Sample records for andean porphyry copper

  1. Porphyry copper deposits of the world (United States)

    U.S. Geological Survey, Department of the Interior — Information on porphyry copper deposits from around the world with grade and tonnage models, a general classification based on geologic setting, mineralogy, with...

  2. Duobaoshan Porphyry Copper Deposit and Its Associated Components

    Institute of Scientific and Technical Information of China (English)


    @@Duobaoshan porphyry copper deposit, situated in Nenjiang County of Heilongjiang Province, Northeast China, lies tectonically in the Mongolian-Okhotsk geosyncline.Duobaoshan porphyry copper ore field consisting of Duobaoshan copper deposit and Tongshan copper deposit contains rich copper associated with molybdenum, gold, silver and osmium (OsX87). In this sense, this porphyry copper ore field will turn into a large industrial base of copper, gold, silver and osmium. At present, in Duobaoshan porphyry copper deposit occurs a usable B+C+-D grade reserve of 3 276 630ton Cu, 122 920 ton Mo, 87 ton gold and 1 417 ton Ag.

  3. Grade-Tonnage Model of Porphyry Copper Deposits of China

    Institute of Scientific and Technical Information of China (English)

    Wang Xueping; Wei Min; Yang Lipei; Zhao Jingman


    A grade-tonnage model is established according to the analysis of 72 porphyry copper deposits recorded in "The Mineral Resources Data Base of China". Based on the analysis of frequency histogram, the cumulative frequency distributing graph and the theoretical model with double logarithmic coordinates of copper deposits, the typical mathematical characteristics of grade-tonnage model of porphyry copper deposits are clarified.

  4. Fluid evolution of Cerro Colorado Porphyry Copper Mine (United States)

    Tsang, Debbie Pui Wai; Wallis, Simon


    The Cerro Colorado porphyry copper deposit is the northernmost currently active copper mine in Chile, producing 90.5kt copper per year. It belongs to one of the Paleocene to early Eocene porphyry copper deposits that are distributed along the western slope of the main Andean Cordillera in Northern Chile (Bouzari & Clark, 2002). Active commercial production began in 1994, and the estimated reserves within the supergene blanket can sustain further 12 years of copper mining. Field studies of the well-exposed geology around the mine site and the access to drilled cores that penetrate into the hypogene zone provide a good opportunity to study the temporal relationship between magmatism, hypogene and supergene ore formation of the region. The geological evolution of Cerro Colorado area can be generalized as follows. The Cretaceous Cerro Empexa Formation, consisting of a sequence of volcanic rocks, mainly andesitic lava and breccia, lahars, some ignimbrite intercalations and dacitic tuff (Charrier, Pinto & Rodrigues, 2007), was intruded by tonalitic to dioritic magma in Middle-Eocene. Magmatic activities generated brecciated rocks accompanying with different alteration zones radiate outward from the intrusion. The mineralized hypogene protore later interacted with ground water, creating the supergene blanket, which is now the principal mining target of Cerro Colorado. Several plutonic lithologies with slight but distinct compositional differences were exposed in the valleys around the mine site. The presence of these several phases of small-scale intrusions suggests the ore genesis may be related to multiple pulses of heating and associated fluid flow. Complementarily, on-site geologists have reported occurrences of early stage biotites vein cutting into phyllitic alteration zone, or across terminal stage quartz-pyrite veins in the drilled cores. These observations are direct evidences of at least two major distinct phases of fluid flow, and imply the ore mineralization

  5. Porphyry copper assessment of the Tibetan Plateau, China: Chapter F in Global mineral resource assessment (United States)

    Ludington, Steve; Hammarstrom, Jane M.; Robinson, Gilpin R., Jr.; Mars, John L.; Miller, Robert J.


    The U.S. Geological Survey collaborated with the China Geological Survey to conduct a mineral-resource assessment of resources in porphyry copper deposits on the Tibetan Plateau in western China. This area hosts several very large porphyry deposits, exemplified by the Yulong and Qulong deposits, each containing at least 7,000,000 metric tons (t) of copper. However, large parts of the area are underexplored and are likely to contain undiscovered porphyry copper deposits.

  6. Porphyry copper assessment of western Central Asia: Chapter N in Global mineral resource assessment (United States)

    Berger, Byron R.; Mars, John L.; Denning, Paul D.; Phillips, Jeffrey D.; Hammarstrom, Jane M.; Zientek, Michael L.; Dicken, Connie L.; Drew, Lawrence J.; with contributions from Alexeiev, Dmitriy; Seltmann, Reimar; Herrington, Richard J.


    The U.S. Geological Survey conducted an assessment of resources associated with porphyry copper deposits in the western Central Asia countries of Kyrgyzstan, Uzbekistan, Kazakhstan, and Tajikistan and the southern Urals of Kazakhstan and Russia as part of a global mineral resource assessment. The purpose of the study was to (1) delineate permissive areas (tracts) for undiscovered porphyry copper deposits; (2) compile a database of known porphyry copper deposits and significant prospects; (3) where data permit, estimate numbers of undiscovered deposits within those permissive tracts; and (4) provide probabilistic estimates the amounts of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) that could be contained in those undiscovered deposits.

  7. Progress in porphyry copper exploration from the Gangdise belt, Tibet, China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Youye; DUO Ji; CHENG Shunbo; GAO Shunbao; DAI Fanghua


    Recent mineral exploration in the Gangdise porphyry copper deposit belt, an important component of the Himalaya-Tethyan metallogenic belt, has led to the discovery of a number of deposits, as exemplified by the world-class Miocene Qulong porphyry Cu deposit. This paper reviews major advances in the studies of ore genesis and metallogenic regularity and progresses in mineral exploration of porphyry Cu deposits in the belt. Existing problems and suggestion for future exploration also are given.

  8. Re-Os Dating of the Pulang Porphyry Copper Deposit in Zhongdian, NW Yunnan, and Its Geological Significance

    Institute of Scientific and Technical Information of China (English)

    ZENG Pusheng; HOU Zengqian; WANG Haiping; QU Wenjun; MENG Yifeng; YANG Zhusen; LI Wenchang


    The Pulang porphyry copper deposit is located in the Zhongdian island arc belt, NW Yunnan, in the central part of the Sanjiang area, SW China, belonging to the southern segment of the Yidun island arc belt on the western margin of the Yangtze Platform. In the Yidun island arc, there occur well-known "Gacun-style" massive sulfide deposits in the northern segment and plenty of porphyry copper deposits in the southern segment, of which the Pulang porphyry copper deposit is one of the representatives. Like the Yulong porphyry copper deposit, this porphyry copper deposit is also one of the most important porphyry copper deposits in the eastern Qinghai-Tibet Plateau. But it is different from other porphyry copper deposits in the eastern Qinghai-Tibet Plateau (e.g. those in the Gangdise porphyry copper belt and Yulong porphyry copper belt) in that it formed in the Indosinian period, while others in the Himalayan period. Because of its particularity among the porphyry copper deposits of China, this porphyry copper deposit is of great significance for the study of the basic geology and the evaluation and prediction of mineral resources in the Zhongdian island arc belt.However, no accurate chronological data are available for determining the timing of mineralization of the porphyry copper deposit. By field observation in the study area and Re-Os dating of molybdenite and K-Ar dating of hydrothermal minerals and whole rock from the typical geological bodies, the timing of mineralization of the porphyry copper deposit has systematically been determined for the first time. The K-Ar age for the hydrothermal mineralization of biotite-quartz monzonitic porphyry that has undergone patassic silicate (biotite and K-feldspar) alteration ranges from 235.4±2.4 to 221.5±2.0 Ma and the Re-Os age for molybdenite in the quartz-molybdenite stage is ~213±3.8 Ma. These data are very close to each other, suggesting that the ore-forming processes of the Pulang porphyry copper deposit was

  9. Porphyry copper assessment of Southeast Asia and Melanesia: Chapter D in Global mineral resource assessment (United States)

    Hammarstrom, Jane M.; Bookstrom, Arthur A.; Dicken, Connie L.; Drenth, Benjamin J.; Ludington, Steve; Robinson, Gilpin R., Jr.; Setiabudi, Bambang Tjahjono; Sukserm, Wudhikarn; Sunuhadi, Dwi Nugroho; Wah, Alexander Yan Sze; Zientek, Michael L.


    The U.S. Geological Survey collaborated with member countries of the Coordinating Committee for Geoscience Programmes in East and Southeast Asia (CCOP) on an assessment of the porphyry copper resources of Southeast Asia and Melanesia as part of a global mineral resource assessment. The region hosts world-class porphyry copper deposits and underexplored areas that are likely to contain undiscovered deposits. Examples of known porphyry copper deposits include Batu Hijau and Grasberg in Indonesia; Panguna, Frieda River, and Ok Tedi in Papua New Guinea; and Namosi in Fiji.

  10. Porphyry copper assessment of eastern Australia: Chapter L in Global mineral resource assessment (United States)

    Bookstrom, Arthur A.; Len, Richard A.; Hammarstrom, Jane M.; Robinson, Gilpin R., Jr.; Zientek, Michael L.; Drenth, Benjamin J.; Jaireth, Subhash; Cossette, Pamela M.; Wallis, John C.


    The U.S. Geological Survey (USGS) conducts national and global assessments of resources (mineral, energy, water, and biologic) to provide science in support of decision making. Mineral resource assessments provide syntheses of available information about where mineral deposits are known and suspected to occur in the Earth’s crust and which commodities may be present, together with estimates of amounts of resources that may be present in undiscovered deposits. The USGS collaborated with geologists of the Geological Survey of New South Wales and Geoscience Australia (formerly the Australian Geological Survey Organisation) on an assessment of Phanerozoic-age porphyry copper resources in Australia. Porphyry copper deposits contain about 11 percent of the identified copper resources in Australia. This study addresses resources of known porphyry copper deposits and expected resources of undiscovered porphyry copper deposits in eastern Australia.

  11. 40Ar/39Ar geochronology of the El Teniente porphyry copper deposit

    International Nuclear Information System (INIS)

    Chile's El Teniente deposit is the largest known porphyry Cu-Mo orebody (>70 Mt Cu ), and is genetically related to Late Miocene-Early Pliocene igneous activity on the western slopes of the Andean Cordillera (cf. Howell and Molloy, 1960, Camus, 1975, Cuadra, 1986, Skewes and Stern, 1995). The deposit is 2700 m long by 1000 to 1700 m wide and is elongated in a N-S direction, with a recognized vertical extent of about 1800 m. Approximately 80% of the copper at El Teniente is distributed within a stockwork of mineralized veinlets and minor hydrothermal breccias within pervasively altered andesites, basalts and gabbros that are part of the Upper Miocene country rocks. Two intrusive bodies occur within the deposit, the Sewell Diorite (actually a tonalite) in the southeast part of the orebody and the dacitic Teniente Porphyry in its northern part. The Teniente Porphyry occurs as a north-south trending dike 1500 m long and 200 m wide. Minor quartz-diorite or tonalite intrusions known as the Central Diorite and the Northern Diorite occur along the eastern side of the deposit. Hydrothermal breccias commonly occur along the contacts of intrusive bodies with the country rocks. The Braden Breccia is a conspicuous diatreme in the center of the deposit that forms a pipe 1200 m in diameter at the surface, narrowing to 600 m at a depth of 1800 m. The Braden diatreme pipe is poorly mineralized (∼0.3% Cu), but it is surrounded by the copper-rich Marginal Breccia, a discontinuous rim of tourmaline-matrix hydrothermal breccia. Latite dikes intrude El Teniente, some forming altered ring dikes that encircle the Braden breccia pipe. After mineralization had ceased, the southern section of the deposit was cut by a 3.8 ± 0.3 Ma lamprophyre dyke, marking the end of igneous activity (Cuadra, 1986). Biotite-dominated K-silicate alteration is widespread within the orebody. In contrast, pervasive phyllic alteration is restricted to 'diorite' intrusions, and to the Braden and Marginal

  12. Genetic Model of an Aborted Porphyry-copper System (United States)

    Papp, D. C.; Nitoi, E.; Szakacs, A.


