a function of the abundances, and are overall significantly lower than the previous model, enabling important new geochemical interpretations of the data.

  4. Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database

    Science.gov (United States)

    Clegg, Samuel M.; Wiens, Roger C.; Anderson, Ryan; Forni, Olivier; Frydenvang, Jens; Lasue, Jeremie; Cousin, Agnes; Payre, Valerie; Boucher, Tommy; Dyar, M. Darby; McLennan, Scott M.; Morris, Richard V.; Graff, Trevor G.; Mertzman, Stanley A; Ehlmann, Bethany L.; Belgacem, Ines; Newsom, Horton E.; Clark, Ben C.; Melikechi, Noureddine; Mezzacappa, Alissa; McInroy, Rhonda E.; Martinez, Ronald; Gasda, Patrick J.; Gasnault, Olivier; Maurice, Sylvestre

    2017-01-01

    The ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity has obtained > 300,000 spectra of rock and soil analysis targets since landing at Gale Crater in 2012, and the spectra represent perhaps the largest publicly-available LIBS datasets. The compositions of the major elements, reported as oxides (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, K2O), have been re-calibrated using a laboratory LIBS instrument, Mars-like atmospheric conditions, and a much larger set of standards (408) that span a wider compositional range than previously employed. The new calibration uses a combination of partial least squares (PLS1) and Independent Component Analysis (ICA) algorithms, together with a calibration transfer matrix to minimize differences between the conditions under which the standards were analyzed in the laboratory and the conditions on Mars. While the previous model provided good results in the compositional range near the average Mars surface composition, the new model fits the extreme compositions far better. Examples are given for plagioclase feldspars, where silicon was significantly over-estimated by the previous model, and for calcium-sulfate veins, where silicon compositions near zero were inaccurate. The uncertainties of major element abundances are described as a function of the abundances, and are overall significantly lower than the previous model, enabling important new geochemical interpretations of the data.

  5. Carbon sequestration via reaction with basaltic rocks: geochemical modeling and experimental results

    Science.gov (United States)

    Rosenbauer, Robert J.; Thomas, Burt; Bischoff, James L.; Palandri, James

    2012-01-01

    Basaltic rocks are potential repositories for sequestering carbon dioxide (CO2) because of their capacity for trapping CO2 in carbonate minerals. We carried out a series of thermodynamic equilibrium models and high pressure experiments, reacting basalt with CO2-charged fluids over a range of conditions from 50 to 200 °C at 300 bar. Results indicate basalt has a high reactivity to CO2 acidified brine. Carbon dioxide is taken up from solution at all temperatures from 50 to 200 °C, 300 bar, but the maximum extent and rate of reaction occurs at 100 °C, 300 bar. Reaction path simulations utilizing the geochemical modeling program CHILLER predicted an equilibrium carbonate alteration assemblage of calcite, magnesite, and siderite, but the only secondary carbonate identified in the experiments was a ferroan magnesite. The amount of uptake at 100 °C, 300 bar ranged from 8% by weight for a typical tholeite to 26% for a picrite. The actual amount of CO2 uptake and extent of rock alteration coincides directly with the magnesium content of the rock suggesting that overall reaction extent is controlled by bulk basalt Mg content. In terms of sequestering CO2, an average basaltic MgO content of 8% is equivalent to 2.6 × 108 metric ton CO2/km3 basalt.

  6. The giant Jiaodong gold province: The key to a unified model for orogenic gold deposits?

    Directory of Open Access Journals (Sweden)

    David I. Groves

    2016-05-01

    Full Text Available Although the term orogenic gold deposit has been widely accepted for all gold-only lode-gold deposits, with the exception of Carlin-type deposits and rare intrusion-related gold systems, there has been continuing debate on their genesis. Early syngenetic models and hydrothermal models dominated by meteoric fluids are now clearly unacceptable. Magmatic-hydrothermal models fail to explain the genesis of orogenic gold deposits because of the lack of consistent spatially – associated granitic intrusions and inconsistent temporal relationships. The most plausible, and widely accepted, models involve metamorphic fluids, but the source of these fluids is hotly debated. Sources within deeper segments of the supracrustal successions hosting the deposits, the underlying continental crust, and subducted oceanic lithosphere and its overlying sediment wedge all have their proponents. The orogenic gold deposits of the giant Jiaodong gold province of China, in the delaminated North China Craton, contain ca. 120 Ma gold deposits in Precambrian crust that was metamorphosed over 2000 million years prior to gold mineralization. The only realistic source of fluid and gold is a subducted oceanic slab with its overlying sulfide-rich sedimentary package, or the associated mantle wedge. This could be viewed as an exception to a general metamorphic model where orogenic gold has been derived during greenschist- to amphibolite-facies metamorphism of supracrustal rocks: basaltic rocks in the Precambrian and sedimentary rocks in the Phanerozoic. Alternatively, if a holistic view is taken, Jiaodong can be considered the key orogenic gold province for a unified model in which gold is derived from late-orogenic metamorphic devolatilization of stalled subduction slabs and oceanic sediments throughout Earth history. The latter model satisfies all geological, geochronological, isotopic and geochemical constraints but the precise mechanisms of auriferous fluid release, like many

  7. Minnesota Pheasant Range

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset delineates the spatial range of wild pheasant populations in Minnesota as of 2002 by dividing the MN state boundary into 2 units: pheasant range and...

  8. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2014-01-01

    We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. We show how to solve substring range reporting with optimal query time and little...... for substring range reporting generalize to substring range counting and substring range emptiness variants. We also obtain non-trivial time-space trade-offs for these problems. Our bounds for substring range reporting are based on a novel combination of suffix trees and range reporting data structures...

  9. Spectroscopic geochemical study of vanadiferous marine sediments of the Gibellini claims, southern Fish Creek Range, Eureka County, Nevada

    Science.gov (United States)

    Böhlke, J.K.; Radtke, A.S.; Heropoulos, Chris; Lamothe, P.J.

    1981-01-01

    Samples of cuttings from three drill holes in the Gibellini claims were analyzed by emission spectroscopic techniques for a large suite of major and trace elements. Unoxidized siliceous "black shale" from drill hole NGA 7 is strongly enriched in Cd, Mo, Sb, Se, V, and Zn, and also contains relatively high concentrations of As, Ba, Cu, Ni, and Tl compared with nonmetalliferous shales. Analyses of 103 samples plotted against depth in drill holes NGA, NG31, and NGA7, and selected XRD data, show the following: 1. Groups of elements with distinct distribution patterns define most of major mineralogic components of the rocks. The "normal shale" component, which includes several detrital and authigenic phases, is indicated by covariations among Ti, Al, Fe, Na, Mg, K, B, Be, Co, Cr, Ga, La, Sc, Sr, and Zr. The shale component is diluted by varying amounts of the following minerals (and associated elements): silica (Si); dolomite (Mg, Ca, Mn, Sr); apatite (Ca, Be, Cr, La, Sr, Y); barite (Ba, Sr); sphalerite (Zn, Cd, Fe?); smithsonite (Cd, Co, Mn, Ni, Zn); bianchite (Cd, Ni, Zn) ; and bokite (V). Pyrite, gypsum, and jarosite were also identified.2. The highly siliceous kerogenous metalliferous Gibellini facies is underlain by argillaceous and (or) dolomitic rocks. The transition zone deduced from the chemical data is not well defined in all instances, but probably represents the bottom of the black shale deposit. 3. Oxidation has reached to variable depths up to at least 150 ft, and has caused profound changes in the distributions of the enriched metals. Molybdenum, Se, and V have been partially removed from the upper parts of the sections and are concentrated near or slightly above the base of the Gibellini facies. Cadmium, Ni, and Zn have been strongly leached and now occur at or below the base of the Gibellini facies. The variable depth of oxidation, the redistribution and separation of the metals, and the complex mineralogy of the deposit may make development of the claim complicated.

  10. [Analysis of perfluoroalkyl substances precursors in human milk from 12 provinces of China].

    Science.gov (United States)

    Yang, Lin; Yu, Xinping; Wang, Meng; Li, Jingguang; Wang, Yuxin; Zhao, Yunfeng; Wu, Yongning

    2015-06-01

    To explore the level of perfluoroalkyl substances (PFASs) precursors in Chinese human milk samples. The human milk samples were collected during the performance of Stockholm convention on survey of human milk in China in 2007. Based on the geographical location and dietary habits, China was divided into the south area and north area which 6 provinces were chosen from each area and there were 12 provinces in all. In each province, one urban site and two rural sites were selected to collect 80-110 samples. Mothers were randomly selected in each site to collect their breast milk. There were 1 237 individual human milk samples in all. For each province, the individual samples from the urban areas and the rural areas were pooled separately resulting in 24 pooled human milk samples. 11 PFAS precursors were measured in pooled samples by ultra-high performance liquid chromatography-tandem quadruple mass spectrometry (UPLC-MS/MS). The dietary exposure assessment of newborns was made. Three PFAS precursors were found above the detection limits, namely, 6:2 FTS, FHUEA, and 6:2 diPAP. Their concentration ranges were PFAS precursor concentration 77.70 pg/ml was found in urban area samples from Shannxi Province. Rural area samples from Hubei had the lowest total PFAS precursor concentration, which was below the LOD. There were significant differences between rural and urban areas in many provinces, such as Shannxi (rural: 1.51 pg/ml; urban: 77.70 pg/ml), Shanghai (rural: 1.13 pg/ml; urban: 71.88 pg/ml), Jiangxi (rural: 65.39 pg/ml; urban: 0.55 pg/ml) and so on. The ranges estimated daily intake of 6:2 FTS, FHUEA and 6:2 diPAP of the samples from 12 provinces were 0.05-4.51, 1.13-6.72 and 1.15-3.34 ng · kg⁻¹ · d⁻¹. The results suggested the human exposure of PFAS precursors in China and the potential health impact of postnatal exposure through breastfeeding to infants. The level of PFAS precursors showed differences in regions, rural and urban places.

  11. Systemic autoimmune rheumatic disease prevalence in Canada: updated analyses across 7 provinces.

    Science.gov (United States)

    Broten, Laurel; Aviña-Zubieta, J Antonio; Lacaille, Diane; Joseph, Lawrence; Hanly, John G; Lix, Lisa; O'Donnell, Siobhan; Barnabe, Cheryl; Fortin, Paul R; Hudson, Marie; Jean, Sonia; Peschken, Christine; Edworthy, Steven M; Svenson, Larry; Pineau, Christian A; Clarke, Ann E; Smith, Mark; Bélisle, Patrick; Badley, Elizabeth M; Bergeron, Louise; Bernatsky, Sasha

    2014-04-01

    To estimate systemic autoimmune rheumatic disease (SARD) prevalence across 7 Canadian provinces using population-based administrative data evaluating both regional variations and the effects of age and sex. Using provincial physician billing and hospitalization data, cases of SARD (systemic lupus erythematosus, scleroderma, primary Sjögren syndrome, polymyositis/dermatomyositis) were ascertained. Three case definitions (rheumatology billing, 2-code physician billing, and hospital diagnosis) were combined to derive a SARD prevalence estimate for each province, categorized by age, sex, and rural/urban status. A hierarchical Bayesian latent class regression model was fit to account for the imperfect sensitivity and specificity of each case definition. The model also provided sensitivity estimates of different case definition approaches. Prevalence estimates for overall SARD ranged between 2 and 5 cases per 1000 residents across provinces. Similar demographic trends were evident across provinces, with greater prevalence in women and in persons over 45 years old. SARD prevalence in women over 45 was close to 1%. Overall sensitivity was poor, but estimates for each of the 3 case definitions improved within older populations and were slightly higher for men compared to women. Our results are consistent with previous estimates and other North American findings, and provide results from coast to coast, as well as useful information about the degree of regional and demographic variations that can be seen within a single country. Our work demonstrates the usefulness of using multiple data sources, adjusting for the error in each, and providing estimates of the sensitivity of different case definition approaches.

  12. The Upper Miocene magmatism of the Island of Elba (Central Italy): compositional characteristics, petrogenesis and implications for the origin of the Tuscany Magmatic Province

    Science.gov (United States)

    Poli, Giampiero; Peccerillo, Angelo

    2016-08-01

    Late Miocene intrusive magmatism of the Island of Elba, Tuscany (central Italy), consists of stocks, laccoliths, sills, and dikes showing dominant monzogranite and granodiorite compositions, with minor leucogranitic dike-sill complexes, aplites and pegmatites. A few mafic rocks occur as dikes, and as microgranular enclaves hosted inside the main intrusions. The Elba magmatism belongs to the Tuscan Magmatic Province, an 8.5 to 0.3 Ma old association of mafic to felsic rocks, of mantle and crustal origin, cropping out in Tuscany and northern Latium. Major and trace element abundances of Elba rocks are extremely variable, testifying to complex origin and evolutionary history for magmas. 87Sr/86Sr (~ 0.708-0.723) and 143Nd/144Nd (~0.5121-0.5124) are close or within the field of upper continental crust, with mafic dikes showing the lowest Sr- and the highest Nd-isotope ratios. Petrological, geochemical and textural data of Elba igneous rocks are better explained by invoking a leading role for multiple mixing processes between crust-derived felsic magmas and mafic-intermediate melts of ultimate mantle origin, accompanied by fractional crystallisation. Proxies of crustal anatectic melts are represented by some highly radiogenic-Sr rocks from northern Monte Capanne pluton. Crustal magmas were formed by melting of sedimentary rocks, likely metagreywakes, at pressures exceeding 0.3 GPa. Mafic-intermediate magmas have calcalkaline to shoshonitic compositions and originated in an anomalous mantle, moderately contaminated by siliceous sediments. Selective enrichments in Sr, Ba and LREE are shown by some intermediate rocks (Orano dikes), revealing the occurrence of a distinct magma type at Elba. Similar compositions are also observed at Capraia island, San Vincenzo and Campiglia (southern Tuscany), suggesting a regional relevance for this magma type. Sr-Ba-LREE-rich rocks do not show obvious genetic relationships with other Tuscany magmas and may represent a distinct end

  13. Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska

    Science.gov (United States)

    Dusel-Bacon, Cynthia; Slack, John F.; Koenig, Alan E.; Foley, Nora K.; Oscarson, Robert L.; Gans, Kathleen D.

    2011-01-01

    This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of sulfide minerals determined by electron microprobe and laser ablation—inductively coupled plasma—mass spectrometry (LA-ICP-MS) techniques. The PDF consists of text, appendix explaining the analytical methods used for the analyses presented in the data tables, a sample location map, and seven data tables. The seven tables are also available as spreadsheets in several file formats. Descriptions and discussions of the Bonnifield deposits are given in Dusel-Bacon and others (2004, 2005, 2006, 2007, 2010).

  14. The leaching behaviour and geochemical fractionation of trace elements in hydraulically disposed weathered coal fly ash.

    Science.gov (United States)

    Nyale, Sammy M; Eze, Chuks P; Akinyeye, Richard O; Gitari, Wilson M; Akinyemi, Segun A; Fatoba, Olanrewaju O; Petrik, Leslie F

    2014-01-01

    A five-step sequential extraction (SE) procedure was used to investigate the leaching behaviour and geochemical partitioning of the trace elements As, Zn, Pb, Ni, Mo, Cr and Cu in a 20-year-old fly ash (FA) dump. The weathered FA, which was hydraulically co-disposed with salt laden brine in slurry form (FA: brine ratio of 1:5), was analyzed and compared with fresh FA. The weathered FA samples were collected from three cores, drilled at a coal-fired power station in the Republic of South Africa while the fresh FA sample was collected from the hoppers in the ash collection system at the power station. The FA samples were sequentially leached using: ultrapure water; ammonium acetate buffer solution (pH 7); ammonium acetate buffer solution (pH 5); hydroxylamine hydrochloride in nitric acid (pH 2) and finally the residues were digested using a combination of HClO4: HF: HNO3 acids. Digestion of as received (unleached) FA samples was also done using a combination of HClO4: HF: HNO3 acids in order to determine the total metal content. The trace element analysis was done using ICP-OES (Varian 710-ES). The SE procedure revealed that the trace elements present in the fresh FA and the weathered FA samples obtained from the three cores could leach upon exposure to different environmental conditions. The trace elements showed continuous partitioning between five geochemical phases i.e., water soluble fraction, exchangeable fraction, carbonate fraction, Fe and Mn fraction and residual fraction. Although the highest concentration of the trace elements (ranging 65.51%-86.34%) was contained in the residual fraction, a considerable amount of each trace element (ranging 4.42%-27.43%) was released from the labile phases (water soluble, exchangeable and carbonate fractions), indicating that the trace species readily leach from the dumped FA under environmental conditions thus pose a danger to the receiving environment and to groundwater.

  15. Human rabies in Zhejiang Province, China.

    Science.gov (United States)

    Ren, Jiangping; Gong, Zhenyu; Chen, Enfu; Lin, Junfen; Lv, Huakun; Wang, Wei; Liu, Shelan; Sun, Jimin

    2015-09-01

    To explore the epidemiological characteristics of human rabies in Zhejiang Province, China. Descriptive and statistical analyses were performed using data collected through interview with human rabies cases or their relatives during 2007 to 2014. A standardized questionnaire was used to collect the data. Two hundred and one cases of human rabies were diagnosed in Zhejiang Province between 2007 and 2014, with a gradually declining annual incidence. Of the rabies cases identified, 61.2% were aged 40-65 years, and the male to female ratio was 2.30:1; 63.7% of cases occurred in the summer and autumn. The two most reported occupations were farmer (69.2%) and rural laborer (15.4%). Wenzhou, Jinhua, and Huzhou were the three cities with the most reported cases. The majority of cases (92.8%) were attributed to canines, and 71.0% of animal vectors were household animals. Less than half of the cases (41.4%) sought wound treatment after exposure. Post-exposure passive immunization was given to 9.7% and active immunization to 2.3%. Cases with a wound on the head/face only had a significantly shorter incubation than those with wounds at other sites (prabies cases occurred among 40-65-year-old male residents of northern, mid-west, and southeast Zhejiang Province. Further health education is needed to increase the coverage of post-exposure prophylaxis (PEP) in people exposed to possible rabid animals and rabies vaccine use in household animals. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Assessing Hospital Disaster Preparedness of Bushehr province

    Directory of Open Access Journals (Sweden)

    Hakimeh Vahedparast

    2013-04-01

    Full Text Available Background: In disasters, large number of causalities rash into the hospitals in order to get health facilities. So, hospitals are the reference point for delivering the health services in all levels for helping to the most percent of injured people. Aim of study was to assess hospital disaster preparedness of Bushehr province. Maretial and Methods: This was a cross-sectional descriptive study which has been done in all Bushehr province hospitals. In order to collect data, we used 210 questions checklist with 10 different aims each aim had consisted of 6 different domains (equipment, working stuff, physical space, structure, protocols and functional chart. The checklists were completed by direct observation and evaluation of equipment, programs and documents based on their domains with different people. Results: The hospital preparedness in traffic base was very poor with mean number of 19/04±16/10 evaluation of security education and management domain with mean number 35/29±26/52, 38/65±19/46, 36/36±24/05, respectively were poor. In logistics, workforce, communications, excused transportation and addition to the hospitals with the mean number of 53/26±26/31, 49/65±27/61, 45/53±18/29, 43/33±19/72, and 40/47±20/37 were estimated as average. The most number was belonged to the emergency with the mean number of 53/80±19/18. Conclusion: The Bushehr province hospitals have not enough preparation against unexpected disasters and cannot be a good supporter for disaster happening, and in the occasions of happenings so many serious problems will occur. It will be suggested that the hospital managers should pay more attention to the unexpected disasters.

  17. Geochemical signature of columbite-tantalite and radiometric survey of radioactive pegmatites in the region of Parelhas, Rio Grande do Norte, Brazil; Assinatura geoquimica de columbita-tantalita e levantamento radiometrico de pegmatitos radioativos da regiao de Parelhas, RN, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Jorge Costa de

    2013-07-01

    This thesis is the result of geochemical, structural and radiometric investigations on radioactive pegmatites of the Borborema Pegmatitic Province in Northeast Brazil. The studied area, located in the surroundings of the city of Parelhas in the region of the Serra da Borborema, is well known for its thousands of pegmatitic bodies exploited in primitive mines called 'garimpos'. The main goal was to find an efficient, cheap and routine inspection procedure to identify the origin of commercialized radioactive columbite-tantalite (coltan) ore. The Brazilian Nuclear Energy Agency (CNEN) controls uranium commerce and nuclear activity in Brazil. Without an effective method to characterize coltan ores from different localities it is impossible to control the trade. The here presented new method was developed by correlating structural features of these pegmatites with the geochemical behavior of their coltan samples. It was found that the variation of the ratio U/Th versus Nb{sub 2}O{sub 5}/Ta{sub 2}O{sub 5} provides geochemical signatures (analytical fingerprints) for the source location of such ore. A test of the new method with coltan samples of commercial batches from the Brazilian states Amapa and Rondonia also generated distinct geochemical signatures. A radiometric survey (CPS) was carried out in several mines and pegmatites to study the environmental impact of gamma radiation. It included in situ measurements of pegmatite walls, host rocks, soil, and accumulated water and revealed that gamma emitters are hardly solubilized and environmental gamma radiation therefore generally is not enhanced to a dangerous level. (author)

  18. Geochemical characteristics of West Molokai shield- and postshield-stage lavas: Constraints on Hawaiian plume models

    Science.gov (United States)

    Xu, Guangping; Frey, Frederick A.; Clague, David A.; Abouchami, Wafa; Blichert-Toft, Janne; Cousens, Brian; Weisler, Marshall

    2007-08-01

    There are systematic geochemical differences between the Hawaiian shields forming the subparallel spatial trends, known as Loa and Kea. These spatial and temporal geochemical changes provide insight into the spatial distribution of geochemical heterogeneities within the source of Hawaiian lavas, and the processes that create the Hawaiian plume. Lavas forming the ˜1.9 Ma West Molokai volcano are important for evaluating alternative models proposed for the spatial distribution of geochemical heterogeneities because (1) the geochemical distinction between Loa and Kea trends may end at the Molokai Fracture Zone and (2) West Molokai is a Loa-trend volcano that has exposures of shield and postshield lavas. This geochemical study (major and trace element abundances and isotopic ratios of Sr, Nd, Hf, and Pb) shows that the West Molokai shield includes lavas with Loa- and Kea-like geochemical characteristics; a mixed Loa-Kea source is required. In contrast, West Molokai postshield lavas are exclusively Kea-like. This change in source geochemistry can be explained by the observed change in strike of the Pacific plate near Molokai Island so that as West Molokai volcano moved away from a mixed Loa-Kea source it sampled only the Kea side of a bilaterally zoned plume.

  19. Landscape and bio- geochemical strategy for monitoring transformation and reclamation of the soil mining sites

    Science.gov (United States)

    Korobova, Elena

    2010-05-01

    Sites of active or abandoned mining represent areas of considerable technogenic impact and need scientifically ground organization of their monitoring and reclamation. The strategy of monitoring and reclamation depends on the scale and character of the physical, chemical and biological consequences of the disturbances. The geochemical studies for monitoring and rehabilitation of the career-dump complexes should methodically account of formation of the particular new landforms and the changes in circulation of the remobilized elements of the soil cover. However, the general strategy should account of both the initial and transformed landscape geochemical structure of the area with due regard to the natural and new content of chemical elements in the environmental components. For example the tailings and waste rocks present new geochemical fields with specifically different concentration of chemical elements that cause formation of new geochemical barriers and landscapes. The way of colonization of the newly formed landscapes depends upon the new geochemical features of the technogenic environment and the adaptive ability of local and intrusive flora. The newly formed biogeochemical anomalies need organization of permanent monitoring not only within the anomaly itself but also of its impact zones. Spatial landscape geochemical monitoring combined with bio-geochemical criteria of threshold concentrations seems to be a helpful tool for decision making on reclamation and operation of the soil mining sites to provide a long-term ecologically sustainable development of the impact zone as a whole.

  20. Contributions to Bryophyte Flora of Zonguldak Province

    Directory of Open Access Journals (Sweden)

    Muhammet ÖREN

    2015-12-01

    Full Text Available With this study, some new bryophyte taxa have been added for the bryophyte flora of Zonguldak. One taxon from Anthoceratophyta (Hornworts, 11 from Marchantiophyta (Liverworts and 55 from Bryophyta (Mosses, totally 67 taxa are determined as new for the bryophyte flora of Zonguldak province with examination of specimens collected from field trips held on different habitats between 2012-2014. Among them, 14 taxa are newly reported from A2 square according to the Henderson grid system. Considering previous studies, the number of specific and infra specific taxa in the research area are reached up to 282.

  1. Timing and duration of the Central Atlantic magmatic province in the Newark and Culpeper basins, eastern U.S.A.

    Science.gov (United States)

    Marzoli, Andrea; Jourdan, Fred; Puffer, John H.; Cuppone, Tiberio; Tanner, Lawrence H.; Weems, Robert E.; Bertrand, Hervé; Cirilli, Simonetta; Bellieni, Giuliano; De Min, Angelo

    2011-03-01

    New major and trace element data and 40Ar/ 39Ar plateau ages constrain the timing, duration and time-related geochemical evolution of the Central Atlantic magmatic province in the U.S.A. (Newark and Culpeper basins) and refine correlations with basaltic lava flows from other Late Triassic-Early Jurassic circum-Atlantic basins. The precise, statistically robust 40Ar/ 39Ar plateau ages were obtained on biotite and on fresh plagioclase and calculated using the latest 40K decay constants. These ages are supported by a general consistency of the Ca/K calculated from 37Ar/ 39Ar of the plateau steps and the Ca/K obtained by detailed electron microprobe analyses on plagioclase phenocrysts. The ages of five analyzed basalt lava flows, from all three lava flow units in the Newark basins, and the ages of two sill samples are indistinguishable, indicating a brief magmatic peak phase at 201.8 ± 0.7 Ma. Recalibrated 40Ar/ 39Ar plateau ages from the entire province indicate a near-synchronous onset and peak volcanic activity at the Triassic-Jurassic boundary within the circum-Atlantic basins from the U.S.A., Canada and Morocco. The early erupted magmas (Moroccan Lower to Upper basalts, the Fundy basin North Mountain Basalt, and Orange Mountain and equivalent U.S.A. flows) yield an enriched geochemical signature (e.g., with relatively high La/Yb), whereas late magmas in the U.S.A. (Hook Mountain and Hampden basalts) and Morocco (Recurrent basalt) yield relatively depleted geochemical compositions (low La/Yb). A slight, but significant age difference for eruption of Hook Mountain and Hampden basalts (200.3 ± 0.9 Ma) and Recurrent basalts (198.2 ± 1.1 Ma) is interpreted as evidence of a diachronous northward rift-drift transition during break-up of Pangea. Our data indicate also a prolonged intrusive sequence that continued until about 195 Ma at the Palisades sill and is consistent with sporadic late CAMP magmatism for dykes from the south-eastern U.S.A. and for intrusions from

  2. Central Colorado Assessment Project (CCAP)-Geochemical data for rock, sediment, soil, and concentrate sample media

    Science.gov (United States)

    Granitto, Matthew; DeWitt, Ed H.; Klein, Terry L.