    The Neogene Sturzii shallow intrusion from the East Carpathians (Bargau Mts., Romania), hosted by Paleogene-Miocene sediments of the Transcarpatian Flysch, developed as an immature porphyry copper structure. It consists of small volumes of dacites, andesites and related contact breccias, having a surface exposure of a few km2. Hydrothermal alteration occurred in the inner part of the intrusive body. The related mineralization consists of pyrite and chalcopyrite either as small veins or disseminated within the rock. A genetic model of the intrusive structure has been developed based on an integrated petrographic, geochemical, isotopic, fluid inclusion and geophysical study. The rapidly ascending calc-alkaline magmas that generated the intrusion are mantle-derived and contaminated with lower-crustal material. Pressure estimations for amphibole reveal significant differences between values corresponding to the crystal cores and rims, suggesting that decompression occurred during its crystallization. The occurrence of exploded fluid inclusions, as well as of primary igneous garnet, also indicate decompression regime during magma uplift and/or storage. All fluid inclusions identified in dacites are aqueous; C-N-S species were not detected. The general evolution of the fluids is toward decreasing salinity with decreasing temperature. Early high-T, high salinity fluids, most likely of magmatic origin, were subjected to a boiling event, related to a change of fluid pressure from litho- to hydrostatic, and followed by dilution with meteoric fluids as indicated by low salinities. These characteristics of the fluids suggest the tendency of the intrusion to evolve towards a porphyry copper system. We estimate that the evolution stopped due to decompression that allowed cold and dilute external fluids to enter the system and because of the small size of the intrusion that cooled down rapidly and could not induce extensive and long-lasting fluid circulation. Since there is no

  13. Geochronologic constraints on magmatic intrusions and mineralization of the Zhunuo porphyry copper deposit in Gangdese, Tibet

    Institute of Scientific and Technical Information of China (English)


    In situ zircon U-Pb ages for the recently discovered Zhunuo porphyry copper deposit in the western part of the Gangdese metallogenic belt in Tibet were determined by sensitive high-resolution ion microprobe (SHRIMP). The ages can be divided into two separate groups, reflecting more than four major tectono-magmatic events in the area. The 62.5±2.5 Ma age of inherited zircons may be related to the volcanic eruption of the Linzizong Group formed shortly after the India-Asia continental collision. The 50.1±3.6 Ma age most likely corresponds to the time of underplating of mantle-derived mafic magma in Gangdese. The 15.6±0.6 Ma age obtained from magmatic zircons is interpreted as the age of crystallization of the Zhunuo ore-forming porphyry. Finally, a molybdenite Re-Os isochron age of 13.72±0.62 Ma is consistent with another zircon U-Pb age of 13.3 ±0.2 Ma, representing the time of copper mineralization. These ages, in combination with available literature data, indicate that magmatic crystallization and copper mineralization in the Gangdese metallogenic belt became gradually younger westward, and further suggest that the Zhunuo porphyry copper deposit was formed in the same tectonic stage as other porphyry copper deposits in the eastern and central Gangdese belt. This conclusion provides critical information for future exploration of porphyry copper deposits in western Gangdese.

  14. Ore-forming fluid constraints on illite crystallinity (IC) at Dexing porphyry copper deposit, Jiangxi Province

    Institute of Scientific and Technical Information of China (English)


    Illite, a distinctive kind of clay minerals of potassiumalteration within the hydrothermal alteration zone, frequently occurs at the Tongchang porphyry copper deposit ore field. The illite crystallinity (IC) value and expandability are mainly affected by water/rock ratio or fluid flux. It was formed by illitization of plagioclase and micas during hydrothermal fluid-rock interaction within the porphyry body and near the contact zone with wall rocks. Moreover, the negative correlation between illite index (IC) and copper grade indicates that within the alteration zone, the smaller the illite crystallinity value, the higher the alteration degree, and the higher the copper grade due to higher water/rock ratio. At lower levels of the porphyry body, however, the illite crystallinity (IC) values are mainly controlled by temperature and time duration.

  15. Lead-isotopic signatures of porphyry copper deposits in oceanic and continental settings, Colombian Andes

    International Nuclear Information System (INIS)

    Three discrete sub-belts of porphyry copper-type mineralization are recognized in the Colombian Andes; a western Eocene sub-belt, an eastern Jurassic to early Cretaceous sub-belt and, between them, a central Miocene sub-belt. Pb-isotopic ratios were determined for pyrite samples collected from 6 porphyry copper centers, 3 in the western sub-belt, 2 in the eastern sub-belt, and one in the central sub-belt. Ratios fall into 3 discrete populations; the most radiogenic values represent the western sub-belt, the least radiogenic represent the eastern sub-belt, and an intermediate value corresponds to the central sub-belt. Ratios therefore become progressively less radiogenic from the western oceanic domain to the eastern cratonic domain. Comparison of the Pb-isotopic ratios with those given in the literature for possible source materials for Columbian porphyry copper leads enables the subcontinental mantle wedge, subducted oceanic crust and subducted metalliferous sediments to be discounted as principal sources. The relatively radiogenic signatures of 5 of the porphyry copper centers appear to be broadly compatible with either a subducted pelagic sediment source or an upper continental crust source, whereas the sixth center, Mocoa, is characterized by a distinctly less radiogenic 206Pb/204Pb ratio. The results are discussed. (author)

  16. Exploration for porphyry-style copper mineralisation near Llandeloy, southwest Dyfed


    P M Allen; Cooper, D. C.; Bide, P.; Cameron, D G; Parker, M.E.; Haslam, H.W.; Easterbrook, G.D.; Basham, I.R.


    Geological, geochemical and geophysical surveys followed by drilling in the area around Llandeloy, southwest Dyfed, have located disseminated copper mineralisa tion of porphyry type associated with intermediate intrusive rocks masked by thick overburden. Intermediate intrusive rocks in the area were selected for investigation as potential hosts for disseminated copper mineralisation on the basis of the known geology and tectonic setting. An initial assessment of the...

  17. Audio-magnetotelluric survey to characterize the Sunnyside porphyry copper system in the Patagonia Mountains, Arizona (United States)

    Sampson, Jay A.; Rodriguez, Brian D.


    The Sunnyside porphyry copper system is part of the concealed San Rafael Valley porphyry system located in the Patagonia Mountains of Arizona. The U.S. Geological Survey is conducting a series of multidisciplinary studies as part of the Assessment Techniques for Concealed Mineral Resources project. To help characterize the size, resistivity, and skin depth of the polarizable mineral deposit concealed beneath thick overburden, a regional east-west audio-magnetotelluric sounding profile was acquired. The purpose of this report is to release the audio-magnetotelluric sounding data collected along that east-west profile. No interpretation of the data is included.

  18. Zircon U-Pb dating of Maherabad porphyry copper-gold prospect area: evidence for a late Eocene porphyry-related metallogenic epoch in east of Iran

    Directory of Open Access Journals (Sweden)

    Azadeh Malekzadeh Shafaroudi


    Full Text Available Eastern Iran has great potential for porphyry copper deposits, as a result of its past subduction zone tectonic setting that lead to extensive alkaline to calc-alkaline magmatic activity in Tertiary time. Maherabad is the first porphyry Cu-Au prospecting area which is discovered in eastern Iran. This is related to a succession o f monzonitic to dioritic porphyries stocks that were emplaced within volcanic rocks. Monzonitic porphyries have basic role in mineralization. Hydrothermal alteration zones are well developed including potassic, sericitic-potassic, quartz-sericite-carbonate-pyrite, quartz-carbonate-pyrite, silicified-propylitic, propylitic, carbonate and silicified zones. Mineralization occurs as Disseminated, stockwork and hydrothermal breccia. Based on early stage of exploration, Cu is between 179- 6830 ppm (ave. 3200 ppm and Au is up to 1000 ppb (ave. 570 ppb. This prospect is gold- rich porphyry copper deposit. Laser-ablation U-Pb dating of two samples from ore-related intrusive rocks indicate that these two monzonitic porphyries crystallized at 39.0 ± 0.8 Ma to 38.2 ± 0.8 Ma, within a short time span of less than ca. 1 Ma during the middle Eocene. This provides the first precise ages for metallogenic episode of porphyry-type mineralization. Also, the initial 87Sr/86Sr and (143Nd/144Ndi was recalculated to an age of 39 Ma. Initial 87Sr/86Sr ratios for monzonitic rocks are 0.7047-0.7048. The (143Nd/144Ndi isotope composition are 0.512694-0.512713. Initial ε Nd isotope values 1.45-1.81. Based on isotopic data the magma had originated beyond the continental crust. The study will be used for tectonic-magmatic setting and evolution of eastern Iran. Keywords: Lut block, Middle Eocene, Zircon, Geochronology, Laser ablation ICP-MS,

  19. Global mineral resource assessment: porphyry copper assessment of Mexico: Chapter A in Global mineral resource assessment (United States)

    Hammarstrom, Jane M.; Robinson, Gilpin R., Jr.; Ludington, Steve; Gray, Floyd; Drenth, Benjamin J.; Cendejas-Cruz, Francisco; Espinosa, Enrique; Pérez-Segura, Efrén; Valencia-Moreno, Martín; Rodríguez-Castañeda, José Luis; Vásquez-Mendoza, Rigobert; Zürcher, Lukas


    Mineral resource assessments provide a synthesis of available information about distributions of mineral deposits in the Earth’s crust. A probabilistic mineral resource assessment of undiscovered resources in porphyry copper deposits in Mexico was done as part of a global mineral resource assessment. The purpose of the study was to (1) delineate permissive areas (tracts) for undiscovered porphyry copper deposits within 1 km of the surface at a scale of 1:1,000,000; (2) provide a database of known porphyry copper deposits and significant prospects; (3) estimate numbers of undiscovered deposits within those permissive tracts; and (4) provide probabilistic estimates of amounts of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) that could be contained in undiscovered deposits for each permissive tract. The assessment was conducted using a three-part form of mineral resource assessment based on mineral deposit models (Singer, 1993). Delineation of permissive tracts primarily was based on distributions of mapped igneous rocks related to magmatic arcs that formed in tectonic settings associated with subduction boundary zones. Using a GIS, map units were selected from digital geologic maps based on lithology and age to delineate twelve permissive tracts associated with Jurassic, Laramide (~90 to 34 Ma), and younger Tertiary magmatic arcs. Stream-sediment geochemistry, mapped alteration, regional aeromagnetic data, and exploration history were considered in conjunction with descriptive deposit models and grade and tonnage models to guide estimates.

  20. On the Paleomagnetism of the Intrusives from the Panguna Porphyry Copper Deposit, Bougainville, Papua New Guinea


    Nedachi, Munetomo; ENJOJI, Mamoru; URASHIMA, Yukitoshi; MANSER, Warren; ネダチ, ムネトモ; エンジョウジ, マモル; ウラシマ, ユキトシ; 根建, 心具; 浦島, 幸世


    The temporal relation between intrusives and mineralization of the Panguna porphyry copper deposit, Bougainville Island, Papua New Guinea, was reexamined using paleomagnetic method. The Kaverong Quartz Diorite intruded at the reversed geomagnetic period of 4.0 to 5.0 Ma. After the geomagnetic polarity changed, the Biotite Granodiorite intruded, and the surrouding rocks were mineralized. These rocks have remanent magnetizations of normal polarity. At the next geomagnetic peri...

  1. Porphyry copper assessment of the Mesozoic of East Asia: China, Vietnam, North Korea, Mongolia, and Russia: Chapter G in Global mineral resource assessment (United States)

    Ludington, Steve; Mihalasky, Mark J.; Hammarstrom, Jane M.; Robinson, Giplin R., Jr.; Frost, Thomas P.; Gans, Kathleen D.; Light, Thomas D.; Miller, Robert J.; Alexeiev, Dmitriy V.


    The U.S. Geological Survey (USGS) collaborated with the China Geological Survey (CGS) to conduct a mineral resource assessment of Mesozoic porphyry copper deposits in East Asia. This area hosts several very large porphyry deposits, exemplified by the Dexing deposit in eastern China that contains more than 8,000,000 metric tons of copper. In addition, large parts of the area are undergoing active exploration and are likely to contain undiscovered porphyry copper deposits.

  2. Porphyry copper assessment of Europe, exclusive of the Fennoscandian Shield: Chapter K in Global mineral resource assessment (United States)

    Sutphin, David M.; Hammarstrom, Jane M.; Drew, Lawrence J.; Large, Duncan E.; Berger, Byron R.; Dicken, Connie L.; DeMarr, Michael W.; with contributions from Billa, Mario; Briskey, Joseph A.; Cassard, Daniel; Lips, Andor; Pertold, Zdeněk; Roşu, Emilian


    The U.S. Geological Survey (USGS) collaborated with European geologists to assess resources in porphyry copper deposits in Europe, exclusive of Scandinavia (Sweden, Denmark, Norway, and Finland) and Russia. Porphyry copper deposits in Europe are Paleozoic and Late Cretaceous to Miocene in age. A number of the 31 known Phanerozoic deposits contain more than 1 million metric tons of contained copper, including the Majdanpek deposit, Serbia; Assarel, Bulgaria; Skouries, Greece; and Rosia Poeni, Romania. Five geographic areas were delineated as permissive tracts for post-Paleozoic porphyry copper deposits. Two additional tracts were delineated to show the extent of permissive igneous rocks associated with porphyry copper mineralization related to the Paleozoic Caledonian and Variscan orogenies. The tracts are based on mapped and inferred subsurface distributions of igneous rocks of specific age ranges that define areas where the occurrence of porphyry copper deposits within 1 kilometer of the Earth’s surface is possible. These tracts range in area from about 4,000 to 93,000 square kilometers. Although maps at a variety of different scales were used in the assessment, the final tract boundaries are intended for use at a scale of 1:1,000,000.