    2010-01-01

    This database was initiated, designed, and populated to collect and integrate geochemical data from central Colorado in order to facilitate geologic mapping, petrologic studies, mineral resource assessment, definition of geochemical baseline values and statistics, environmental impact assessment, and medical geology. The Microsoft Access database serves as a geochemical data warehouse in support of the Central Colorado Assessment Project (CCAP) and contains data tables describing historical and new quantitative and qualitative geochemical analyses determined by 70 analytical laboratory and field methods for 47,478 rock, sediment, soil, and heavy-mineral concentrate samples. Most samples were collected by U.S. Geological Survey (USGS) personnel and analyzed either in the analytical laboratories of the USGS or by contract with commercial analytical laboratories. These data represent analyses of samples collected as part of various USGS programs and projects. In addition, geochemical data from 7,470 sediment and soil samples collected and analyzed under the Atomic Energy Commission National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) program (henceforth called NURE) have been included in this database. In addition to data from 2,377 samples collected and analyzed under CCAP, this dataset includes archived geochemical data originally entered into the in-house Rock Analysis Storage System (RASS) database (used by the USGS from the mid-1960s through the late 1980s) and the in-house PLUTO database (used by the USGS from the mid-1970s through the mid-1990s). All of these data are maintained in the Oracle-based National Geochemical Database (NGDB). Retrievals from the NGDB and from the NURE database were used to generate most of this dataset. In addition, USGS data that have been excluded previously from the NGDB because the data predate earliest USGS geochemical databases, or were once excluded for programmatic reasons

  3. [Geochemical distribution of dissolved bismuth in the Yellow Sea and East China Sea].

    Science.gov (United States)

    Wu, Xiao-Dan; Song, Jin-Ming; Wu, Bin; Li, Xue-Gang

    2014-01-01

    Occurrence level, geochemical distribution of dissolved bismuth and its coupling relationship to eco-environment were investigated in the Yellow Sea and East China Sea to explore the source and influencing factors. The results showed that the concentration of dissolved bismuth was within the range of 0-0. 029 microg x L(-1) at the surface and 0.001-0.189 microg x L(-1) at the bottom, with the averages of 0.008 and 0.016 microg x L(-1), respectively. Horizontally, low value of dissolved bismuth exhibited the bidirectional extension feature, indicating that it could trace the path of Changjiang Diluted Water. High value of dissolved bismuth was observed where the Subei Costal Current and Yellow Sea Warm Current flowed and the Changjiang Diluted Water and Zhejiang-Fujian Coastal Current met, suggesting that it was controlled by the cycle of current system. Vertically, the coastal water was fully mixed by water convection and eddy mixing, and was divided from the stratified water by strong tidal front, which blocked the transport of dissolved bismuth to the open sea. Thus, the concentration in front area was significantly higher than that in the open sea. Diurnal variation of dissolved bismuth was related to the hydrodynamic conditions (tide, suspension and thermocline) instead of the environmental factors (temperature and salinity). Positive relationship to SPM (suspended particulate matter) clarified that bismuth was prone to release from solid phase to liquid phase. Furthermore, conditions with temperature ranging 22-27 degrees C, salinity ranging 28-31 and pH ranging 7.9-8.1 were shown to be optimal for the release process.

  4. Molecular Identification of Giardia duodenalis Isolates from Fars Province, Iran.

    Directory of Open Access Journals (Sweden)

    Mohammad Rayani

    2014-03-01

    Full Text Available Giardia duodenalis is one of the most common human intestinal protozoan parasites worldwide and is endemic throughout the world with a vast range of mammalian hosts. The present study aimed to identify the prevalence of G. duodenalis isolates and determine the most common of its assemblages in the patients referring to health centers and hospitals in Fars province, Iran that will be subjected to further molecular investigation.We collected 1000 human fecal samples from health centers and hospitals in Shiraz, Iran in a one year period from September 2009 to August 2010. Microscopic examination for the presence of G. duodenalis cysts and trophozoites was performed by direct wet mount before and after the concentration techniques. Extraction of DNA was performed by Phenol-Chloroform-Isoamylalcohol (PCI. G. duodenalis-positive specimens were analyzed by PCR. A fragment of the SSU-rDNA (292 bp gene was amplified by PCR using the forward primer RH11 and the reverse primer RH4. Genotyping was performed using sequence analysis of G. duodenalis glutamate dehydrogenase gene using primers GDHeF, GDHiF, and GDHiR.The prevalence of Giardia infection was 10.7% (107/1000 examined based on microscopic examination. PCR identified 80% (40/50 of the samples as positive for G. duodenalis based on SSU-rDNA amplification on sucrose gradient samples. Besides, genotyping results indicated 32 isolates (80% as assemblage AII and 8 isolates (20% as assemblage BIII and BIV based on the DNA sequence analysis of the glutamate dehydrogenase locus of G. duodenalis.The findings of this study emphasize that Iran (Fars Province is a favorable area for giardiasis with an anthroponotic infection route.

  5. Behaviour of major, minor and trace elements (including REEs during kaolinization processes at Zonouz deposit, northeast of Marand, East Azarbaidjan province

    Directory of Open Access Journals (Sweden)

    Vahideh Alipour

    2011-11-01

    Full Text Available The Zonouz kaolin deposit is located ~15 km northeast of Marand, East-Azarbaidjan province. Based on physical features in field investigations, such as color, five distinct kaolin types including (1 white, (2 lemon, (3 gray, (4 brown, and (5 yellow are distinguished in the deposit. Field evidence and petrographic studies indicate that the deposit is genetically close to trachy-andesite rocks. According to mineralogical data, the deposit contains quartz, kaolinite, montmorillonite, calcite, pyrophyllite, chlorite, muscovite-illite, dolomite, hematite, and anatase minerals. Geochemical data indicate that function of alteration processes on trachy-andesite rocks during development of Zonouz ore deposit was accompanied by leaching of elements such as Al, Na, K, Rb, Ba, V, Hf, Cu, Zr, Tm, Yb, and Lu, enrichment of elements such as U, Nb, and Ta, and leaching-fixation of elements such as Si, Fe, Ca, Mg, Ti, Mn, P, Cs, Sr, Th, Co, Cr, Ni, Y, Ga, LREE, Tb, Dy, Ho, and Er. Incorporation of obtained results from mineralogical and geochemical studies show that physico-chemical conditions of alteration environment, the relative stability of primary minerals, surface adsorption, preferential sorption by metallic oxides, existing of organic matters, scavenging and concentration processes, and fixation in neomorphic mineralogical phases played important role in distribution of elements in the deposit. Geochemical studies show that development of the deposit is relative to two types of processes, (1 hypogene and (2 supergene. The distribution pattern of REEs indicates that differentiation degree of LREEs from HREEs in supergene kaolins is more than hypogene kaolins. Geochemical studies indicate that minerals such as Mn-oxides, zircon, anatase, hematite, cerianite, and secondary phosphates (monazite, rhabdophane, churchite, and zenotime are the potential hosts for rare earth elements in this deposit.

  6. Fingerprints of environmental stressors in three selected Slovenian gravel-bed rivers: geochemical and isotopic approach

    Science.gov (United States)

    Kanduč, Tjaša; Kocman, David; Debeljak, Barbara; Mori, Nataša

    2016-04-01

    Rivers are severely impacted by a range of simultaneous processes including water pollution, flow and channel alteration, over-fishing, invasive species and climate change. Systematic studies of river water geochemistry provide important information on chemical weathering of bedrock/soil and natural anthropogenic processes that may control the dissolved chemical loads, while the isotopic studies of biological components of river systems (macrophytes, periphyton, heterotrophic biofilm, invertebrates, fish) contribute to the understanding how the system response to human impacts by means of functional response. In this contribution, insights in the fingerprints of various environmental stressors in three gravel-bed rivers (River Kamni\\vska Bistrica, River Idrijca and River Sava) in Slovenia, using geochemical and stable isotope approach are discussed. Gravel bed of all three rivers investigated is composed of carbonates and clastic rocks. The Sava and Kamni\\vska Bistrica Rivers have alpine high mountain snow-rain regime. The Idrijca River is a boundary river between the Adriatic and Black Sea catchments and has rain-snow discharge regime with torrential character. Geochemical methods (ICP-OES, IC, total alkalinity after Gran) and isotope mass - spectrometric methods (isotopic composition of dissolved inorganic carbon, particulate organic carbon and isotopic composition of carbon in carbonates) were used to evaluate biogeochemical processes in rivers. Isotopic composition of carbon and nitrogen of the moss Fontinalis antipyretica (the whole vegetative shoot) and isotopic composition of carbon of heterotrophic biofilm was also analyzed in order to better understand the fluxes and fractionation of carbon and nitrogen across trophic levels. Geochemical composition of all investigated rivers is HCO3--Ca2+-Mg2+ with different Mg2+/Ca2+ ratios as follows: around 0.33 for Kamni\\vska Bistrica and River Sava in Slovenia and above 0.75 for River Idrijca. In the Kamni

  7. New Results for the Multi-stage Geochemical Evolution of the Manihiki and Hikurangi Plateaus (Invited)

    Science.gov (United States)

    Hoernle, K.; Timm, C.; Hauff, S. F.; Rupke, L.; Werner, R.; van den Bogaard, P.; Michael, P. J.; Coffin, M.; Mortimer, N. N.; Davy, B. W.

    2009-12-01

    The Hikurangi and Manihiki Plateaus, extensively sampled on the SONNE 168 and 193 cruises, have a similar temporal and geochemical evolution. The two plateaus began with a main tholeiitic plateau stage (c. 126-116 Ma) followed by a later (seamount-forming) alkalic stage of volcanism (lasting more than 30 Ma on each plateau). The tholeiitic lavas have largely similar compositions to the Kwaimbaita/Kroenke and Singgalo lavas from the Ontong Java Plateau (OJP), but some from the Suvarov Trough on the Manihiki Plateau have distinct compositions similar to those reported by Ingle et al. (2007, Geology). Glasses from the tholeiitic plateau stage lavas from two different sites on the Manihiki Plateau have CO2 and H2O contents indicating depths of eruption of 900± 200 m and 1300 ± 200 m. The H2O/Ce ratios (220-400) are at the high end of MORB, similar to the OJP, and therefore volatiles are unlikely to play a major role in melt generation. Using the method of Herzberg and Asimov (2008, G3), the Manihiki tholeiites can be generated by ~30% melting of a peridotitic source at temperatures of ~1510°C (similar to results from the OJP). The S contents are even lower than for the OJP, suggesting that the source was depleted in S. The tholeiitic plateau stage lavas are characterized by generally flat incompatible element patterns on multi-element diagrams, similar to other oceanic plateaus such as the OJP. The mafic alkalic late stage lavas, on the other hand, have steep patterns (characteristic of ocean island basalts), indicating lower degrees of melting and/or enrichment in highly to moderately incompatible elements and residual garnet in the source relative to the plateau stage. The Sr-Nd-Pb-Hf isotope data for the plateau rocks indicate compositions ranging from E-MORB (or FOZO)-like, similar to the major Kwaimbaita/Kroenke compositional group of lavas on the OJP, to EM1-type compositions, characteristic of the Singgalo endmember on the OJP. The late-stage alkalic rocks

  8. Drought Characteristics over the Western Cape Province, South Africa

    National Research Council Canada - National Science Library

    Christina M Botai; Joel O Botai; Jaco P de Wit; Katlego P Ncongwane; Abiodun M Adeola

    2017-01-01

    .... The present study assessed drought conditions using two categories of drought indicators computed from precipitation data sets measured by weather stations across the Western Cape Province, South...

  9. Environmental risk assessment of lead-zinc mining: a case study of Adudu metallogenic province, middle Benue Trough, Nigeria.