  3. Porphyry copper assessment of the Tethys region of western and southern Asia: Chapter V in Global mineral resource assessment (United States)

    Zürcher, Lukas; Bookstrom, Arthur A.; Hammarstrom, Jane M.; Mars, John C.; Ludington, Stephen; Zientek, Michael L.; Dunlap, Pamela; Wallis, John C.; Drew, Lawrence J.; Sutphin, David M.; Berger, Byron R.; Herrington, Richard J.; Billa, Mario; Kuşcu, Ilkay; Moon, Charles J.; Richards, Jeremy P.


    A probabilistic mineral resource assessment of undiscovered resources in porphyry copper deposits in the Tethys region of western and southern Asia was carried out as part of a global mineral resource assessment led by the U.S. Geological Survey (USGS). The purpose of the study was to delineate geographic areas as permissive tracts for the occurrence of porphyry copper deposits at a scale of 1:1,000,000 and to provide probabilistic estimates of amounts of copper likely to be contained in undiscovered porphyry copper deposits in those tracts. The team did the assessment using the USGS three-part form of mineral resource assessment, which is based on (1) mineral deposit and grade-tonnage models constructed from known deposits as analogs for undiscovered deposits, (2) delineation of permissive tracts based on geoscientific information, and (3) estimation of numbers of undiscovered deposits.

  4. Porphyry copper deposit model: Chapter B in Mineral deposit models for resource assessment (United States)

    Ayuso, Robert A.; Barton, Mark D.; Blakely, Richard J.; Bodnar, Robert J.; Dilles, John H.; Gray, Floyd; Graybeal, Fred T.; Mars, John L.; McPhee, Darcy K.; Seal, Robert R., II; Taylor, Ryan D.; Vikre, Peter G.


    This report contains a revised descriptive model of porphyry copper deposits (PCDs), the world's largest source (about 60 percent) and resource (about 65 percent) of copper and a major source of molybdenum, gold and silver. Despite relatively low grades (average 0.44 percent copper in 2008), PCDs have significant economic and societal impacts due to their large size (commonly hundreds of millions to billions of metric tons), long mine lives (decades), and high production rates (billions of kilograms of copper per year). The revised model describes the geotectonic setting of PCDs, and provides extensive regional- to deposit-scale descriptions and illustrations of geological, geochemical, geophysical, and geoenvironmental characteristics. Current genetic theories are reviewed and evaluated, knowledge gaps are identified, and a variety of exploration and assessment guides are presented. A summary is included for users seeking overviews of specific topics.


    Institute of Scientific and Technical Information of China (English)

    LI Guangming; RUI Zongyao


    Recent examination and assessment about the porphyry copper deposits in Gangdise metallogenic belt in southern Tibet have revealed that these porphyry copper deposits are highly prospective. Several methods have been used for the isotopic dating of the Qulong, Tinggong and Chongjiang porphyry copper deposits, which gives out a petrogenetic age of 17.58±0.74Ma (single-zircon dating of SHRIMP), a metallogenetic age of 15.99±0.32Ma (Re-Os isochron dating) and an alteration age ranging between12.00Ma and 16.5Ma (K-Ar dating). The metallogenetic age is in general agreement with the alteration age.It can be seen that the petrogenetic and metallogenetic ages for the porphyry copper deposits in Gangdise metallogenic belt are noticeably later than the age for the collisional granitic intrusion in this belt. The authors contend that the porphyry copper deposits in the study area were formed in a post-collisional extensional tectonic setting, and are closely related to the delamination of the mountain roots of the orogenic belts and the uplifting of the Qinghai-Tibet Plateau.

  6. Consequences of fractal grade distribution for bulk sorting of a copper porphyry deposit

    Institute of Scientific and Technical Information of China (English)

    Peter Coghill; David Miljak; Elizabeth Williams


    We show the presence of fractal ordering of copper grade in bore core data at short range in the Cadia Ridgeway porphyry deposit and measure its persistence after mining by monitoring the output of the mine every 20 s for a month using a large scale, zero field magnetic resonance sensor. A simple model is used to investigate this connection and its consequences for sorting of the ore. Fractal distributions, and their associated power laws, have two features highly favourable for segregating ore:a large proportion of low-grade pods and the large scale spatial clustering of grade.

  7. Mineralization episode of porphyry copper deposits in the Jinshajiang-Red River mineralization belt: Re-Os dating

    Institute of Scientific and Technical Information of China (English)

    WANG Denghong; QU Wenjun; LI Zhiwei; YIN Hanlong; CHEN Yuchuan


    Re-Os isotopic dating for the molybdenites from the porphyry copper deposits of the Jinshajiang-Red River mineralization belt in Yunnan Province yields isochron ages of 33.9±1.1 Ma for the Machangqing deposit and 34.4±0.5 Ma for the Tongchang deposit. This result shows that both the Machangqing and the Tongchang porphyry Cu-Mo deposits from two different ore-fields formed simultaneously. This new data and the published Re-Os model ages of molybdenite (35.4 Ma, 35.9 Ma, 36.2 Ma) of the Yulong porphyry copper deposit in Tibet, which is located in the same Jinshajiang-Red River mineralization belt as the Machangqing deposit and the Tongchang deposit, suggest that these three Cenozoic porphyry copper deposits in the Jinshajiang-Red River mineralization belt were contemporary for their mineralization episode. That is to say, even their present locality is far away and nearly iso-distantly distributed, these three porphyry Cu(Mo) deposits belong to the same mineralization episode at the end of Eocene.

  8. Predictive magnetic exploration models for porphyry copper and iron-oxide copper-gold deposits

    International Nuclear Information System (INIS)

    Complete text of publication follows. Magnetics is the most widely used geophysical method in hard rock exploration and magnetic surveys are an integral part of exploration programmes for porphyry and IOCG deposits. However, the magnetic signatures of these deposits are extremely variable and exploration that is based simply on searching for signatures that resemble those of known deposits is rarely successful. A number of well-known geological models of porphyry and epithermal deposits are routinely used in exploration, even though most deposits fail to match the idealised models closely, due to post-emplacement tectonic disruption, asymmetric alteration zoning due to emplacement along a contact between contrasting country rock types, and so on. The variability of magnetic signatures of these deposits reflects strong dependence of magnetic signatures on local geological setting. Post-emplacement tilting of mineralized systems and dismemberment by faulting are very common and drastically modify the geophysical signatures. Burial of a deposit by younger sedimentary or volcanic rocks also modifies the anomaly pattern. Conversely, exhumation and partial erosion of the system produces a very different magnetic signature. In older deposits, metamorphism can substantially modify the magnetic mineralogy of the deposits and host rocks, with concomitant changes in the magnetic anomaly pattern. Suites of magnetic models, based on realistic geological scenarios and informed by petrophysical data and magnetic petrological principles, illustrate these effects and allow plausible predictions of magnetic signatures of porphyry Cu and Cu-Au deposits and magnetic and gravity signatures of IOCG deposits, based on provincial and local geological settings. A classification scheme for magnetic signatures of porphyry deposits has been developed, based on these models and on a database of geological, petrophysical and geophysical characteristics of deposits from many provinces around the

  9. Porphyry copper assessment of East and Southeast Asia: Philippines, Taiwan (Republic of China), Republic of Korea (South Korea), and Japan: Chapter P in Global mineral resource assessment (United States)

    Hammarstrom, Jane M.; Bookstrom, Arthur A.; Demarr, Michael W.; Dicken, Connie L.; Ludington, Stephen; Robinson, Gilpin R., Jr.; Zientek, Michael L.


    The U.S. Geological Survey collaborated with member countries of the Coordinating Committee for Geoscience Programmes in East and Southeast Asia (CCOP) on an assessment of the porphyry copper resources of East and Southeast Asia as part of a global mineral resource assessment. The assessment covers the Philippines in Southeast Asia, and the Republic of Korea (South Korea), Taiwan (Province of China), and Japan in East Asia. The Philippines host world class porphyry copper deposits, such as the Tampakan and Atlas deposits. No porphyry copper deposits have been discovered in the Republic of Korea (South Korea), Taiwan (Province of China), or Japan.

  10. 斑岩铜矿床研究进展%Review of Porphyry Copper Deposit

    Institute of Scientific and Technical Information of China (English)

    张云国; 周朝宪


    斑岩铜矿不但形成于环太平洋成矿域,还形成于特提斯成矿域和中亚成矿域(古亚洲洋成矿域)。成矿物质来源于深部,经过“洋壳一地幔熔岩流”、“原始岩浆”、“浅部富矿岩浆”和“岩浆结晶一成矿”4个阶段,其中在“原始弧岩浆”阶段,通过MASH过程,有大量成矿物质和能量的聚集。成矿流体为富H2O、高温、高压、高盐度、强氧化性、高氧逸度的富矿气液相流体,这些特点有利于成矿物质在岩浆一热液分离过程中向流体富集,并以氯络合物的形式运移。随着成矿流体的上侵,温度和压力的降低是成矿物质沉淀的主要影响因素。磁铁矿的结晶为成矿流体提供了大量的S2-离子,也是导致成矿物质沉淀的主要因素。斑岩型蚀变带从里向外为石英内核、钾化带、SCC带和泥化带,铜矿化主要发育在矿化带外围以及SCC带。目前,斑岩铜矿成矿模型主要有经典模型、系统模型和多阶段叠加模型。%Porphyry copper deposit as the largest source of Cu is one of the most important deposits in the world. Porphyry Copper Deposit not only occured in Circum-Pacific ore-forming region, but also oceured in Tethys ore-forming region and Middle-Asian(Paleo-Asian Oceanic) ore-forming region. The mineralization materials de- rived from the deep. Porphyry forms through four stages: "Oceanic Crust-Mantle Lava Flow"," Original Magma", "Shallow Ore Magma"," Crystallization of Magma-Minerali- zation". In the stage of "Original Magma", much met- allogenic materials and energy gather through the process of "MASH". Ore-forming fluids are high-grade fliuds of gas-liquid phase, which are of fluid-rich, high temperature, high pressure, high salinity, strong oxidizing, high ox- ygen fugacity. The characteristics of ore-torming fluids are favorable tbr metallogenic materials to gather from mag- mas to fluids in the

  11. Quantitative Mineral Resource Assessment of Copper, Molybdenum, Gold, and Silver in Undiscovered Porphyry Copper Deposits in the Andes Mountains of South America (United States)

    Cunningham, Charles G.; Zappettini, Eduardo O.; Vivallo S., Waldo; Celada, Carlos Mario; Quispe, Jorge; Singer, Donald A.; Briskey, Joseph A.; Sutphin, David M.; Gajardo M., Mariano; Diaz, Alejandro; Portigliati, Carlos; Berger, Vladimir I.; Carrasco, Rodrigo; Schulz, Klaus J.


    Quantitative information on the general locations and amounts of undiscovered porphyry copper resources of the world is important to exploration managers, land-use and environmental planners, economists, and policy makers. This publication contains the results of probabilistic estimates of the amounts of copper (Cu), molybdenum (Mo), gold (Au), and silver (Ag) in undiscovered porphyry copper deposits in the Andes Mountains of South America. The methodology used to make these estimates is called the 'Three-Part Form'. It was developed to explicitly express estimates of undiscovered resources and associated uncertainty in a form that allows economic analysis and is useful to decisionmakers. The three-part form of assessment includes: (1) delineation of tracts of land where the geology is permissive for porphyry copper deposits to form; (2) selection of grade and tonnage models appropriate for estimating grades and tonnages of the undiscovered porphyry copper deposits in each tract; and (3) estimation of the number of undiscovered porphyry copper deposits in each tract consistent with the grade and tonnage model. A Monte Carlo simulation computer program (EMINERS) was used to combine the probability distributions of the estimated number of undiscovered deposits, the grades, and the tonnages of the selected model to obtain the probability distributions for undiscovered metals in each tract. These distributions of grades and tonnages then can be used to conduct economic evaluations of undiscovered resources in a format usable by decisionmakers. Economic evaluations are not part of this report. The results of this assessment are presented in two principal parts. The first part identifies 26 regional tracts of land where the geology is permissive for the occurrence of undiscovered porphyry copper deposits of Phanerozoic age to a depth of 1 km below the Earth's surface. These tracts are believed to contain most of South America's undiscovered resources of copper. The

  12. Late Carboniferous porphyry copper mineralization at La Voluntad, Neuquén, Argentina: Constraints from Re-Os molybdenite dating (United States)

    Garrido, Mirta; Barra, Fernando; Domínguez, Eduardo; Ruiz, Joaquin; Valencia, Victor A.