    Science.gov (United States)

    Igwe, Ogbonnaya; Una, Chuku Okoro; Abu, Ezekiel; Adepehin, Ekundayo Joseph

    2017-09-07

    Assessment of the impacts of lead-zinc mining in Adudu-Imon metallogenic province was carried out. Reconnaissance and detailed field studies were done. Lithologies, stream sediments, farmland soils, mine tailings, artificial pond water, stream water, well water, and borehole water were collected and subjected to atomic absorption spectrometry (AAS) and X-ray fluorescence (XRF) analyses. Geochemical maps were generated using ArcGIS 10.1. Significant contamination with cadmium (Cd), iron (Fe), and lead (Pb) was recorded in the collected water samples. Virtually all collected soil samples were observed to be highly contaminated when compared with the European Union environmental policy standard. The discharge of mining effluents through farmlands to the Bakebu stream, which drains the area, further exposes the dwellers of this environment to the accumulation of potentially harmful metals (PHMs) in their bodies through the consumption of food crops, aquatic animals, and domestic uses of the water collected from the stream channels. The study revealed non-conformity of past mining operations in the Adudu-Imon province to existing mining laws in Nigeria. Inhabitants of this region should stop farming in the vicinity of the mines, fishing from the Bakebu stream channels should be discouraged, and domestic use of the water should be condemned, even as concerned government agencies put necessary mercenaries in place to ensure conformity of miners to standard mining regulations in Nigeria.

  10. An olivine-free mantle lithology as a source for mantle-derived magmas: the role of metasomes in the Ethiopian-Arabian large igneous province.

    Science.gov (United States)

    Rooney, T. O.; Nelson, W. R.; Ayalew, D.; Yirgu, G.; Herzberg, C. T.; Hanan, B. B.

    2014-12-01

    Peridotite constitutes most of the Earth's upper mantle, and it is therefore unsurprising that most mantle-derived magmas exhibit evidence of past equilibrium with olivine-dominated source. There is mounting evidence, however, for the role of pyroxenite in magma generation within upwelling mantle plumes; a less documented non-peridotite source of melts are metasomatic veins (metasomes) within the lithospheric mantle. Melts derived from metasomes may exhibit extreme enrichment or depletion in major and trace elements. We hypothesize that phenocrysts such as olivine, which are commonly used to probe basalt source lithology, will reflect these unusual geochemical signals. Here we present preliminary major and trace element analyses of 60 lavas erupted from a small Miocene shield volcano located within the Ethiopian flood basalt province. Erupted lavas are intercalated with lahars and pyroclastic horizons that are overlain by a later stage of activity manifested in small cinder cones and flows. The lavas form two distinctive petrographic and geochemical groups: (A) an olivine-phyric, low Ti group (1.7-2.7 wt. % TiO2; 4.0-13.6 wt. % MgO), which geochemically resembles most of the basalts in the region. These low Ti lavas are the only geochemical unit identified in the later cinder cones and associated lava flows. (B) a clinopyroxene-phyric high Ti group (1-6.7 wt. % TiO2; 1.0-9.5 wt. % MgO), which resembles the Oligocene HT-2 flood basalts. This unit is found intercalated with low Ti lavas within the Miocene shield. In comparison to the low Ti group, the high Ti lavas exhibit a profound depletion in Ni, Cr, Al, and Si, and significant enrichment in Ca, Fe, V, and the most incompatible trace elements. When combined with a diagnostic negative K anomaly in primitive-mantle normalized diagrams and Na2O>K2O, the geochemical data point towards a source which is rich in amphibole, devoid of olivine, and perhaps containing some carbonate. Our preliminary results have identified

  11. Predictions of hydrothermal alteration within near-ridge oceanic crust from coordinated geochemical and fluid flow models

    Science.gov (United States)

    Wetzel, L.R.; Raffensperger, J.P.; Shock, E.L.

    2001-01-01

    Coordinated geochemical and hydrological calculations guide our understanding of the composition, fluid flow patterns, and thermal structure of near-ridge oceanic crust. The case study presented here illustrates geochemical and thermal changes taking place as oceanic crust ages from 0.2 to 1.0 Myr. Using a finite element code, we model fluid flow and heat transport through the upper few hundred meters of an abyssal hill created at an intermediate spreading rate. We use a reaction path model with a customized database to calculate equilibrium fluid compositions and mineral assemblages of basalt and seawater at 500 bars and temperatures ranging from 150 to 400??C. In one scenario, reaction path calculations suggest that volume increases on the order of 10% may occur within portions of the basaltic basement. If this change in volume occurred, it would be sufficient to fill all primary porosity in some locations, effectively sealing off portions of the oceanic crust. Thermal profiles resulting from fluid flow simulations indicate that volume changes along this possible reaction path occur primarily within the first 0.4 Myr of crustal aging. ?? 2001 Elsevier Science B.V. All rights reserved.

  12. 40Ar/39Ar geochronology and geochemical reconnaissance of the Eocene Lowland Creek volcanic field, west-central Montana

    Science.gov (United States)

    Dudas, F.O.; Ispolatov, V.O.; Harlan, S.S.; Snee, L.W.

    2010-01-01

    We report geochronological and geochemical data for the calc-alkalic Lowland Creek volcanic field (LCVF) in westcentral Montana. 40Ar/ 39Ar age determinations show that the LCVF was active from 52.9 to 48.6 Ma, with tuff-forming eruptions at 52.9 ?? 0.14 and 51.8 ?? 0.14 Ma. These dates span the age range of vigorous Eocene igneous activity in the Kamloops-Absaroka-Challis belt. The LCVF evolved upward from basal rhyolites (SiO 2>71 wt%) to dacites and andesites (SiO 2 > 62 wt%). Compositional change parallels a transition from early explosive volcanism to late effusive activity. Four geochemical components can be detected in the rocks. A component with 206Pb/204Pb 18.3 and epsilon;Nd>-9 contain a third component; and an andesite with low Nd content and epsilon;Nd near-9 probably contains a fourth component. The first three components probably derive from the lower and middle crust, whereas the fourth is probably from the lithospheric mantle. ?? 2010 by The University of Chicago.

  13. The cause and source of melting for the most recent volcanism in Tibet: A combined geochemical and geophysical perspective

    Science.gov (United States)

    Wei, Feixiang; Prytulak, Julie; Xu, Jiandong; Wei, Wei; Hammond, James O. S.; Zhao, Bo

    2017-09-01

    We investigate the youngest volcanic activity on the Tibetan Plateau by combining observations from petrologic, geochemical and seismic tomography studies. Recent (from 2.80 Ma to present) post-collisional potassium-rich lavas from the Ashikule Volcanic Basin (AVB) in northwestern Tibet are characterised by remarkably enriched light rare earth elements (LREE) relative to heavy rare earth elements (HREE), and enriched large ion lithophile element (LILE) relative to high field strength elements (HFSE). Strontium and neodymium isotopic compositions are surprisingly restricted, and show little evidence for mixing or crustal contamination, despite the thick crust upon which they are erupted. Geochemical characteristics indicate a homogeneous source, highly enriched in trace elements, which is most consistent with derivation from long-lived subcontinental lithospheric mantle (SCLM). P-wave anisotropy tomography documents a gap between the north-subducting Indian slab and south-subducting Tarim slab directly beneath the AVB. We propose that volcanism in northwestern Tibet is associated with the progressive closure of this gap, during which shear heating of the SCLM can generate localised melting, with deep-seated faults providing a mechanism for erupted lavas to escape large-scale crustal contamination and fractionation in magma reservoirs. Thus, shear heating may provide an explanation for the restricted range of radiogenic isotope compositions from a SCLM source that should be, by its nature, heterogeneous on a large scale.

  14. The effect of a confining unit on the geochemical evolution of ground water in the Upper Floridan aquifer system

    Science.gov (United States)

    Wicks, C.M.; Herman, J.S.

    1994-01-01

    In west-central Florida, sections of the Upper Floridan aquifer system range in character from confined to leaky to unconfined. The confining unit is the Hawthorn Formation, a clay-rich sequence. The presence or absence of the Hawthorn Formation affects the geochemical evolution of the ground water in the Upper Floridan aquifer system. Mass-balance and mass-transfer models suggest that, in unconfined areas, the geochemical reactions are dolomite dissolution, ion exchange (Mg for Na, K), sulfate reduction, calcite dissolution, and CO2 exchange. In the areas in which the Hawthorn Formation is leaky, the evolution of the ground water is accounted for by ion exchange, sulfate reduction, calcite dissolution, and CO2 exchange. In the confined areas, no ion exchange and only limited sulfate reduction occur, and the chemical character of the ground water is consistent with dolomite and gypsum dissolution, calcite precipitation, and CO2 ingassing. The Hawthorn Formation acts both as a physical barrier to the transport of CO2 and organic matter and as a source of ion-exchange sites, but the carbonate-mineral reactions are largely unaffected by the extent of confinement of the Upper Floridan aquifer. ?? 1994.

  15. A general framework of TOPSIS method for integration of airborne geophysics, satellite imagery, geochemical and geological data

    Science.gov (United States)

    Abedi, Maysam; Norouzi, Gholam-Hossain

    2016-04-01

    This work presents the promising application of three variants of TOPSIS method (namely the conventional, adjusted and modified versions) as a straightforward knowledge-driven technique in multi criteria decision making processes for data fusion of a broad exploratory geo-dataset in mineral potential/prospectivity mapping. The method is implemented to airborne geophysical data (e.g. potassium radiometry, aeromagnetic and frequency domain electromagnetic data), surface geological layers (fault and host rock zones), extracted alteration layers from remote sensing satellite imagery data, and five evidential attributes from stream sediment geochemical data. The central Iranian volcanic-sedimentary belt in Kerman province at the SE of Iran that is embedded in the Urumieh-Dokhtar Magmatic Assemblage arc (UDMA) is chosen to integrate broad evidential layers in the region of prospect. The studied area has high potential of ore mineral occurrences especially porphyry copper/molybdenum and the generated mineral potential maps aim to outline new prospect zones for further investigation in future. Two evidential layers of the downward continued aeromagnetic data and its analytic signal filter are prepared to be incorporated in fusion process as geophysical plausible footprints of the porphyry type mineralization. The low values of the apparent resistivity layer calculated from the airborne frequency domain electromagnetic data are also used as an electrical criterion in this investigation. Four remote sensing evidential layers of argillic, phyllic, propylitic and hydroxyl alterations were extracted from ASTER images in order to map the altered areas associated with porphyry type deposits, whilst the ETM+ satellite imagery data were used as well to map iron oxide layer. Since potassium alteration is generally the mainstay of porphyry ore mineralization, the airborne potassium radiometry data was used. The geochemical layers of Cu/B/Pb/Zn elements and the first component of PCA

  16. Payenia volcanic province, southern Mendoza, Argentina

    DEFF Research Database (Denmark)

    Søager, Nina; Holm, Paul Martin; Llambias, Eduardo Jorge

    2013-01-01

    to the low thickness of the lithospheric mantle and preheating of the lower crust by earlier Mio-Pliocene volcanism. Rare earth element modelling of mantle melting calls for enriched source compositions and a beginning of melting within the garnet stability field for all Payenia basalts. The Río Colorado......The Pleistocene to Holocene Payenia volcanic province is a backarc region of 60,000 km2 in Mendoza, Argentina, which is dominated by transitional to alkaline basalts and trachybasalts. We present major and trace element compositions of 139 rocks from this area of which the majority are basaltic...... rocks with 4 to 12 wt.% MgO and 44 to 50 wt.% SiO2. The southern Payenia province is dominated by intraplate basalts and the trace element patterns of the Río Colorado and Payún Matrú lavas suggest little or no influence from subducted slab components. The mantle source of these rocks is similar to some...

  17. Phosphorus geochemical cycling inferences from high frequency lake monitoring

    Science.gov (United States)

    Crockford, Lucy; Jordan, Philip; Taylor, David

    2013-04-01

    Freshwater bodies in Europe are required to return to good water quality status under the Water Framework Directive by 2015. A small inter-drumlin lake in the northeast of Ireland has been susceptible to eutrophic episodes and the presence of algal blooms during summer since annual monitoring began in 2002. While agricultural practice has been controlled by the implementation of the Nitrates Directive in 2006, the lake is failing to recover to good water quality status to meet with the Water Framework Directive objectives. Freshwaters in Ireland are regarded, in the main, as phosphorus (P) limited so identifying the sources of P possibly fuelling the algal blooms may provide an insight into how to improve water quality conditions. In a lake, these sources are divided between external catchment driven loads, as a result of farming and point sources, and P released from sediments made available to photic waters through internal lake mechanisms. High frequency sensors on data-sondes, installed on the lake in three locations, have provided chlorophyll a, redox potential, dissolved oxygen, temperature, pH, conductivity and turbidity data since March 2010. A data-sonde was installed in the hypolimnion to observe the change in lake conditions as P is released from lake sediments as a result of geochemical cycling with iron during anoxic periods. As compact high frequency sampling equipment for P analysis is still in its infancy for freshwaters, a proxy measurement of geochemical cycling in lakes would be useful to determine fully the extent of P contribution from sediments to the overall P load. Phosphorus was analysed once per month along with a number of other parameters and initial analysis of the high frequency data has shown changes in readings when known P release from lake sediments has occurred. Importantly, these data have shown when these P enriched hypolimnetic waters may be re-introduced to shallower waters in the photic zone, by changes in dissolved oxygen

  18. Geochemical databases: minding the pitfalls to avoid the pratfalls

    Science.gov (United States)

    Goldstein, S. L.; Hofmann, A. W.

    2011-12-01

    The field of geochemistry has been revolutionized in recent years by the advent of databases (PetDB, GEOROC, NAVDAT, etc). A decade ago, a geochemical synthesis required major time investments in order to compile relatively small amounts of fragmented data from large numbers of publications, Now virtually all of the published data on nearly any solid Earth topic can be downloaded to nearly any desktop computer with a few mouse clicks. Most solid Earth talks at international meetings show data compilations from these databases. Applications of the data are playing an increasingly important role in shaping our thinking about the Earth. They have changed some fundamental ideas about the compositional structure of the Earth (for example, showing that the Earth's "trace element depleted upper mantle" is not so depleted in trace elements). This abundance of riches also poses new risks. Until recently, important details associated with data publication (adequate metadata and quality control information) were given low priority, even in major journals. The online databases preserve whatever has been published, irrespective of quality. "Bad data" arises from many causes, here are a few. Some are associated with sample processing, including incomplete dissolution of refractory trace minerals, or inhomogeneous powders, or contamination of key elements during preparation (for example, this was a problem for lead when gasoline was leaded, and for niobium when tungsten-carbide mills were used to powder samples). Poor analytical quality is a continual problem (for example, when elemental abundances are at near background levels for an analytical method). Errors in published data tables (more common than you think) become bad data in the databases. The accepted values of interlaboratory standards change with time, while the published data based on old values stay the same. Thus the pitfalls associated with the new data accessibility are dangerous in the hands of the inexperienced

  19. Substring Range Reporting

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2011-01-01

    We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. – We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. – We show how to solve substring range reporting with optimal query time and little...... range reporting are based on a novel combination of suffix trees and range reporting data structures. The reductions are simple and general and may apply to other combinations of string indexing with range reporting....

  20. [Response and Control Factors of Groundwater to Extreme Weather, Jiguan Cave, Henan Province, China].

    Science.gov (United States)

    Liu, Xiao; Yang, Yan; Peng, Tao; Zhao, Jing-yao; Ren, Xiao-feng; Zhang, Yin-huan; Nie Xu-dong; Li, Jian-cang; Ling, Xin-you; Zhang, Zhi-qin

    2015-05-01

    Geochemical dynamics of cave water were monitored to unveil its variation and controlling factors from October 2009 to December 2013 in Jiguan Cave,west of Henan province,southeastern coast of the loess plateau. The results showed that: (1) the hydrochemical types of the cave water are HCO(3-)-Ca(2+)-Mg2+ and HCO(3-)-Mg(2+)-Ca2+. HCO(3-) are over 80% of the anions, Ca2+ and Mg2+ are the dominate cations, and ground river keeping in erosion and pool water drips in deposition all the year. (2) Dripping water and pool water in Ji guan cave can respond perfectly to the change of external climate environment, which geochemistry indexes possess the extraordinary seasonal effects. (3) The concentration changes of the Ca2+, Mg2+ , SO4(2-) responded sensitively to annual precipitation change. Ca2+, Mg2+, SO4(2-) rise in waterlogging year and fall in drought year. Because HCO(3-) controlled by CO2 concentration. HCO(3-) concentration showed a unconspicuous response to the change of external climate environment. (4) The concentration changes of Ca2+, Mg2+, SO4(2-) have no obvious seasonal variation and showed a unconspicuous response to the change of external climate environment.

  1. Supracrustal suite of the Precambrian crystalline crust in the Ghor Province of Central Afghanistan

    Directory of Open Access Journals (Sweden)

    Gediminas Motuza

    2017-01-01

    Full Text Available The Proterozoic pre-Ediacaran metamorphic basement of the southern Tajik (North Afghanistan continental block and the adjacent Band-e-Bayan zone is exposed in the Ghor Province of Central Afghanistan. It is predominantly composed of the EW-striking supracrustal succession consisting of interbedded felsic schists and gneisses (metapsammites, amphibolites (metabasalts, calcite and dolomite marbles. The metamorphic facies changes from greenschist in the Band-e-Bayan zone to amphibolite facies in the Tajik block. The supracrustal rocks of the Band-e-Bayan zone and Tajik block possess common features suggesting that the former represents a tectonized part of the latter. The geochemical characteristics of metapsammites indicate derivation of the clastic material from a continental arc and, partly from a passive continental margin, whereas the composition of metabasalts suggests their possible formation in a continental rift basin. The tectonic setting of supracrustal unit could be interpreted as a back-arc type basin. We presume that the Tajik microcontinent split off the Gondwana supercontinent along an ancient rift zone during the late Paleozoic.

  2. Silicic ash beds bracket Emeishan Large Igneous province to < 1 m.y. at ~ 260 Ma

    Science.gov (United States)

    Huang, Hu; Cawood, Peter A.; Hou, Ming-Cai; Yang, Jiang-Hai; Ni, Shi-Jun; Du, Yuan-Sheng; Yan, Zhao-Kun; Wang, Jun

    2016-11-01

    Claystone beds directly below and above the Emeishan basalts in SW China formed around the Guadalupian-Lopingian (G - L) boundary. Zircons from both levels give U-Pb ages of 260 Ma, and are identical within-error to ages reported for the Emeishan Large Igneous Province (LIP). The claystones lack Nb - Ta anomalies on primitive mantle normalized elemental diagrams; zircons from these claystones have a geochemical affinity to within-plate-type magmas. These features, combined with the strong negative Eu anomalies in the zircons and high Al2O3/TiO2 ratios, indicate that claystones around the G - L boundary have a silicic volcanic component related to Emeishan LIP. Zircons from the underlying claystone bed have much higher U/Yb and Th/Nb ratios and lower εHf(t) values than those overlying the LIP, suggesting that early-stage silicic volcanic rocks had a higher crustal contamination or assimilation during magmatic processes. In terms of stratigraphic correlation, our data demonstrate that silicic eruptions occurred not only at the end, but also at the beginning of the Emeishan LIP, and the overall duration of the main basaltic phase was short (< 1 m.y).

  3. Compact Antenna Range

    Data.gov (United States)

    Federal Laboratory Consortium — Facility consists of a folded compact antenna range including a computer controlled three axis position table, parabolic reflector and RF sources for the measurement...

  4. Dryden Aeronautical Test Range

    Data.gov (United States)

    Federal Laboratory Consortium — Recently redesignated to honor Dr. Hugh L. Dryden, NASA's Dryden Aeronautical Test Range (DATR) supports aerospace flight research and technology integration, space...

  5. Pinon-juniper management research at Corona Range and Livestock Research Center in Central New Mexico

    Science.gov (United States)

    Andres Cibils; Mark Petersen; Shad Cox; Michael Rubio

    2008-01-01

    Description: New Mexico State University's Corona Range and Livestock Research Center (CRLRC) is located in a pinon-juniper (PJ)/grassland ecotone in the southern Basin and Range Province in south central New Mexico. A number of research projects conducted at this facility revolve around soil, plant, livestock, and wildlife responses to PJ woodland management. The...

  6. Cool seafloor hydrothermal springs reveal global geochemical fluxes

    Science.gov (United States)

    Wheat, C. Geoffrey; Fisher, Andrew T.; McManus, James; Hulme, Samuel M.; Orcutt, Beth N.

    2017-10-01

    We present geochemical data from the first samples of spring fluids from Dorado Outcrop, a basaltic edifice on 23 M.y. old seafloor of the Cocos Plate, eastern Pacific Ocean. These samples were collected from the discharge of a cool hydrothermal system (CHS) on a ridge flank, where typical reaction temperatures in the volcanic crust are low (2-20 °C) and fluid residence times are short. Ridge-flank hydrothermal systems extract 25% of Earth's lithospheric heat, with a global discharge rate equivalent to that of Earth's river discharge to the ocean; CHSs comprise a significant fraction of this global flow. Upper crustal temperatures around Dorado Outcrop are ∼15 °C, the calculated residence time is concentrations in spring fluids are indistinguishable from those of bottom seawater; however, concentrations of Rb, Mo, V, U, Mg, phosphate, Si and Li are different. Applying these observed differences to calculated global CHS fluxes results in chemical fluxes for these ions that are ≥15% of riverine fluxes. Fluxes of K and B also may be significant, but better analytical resolution is required to confirm this result. Spring fluids also have ∼50% less dissolved oxygen (DO) than bottom seawater. Calculations of an analytical model suggest that the loss of DO occurs primarily (>80%) within the upper basaltic crust by biotic and/or abiotic consumption. This calculation demonstrates that permeable pathways within the upper crust can support oxic water-rock interactions for millions of years.

  7. Geochemical effects of electro-osmosis in clays

    KAUST Repository

    Loch, J. P. Gustav

    2010-02-13

    Geochemical effects of electro-osmosis in bentonite clay are studied in the laboratory, where a 6 mm thick bentonite layer is subjected to direct current. Acidification and alkalization near anode and cathode are expected, possibly causing mineral deterioration, ion mobilization and precipitation of new solids. Afterwards the clay is analysed by XRF and anolyte and catholyte are analysed by ICP-MS. In addition, as a preliminary experiment treated bentonite is analysed by high resolution μ-XRF. Electro-osmotic flow is observed. Due to its carbonate content the bentonite is pH-buffering. Alkalization in the catholyte is substantial. Ca, Na and Sr are significantly removed from the clay and accumulate in the catholyte. Recovery in the catholyte accounts for a small fraction of the element-loss from the clay. The rest will have precipitated in undetected solid phases. μ-XRF indicates the loss of Ca-content throughout the bentonite layer. © The Author(s) 2010.

  8. Geochemical Characterization of Groundwater in a Volcanic System

    Directory of Open Access Journals (Sweden)

    Carmelo Bellia

    2015-06-01

    Full Text Available A geochemical investigation was undertaken at Mt. Etna Volcano to better define groundwater characteristics of its aquifers. Results indicate that the Na–Mg ± Ca–HCO3− ± (SO42− or Cl− type accounts for more than 80% of the groundwater composition in the volcano. The remaining 20% is characterized by elevated Ca2+. Waters along coastal areas are enriched in SO42− or Cl−, mainly due to mixing with seawater and anthropogenic effects. The majority of the samples showed values between −4‰ to −9‰ for δ18O and −19‰ to −53‰ for δ2H, suggesting that precipitation is the predominant source of recharge to the aquifers, especially in the west of the study area. The analysis of δ13C and pCO2 shows values 1 to 3 times higher than those expected for waters in equilibrium with the atmosphere, suggesting a partial gas contribution from deep sources. The diffusion of gasses is likely to be controlled by tectonic structures in the volcano. The ascent of deep brines is also reflected in the CO2 enrichment (up to 2.2 bars and enriched δ2H/δ18O compositions observed in the salt mounts of Paternò.

  9. ORGANIC GEOCHEMICAL STUDIES. I. MOLECULAR CRITERIA FOR HYDROCARBONGENESIS

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Eugene D.; Calvin, Kevin

    1967-09-22

    In recent years the search for life-forms at the earliest periods of geological time has been continued not only at the morphological level but also at the molecular level. This has been possible as a result of the increase in the biochemical knowledge and with the advent of analytical techniques that are capable of describing the intimate molecular architecture of individual molecules in acute detail. The fundamental premises upon which this organic geochemical approach rest are the following: that certain molecules, possessing a characteristic structural skeleton, show a reasonable stability to degradation over long periods of geological time; that their structural specificity can be understood in terms of known biosynthetic sequences; and that their formation by any non-biological means is of negligible probability. In this manuscript it is proposed to critically re-examine these premises and to establish criteria whereby one can differentiate molecules derived from biological systems from those that have their origin in non-biological processes. The importance of establishing such criteria lies in the significance these criteria have in determining whether life exists, or has existed, on other planets. Within the very near future it may be possible to provide an initial answer to this question when the first lunar samples are returned to the earth for analysis.

  10. Modeling Background Radiation in our Environment Using Geochemical Data

    Energy Technology Data Exchange (ETDEWEB)

    Malchow, Russell L.; Marsac, Kara [University of Nevada, Las Vegas; Burnley, Pamela [University of Nevada, Las Vegas; Hausrath, Elisabeth [Uniiversity of Nevada, Las Vegas; Haber, Daniel [University of Nevada, Las Vegas; Adcock, Christopher [University of Nevada, Las Vegas

    2015-02-01

    Radiation occurs naturally in bedrock and soil. Gamma rays are released from the decay of the radioactive isotopes K, U, and Th. Gamma rays observed at the surface come from the first 30 cm of rock and soil. The energy of gamma rays is specific to each isotope, allowing identification. For this research, data was collected from national databases, private companies, scientific literature, and field work. Data points were then evaluated for self-consistency. A model was created by converting concentrations of U, K, and Th for each rock and soil unit into a ground exposure rate using the following equation: D=1.32 K+ 0.548 U+ 0.272 Th. The first objective of this research was to compare the original Aerial Measurement System gamma ray survey to results produced by the model. The second objective was to improve the method and learn the constraints of the model. Future work will include sample data analysis from field work with a goal of improving the geochemical model.