    The La Voluntad porphyry Cu-Mo deposit in Neuquén, Argentina, is one of several poorly known porphyry-type deposits of Paleozoic to Early Jurassic age in the central and southern Andes. Mineralization at La Voluntad is related to a tonalite porphyry from the Chachil Plutonic Complex that intruded metasedimentary units of the Piedra Santa Complex. Five new Re-Os molybdenite ages from four samples representing three different vein types (i.e., quartz-molybdenite, quartz-sericite-molybdenite and quartz-sericite-molybdenite ± chalcopyrite-pyrite) are identical within error and were formed between ~312 to ~316 Ma. Rhenium and Os concentrations range between 34 to 183 ppm and 112 to 599 ppb, respectively. The new Re-Os ages indicate that the main mineralization event at La Voluntad, associated to sericitic alteration, was emplaced during a time span of 1.7 ± 3.2 Ma and that the deposit is Carboniferous in age, not Permian as previously thought. La Voluntad is the oldest porphyry copper deposit so far recognized in the Andes and indicates the presence of an active magmatic arc, with associated porphyry style mineralization, at the proto-Pacific margin of Gondwana during the Early Pennsylvanian.

  13. Characteristics and evolution of ore-forming fluids of the Chongjiang copper deposit in the Gangdise porphyry copper belt, Tibet

    Institute of Scientific and Technical Information of China (English)

    Yuling Xie; Jiuhua Xu; Guangming Li; Zhiming Yang; Longsheng Yi


    Petrography, microthermometry, and scanning electron microscope/energy dispersive spectrometer (SEM/EDS) studies were performed on the fluid inclusions in the ore-bearing quartz veins and quartz phenocrysts in the porphyry of the Chongjiang porphyry copper deposit. The analyses of the fluid inclusions indicate that the ore-forming fluids were exsolved from magma. They are near-saturated, supercritical, rich in volatile constituents, and have the capture temperature of 362-389°C and salinities of 17.7wt%-18.9wt% NaCl eq. With the decreasing of temperature and pressure, the supercritical fluids were separated into a low salinity vapor phase and a high salinity liquid phase. During quartz-sericitization, the high salinity fluid boiled and separated into a low salinity vapor phase and a high salinity liquid phase. The high salinity inclusions that formed in the boiling process had daughter mineral melting temperatures higher than the homogenization temperatures of the vapor and liquid phases. The late fluids that are responsible for argillization are of lower temperature and salinity.

  14. Alteration zone Mapping in the Meiduk and Sar Cheshmeh Porphyry Copper Mining Districts of Iran using Advanced Land Imager (ALI) Satellite Data


    A. Beiranvand Pour; M. Hashim


    This study evaluates the capability of Earth Observing-1 (EO1) Advanced Land Imager (ALI) data for hydrothermal alteration mapping in the Meiduk and Sar Cheshmeh porphyry copper mining districts, SE Iran. Feature-oriented principal components selection, 4/2, 8/9, 5/4 band ratioing were applied to ALI data for enhancing the hydrothermally altered rocks associated with porphyry copper mineralization, lithological units and vegetation. Mixture-tuned matched-filtering (MTMF) was tested to discrim...

  15. Porphyry copper assessment of Central America and the Caribbean Basin: Chapter I in Global mineral resource assessment (United States)

    Gray, Floyd; Hammarstrom, Jane M.; Ludington, Stephen; Zürcher, Lukas; Nelson, Carl E.; Robinson, Gilpin R., Jr.; Miller, Robert J.; Moring, Barry C.


    Mineral resource assessments provide a synthesis of available information about distributions of mineral deposits in the Earth’s crust. The U.S. Geological Survey prepared a probabilistic mineral resource assessment of undiscovered resources in porphyry copper deposits in Central America and the Caribbean Basin in collaboration with geoscientists from academia and the minerals industry. The purpose of the study was to (1) delineate permissive areas (tracts) for undiscovered porphyry copper deposits within 1 kilometer of the surface at a scale of 1:1,000,000; (2) provide a database of known porphyry copper deposits and significant prospects; (3) estimate numbers of undiscovered deposits within the permissive tracts; and (4) provide probabilistic estimates of amounts of copper, molybdenum, gold, and silver that could be contained in undiscovered deposits. The assessment was done using a three-part mineral resource assessment based on established mineral deposit models. Permissive tracts were delineated based primarily on distributions of mapped igneous rocks related to magmatic arcs that formed in tectonic settings associated with convergent plate margins. Five permissive tracts were delineated: the Early Cretaceous through Eocene Santiago tract, the Late Cretaceous through Oligocene Chortis tract, the Paleocene through Oligocene Darién tract, the Miocene and Pliocene Cocos tract, and the Eocene to Holocene Lesser Antilles tract. These tracts range in size from about 3,000 to about 204,000 square kilometers.

  16. Speciation and leachability of copper in mine tailings from porphyry copper mining

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Yianatos, Juan B; Ottosen, Lisbeth M.


    Mine tailing from the El Teniente-Codelco copper mine situated in VI Region of Chile was analysed in order to evaluate the mobility and speciation of copper in the solid material. Mine tailing was sampled after the rougher flotation circuits, and the copper content was measured to 1150mgkg^-^1 dry...

  17. Lead and zinc geochemical behavior based on geological characteristics in Parkam Porphyry Copper System, Kerman, Iran

    Institute of Scientific and Technical Information of China (English)

    Seyyed; Saeed; Ghannadpour; Ardeshir; Hezarkhani


    Parkam(Sarah) porphyry system is located on the metallogenic belt of Kerman, Iran. Due to existence of some copper-rich resources in this region, finding out the exact statistical characteristics such as distribution of data population, mean, variance and data population behavior of elements like Cu, Mo, Pb and Zn is necessary for interpreting their geological behavior. For this reason, precise calculation of statistical characteristics of Pb and Zn grade datasets was performed and results were interpreted geologically. The natures of Pb and Zn distributions were initially identified and their distributions were normalized through statistical treatment. Subsequently, the variograms were calculated for each exploration borehole and show that both Pb and Zn geochemical variates are spatially correlated. According to the similarity of the behavior of Pb and Zn in these calculations, it is decided to measure their exact behavior applying K-means clustering method. K-means clustering results show that the Zn grade varies linearly relative to that of Pb values and their behavior is similar. Based on the geochemical behavior similarity of Pb and Zn, throughout the pervasive secondary hydrothermal activity, they are remobilized in the similar manner, from the deep to the shallow levels of the mineralization zones. However, statistical analysis suggests that hydrothermal activity associated with secondary waters in Parkam is effective in remobilizing and enriching both Pb and Zn since they have similar geochemical characteristics. However, the process does not result in generation of economic concentrations.

  18. Lead and zinc geochemical behavior based on geological characteristics in Parkam Porphyry Copper System, Kerman, Iran

    Institute of Scientific and Technical Information of China (English)

    Seyyed Saeed Ghannadpour; Ardeshir Hezarkhani


    Parkam (Sarah) porphyry system is located on the metallogenic belt of Kerman, Iran. Due to existence of some copper-rich resources in this region, finding out the exact statistical characteristics such as distribution of data population, mean, variance and data population behavior of elements like Cu, Mo, Pb and Zn is necessary for interpreting their geological behavior. For this reason, precise calculation of statistical characteristics of Pb and Zn grade datasets was performed and results were interpreted geologically. The natures of Pb and Zn distributions were initially identified and their distributions were normalized through statistical treatment. Subsequently, the variograms were calculated for each exploration borehole and show that both Pb and Zn geochemical variates are spatially correlated. According to the similarity of the behavior of Pb and Zn in these calculations, it is decided to measure their exact behavior applyingK-means clustering method.K-means clustering results show that the Zn grade varies linearly relative to that of Pb values and their behavior is similar. Based on the geochemical behavior similarity of Pb and Zn, throughout the pervasive secondary hydrothermal activity, they are remobilized in the similar manner, from the deep to the shallow levels of the mineralization zones. However, statistical analysis suggests that hydrothermal activity associated with secondary waters in Parkam is effective in remobilizing and enriching both Pb and Zn since they have similar geochemical characteristics. However, the process does not result in generation of economic concentrations.

  19. The mass balance calculation of hydrothermal alteration in Sarcheshmeh porphyry copper deposit

    Directory of Open Access Journals (Sweden)

    Mohammad Maanijou


    Full Text Available Sarcheshmeh porphyry copper deposit is located 65 km southwest of Rafsanjan in Kerman province. The Sarcheshmeh deposit belongs to the southeastern part of Urumieh-Dokhtar magmatic assemblage (i.e., Dehaj-Sarduyeh zone. Intrusion of Sarcheshmeh granodiorite stock in faulted and thrusted early-Tertiary volcano-sedimentary deposits, led to mineralization in Miocene. In this research, the mass changes and element mobilities during hydrothermal process of potassic alteration were studied relative to fresh rock from the deeper parts of the plutonic body, phyllic relative to potassic, argillic relative to phyllic and propylitic alteration relative to fresh andesites surrounding the deposit. In the potassic zone, enrichment in Fe2O3 and K2O is so clear, because of increasing Fe coming from biotite alteration and presence of K-feldspar, respectively. Copper and molybdenum enrichments resulted from presence of chalcopyrite, bornite and molybdenite mineralization in this zone. Enrichment of SiO2 and depletion of CaO, MgO, Na2O and K2O in the phyllic zone resulted from leaching of sodium, calcium and magnesium from the aluminosilicate rocks and alteration of K-feldspar to sericite and quartz. In the argillic zone, Al2O3, CaO, MgO, Na2O and MnO have also been enriched in which increasing Al2O3 may be from kaolinite and illite formation. Also, enrichment in SiO2, Al2O3 and CaO in propylitic alteration zone can be attributed to the formation of chlorite, epidote and calcite as indicative minerals of this zone.

  20. Fluid inclusion characteristics and molybdenite Re-Os geochronology of the Qulong porphyry copper-molybdenum deposit, Tibet (United States)

    Li, Yang; Selby, David; Feely, Martin; Costanzo, Alessandra; Li, Xian-Hua


    The Qulong porphyry copper and molybdenum deposit is located at the southwest margin of the Lhasa Terrane and in the eastern region of the Gangdese magmatic belt. It represents China's largest porphyry copper system, with ˜2200 million tonnes of ore comprising 0.5 % Cu and 0.03 % Mo. The mineralization is associated with Miocene granodiorite, monzogranite and quartz-diorite units, which intruded into Jurassic volcanic units in a post-collisional (Indian-Asian) tectonic setting. Field observations and core logging demonstrate the alteration and mineralization at Qulong are akin to typical porphyry copper systems in subduction settings, which comprise similar magmatic-hydrothermal, potassic, propylitic and phyllic alteration assemblages. Molybdenite Re-Os geochronology confirms the relative timeframe defined by field observations and core logging and indicates that the bulk copper and molybdenum at Qulong were deposited within 350,000 years: between 16.10 ± 0.06 [0.08] (without and with decay constant uncertainty) and 15.88 ± 0.06 [0.08] Ma. This duration for mineralization is in direct contrast to a long-lived intrusive episode associated with mineralization based on previous zircon U-Pb data. Our fluid inclusion study indicates that the ore-forming fluid was oxidized and contained Na, K, Ca, Fe, Cu, Mo, Cl and S. The magmatic-hydrothermal transition occurred at ˜425 °C under lithostatic pressure, while potassic, propylitic and phyllic alteration occurred at hydrostatic pressure with temperature progressively decreasing from 425 to 280 °C. The fluid inclusion data presented here suggests that there has been ˜2.3 km of erosion at Qulong after its formation, and this erosion may be related to regional uplift of the Lhasa Terrane.