  11. Novorossiysk agglomeration landscapes and cement production: geochemical impact assessment

    Science.gov (United States)

    Alekseenko, A. V.; Pashkevich, M. A.

    2016-09-01

    The article deals with assessing the environmental impact of marl mining and cement production in Novorossiysk city (Krasnodar krai, Russia). The existing methods of studying the environmental effects caused by the cement industry have been reviewed. Soil and aquatic vegetation sampling has been carried out and the gross concentration of metals in the samples has been defined. The research has been conducted in the certified and accredited laboratory using emission spectral analysis. The external control has been carried out via X-ray fluorescence analysis. Based on the collected data, main chemical pollutants in soil cover and water area near the cement plant have been identified. The contaminants released by urban enterprises and motor vehicle emissions, as well as fugitive dust from dumps and the cement factory, lead to multi-element lithogeochemical anomaly at geochemical barriers in soils. Accumulation of pollutants in soil depends on the type of land use and the area relief. The most contaminated aquatic landscapes have been identified in the inner bay. According to this information, the technical proposals can be prepared for environmental safety management in strongly polluted city areas, as well as for the reclamation design in the areas currently experiencing the negative impact of cement production.

  12. Geochemical Triggers of Arsenic Mobilization during Managed Aquifer Recharge.

    Science.gov (United States)

    Fakhreddine, Sarah; Dittmar, Jessica; Phipps, Don; Dadakis, Jason; Fendorf, Scott

    2015-07-07

    Mobilization of arsenic and other trace metal contaminants during managed aquifer recharge (MAR) poses a challenge to maintaining local groundwater quality and to ensuring the viability of aquifer storage and recovery techniques. Arsenic release from sediments into solution has occurred during purified recycled water recharge of shallow aquifers within Orange County, CA. Accordingly, we examine the geochemical processes controlling As desorption and mobilization from shallow, aerated sediments underlying MAR infiltration basins. Further, we conducted a series of batch and column experiments to evaluate recharge water chemistries that minimize the propensity of As desorption from the aquifer sediments. Within the shallow Orange County Groundwater Basin sediments, the divalent cations Ca(2+) and Mg(2+) are critical for limiting arsenic desorption; they promote As (as arsenate) adsorption to the phyllosilicate clay minerals of the aquifer. While native groundwater contains adequate concentrations of dissolved Ca(2+) and Mg(2+), these cations are not present at sufficient concentrations during recharge of highly purified recycled water. Subsequently, the absence of dissolved Ca(2+) and Mg(2+) displaces As from the sediments into solution. Increasing the dosages of common water treatment amendments including quicklime (Ca(OH)2) and dolomitic lime (CaO·MgO) provides recharge water with higher concentrations of Ca(2+) and Mg(2+) ions and subsequently decreases the release of As during infiltration.

  13. Lagrangian simulation of mixing and reactions in complex geochemical systems

    Science.gov (United States)

    Engdahl, Nicholas B.; Benson, David A.; Bolster, Diogo

    2017-04-01

    Simulations of detailed geochemical systems have traditionally been restricted to Eulerian reactive transport algorithms. This note introduces a Lagrangian method for modeling multicomponent reaction systems. The approach uses standard random walk-based methods for the particle motion steps but allows the particles to interact with each other by exchanging mass of their various chemical species. The colocation density of each particle pair is used to calculate the mass transfer rate, which creates a local disequilibrium that is then relaxed back toward equilibrium using the reaction engine PhreeqcRM. The mass exchange is the only step where the particles interact and the remaining transport and reaction steps are entirely independent for each particle. Several validation examples are presented, which reproduce well-known analytical solutions. These are followed by two demonstration examples of a competitive decay chain and an acid-mine drainage system. The source code, entitled Complex Reaction on Particles (CRP), and files needed to run these examples are hosted openly on GitHub (https://github.com/nbengdahl/CRP), so as to enable interested readers to readily apply this approach with minimal modifications.

  14. Geochemical Characterization of Copper Tailings after Legume Revegetation

    Directory of Open Access Journals (Sweden)

    Justine Perry T. Domingo

    2014-12-01

    Full Text Available Knowledge on the geochemistry of mine tailings is important in understanding the challenges in establishing vegetation cover on tailings dumps and mined out areas. In this study, the mineralogy and trace element composition of copper tailings were examined. Two legume species, Calopogonium mucunoides and Centrosema molle, were utilized to investigate the possible effects of these plants in the geochemical development of mine tailings into soil-like material. The initial mineralogical and chemical analysis of the tailings samples indicated poor conditions for plant growth—minimal levels of major nutrients and organic matter as well as elevated copper concentrations. Despite these conditions, the two legume species exhibited good growth rates. Both legumes have likewise signif icantly reduced heavy metal concentrations in the tailings, indicating the possibility of metal hyperaccumulation in the plant tissue. The mineral composition has been retained even after revegetation; nevertheless, breakdown of primary minerals and subsequent formation of clay minerals were detected. These results provide insights on the transformation of toxic materials into habitable substrates for sustained plant growth.

  15. On Range of Skill

    DEFF Research Database (Denmark)

    Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2008-01-01

    size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...

  16. Range Scheduling Aid (RSA)

    Science.gov (United States)

    Logan, J. R.; Pulvermacher, M. K.

    1991-01-01

    Range Scheduling Aid (RSA) is presented in the form of the viewgraphs. The following subject areas are covered: satellite control network; current and new approaches to range scheduling; MITRE tasking; RSA features; RSA display; constraint based analytic capability; RSA architecture; and RSA benefits.

  17. Oil samples and geochemical analyses of Afghanistan and adjacent areas (oilafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains points that describe the location of oil samples collected in Afghanistan and adjacent areas, and the results of organic geochemical analysis.

  18. Geochemical and mineralogical maps for soils of the conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Geochemical and mineralogical maps along with a histogram, boxplot, and empirical cumulative distribution function plot for each element or mineral whose data are...

  19. Debba China presentation on optimal field sampling for exploration targets and geochemicals

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-10-01

    Full Text Available A presentation was done at the Chinese Academy of Geological Science in October 2008 on optimal field sampling for both exploration targets and sampling for geochemicals in mine tailing areas...

  20. The effect of sterilization on biological, organic geochemical and morphological information in natural samples

    Science.gov (United States)

    Hochstein, L. I.; Kvenvolden, K. A.; Philpott, D. E.

    1974-01-01

    The loss of biological, organic geochemical, and morphological science information that may occur should a Mars surface sample be sterilized prior to return to earth is examined. Results of experimental studies are summarized.

  1. Some geochemical characteristics of the Pachuca Obsidian Region: a strategy for interpreting artifact groups

    Energy Technology Data Exchange (ETDEWEB)

    Neivens, M.; Harbottle, G.; Kimberlin, J.

    1981-01-01

    Obsidian research has revealed geochemical anomalies. Neutron activation analysis was used to analyze the samples. Correlations were made between element pairs (Sc and Fe, Ba and Co). Tests were made for homogeneity. 5 figures. (DLC)

  2. Searching and detecting earthquake geochemical precursors in CO2-rich groundwaters from Galicia, Spain

    National Research Council Canada - National Science Library

    PÉREZ, NEMESIO M; HERNÁNDEZ, P. A; IGARASHI, G; TRUJILLO, I; NAKAI, S; SUMINO, H; WAKITA, H

    2008-01-01

    ...), and these events changed the seismic hazard map used for the building code in Spain. Searching for earthquake precursors of these seismic events was performed, and precursory geochemical signatures of the 1995 and 1997 Galicia earthquakes were detected...

  3. Fluid inclusion, geochemical, Rb-Sr and Sm-Nd isotope studies on ...

    Indian Academy of Sciences (India)

    10

    . 399 geochemical and geochronological similarities (Torsvik et al. 2001b; Ashwal et al. 400. 2002; Pandit et al. 2003; Collins 2006, Pradhan et al. 2010). In Australia,. 401. Neoproterozoic magmatism is reported of 850-780 Ma (Turner et al.

  4. The New Frontiers Venus In Situ Atmospheric and Geochemical Explorer (VISAGE) Mission Proposal

    Science.gov (United States)

    Esposito, L. W.; Atkinson, D. H.; Baines, K. H.

    2017-09-01

    The New Frontiers Venus In Situ Atmospheric and Geochemical Explorer (VISAGE) Mission Proposal submitted to 2017 New Frontiers 4 program by University of Colorado, managed by Caltech/Jet Propulsion Laboratory.

  5. Anthropogenic effects on sediment quality offshore southwestern Taiwan: Assessing the sediment core geochemical record

    Digital Repository Service at National Institute of Oceanography (India)

    Selvaraj, K.; Parthiban, G.; Chen, C.T.A.; Lou, J.Y.

    Slag material was dumped in two sites off southwestern Taiwan by the China Steel Corporation during 1984-1995. By geochemically analyzing four sediment cores, the impact of slag on the sediment chemistry is investigated. Elemental profiles from...

  6. Geochemical and geochronological constraints on the origin and evolution of rocks in the active Woodlark Rift of Papua New Guinea

    Science.gov (United States)

    Zirakparvar, Nasser Alexander

    fragments of an active margin'. This chapter uses a panoply of geochronological (U-Pb zircon) and geochemical (Lu-Hf and Sm-Nd isotopes, trace/REEs, and major elements) tools to investigate the origin the major lithostratigraphic units in the Woodlark Rift. Important findings in this chapter include the establishment of a tectonic link between sialic metamorphic rocks in the Woodlark Rift and the remnants of a Late Cretaceous aged bi-modal volcanic province along Australia's northern Queensland coast. This link is important because it identifies another rifted fragment of the former Australian continental margin in Gondwana, and demonstrates the complexity of recognizing the dispersed fragments of active margins. Another important finding of this chapter is that Quaternary aged high silica rhyolites erupted in the western Woodlark Rift have mantle isotopic and geochemical signatures, and are therefore not the extrusive equivalents of partially melted metamorphic rocks found in the lower plates of large metamorphic core complexes. This is important because it signifies that lithospheric rupture has already occurred, despite the fact that mid-ocean ridge basalts are not yet being erupted and there are still topographically prominent metamorphic core complexes in the region. This chapter is not yet published, but is being prepared for submission to Gondwana Research. The third chapter is entitled 'Zircon growth in rapidly evolving plate boundary zones: Evidence from the active Woodlark Rift of Papua New Guinea'. The original purpose of this chapter was simply to use U-Pb dating of zircons from felsic and intermediate gneisses in the Woodlark Rift to understand the history of rocks from (U)HP terranes that don't preserve the (U)HP metamorphic paragenesis. It was soon realized that the types of U-Pb zircon analyses typically performed on a SIMS instrument were going to be insufficient to fully understand the geochemical and geochronological records within zircons from these

  7. Geochemical partitioning of lead in biogenic carbonate sediments in a coral reef depositional environment.

    Science.gov (United States)

    Horta-Puga, Guillermo

    2017-03-15

    The fate of trace elements in reef depositional environments has not been extensively investigated. The aim of this study was to determine the partitioning of Pb in sediments of the Veracruz Reef System, and its relation to local environmental sources. Lead was determined in four geochemical fractions: exchangeable (3.8±0.4μgg-1), carbonate (57.0±13.6μgg-1), organic matter (2.0±0.9μgg-1), and mineral (17.5±5.4μgg-1). For the mineral fraction, lead concentrations were higher in those reefs influenced by river discharge or by long-distance transport of terrigenous sediments. The bioavailable concentration of lead (range: 21.9-85.6μgg-1) indicates that the Veracruz Reef System is a moderately polluted area. As expected, the carbonate fraction contained the highest proportion of Pb (70%), and because the reef framework is largely made up of by biogenic carbonate sediments, hence, it is therefore the most important repository of Pb in coral reef depositional environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Radiogenic heat production of crustal rocks: An assessment based on geochemical data

    Science.gov (United States)

    Wollenberg, H. A.; Smith, A. R.

    A survey of the geochemical literature and unpublished data has resulted in the classification of U, Th, and K concentrations by rock type. Over 2500 data entries have been compiled, permitting calculation of their radiogenic heat production. In the igneous rocks mean heat production ranges from highs of 12-20 heat production units (HPU: µWm-3) in some peralkaline intrusives, through ˜ 4 HPU in acidic, ˜ 2 in intermediate, and ˜ 1 in basic rocks, to a low of 0.3 HPU in ultramafic rocks. Siliceous clastic rocks generally have greater heat production (2 to 4 HPU) than do chemical sedimentary rocks, including the carbonates (0.4 to 2 HPU). The heat production of metamorphic rocks generally depends on the radioelement contents of their igneous and sedimentary predecessors, modified by metamorphic processes. Based on estimates of the proportion of the continental crust that specific rock types occupy, the weighted mean radiogenic heat production of the upper continental crust estimated from this data base is ˜ 3 HPU.

  9. Geochemical pattern of soils in Bobovdol valley, Bulgaria. Assessment of Cd and Co contents

    Directory of Open Access Journals (Sweden)

    Ivona Nikova

    2016-07-01

    Full Text Available The chemical composition of soils spread in the Bobov dol valley was studied in order to reveal the natural and anthropogenic patterns of Cd and Co spatial distribution. A sampling procedure based on the irregular grid of points and validated analytical methods were used in the field and laboratory studies. It is found that Cd content varies from 0.21 to 0.90 mg kg-1 in studied soils and the average value of 0.55 mg kg-1 coincides with concentration demarcating soil pollution (0.5 mg kg-1. Co content ranges from 2.22 to 15.76 mg kg-1 and in 70 % of sampled points exceeds the natural background content of 7.8 mg kg-1 found in local rocks. Still, Cd enrichment of studied soils is more significant than Co’s with coefficient of Clarke concentration of 3.67. Hence, the secondary deposition of studied elements as a result of the Bobov dol Thermal power plant air emissions is verified by results obtained. The spatial distribution of Cd and Co is featured with an altitudinal gradient in deposition and a trend of quantitative depletion in the South of Plant. Soil organic matter and pH have no influence on the content and spatial distribution of studied elements. Elements iron affinity governs their geochemical linkage in soils although cobalt occurs allied with aluminum and titanium.

  10. Gas Hydrate System of Shenhu Area, Northern South China Sea: Geochemical Results

    Directory of Open Access Journals (Sweden)

    Nengyou Wu

    2011-01-01

    Full Text Available The drilling recovered high-concentration methane hydrates (maximum 26–48% in a disseminated form in silty clay sediments in Shenhu area of Pearl River Mouth Basin, South China Sea. Combining the geochemical data, the gas hydrate-bearing sediments are 10 m to 43 m in thickness and located just above the base of the gas hydrate stability zone. The methane content is 96.10–99.91% with small amount of ethane and propane. The baseline chlorinity of pore waters shows 10% lower than that of shallow sediments below and inside the gas hydrate zone. The methane/ethane ratios are higher than 1000 above the gas hydrate zone and less than 1000 at the interval of gas hydrate zone. The depth of sulphate methane interface varies from site to site as 17 to 27 mbsf. These results show that the methane of gas hydrate was mainly originated from microbial activity and the upward methane flux is minor. This is evidenced by the δC13CH4 values of headspace gases from the gravity piston cores and released gases from pressure cores, which range from −74.3‰  PDB to −46.2‰  PDB, with the majority less than −55%‰  PDB. The hydrate deposit is a distributed gas hydrate system in Shenhu area.

  11. Experimental Investigation and Simplistic Geochemical Modeling of CO2 Mineral Carbonation Using the Mount Tawai Peridotite

    Directory of Open Access Journals (Sweden)

    Omeid Rahmani

    2016-03-01

    Full Text Available In this work, the potential of CO2 mineral carbonation of brucite (Mg(OH2 derived from the Mount Tawai peridotite (forsterite based (Mg2SiO4 to produce thermodynamically stable magnesium carbonate (MgCO3 was evaluated. The effect of three main factors (reaction temperature, particle size, and water vapor were investigated in a sequence of experiments consisting of aqueous acid leaching, evaporation to dryness of the slurry mass, and then gas-solid carbonation under pressurized CO2. The maximum amount of Mg converted to MgCO3 is ~99%, which occurred at temperatures between 150 and 175 °C. It was also found that the reduction of particle size range from >200 to <75 µm enhanced the leaching rate significantly. In addition, the results showed the essential role of water vapor in promoting effective carbonation. By increasing water vapor concentration from 5 to 10 vol %, the mineral carbonation rate increased by 30%. This work has also numerically modeled the process by which CO2 gas may be sequestered, by reaction with forsterite in the presence of moisture. In both experimental analysis and geochemical modeling, the results showed that the reaction is favored and of high yield; going almost to completion (within about one year with the bulk of the carbon partitioning into magnesite and that very little remains in solution.

  12. Investigation of Coastal Hydrogeology Utilizing Geophysical and Geochemical Tools along the Broward County Coast, Florida

    Science.gov (United States)

    Reich, Christopher D.; Swarzenski, Peter W.; Greenwood, W. Jason; Wiese, Dana S.

    2008-01-01

    Geophysical (CHIRP, boomer, and continuous direct-current resistivity) and geochemical tracer studies (continuous and time-series 222Radon) were conducted along the Broward County coast from Port Everglades to Hillsboro Inlet, Florida. Simultaneous seismic, direct-current resistivity, and radon surveys in the coastal waters provided information to characterize the geologic framework and identify potential groundwater-discharge sites. Time-series radon at the Nova Southeastern University National Coral Reef Institute (NSU/NCRI) seawall indicated a very strong tidally modulated discharge of ground water with 222Rn activities ranging from 4 to 10 disintegrations per minute per liter depending on tidal stage. CHIRP seismic data provided very detailed bottom profiles (i.e., bathymetry); however, acoustic penetration was poor and resulted in no observed subsurface geologic structure. Boomer data, on the other hand, showed features that are indicative of karst, antecedent topography (buried reefs), and sand-filled troughs. Continuous resistivity profiling (CRP) data showed slight variability in the subsurface along the coast. Subtle changes in subsurface resistivity between nearshore (higher values) and offshore (lower values) profiles may indicate either a freshening of subsurface water nearshore or a change in sediment porosity or lithology. Further lithologic and hydrologic controls from sediment or rock cores or well data are needed to constrain the variability in CRP data.

  13. Geochemical fractions of rare earth elements in soil around a mine tailing in Baotou, China.

    Science.gov (United States)

    Wang, Lingqing; Liang, Tao

    2015-07-22

    Rare earth mine tailing dumps are environmental hazards because tailing easily leaches and erodes by water and wind. To assess the influence of mine tailing on the geochemical behavior of rare earth elements (REEs) in soil, sixty-seven surface soil samples and three soil profile samples were collected from different locations near China's largest rare earth mine tailing. The total concentration of REEs in surface soils ranged from 156 to 5.65 × 10(4) mg·kg(-1) with an average value of 4.67 × 10(3) mg·kg(-1), which was significantly higher than the average value in China (181 mg·kg(-1)). We found obvious fractionation of both light and heavy REEs, which was supported by the North American Shale Composite (NASC) and the Post-Archean Average Australian Shale (PAAS) normalized concentration ratios calculated for selected elements (La(N)/Yb(N), La(N)/Sm(N) and Gd(N)/Yb(N)). A slightly positive Ce anomaly and a negative Eu anomaly were also found. For all 14 REEs in soils, enrichment was intensified by the mine tailing sources and influenced by the prevailing wind.

  14. High Resolution ITRAX Analysis of Les Echets (France) Sedimentary Sequence: Linking Geochemical, Biological and Physical Proxies

    Science.gov (United States)

    Wohlfarth, B.; Kylander, M. E.; Ampel, L.; Veres, D.

    2008-12-01

    We present a 30 m long, high-resolution, independently-dated multi-proxy lake sediment record from Les Echets in south-central France which covers the later part of Marine Isotope Stage (MIS) 3 and MIS 2 (40 and 16 ka BP). The sediments in the lower part of the studied sequence are composed of alternating organic rich and minerogenic layers, while the upper part consists predominantly of silt and clay. Organic geochemical, geophysical and biological environmental indicators (grain size, mineral magnetic parameters, TOC, TN, LOI, stable carbon isotopes, rock eval, biogenic silica, and diatom assemblages) show alternating phases of higher and low lake organic productivity which are interpreted as a response to DO climate variability. XRF is a well-established analytical tool that has recently taken a new direction with the introduction of core scanning systems. The ITRAX XRF core scanning system is non-destructive, acquires continuous data for a broad range of elements in situ as well as generates radiographic images. The Les Echets sequence was analysed using the ITRAX at 1 mm resolution. The radiographic images show significant changes that were not revealed by lithostratigraphic descriptions. Distinct, dense layers are associated with changes in elemental intensities which would have been missed using traditional sub-sampling techniques. The high resolution elemental profiles show associations between certain elements (Rb, Si, Ti and K; Sr and Ca) which can be linked to lake productivity and catchment erosion and by extension, paleoclimatic changes.

  15. Geochemical characteristics of igneous rocks associated with epithermal mineral deposits—A review

    Science.gov (United States)

    du Bray, Edward A.

    2017-01-01

    Newly synthesized data indicate that the geochemistry of igneous rocks associated with epithermal mineral deposits varies extensively and continuously from subalkaline basaltic to rhyolitic compositions. Trace element and isotopic data for these rocks are consistent with subduction-related magmatism and suggest that the primary source magmas were generated by partial melting of the mantle-wedge above subducting oceanic slabs. Broad geochemical and petrographic diversity of individual igneous rock units associated with epithermal deposits indicate that the associated magmas evolved by open-system processes. Following migration to shallow crustal reservoirs, these magmas evolved by assimilation, recharge, and partial homogenization; these processes contribute to arc magmatism worldwide.Although epithermal deposits with the largest Au and Ag production are associated with felsic to intermediate composition igneous rocks, demonstrable relationships between magmas having any particular composition and epithermal deposit genesis are completely absent because the composition of igneous rock units associated with epithermal deposits ranges from basalt to rhyolite. Consequently, igneous rock compositions do not constitute effective exploration criteria with respect to identification of terranes prospective for epithermal deposit formation. However, the close spatial and temporal association of igneous rocks and epithermal deposits does suggest a mutual genetic relationship. Igneous systems likely contribute heat and some of the fluids and metals involved in epithermal deposit formation. Accordingly, deposit formation requires optimization of source metal contents, appropriate fluid compositions and characteristics, structural features conducive to hydrothermal fluid flow and confinement, and receptive host rocks, but not magmas with special compositional characteristics.

  16. Home range and travels

    Science.gov (United States)

    Stickel, L.F.; King, John A.

    1968-01-01

    The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels

  17. Mineralogical and geochemical features of the Oleninskoe gold occurrence (Kola region, Russia)

    Science.gov (United States)

    Galkin, N.; Gavrilenko, B.

    2003-04-01

    The Oleninskoe gold occurrence is situated within the Archean Kolmozero-Voron’ja suture structure. The host rocks are basalts and gabbro-diabases metamorphosed in the amphibolite facies. The mineralized zone is bordered in the west by a major fault intersecting the entire structure. The thickness of the zone is approximately 50 m, it strikes over 1.5 km, and dips to at least 100 m. The alteration processes in the rocks of the Oleninskoe occurrence are represented mainly by the silicification (thin quartz veinlet), biotitization, epidotization, diopsidization etc. Based on study of fissure systems in the host rocks, it is established that ore bodies tend to an intersection of disjunctive dislocations of the lower order represented by steep longitudinal and transversal fissures. Pyrrhotite-arsenopyrite mineralization of the Oleninskoe gold occurrence is of the streaky-disseminated type. It can be referred to low-sulfide gold-quartz formation. The major ore minerals are pyrrhotite, arsenopyrite, native gold, electrum, native silver, chalcopyrite, blende, galena and silver sulphosalts. The primary gold-bearing mineral is arsenopyrite, in which early gold is emulsive. The size of gold grains varies from 0.001 mm up to 0.2 mm. Later gold is represented by veinlets in sulphides and silicates being 0.1 up to 0.5 mm in size. On the basis of 100 individual geochemical analyses, primary geochemical aureoles of Au, Ag and As were mapped. That allowed to reveal a pod-like shape and orientation of the ore bodies. The orientation of the ore bodies coincides spatially with crystallization and metamorphic schistosity of host rocks and corresponds to the general direct strike of the Archean Kolmozero-Voron’ja structure. It is noted according to the primary aureoles that the rocks with highest concentration of Au, Ag and As tend to the contact of gabbro-diabases and muscovite-quartz metasomatic rocks. The gold composition in the Archean Kolmozero-Voron’ja structure ranges from

  18. Geochemical,Petrological and Mineralogical Investigation of Nickeliferous Laterite Goynukbelen, Turkey.

    Science.gov (United States)

    Kabiru, Mohammed; Kumral, Mustafa; Kocaturk, Huseyin; Gumus, Lokman; Kaya, Mustafa

    2017-04-01

    The obduction and tectonically emplacement of ophiolite during late Cretaceous in the Goynukbelen terrane has acted as a potential source for the enrichment of nickeliferous laterite. These ultramafic rocks are highly susceptible to intense chemical and mechanical weathering which are very unstable at surface environment. The lithologies of the rock unit consist of Dunite and peridotite which are unstable and metamorphosed serpentinite and lizardite which are stable ore forming minerals. The laterite is formed as a result of weathering of the above rock types with interplaying role of climate and topography. The terrane provides the ingredients for the association of laterites. The geochemical, petrological and mineralogical associations of low grade laterite samples that are related to nickeliferous mineralization, the lithological profile of the area were studied looking at the different possible areas of enrichment of such a deposit. Weathering of olivine rich ultramafic rocks result in the breakdown of Magnesium and Silica which are replaced in the lattice with Nickel and Iron are precipitate as ferric hydroxide which form oxide deposit. Nickel bearing mineralogy, hydrous magnesium silicate, smectite, Violarite which is a supergene sulfide mineral that indicate weathering and oxidation of primary pentladite, ullmannite which replaces awaruite in it mineral form, Nickeline,Trevorite, Rammelsbergite and gerdoffite also seen. Petrographic indication shows that serpentinization benefic the Nickeliferous ore forming process as they provide adequate texture and porosity for water channel that facilitate the hydrolysis which breakdown silica, increasing the instability of the rock while paving a way for the formation of lizardite which is an ore forming mineral. From the geochemical analyses the Nickel concentration ranges from 1000-4000PPM. Nickeliferous laterite indicates a supergene enrichment which is favour by the ultramafic parent rock, climate and topography