  1. Alteration zone Mapping in the Meiduk and Sar Cheshmeh Porphyry Copper Mining Districts of Iran using Advanced Land Imager (ALI Satellite Data

    Directory of Open Access Journals (Sweden)

    A. Beiranvand Pour


    Full Text Available This study evaluates the capability of Earth Observing-1 (EO1 Advanced Land Imager (ALI data for hydrothermal alteration mapping in the Meiduk and Sar Cheshmeh porphyry copper mining districts, SE Iran. Feature-oriented principal components selection, 4/2, 8/9, 5/4 band ratioing were applied to ALI data for enhancing the hydrothermally altered rocks associated with porphyry copper mineralization, lithological units and vegetation. Mixture-tuned matched-filtering (MTMF was tested to discriminate the hydrothermal alteration areas of porphyry copper mineralization from surrounding environment using the shortwave infrared bands of ALI. Results indicate that the tested methods are able to yield spectral information for identifying vegetation, iron oxide/hydroxide and clay minerals, lithological units and the discrimination of hydrothermally altered rocks from unaltered rocks using ALI data.

  2. Hydrothermal alteration and its effects on the magnetic properties of Los Pelambres, a large multistage porphyry copper deposit (United States)

    Tapia, Joseline; Townley, Brian; Córdova, Loreto; Poblete, Fernando; Arriagada, César


    The Los Pelambres porphyry copper deposit is located 190 km north of Santiago, Chile. A paleomagnetic and mineralogical study was conducted at this deposit to determine the effects of hydrothermal alteration on the magnetic properties and minerals of rocks within the deposit when compared to the surrounding country rock. In the Los Pelambres deposit, magnetic properties of rocks are carried by titano-hematite and titano-magnetite solid solution minerals, where the former commonly indicates the exsolution of rutile. Magnetic minerals of intrusive rocks from the greater Los Pelambres region show that magmatic titano-magnetites and magnetites are the main magnetization carriers. The hydrothermal fluid associated with rutile exsolution textures could have played an important role in the mineralization of Cu in this deposit. The paleomagnetic properties in the Los Pelambres deposit can be divided in three main groups: (i) HMRG (high magnetic remanence group), (ii) HMSG (high magnetic susceptibility group), and (iii) LMSG (low magnetic susceptibility/remanence group). In-situ magnetic properties of the HMSG and LMSG are similar to the formations and units present regionally, however HRMG samples clearly differ from the country rocks. The high variability of in-situ magnetic properties presented in the Los Pelambres deposit has also been characteristic of other porphyry copper deposits in Chile (e.g., Chuquicamata and El Teniente). Regarding the field of exploration geophysics and porphyry copper deposits, this study suggests that phyllic, chloritic, and potassic alterations are related to low, intermediate, and high in-situ NRM, respectively, suggesting that geophysical methods must target a noisy magnetic signal depending on the scale of the study. The knowledge and results obtained are especially meaningful because magnetic surveys conducted for exploration do not commonly allow for the detection of ore mineralization.

  3. Lead isotope compositions of Late Cretaceous and early Tertiary igneous rocks and sulfide minerals in Arizona: Implications for the sources of plutons and metals in porphyry copper deposits (United States)

    Bouse, R.M.; Ruiz, J.; Titley, S.R.; Tosdal, R.M.; Wooden, J.L.


    Porphyry copper deposits in Arizona are genetically associated with Late Cretaceous and early Tertiary igneous complexes that consist of older intermediate volcanic rocks and younger intermediate to felsic intrusions. The igneous complexes and their associated porphyry copper deposits were emplaced into an Early Proterozoic basement characterized by different rocks, geologic histories, and isotopic compositions. Lead isotope compositions of the Proterozoic basement rocks define, from northwest to southeast, the Mojave, central Arizona, and southeastern Arizona provinces. Porphyry copper deposits are present in each Pb isotope province. Lead isotope compositions of Late Cretaceous and early Tertiary plutons, together with those of sulfide minerals in porphyry copper deposits and of Proterozoic country rocks, place important constraints on genesis of the magmatic suites and the porphyry copper deposits themselves. The range of age-corrected Pb isotope compositions of plutons in 12 Late Cretaceous and early Tertiary igneous complexes is 206Pb/204Pb = 17.34 to 22.66, 207Pb/204Pb = 15.43 to 15.96, and 208Pb/204Pb = 37.19 to 40.33. These Pb isotope compositions and calculated model Th/U are similar to those of the Proterozoic rocks in which the plutons were emplaced, thereby indicating that Pb in the younger rocks and ore deposits was inherited from the basement rocks and their sources. No Pb isotope differences distinguish Late Cretaceous and early Tertiary igneous complexes that contain large economic porphyry copper deposits from less rich or smaller deposits that have not been considered economic for mining. Lead isotope compositions of Late Cretaceous and early Tertiary plutons and sulfide minerals from 30 metallic mineral districts, furthermore, require that the southeastern Arizona Pb province be divided into two subprovinces. The northern subprovince has generally lower 206Pb/204Pb and higher model Th/U, and the southern subprovince has higher 206Pb/204Pb and

  4. From a long-lived upper-crustal magma chamber to rapid porphyry copper emplacement: Reading the geochemistry of zircon crystals at Bajo de la Alumbrera (NW Argentina) (United States)

    Buret, Yannick; von Quadt, Albrecht; Heinrich, Christoph; Selby, David; Wälle, Markus; Peytcheva, Irena


    The formation of world class porphyry copper deposits reflect magmatic processes that take place in a deeper and much larger underlying magmatic system, which provides the source of porphyry magmas, as well as metal and sulphur-charged mineralising fluids. Reading the geochemical record of this large magmatic source region, as well as constraining the time-scales for creating a much smaller porphyry copper deposit, are critical in order to fully understand and quantify the processes that lead to metal concentration within these valuable mineral deposits. This study focuses on the Bajo de la Alumbrera porphyry copper deposit in Northwest Argentina. The deposit is centred on a dacitic porphyry intrusive stock that was mineralised by several pulses of porphyry magma emplacement and hydrothermal fluid injections. To constrain the duration of ore formation, we dated zircons from four porphyry intrusions, including pre-, syn- and post-mineralisation porphyries based on intersection relations between successive intrusion and vein generations, using high precision CA-ID-TIMS. Based on the youngest assemblages of zircon grains, which overlap within analytical error, all four intrusions were emplaced within 29 ka, which places an upper limit on the total duration of hydrothermal mineralisation. Re/Os dating of hydrothermal molybdenite fully overlaps with this high-precision age bracket. However, all four porphyries contain zircon antecrysts which record protracted zircon crystallisation during the ∼200 ka preceding the emplacement of the porphyries. Zircon trace element variations, Ti-in-zircon temperatures, and Hf isotopic compositions indicate that the four porphyry magmas record a common geochemical and thermal history, and that the four intrusions were derived from the same upper-crustal magma chamber. Trace element zoning within single zircon crystals confirms a fractional crystallisation trend dominated by titanite and apatite crystallisation. However, zircon

  5. Ridge subduction and porphyry copper-gold mineralization:An overview

    Institute of Scientific and Technical Information of China (English)


    Many large porphyry Cu-Au deposits are connected to adakitic rocks known to be closely associated with ridge subduction. For example, there are several subducting ridges along the east Pacific margin, e.g., in Chile, Peru, and South America, most of which are associated with large porphyry Cu-Au deposits. In contrast, there are much fewer ridge subductions on the west Pacific margin and porphyry Cu-Au deposits are much less there, both in terms of tonnage and the number of deposits. Given that Cu and Au are moderately incompatible elements, oceanic crust has much higher Cu-Au concentrations than the mantle and the continental crust, and thus slab melts with their diagnostic adakitic chemistry have systematically higher Cu and Au, which is favorable for mineralization. Considering the geotherm of subducting slabs in the Phanerozoic, ridge subduction is the most favorable tectonic setting for this. Therefore, slab melting is the likely link in the spatial association between ridge subduction and Cu-Au deposits. Geochemical signatures of slab melting and hence maybe ridge subduction in less eroded regions in eastern China, the central Asian orogenic belt etc. may indicate important exploration targets for large porphyry Cu-Au deposits.

  6. Ore-forming fluid constraints on illite crystallinity (IC) at Dexing porphyry copper deposit, Jiangxi Province

    Institute of Scientific and Technical Information of China (English)

    JIN; Zhangdong


    [1]uatier, M. D., Peacor, D. R., O’Neil, J. R., Smectite-illite transition in Barbados accretionary wedge sediments: TEM and AEM evidence for dissolution/crystallization at low temperature, Clays and Clay Minerals, 1992, 40(1): 65.[2]Eberl, D., Hower, J., Kinetics of illite formation, Geological Society of America Bulletin, 1976, 9: 1326[3]Elliott, W. C., Matisoff, G., Evaluation of kinetic models for smectite to illite transformation, Clays and Clay Minerals, 1996, 44(1): 77.[4]Ji Junfeng, Browne, P. R. L., Liu Yingjun et al., Kinetic model for the smectite to illite transformation in active geothermal system, Chinese Science Bulletin (in Chinese), 1997, 42 (21): 2313[5]Pollastro, R. M., Considerations and applications of the illite/smectite geothermometer in hydrocarbonbearing rocks of Miocene to Mississippian age, Clays and Clay Minerals, 1993, 41(1): 119[6]Harvey, C. C., Browne, P. R. L., Mixed-layer clay geothermometry in the Wairakei geothermal field, New Zealand, Clays and Clay Minerals, 1991, 39(3): 614[7]Whitney, G., Role of water in the smectite-to-illite reaction, Clays and Clay Minerals, 1990, 38 (2): 343.[8]Inoue, A., Kitagawa, R., Morphological characteristics of illitic clay minerals from a hydrothermal system, American Mineralogist, 1994, 79: 700.[9]Velde, B., Vasseur, G., Estimation of the diagenetic smectite to illite in time-temperature space, American Mineralogist, 1992, 77: 967.[10]hu Xun, Huang Chongke, Rui Zongyao et al., Dexing Porphyry Copper Deposit (in Chinese), Beijing: Geological Publishing House, 1983.[11]Kisch, H. J., Illite crystallinity: recommendation on sample preparation, X-ray diffraction settings and interlaboratory samples, Journal of Metamorphic Geology, 1991, 9: 665.[12]Eberl, D. D., Velde, B., Beyond the Kübler Index, Clay Minerals, 1989, 24(3): 571.[13]Srodon, J., Eberl, D. D., Illite. Micas, Reviews in Mineralogy (ed. Bailey, S. W.), 1984, 13: 495.[14]Yao, Y. C

  7. Geochronological stages of magmatism of Sorsk copper-molybdenum-porphyry are district, Kuznetsk Alatau (K-Ar, Ar-Ar and Rb-Sr methods)

    International Nuclear Information System (INIS)

    Studies on biotite, amphibole and feldspar rocks were conducted through K-Ar, 39Ar-40Ar and Rb-Sr methods for evaluation of geochronological stages of magmatism development of the Sorsk copper-molybdenum-porphyry ore district. It is shown that general duration of magmatism development at the Sorsk district exceeds 100 mln years with intervals between individual magmatic pulses about 30 mln years. Dating by magmatites, related to ore-bearing porphyry complex and ore-metasotamic formations, is within the interval of 380-400 mln years. 13 refs.; 2 figs

  8. The formation of Qulong adakites and their relationship with porphyry copper deposit: Geochemical constraints (United States)

    Hu, Yong-bin; Liu, Ji-qiang; Ling, Ming-xing; Ding, Wei; Liu, Yan; Zartman, Robert E.; Ma, Xiu-feng; Liu, Dun-yi; Zhang, Chan-chan; Sun, Sai-jun; Zhang, Li-peng; Wu, Kai; Sun, Wei-dong


    Qulong porphyry Cu deposit is the largest Cu deposit in China so far discovered, with total reserves of 10.6 Mt Cu@0.5% and 0.5 Mt Mo@0.03%. The petrogenesis of the Miocene intrusion and its genetic association with Cu mineralization have been debated. This study presents new results on whole rock major and trace elements, Sr-Nd isotopes, zircon U-Pb dating, Hf-O isotopic compositions of the Qulong ore-bearing and barren adakites. All the Qulong adakites studied here have low MgO (adakites in the circum-Pacific region and other places in general. Ore-bearing adakites have systematically higher SiO2 and K2O compared with barren ones, likely due to the addition of Si and K during alteration and mineralization. Magmatic zircons from these two series of intrusions have U-Pb ages of 16.6 ± 0.5-17.0 ± 0.6 Ma and 16.7 ± 0.3-17.4 ± 0.4 Ma, respectively, which are identical to each other within analytical errors but are systematically older than although marginally overlap with the Re-Os isochron ages of 15.36 ± 0.21-16.41 ± 0.48 Ma. The Qulong porphyries have geochemical characteristics of typical adakites, with Sr = 259-1195 ppm, Y = 1.91-9.12 ppm, Yb = 0.2-0.92 ppm, Sr/Y = 49-202 ppm, and (La/Yb)n = 13-49 for both ore-bearing and barren adakites. In a Sr/Y versus (La/Yb)n diagram, most of the samples plot in the low part of circum-Pacific field, close to the field defined by Dabie adakites. Some of the ore-bearing adakites even plot in the Dabie adakite field, indicating that both slab melts and lower continental crust melts have been involved. Zircons from the ore-bearing adakites have δ18O ranging from 5.1 to 7.3‰ (average 6.4‰) and εHf(t) from 1.9 to 10.4‰, which plot close to MORB. Similarly, zircons from the barren adakite have δ18O ranging from 4.0 to 7.4‰ (average 6.3‰) and εHf(t) from 5.6 to 9.3‰, mostly plotting close to MORB values, too. In-situ zircon Hf-O isotopic measurements for the most samples yield a binary mixing trend between