  19. Geochemical constraints on the link between volcanism and plutonism at the Yunshan caldera complex, SE China

    Science.gov (United States)

    Yan, Lili; He, Zhenyu; Beier, Christoph; Klemd, Reiner

    2018-01-01

    The Yunshan caldera complex is part of a larger scale, ca. 2000-km-long volcanic-plutonic complex belt in the coastal region of SE China. The volcanic rocks in the caldera complex are characterized by high-silica peraluminous and peralkaline rhyolites associated with an intracaldera porphyritic quartz monzonite pluton. In this study, we present zircon U-Pb, Hf and stable O isotopes along with geochemical data of both volcanic and plutonic rocks to evaluate the potential petrogenetic link between volcanism and plutonism in the Yunshan caldera complex. SHRIMP zircon U-Pb geochronology of both volcanic and plutonic rocks yields almost identical ages ranging from 95.6 to 93.1 Ma. The peraluminous and peralkaline rhyolites show negative anomalies of Sr, P, Ti and Ba and to a lesser extent negative Nb and Ta anomalies, along with positive Rb anomalies and `seagull-like' rare earth element (REE) patterns with negative Eu anomalies and low (La/Yb)N ratios. The intracaldera porphyritic quartz monzonite displays minor negative Rb, Nb, Ta, Sr, P and Ti anomalies and a positive Ba anomaly with REE patterns characterized by relatively high (La/Yb)N ratios and lack significant Eu anomalies. The peraluminous and peralkaline rhyolites and the porphyritic quartz monzonite exhibit consistent ɛ Nd( t) of - 3.7 to - 2.2 and display zircon ɛ Hf( t) values of - 2.1 to 3.7. They further have similar, mantle-like, zircon oxygen isotopic compositions (δ18OVSMOW mainly = 4.63 to 5.76‰). We interpret these observations to be in agreement with a crystal mush model in which the parental magma of the volcanic and plutonic rocks of the Yunshan caldera complex was likely produced by interaction of asthenosphere melts with subduction-influenced enriched mantle wedge. The peralkaline rhyolites are interpreted to represent the most differentiated magma that has subsequently experienced significant fluid-melt interactions, whereas the porphyritic quartz monzonite may be representative of the

  20. Use of Geochemical Indices in Environmental Assessment of Soil; the Predictable and the Predictably Unpredictable

    Science.gov (United States)

    Mikkonen, Hannah; Clarke, Bradley; van de Graaff, Robert; Reichman, Suzie

    2016-04-01

    Geochemical correlations between common contaminants (Pb, Ni, As, Cr, Co and Zn) and earth metals, Fe and Mn, have been recommended as empirical tools to estimate "background" concentrations of metals in soil. A limited number of studies indicate that geochemical ratios between Pb, Ni, As, Cr, Co, V and Zn with scavenger metals Fe or Mn, are consistent between soils collected from different regions (Hamon et al. 2004, Myers and Thorbjornsen 2004). These studies have resulted in the incorporation of geochemical indices into Australian guidance, for derivation of ecological investigation levels for Ni, Cr, Cu and Zn. However, little research has been undertaken to assess the variation of geochemical patterns between soils derived from different parent materials or different weathering environments. A survey of background soils derived from four different parent materials, across Victoria, Australia, was undertaken, comprising collection of samples (n=640) from the surface (0 to 0.1 m) and sub-surface (0.3 to 0.6 m). Soil samples were collected from urban and rural areas of low disturbance, away from point sources of contamination. Samples were analysed for metals/metalloids and soil physical and chemical properties. Statistical review of results included regression and multivariate analysis. The results of the soil survey were compared against geochemical relationships reported within Australia and internationally. Compilation of results from this study and international data sets, indicates that geochemical relationships for metals Cr and V (in the format of log[Cr] = alog[Fe] +c) are predictable, not only between soils derived from different parent materials, but also between soils of different continents. Conversely, relationships between Zn and Fe, Pb and Fe, Cu and Fe, Co and Mn are variable, particularly within soils derived from alluvial sediments, which may have undergone periods of reducing conditions, resulting in dissociation from metal oxides. Broad

  1. Magmatic Processes in Monogenetic Eruptions, Procida Island, Campi Flegrei, Italy: Geochemical Evidence From Melt Inclusions

    Science.gov (United States)

    Severs, M. J.; Fedele, L.; Esposito, R.; Bodnar, R.; Petrosino, P.; Lima, A.; de Vivo, B.; Shimizu, N.

    2008-12-01

    Campi Flegrei is an active volcanic complex located in the greater Naples area, which has produced more than 50 eruptions over the past 60,000 years. These have ranged from small eruptions such as Monte Nuovo eruption of 1538 CE to extremely large eruptions such as the Campanian Ignimbrite (150-200 DRE; Barbieri et al., 1978). The volcanic field includes the mainland area located to the west of Naples and also the two islands of Ischia and Procida. The volcanic products range from basalts to shoshonitic phonolites and trachytes, with the more evolved magmas being more abundant. Three eruptive units from Procida Island have been studied to observe geochemical trends over time within a small area and to better understand magmatic processes between monogenetic eruptions. Juvenile samples from Pozzo Vecchio, Breccia Museo, and Solchiara were collected to examine the geochemistry of the mineral phases present and melt inclusions (MIs) found within the phenocrysts. Solchiara contained phenocrysts of olivine and clinopyroxene, whereas Breccia Museo and Pozzo Vecchio samples contained clinopyroxene and sanidine as the dominant phenocryst phases. Melt inclusions from Solchiara have narrow compositional ranges in major and trace elements (i.e., CaO, TiO2, Zr, Dy, La) over a large range in SiO2 contents (47 to 55 wt%) while MI from the Breccia Museo have a limited range of SiO2 contents (57 to 61 wt%) with a wider range for major and trace elements (i.e., FeO, Al2O3, CaO, La, Th, Rb). Pozzo Vecchio MI from clinopyroxene and sanidine define different chemical compositions, but petrographic evidence does not suggest a xenocrystic origin for either mineral phase. This suggests that Pozzo Vecchio is the result of magma mixing. Modeling of fractional crystallization of olivine, clinopyroxene, and sanidine are capable of producing most of the trends in major and trace elements between the most primitive samples to the most evolved samples. Volatile concentrations between the

  2. Geochemical and isotopic investigations on the thermal and mineral underground waters from the Republic of Moldova

    Science.gov (United States)

    Nisi, Barbara; Bogdevich, Oleg; Vaselli, Orlando; Nicoara, Igor; Tassi, Franco; Culighin, Elena; Mogorici, Cristina; Jeleapov, Victor; Mussi, Mario

    2017-04-01

    geochemical point of view, the Moldavian waters showed neutral to alkaline pH, Total Dissolved Solids between 515 and 75,846 mg/L and mostly negative Eh values. They displayed a relatively high variability in terms of composition, being classified as Ca(Mg)-HCO3(SO4), Na-Cl and Na-HCO3. In the mineralized waters from the Baden-Sarmatian aquifer, trace element distribution revealed significant anomalies for F-, I- and Br- (up to 13.2, 23.7 and 140.5 mg L-1, respectively). Moreover, high values of As and Ni were found in the Dubasari waters (up to 13.8 μg L-1 and 43 μg L-1, respectively). Dissolved gases were mainly dominated by N2 (from 0.16 to 0.78 mmol/L), while CO2 and CH4 were between 0.02 and 0.66 mmol/L and 0.00005 and 0.44 mmol/L, respectively. Oxygen and hydrogen isotopic ratios were ranging from -15.8 to -0.9 ‰ (V-SMOW) and from -104.5 to -32.8 ‰ (V-SMOW), respectively, suggesting a meteoric source slightly modified by prolonged water-rock interactions. Carbon isotopes in dissolved CO2 were very variable (13δ-CO2from -25.2 to +2.8 ), the most positive values being associated with the waters collected from the oil field in the southernmost part of the country. Finally, water ages by using tritium units (presently in progress) will be used to trace the flow of the youngest waters.

  3. Modelling of leaching and geochemical processes in an aged MSWIBA subbase layer

    Energy Technology Data Exchange (ETDEWEB)

    Bendz, David; Suer, Pascal; Sloot, Hans van der; Kosson, David; Flyhammar, Peter

    2009-07-15

    average with a spatial variability in the sub base layer ranging from LS:1 to LS:50. The geochemical speciation modeling was carried out for major, minor and trace elements and integrate mineral dissolution/precipitation, iron-oxide adsorption, incorporation in ettringite solid solution, clay interaction and interaction with dissolved and particulate organic matter. The geochemical model was parameterized with data on HFO, TOC and IC. The governing mineral assembly was selected, based on this experience. Iron-oxide sorption was shown to be important for many trace elements (metals as well as oxyanions). The role of organic matter (both dissolved and particulate) is important for elements like Cu, Cr, Cd, Pb (although the major fraction of the available content is associated with the mineral phases). Obviously, proper mineral solubility data are limited for some elements, like Sb, B, Se. The model fit for macroelements was good and for trace elements the match is quite acceptable. The model confirms that Cu, Cr, Pb, and partially Zn, in solution is bound to DOC. The elements Zn, Cd and Ni are present in the solution mainly as free ions. It is important to realize that for ecotoxicity evaluations the free element is of importance and the DOC associated metal is not affecting many organisms. In the solid phase As is entirely associated with iron oxides. Other elements where iron oxides plays an important role are: Pb, Cd and Cu. The elements Cu, Zn and Ni are mainly associated with the solid phase as minerals: malachite (copper hydroxide carbonate) willemite (zinc silicate), nickel silicate and iron chromate. The result implies that release of elements could be predicted for a bottom ash under certain environmental conditions if available HFO and TOC are measured. The major environmental conditions that needs to be specified are: pH, DOC and DIC of intruding water and degree of exposure to atmosphere

  4. Merging high resolution geophysical and geochemical surveys to reduce exploration risk at glass buttes, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Patrick [Ormat Nevada, Inc., Reno, NV (United States); Fercho, Steven [Ormat Nevada, Inc., Reno, NV (United States); Perkin, Doug [Ormat Nevada, Inc., Reno, NV (United States); Martini, Brigette [Corescan Inc., Ascot (Australia); Boshmann, Darrick [Oregon State Univ., Corvallis, OR (United States)

    2015-06-01

    The engineering and studies phase of the Glass Buttes project was aimed at reducing risk during the early stages of geothermal project development. The project’s inclusion of high resolution geophysical and geochemical surveys allowed Ormat to evaluate the value of these surveys both independently and in combination to quantify the most valuable course of action for exploration in an area where structure, permeability, and temperature are the most pressing questions. The sizes of the thermal anomalies at Glass Buttes are unusually large. Over the course of Phase I Ormat acquired high resolution LIDAR data to accurately map fault manifestations at the surface and collected detailed gravity and aeromagnetic surveys to map subsurface structural features. In addition, Ormat collected airborne hyperspectral data to assist with mapping the rock petrology and mineral alteration assemblages along Glass Buttes faults and magnetotelluric (MT) survey to try to better constrain the structures at depth. Direct and indirect identification of alteration assemblages reveal not only the geochemical character and temperature of the causative hydrothermal fluids but can also constrain areas of upflow along specific fault segments. All five datasets were merged along with subsurface lithologies and temperatures to predict the most likely locations for high permeability and hot fluids. The Glass Buttes temperature anomalies include 2 areas, totaling 60 km2 (23 mi2) of measured temperature gradients over 165° C/km (10° F/100ft). The Midnight Point temperature anomaly includes the Strat-1 well with 90°C (194 °F) at 603 m (1981 ft) with a 164 °C/km (10°F/100ft) temperature gradient at bottom hole and the GB-18 well with 71°C (160 °F) at 396 m (1300 ft) with a 182°C/km (11°F/100ft) gradient. The primary area of alteration and elevated temperature occurs near major fault intersections associated with Brothers Fault Zone and Basin and Range systems. Evidence for faulting is

  5. Carbonatite associated with ultramafic diatremes in the Avon Volcanic District, Missouri, USA: Field, petrographic, and geochemical constraints

    Science.gov (United States)

    Shavers, Ethan J.; Ghulam, Abduwasit; Encarnacion, John; Bridges, David L.; Luetkemeyer, P. Benjamin

    2016-04-01

    Here we report field, petrographic, and geochemical analyses of the southeast Missouri Avon Volcanic District intrusive rocks and present the first combined textural and geochemical evidence for