  9. Re-Os age for molybdenite from the Gangdese porphyry copper belt on Tibetan plateau:Implication for geodynamic setting and duration of the Cu mineralization

    Institute of Scientific and Technical Information of China (English)

    HOU Zengqian; QU Xiaoming; WANG Shuxian; DU Andao; GAO Yongfeng; HUANG Wei


    The Gangdese porphyry copper belt consists of one large and five middle-small deposits in addition to dozens of ore-bearing porphyry bodies. The belt trends 350 km long along the EW-striking Gangdese batholith, and locally occurs as a string of beads extending about 50 km within the SN-trending rifting zones (grabens) on the Tibetan plateau. Monzonitic granite- porphyry and quartz monzonitic porphyry, as dominant host rocks, are shoshonitic and potassic calc-alkaline. Available dating data indicate that the ages of the shallow-level emplacement for these porphyries vary from 10 Ma to 18 Ma, which are identical to that of associated potassic calc-alkaline volcanic rocks (10-15 Ma) and mafic dykes (13-18 Ma).The timing and duration of Cu mineralization events are constrained by Re-Os ages for molybdenites from three porphyry copper deposits in the Gangdese porphyry copper belt. Five molybdenite samples from the Nanmu deposit yielded an 187Re-187Os isochron with a highly precise age of (14.76±0.22) Ma; six molybdenites from the Chongjiang deposit gave an isochron age of (14.04±0.16) Ma. Re-Os model ages for two molybdenite samples from Lakang'e deposit vary from 13.5 Ma to 13.6 Ma, which are basically identical to isochron ages mentioned above. All the thirteen samples from these three deposits yielded a linear array in the isochron diagram with a higher correlation coefficient of 0.99719 and an isochron age of (14.39±0.22) Ma (1σ error), suggesting an coeval event of the Cu mineralization and a shared source of ore materials for the Gangdese porphyry copper belt. Compared with the longer-lived felsic magmatic-hydrothermal system, the Cu mineralization is a relatively short event with duration of about 0.5 Ma, and usually occurs in the later-stage of the complicate magmatic system.The emplacement age of the Gangdese porphyries indicates that they intruded after the rapid rising of the Gangdese Mountains at 21-23 Ma, and formed in a post-collision crustal extension

  10. Re-Os age for molybdenite from the Gangdese porphyry copper belt on Tibetan plateau: Implication for geodynamic setting and duration of the Cu mineralization

    Institute of Scientific and Technical Information of China (English)

    HOU; Zengqian; QU; Xiaoming; WANG; Shuxian; DU; Andao; GAO


    The Gangdese porphyry copper belt consists of one large and five middle-small deposits in addition to dozens of ore-bearing porphyry bodies. The belt trends 350 km long along the EW-striking Gangdese batholith, and locally occurs as a string of beads extending about 50 km within the SN-trending rifting zones (grabens) on the Tibetan plateau. Monzonitic granite- porphyry and quartz monzonitic porphyry, as dominant host rocks, are shoshonitic and potassic calc-alkaline. Available dating data indicate that the ages of the shallow-level emplacement for these porphyries vary from 10 Ma to 18 Ma, which are identical to that of associated potassic calc-alkaline volcanic rocks (10-15 Ma) and mafic dykes (13-18 Ma).The timing and duration of Cu mineralization events are constrained by Re-Os ages for molybdenites from three porphyry copper deposits in the Gangdese porphyry copper belt. Five molybdenite samples from the Nanmu deposit yielded an 187Re-187Os isochron with a highly precise age of (14.76±0.22) Ma; six molybdenites from the Chongjiang deposit gave an isochron age of (14.04±0.16) Ma. Re-Os model ages for two molybdenite samples from Lakang'e deposit vary from 13.5 Ma to 13.6 Ma, which are basically identical to isochron ages mentioned above. All the thirteen samples from these three deposits yielded a linear array in the isochron diagram with a higher correlation coefficient of 0.99719 and an isochron age of (14.39±0.22) Ma (1σ error), suggesting an coeval event of the Cu mineralization and a shared source of ore materials for the Gangdese porphyry copper belt. Compared with the longer-lived felsic magmatic-hydrothermal system, the Cu mineralization is a relatively short event with duration of about 0.5 Ma, and usually occurs in the later-stage of the complicate magmatic system.The emplacement age of the Gangdese porphyries indicates that they intruded after the rapid rising of the Gangdese Mountains at 21-23 Ma, and formed in a post-collision crustal extension

  11. The Jebel Ohier deposit—a newly discovered porphyry copper-gold system in the Neoproterozoic Arabian-Nubian Shield, Red Sea Hills, NE Sudan (United States)

    Bierlein, F. P.; McKeag, S.; Reynolds, N.; Bargmann, C. J.; Bullen, W.; Murphy, F. C.; Al-Athbah, H.; Brauhart, C.; Potma, W.; Meffre, S.; McKnight, S.


    Ongoing exploration in the Red Sea Hills of NE Sudan has led to the identification of a large alteration-mineralization system within a relatively undeformed Neoproterozoic intrusive-extrusive succession centered on Jebel Ohier. The style of mineralization, presence of an extensive stockwork vein network within a zoned potassic-propylitic-argillic-advanced argillic-altered system, a mineralization assemblage comprising magnetite-pyrite-chalcopyrite-bornite (±gold, silver and tellurides), and the recurrence of fertile mafic to intermediate magmatism in a developing convergent plate setting all point to a porphyry copper-gold association, analogous to major porphyry Cu-Au-Mo deposits in Phanerozoic supra-subduction settings such as the SW Pacific. Preliminary U-Pb age dating yielded a maximum constraint of c. 730 Ma for the emplacement of the stockwork system into a significantly older ( c. 800 Ma) volcanic edifice. The mineralization formed prior to regional deformation and accretion of the host terrane to a stable continental margin at by c. 700 Ma, thus ensuring preservation of the deposit. The Jebel Ohier deposit is interpreted as a relatively well-preserved, rare example of a Neoproterozoic porphyry Cu-Au system and the first porphyry Cu-Au deposit to be identified in the Arabian-Nubian Shield.

  12. Geologic and environmental characteristics of porphyry copper deposits with emphasis on potential future development in the Bristol Bay Watershed, Alaska (United States)

    Seal, Robert R., II


    This report is prepared in cooperation with the Bristol Bay Watershed Assessment being conducted by the U.S. Environmental Protection Agency. The goal of the assessment is to help understand how future large-scale development in this watershed may affect water quality and the salmon fishery. Mining has been identified as a potential source of future large scale development in the region, especially because of the advanced stage of activity at the Pebble prospect. The goal of this report is to summarize the geologic and environmental characteristics of porphyry copper deposits in general, largely on the basis of literature review. Data reported in the Pebble Project Environmental Baseline Document, released by the Pebble Limited Partnership in 2011, are used to enhance the relevance of this report to the Bristol Bay watershed. The geologic characteristics of mineral deposits are paramount to determining their geochemical signatures in the environment. The geologic characteristics of mineral deposits are reflected in the mineralogy of the mineralization and alteration assemblages; geochemical associations of elements, including the commodities being sought; the grade and tonnage of the deposit; the likely mining and ore-processing methods used; the environmental attributes of the deposit, such as acid-generating and acid-neutralizing potentials of geologic materials; and the susceptibility of the surrounding ecosystem to various stressors related to the deposit and its mining, among other features (Seal and Hammarstrom, 2003). Within the Bristol Bay watershed, or more specifically the Nushagak and Kvichak watersheds, the geologic setting is permissive for the occurrence of several mineral deposit types that are amenable for large-scale development. Of these deposit types, porphyry copper deposits (e.g., Pebble) and intrusion-related gold deposits (e.g., Shotgun) are the most important on the basis of the current maturity of exploration activities by the mining

  13. Petrochemistry of igneous rocks of the California-Vetas mining district, Santander, Colombia: Implications for northern Andean tectonics and porphyry Cu (-Mo, Au) metallogeny (United States)

    Bissig, Thomas; Mantilla Figueroa, Luis Carlos; Hart, Craig J. R.


    Porphyry Mo and Cu mineralization in the California-Vetas mining district is contemporaneous with 10.9 to 8.4 Ma granodiorite porphyry stocks and overprinted by Au-Ag mineralization of epithermal affinity. Mineralization is hosted by Grenvillian aged paragneisses (Bucaramanga Gneiss of the Santander Massif) and late Triassic to early Jurassic granitic rocks. All intrusive rocks are high-K calc-alkaline. Late Triassic to early Jurassic rocks include peraluminous granites with more than 70 wt.% SiO2 as well as metaluminous diorites, tonalites and granodiorites with SiO2 between 54.9 and 60.4 wt.%. Late Miocene rocks are weakly peraluminous granodiorite porphyries with SiO2 between 61 and 67 wt.% SiO2. Late Miocene rocks share some characteristics with adakite-like rocks which are widely associated with porphyry and epithermal style mineralization elsewhere in the Andes. They have high Ba (930 to 1500 ppm) and high Ba/La (28 to 50), high Sr (850 to 1100 ppm) and Sr/Y (48-78) and depleted middle rare earth elements (MREE) compared to the Mesozoic granites, which have 400 to 700 ppm Ba (Ba/La 14 to 25) and 80 to 150 ppm Sr (Sr/Y 2.5 to 14), and Mesozoic diorites and tonalites, which have ~ 900 to 1200 ppm Ba (Ba/La 20 to 32) and ~ 610 to 750 ppm Sr (Sr/Y 22 to 25). Miocene granodiorite porphyries, in contrast to Mesozoic intrusive rocks have only weak negative Eu anomalies. The Miocene rocks have 87Sr/86Sr ratios of 0.7052 to 0.7067 and εNd of - 1.9 to - 5.4 and are significantly more isotopically primitive than all other rocks in the study area including the Mesozoic diorites to tonalites (87Sr/86Sr = 0.7082 and 0.7092; εNd = - 6.7 and - 7.2), granites (87Sr/86Sr = 0.730 (n = 2); εNd = - 8.2 and - 8.3) and Bucaramanga Gneiss (0.718 to 0.743; εNd = - 10.8 to - 14.1). Lead isotope data are broadly consistent with the Sr and Nd isotope data and the Miocene porphyries have the lowest 207Pb/204Pb ratios but overlap with the Mesozoic diorites to tonalites in their 206Pb

  14. Re-Os molybdenite and LA-ICPMS-MC U-Pb zircon geochronology for the Milpillas porphyry copper deposit: insights for the timing of mineralization in the Cananea District, Sonora, Mexico


    Víctor A. Valencia; Benito Noguez Alcántara; Fernando Barra; Joaquín Ruiz; George Gehrels; Francisco Quintanar; Martín Valencia Moreno


    New geochronological data presented here improves the understanding of the temporal evolution of the Cananea Mining District, and particularly of the Milpillas porphyry copper deposit (northeastern Sonora, Mexico). Uranium-lead zircon analyses, using laser ablation ICP-MS multi-collector, from the quartz monzonite porphyry unit that host the mineralization at the Milpillas deposit, yielded a crystallization age of 63.9 ± 1.3 Ma (2-sigma). Re-Os molybdenite ages from two drill core samples fro...

  15. Bio-Remediation of Acid Mine Drainage in the Sarcheshmeh Porphyry Copper Mine by Fungi: Batch and Fixed Bed Process

    Directory of Open Access Journals (Sweden)

    Hanieh Soleimanifar


    Full Text Available Acid mine drainage (AMD containing high concentrations of iron and sulphate, low pH and variableconcentrations of heavy metals leads to many environmental problems. The concentrations of Cu and Mnare high in the AMD of the Sarcheshmeh porphyry copper mine, Kerman province, south of Iran. In thisstudy, the bio-remediation of Cu and Mn ions from acid mine drainage was investigated using two nativefungi called Aspergillus niger and Phanerochaete chrysosporium which were extracted from the soil andsediment samples of the Shour River at the Sarcheshmeh mine. The live fungi was first harvested andthen killed by boiling in 0.5 N NaOH solution. The biomass was finally dried at 60 C for 24 h andpowdered. The optimum biosorption parameters including pH, temperature, the amount of biosorbent andcontact time were determined in a batch system. The optimum pH varied between 5 and 6. It was foundthat the biosorption process increased with an increase in temperature and the amount of biosorbent.Biosorption data were attempted by Langmuir and Freundlich isotherm models and showed a good match.Kinetic studies were also carried out in the present study. The results show that the second-order kineticsmodel fits well the experimental data. The biosorption experiments were further investigated with acontinuous system to compare the biosorption capacities of two systems. The results show thatbiosorption process using a continuous system increases efficiency up to 99%. A desorption process waseventually performed in order to recover Copper and Manganese ions. This process was successful andfungi could be used again.

  16. Economic filters for evaluating porphyry copper deposit resource assessments using grade-tonnage deposit models, with examples from the U.S. Geological Survey global mineral resource assessment: Chapter H in Global mineral resource assessment (United States)

    Robinson, Gilpin R., Jr.; Menzie, W. David


    An analysis of the amount and location of undiscovered mineral resources that are likely to be economically recoverable is important for assessing the long-term adequacy and availability of mineral supplies. This requires an economic evaluation of estimates of undiscovered resources generated by traditional resource assessments (Singer and Menzie, 2010). In this study, simplified engineering cost models were used to estimate the economic fraction of resources contained in undiscovered porphyry copper deposits, predicted in a global assessment of copper resources. The cost models of Camm (1991) were updated with a cost index to reflect increases in mining and milling costs since 1989. The updated cost models were used to perform an economic analysis of undiscovered resources estimated in porphyry copper deposits in six tracts located in North America. The assessment estimated undiscovered porphyry copper deposits within 1 kilometer of the land surface in three depth intervals.

  17. Porphyry copper assessment of the Central Asian Orogenic Belt and eastern Tethysides: China, Mongolia, Russia, Pakistan, Kazakhstan, Tajikistan, and India: Chapter X in Global mineral resource assessment (United States)

    Mihalasky, Mark J.; Ludington, Stephen; Hammarstrom, Jane M.; Alexeiev, Dmitriy V.; Frost, Thomas P.; Light, Thomas D.; Robinson, Gilpin R., Jr.; Briggs, Deborah A.; Wallis, John C.; Miller, Robert J.; Bookstrom, Arthur A.; Panteleyev, Andre; Chitalin, Andre; Seltmann, Reimar; Guangsheng, Yan; Changyun, Lian; Jingwen, Mao; Jinyi, Li; Keyan, Xiao; Ruizhao, Qiu; Jianbao, Shao; Gangyi, Shai; Yuliang, Du


    The U.S. Geological Survey collaborated with international colleagues to assess undiscovered resources in porphyry copper deposits in the Central Asian Orogenic Belt and eastern Tethysides. These areas host 20 known porphyry copper deposits, including the world class Oyu Tolgoi deposit in Mongolia that was discovered in the late 1990s. The study area covers major parts of the world’s largest orogenic systems. The Central Asian Orogenic Belt is a collage of amalgamated Precambrian through Mesozoic terranes that extends from the Ural Mountains in the west nearly to the Pacific Coast of Asia in the east and records the evolution and final closure of the Paleo-Asian Ocean in Permian time. The eastern Tethysides, the orogenic belt to the south of the Central Asian Orogenic Belt, records the evolution of another ancient ocean system, the Tethys Ocean. The evolution of these orogenic belts involved magmatism associated with a variety of geologic settings appropriate for formation of porphyry copper deposits, including subduction-related island arcs, continental arcs, and collisional and postconvergent settings. The original settings are difficult to trace because the arcs have been complexly deformed and dismembered by younger tectonic events. Twelve mineral resource assessment tracts were delineated to be permissive for the occurrence of porphyry copper deposits based on mapped and inferred subsurface distributions of igneous rocks of specific age ranges and compositions. These include (1) nine Paleozoic tracts in the Central Asian Orogenic Belt, which range in area from about 60,000 to 800,000 square kilometers (km2); (2) a complex area of about 400,000 km2 on the northern margin of the Tethysides, the Qinling-Dabie tract, which spans central China and areas to the west, encompassing Paleozoic through Triassic igneous rocks that formed in diverse settings; and (3) assemblages of late Paleozoic and Mesozoic rocks that define two other tracts in the Tethysides, the 100

  18. Mineralogical study on volcanic ash of the eruption on September 27, 2014 at Ontake volcano, central Japan: correlation with porphyry copper systems (United States)

    Minami, Yusuke; Imura, Takumi; Hayashi, Shintaro; Ohba, Tsukasa


    The volcanic ash of the eruption on September 27, 2014 at Ontake volcano consists mostly of altered rock fragments. The ash contains partly altered volcanic rock fragments consisting of primary igneous minerals (plagioclase, orthopyroxene, titanomagnetite, and feldspars) and volcanic glass accompanied by alteration minerals to some extents, and contains no juvenile fragments. These features indicate that the eruption was a non-juvenile hydrothermal eruption that was derived from the hydrothermal system developed under the crater. The major minerals derived from hydrothermal alteration zones are silica mineral, kaolin-group mineral, smectite, pyrophyllite, muscovite, alunite, anhydrite, gypsum, pyrite, K-feldspar, albite, and rutile. Minor chlorite, biotite, and garnet are accompanied. Five types of alteration mineral associations are identified from observations on individual ash particles: silica-pyrite, silica-pyrite ± alunite ± kaolin, silica-pyrophyllite-pyrite, silica-muscovite ± chlorite, and silica-K-feldspar ± albite ± garnet ± biotite. The associations indicate development of advanced argillic, sericite, and potassic alteration zones under the crater. Occurrence of anhydrite veinlet and the set of alteration zones indicate hydrothermal alteration zones similar to late-stage porphyry copper systems. Comparing the mineral associations with the geologic model of the late-stage porphyry copper systems, the source depths of mineral associations are estimated to range from near surface to >2 km. The depths of advanced argillic alteration, sericite, and potassic zones are 0 to ~2, ~1.5 to ~2, and >2 km, respectively.

  19. Prediction of AMD generation potential in mining waste piles, in the Sarcheshmeh porphyry copper deposit, Iran. (United States)

    Modabberi, Soroush; Alizadegan, Ali; Mirnejad, Hassan; Esmaeilzadeh, Esmat


    This study investigates the possibility of acid mine drainage (AMD) generation in active and derelict mine waste piles in Sarcheshmeh Copper Mine produced in several decades, using static tests including acid-base accounting (ABA) and net acid-generating pH (NAGpH). In this study, 51 composite samples were taken from 11 waste heaps, and static ABA and NAGpH tests were carried out on samples. While some piles are acid producing at present and AMD is discharging from the piles, most of them do not show any indication on their AMD potential, and they were investigated to define their acid-producing potential. The analysis of data indicates that eight waste piles are potentially acid generating with net neutralization potentials (NNPs) of -56.18 to -199.3, net acid generating of 2.19-3.31, and NPRs from 0.18 to 0.44. Other waste piles exhibited either a very low sulfur, high carbonate content or excess carbonate over sulfur; hence, they are not capable of acid production or they can be considered as weak acid producers. Consistency between results of ABA and NAGpH tests using a variety of classification criteria validates these tests as powerful means for preliminary evaluation of AMD/ARD possibilities in any mining district. It is also concluded that some of the piles with very negative NNPs are capable to produce AMD naturally, and they can be used in heap leaching process for economic recovery of trace amounts of metals without applying any biostimulation methods. PMID:23813094

  20. Stable isotope (S, O, H and C) studies of the phyllic and potassic phyllic alteration zones of the porphyry copper deposit at Sungun, East Azarbaidjan, Iran (United States)

    Calagari, Ali Asghar


    The porphyry copper deposit (PCD) at Sungun is located in East Azarbaidjan, NW of Iran. The magmatic suites in the Sungun area are a part of the NW-SE trending Cenozoic magmatic belt of Iran. The Sungun porphyries occur as stocks and dikes. The stocks are divided into two groups, I and II. Porphyry Stock II, ranging in composition from quartz monzonite through granodiorite to granite, hosts the Sungun PCD. Four distinct types of hypogene alterations were recognized at Sungun: (1) potassic; (2) potassic-phyllic; (3) phyllic; and (4) propylitic. Stable isotope (S, O, H, and C) studies were restricted to within the phyllic and potassic-phyllic alteration zones, where numerous cross-cutting quartz, sulfides, carbonates, and sulfate veinlets are present. The objective of these studies was to determine the origin of the ore-forming solutions, and their important components (e.g. sulfur and carbon). Twenty sulfide and four sulfate samples were taken from sulfide and gypsum veinlets within Porphyry Stock II and the associated skarn zone for sulfur isotopic analyses. The δ34S values of sulfides (pyrite, chalcopyrite, molybdenite, galena, sphalerite) and sulfate (gypsum) range from -4.6 to -0.2‰ (mean of -1.5‰) and from 10.9 to 14.4‰ (mean of 12.9‰), respectively. These values are almost analogous to those from El Salvador (Chile) and Ajo (Arizona), and Twin Buttes (Arizona), and strongly suggest a magmatic source for the sulfur at Sungun. Twenty-eight fluid inclusion-rich quartz samples from quartz veinlets beneath the supergene zones of the Porphyry Stock II were chosen for O and H isotopic analyses. The δ18O (of quartz) and δD (of fluid inclusions in quartz) values range from 8.3 to 10.2‰ (mean of 9.2‰) and -58 to -75‰ (mean of -66‰) relative to Standard Mean Ocean Water (SMOW), respectively. The calculated δ18O values of the fluids range from 4.4‰ (T=375 ° C) to 7.6‰ (T=570 ° C) with a mean of 6.4‰. The δ18O and δD values of the fluids lie

  1. Isolation and characterization of lost copper and molybdenum particles in the flotation tailings of Kennecott copper porphyry ores (United States)

    Tserendavga, Tsend-Ayush

    The importance of flotation separation has long been, and continues to be, an important technology for the mining industry, especially to metallurgical engineers. However, the flotation process is quite complex and expensive, in addition to being influenced by many variables. Understanding the variables affecting flotation efficiency and how valuable minerals are lost to the tailings gives metallurgists an advantage in their attempts to increase efficiency by designing operations to target the areas of greatest potential value. A successful, accurate evaluation of lost minerals in the tailings and appropriate solutions to improve flotation efficiency can save millions of dollars in the effective utilization of our mineral resources. In this dissertation research, an attempt has been made to understand the reasons for the loss of valuable mineral particles in the tailings from Kennecott Utah Copper ores. Possibilities include liberation, particle aggregation (slime coating) and surface chemistry issues associated with the flotation separation. This research generally consisted of three main aspects. The first part involved laboratory flotation experiments and factors, which affect the flotation efficiency. Results of flotation testing are reported that several factors such as mineral exposure/liberation and slime coating and surface oxidation strongly affect the flotation efficiency. The second part of this dissertation research was to develop a rapid scan dual energy (DE) methodology using 2D radiography to identify, isolate, and prepare lost sulfide mineral particles with the advantages of simple sample preparation, short analysis time, statistically reliable accuracy and confident identification. The third part of this dissertation research was concerned with detailed characterization of lost particles including such factors as liberation, slime coating, and surface chemistry characteristics using advanced analytical techniques and instruments. Based on the

  2. Early Carboniferous adakitic rocks in the area of the Tuwu deposit, eastern Tianshan, NW China: Slab melting and implications for porphyry copper mineralization (United States)

    Wang, Yin-Hong; Xue, Chun-Ji; Liu, Jia-Jun; Wang, Jian-Ping; Yang, Jun-Tao; Zhang, Fang-Fang; Zhao, Ze-Nan; Zhao, Yun-Jiang; Liu, Bin


    Existing geochronological and geochemical data for the Early Carboniferous magmatic rocks in the eastern Tianshan, Xinjiang, have been interpreted in a variety of theories regarding petrogenesis and geodynamic setting. The proposed settings include rift, back-arc basin, passive continental margin, island arc, ridge subduction, and post-collisional environment. To evaluate these possibilities, we present new SHRIMP zircon U-Pb geochronology and geochemical data, whole-rock geochemical, Hf isotope, and S isotope data for tonalitic rocks and ores associated with the Tuwu porphyry copper deposit located in the center of the late Paleozoic Dananhu-Tousuquan arc, eastern Tianshan. SHRIMP zircon U-Pb dating indicates that the magmatic activity and thus associated copper mineralization occurred ca.332 Ma. The tonalitic rocks are calc-alkaline granites with A/CNK values ranging from 1.16 to 1.58; are enriched in K, Rb, Sr, and Ba; and are markedly depleted in Nb, Ta, Ti, and Th. They show geochemical affinities similar to adakites, with high Sr, Al2O3, and Na2O contents and La/Yb ratios; low Y and Yb contents; and slight positive Eu anomalies. In situ Hf isotopic analyses of zircons yielded positive initial εHf(t) values ranging from 6.9 to 17.2. The δ34S values of the ore sulfides range from -3.0‰ to +1.7‰, reflecting a deep sulfur source. Our results indicate that the paleo-Tianshan oceanic slab was being simultaneously subducted northward beneath the Dananhu-Tousuquan arc, and southward beneath the Aqishan-Yamansu arc during the Early Carboniferous. The Tuwu adakitic tonalitic rocks were derived from the partial melting of the subducted paleo-Tianshan oceanic slab, which was subsequently hybridized by mantle wedge peridotites. The slab-derived magmas have considerably high copper contents and are highly oxidized, thus leading to porphyry copper mineralization. Such Early Carboniferous tonalitic rocks that are widespread in the eastern Tianshan define a province

  3. Searching Structural Control on the Evolution of the Reservoir Permeability in the Porphyry Copper-Molybdenum Rio Blanco - Los Bronces District: Structural Geology and Passive Seismic Tomography (United States)

    Comte, D.; Carrizo, D.; Vela, I.; Silva, W.


    Understand main factors that controls the crustal permeability related to giant ore deposits is a crucial goal for improving metallogenic models. Subsurface data at distrital scales, remains a key factor to reach that goal, however use of regional geophysical methodologies are still extremely expensive and poorly developed on ore exploration. We present the results associated to distrital structural analyses, combined with passive seismic tomography in a case study in Central Andes. Tectono-magmatic evolution of the Rio Blanco-Los Bronces District (Porphyry Cu-Mo Deposit) involves a complex interaction of different processes along the time which includes: Pre-Mesozoic structural inheritance, Oligo-Miocene extension, Mio-Pliocene orogenic shortening with the respective tectonic inversion associated to the uplift of the Andean western margin. Miocene volcano sedimentary units (Abanico Formation) and Pliocene syn-orogenic volcanic units form the deformed host distrital structure. These rocks are part of a trench-linked Andean deformation belt that accommodates EW shortening by NS- strike faults and NS-axes fault related folds. This structural belt controls the uplift of the western margin of the Andes by tectonic inversion of Miocene rift-type structural geometries. The reservoir structure is interpreted by the emplacement of a batholith in the core of the transfer zone between two NS-strike reverse faults, where the ore bodies are located in the center of an anticline general structure showing NW-SE mineralization trend. In turn, NE trending faults dislocate ore bodies in the transfer zone. The reservoir structure is interpreted by the emplacement of a Mio-Pliocene syntectonic batholith in the middle of a transfer zone between two NS-strike reverse faults, where the ore bodies are located in the axis of the anticlinal general structure. Passive seismic tomography results suggest a NNW-strike zone formed by fractured or/and hydrated rocks. This zone is spatially

  4. The geology, structure and mineralisation of the Oyu Tolgoi porphyry copper-gold-molybdenum deposits, Mongolia:A review

    Institute of Scientific and Technical Information of China (English)

    T.M. Mike Porter


    The Oyu Tolgoi cluster of seven porphyry Cu-Au-Mo deposits in southern Mongolia, define a narrow, linear, 12 km long, almost continuously mineralised trend, which contains in excess of 42 Mt of Cu and 1850 t of Au, and is among the largest high grade porphyry Cu-Au deposits in the world. These deposits lie within the Gurvansayhan island-arc terrane, a fault bounded segment of the broader Silurian to Carboniferous Kazakh-Mongol arc, located towards the southern margin of the Central Asian Orogenic Belt, a collage of magmatic arcs that were periodically active from the late Neoproterozoic to Permo-Triassic, extending from the Urals Mountains to the Pacific Ocean. Mineralisation at Oyu Tolgoi is associated with multiple, overlapping, intrusions of late Devonian (w372 to 370 Ma) quartz-monzodiorite intruding Devonian (or older) juvenile, probably intra-oceanic arc-related, basaltic lavas and lesser volcaniclastic rocks, unconformably overlain by late Devonian (w370 Ma) basaltic to dacitic pyroclastic and volcano sedimentary rocks. These quartz-monzodiorite intrusions range from early-mineral porphyritic dykes, to larger, linear, syn-, late- and post-mineral dykes and stocks. Ore was deposited within syn-mineral quartz-monzodiorites, but is dominantly hosted by augite basalts and to a lesser degree by overlying dacitic pyroclastic rocks. Following ore deposition, an allochthonous plate of older Devonian (or pre-Devonian) rocks was overthrust and a post-ore biotite granodiorite intruded at w365 Ma. Mineralisation is characterised by varying, telescoped stages of intrusion and alteration. Early A-type quartz veined dykes were followed by Cu-Au mineralisation associated with potassic alteration, mainly K-feldspar in quartz-monzodiorite and biotite-magnetite in basaltic hosts. Downward reflux of cooled, late-magmatic hydrothermal fluid resulted in intense quartz-sericite retrograde alteration in the upper parts of the main syn-mineral intrusions, and an equivalent chlorite

  5. Zircon U-Pb and molybdenite Re-Os geochronology and Sr-Nd-Pb-Hf isotopic constraints on the genesis of the Xuejiping porphyry copper deposit in Zhongdian, Northwest Yunnan, China (United States)

    Leng, Cheng-Biao; Zhang, Xing-Chun; Hu, Rui-Zhong; Wang, Shou-Xu; Zhong, Hong; Wang, Wai-Quan; Bi, Xian-Wu


    The Xuejiping porphyry copper deposit is located in northwestern Yunnan Province, China. Tectonically, it lies in the southern part of the Triassic Yidun island arc. The copper mineralization is mainly hosted in quartz-dioritic and quartz-monzonitic porphyries which intruded into clastic-volcanic rocks of the Late Triassic Tumugou Formation. There are several alteration zones including potassic, strong silicific and phyllic, argillic, and propylitic alteration zones from inner to outer of the mineralized porphyry bodies. The ages of ore-bearing quartz-monzonitic porphyry and its host andesite are obtained by using the zircon SIMS U-Pb dating method, with results of 218.3 ± 1.6 Ma (MSWD = 0.31, N = 15) and 218.5 ± 1.6 Ma (MSWD = 0.91, N = 16), respectively. Meanwhile, the molybdenite Re-Os dating yields a Re-Os isochronal age of 221.4 ± 2.3 Ma (MSWD = 0.54, N = 5) and a weighted mean age of 219.9 ± 0.7 Ma (MSWD = 0.88). They are quite in accordance with the zircon U-Pb ages within errors. Furthermore, all of them are contemporary with the timing of the Garzê-Litang oceanic crust subduction in the Yidun arc. Therefore, the Xuejiping deposit could be formed in a continental margin setting. There are negative ɛNd(t) values ranging from -3.8 to -2.1 and relatively high initial 87Sr/86Sr ratios from 0.7051 to 0.7059 for the Xuejiping porphyries and host andesites. The (206Pb/204Pb)t, (207Pb/204Pb)t and (208Pb/204Pb)t values of the Xuejiping porphyries and host andesites vary from 17.899 to 18.654, from 15.529 to 15.626, and from 37.864 to 38.52, respectively, indicative of high radiogenic Pb isotopic features. In situ Hf isotopic analyses on zircons by using LA-MC-ICP-MS exhibit that there are quite uniform and slightly positive ɛHf(t) values ranging from -0.2 to +3.2 (mostly between 0 and +2), corresponding to relatively young single-stage Hf model ages from 735 Ma to 871 Ma. These isotopic features suggest that the primary magmas of the Xuejiping porphyries and

  6. Systematic sulfur stable isotope and fluid inclusion studies on veinlet groups in the Sarcheshmeh porphyry copper deposit: based on new data

    Directory of Open Access Journals (Sweden)

    Mohammad Maanijou


    Full Text Available Mineralization occurred by intrusion of granodioritic stock of middle Miocene in volcano–sedimenrary rocks in Sarcheshmeh of early Tertiary age. This research is based on samples of new drilled boreholes and benches of 2500m elevation. Based on mineralogy and crosscutting relationships, at least four groups of veinlets pertaining to four stages of mineralization were recognized. Sulfur isotope studies in the Sarcheshmeh porphyry copper deposit were conducted on pyrite, chalcopyrite, molybdenite and anhydrites of four groups of veinlets. The δ34S values in the sulfides and sulfates range from -2.2 to 1.27‰ and from 10.2 to 14.5 ‰, respectively. The average δ34S value in the sulfides is 1‰ and that for the sulfates is about 13‰. Considering these results, it can be concluded that the sulfides made up of a fluid that its sulfur has a magmatic origin. Also, fluid inclusions of different veinlet groups were studied, showing high temperature, high salinity and the occurrence of boiling in the mineralizing fluids. Moreover, these studies indicate presence of three types of fluids including magmatic, meteoritic and mixture of these two fluids in alteration and mineralizion processes.

  7. Distribution of trace elements in soils surrounding the El Teniente porphyry copper deposit, Chile: the influence of smelter emissions and a tailings deposit (United States)

    Kelm, U.; Helle, S.; Matthies, R.; Morales, A.


    In the area surrounding the El Teniente giant porphyry copper deposit, eight soil sites were sampled at three depth levels in the summer 2004. The sites were selected for their theoretical potential of being influenced by past SO2 emissions from the smelter and/or seepage from a now idle tailings impoundment. The soil mineralogy, grain size distribution, total organic matter contents, major element composition, cation exchange capacity, and Cu, Mo, Pb, Zn, As and SO4 2- concentrations were determined for all samples after nitric acid extraction and separate leaches by ammonium acetate (pH 7) and sodium acetate (pH 5). For water rinses, only Cu could be determined with the analytical set-up used. Cu and SO4 2- enrichment in topsoils was found at six sites either downwind from the smelter or within the combined influence of the smelter and the tailings impoundment. Both elements were released partially by ammonium and sodium acetate extractions. Due to the scarce background trace element concentrations of soil and rock outside the immediate mine area, assessment of trace element mobility for Mo, Zn, Pb and As was difficult. Arsenic was found to be concentrated in soil horizons with high smectite and/or organic matter contents. Mo appears to be linked to the presence of windblown tailings sediment in the soils. Mobilization of Mo, Zn, and As for the acetate extractions was minimal or below the detection limits for the AAS technique used. The presence of windblown tailings is considered to be an additional impact on the soils in the foothills of the El Teniente compound, together with the potential of acidity surges and Cu mobilization in topsoils after rainfalls. Two sites located at the western limit of the former SO2 saturated zone with strongly zeolitized soils and underlying rock did not show any Cu or SO4 2- enrichment in the topsoils, and remaining total trace element concentrations were below the known regional background levels.

  8. Temporal evolution of bacterial communities associated with the in situ wetland-based remediation of a marine shore porphyry copper tailings deposit. (United States)

    Diaby, N; Dold, B; Rohrbach, E; Holliger, C; Rossi, P


    Mine tailings are a serious threat to the environment and public health. Remediation of these residues can be carried out effectively by the activation of specific microbial processes. This article presents detailed information about temporal changes in bacterial community composition during the remediation of a section of porphyry copper tailings deposited on the Bahía de Ite shoreline (Peru). An experimental remediation cell was flooded and transformed into a wetland in order to prevent oxidation processes, immobilizing metals. Initially, the top oxidation zone of the tailings deposit displayed a low pH (3.1) and high concentrations of metals, sulfate, and chloride, in a sandy grain size geological matrix. This habitat was dominated by sulfur- and iron-oxidizing bacteria, such as Leptospirillum spp., Acidithiobacillus spp., and Sulfobacillus spp., in a microbial community which structure resembled acid mine drainage environments. After wetland implementation, the cell was water-saturated, the acidity was consumed and metals dropped to a fraction of their initial respective concentrations. Bacterial communities analyzed by massive sequencing showed time-dependent changes both in composition and cell numbers. The final remediation stage was characterized by the highest bacterial diversity and evenness. Aside from classical sulfate reducers from the phyla δ-Proteobacteria and Firmicutes, community structure comprised taxa derived from very diverse habitats. The community was also characterized by an elevated proportion of rare phyla and unaffiliated sequences. Numerical ecology analysis confirmed that the temporal population evolution was driven by pH, redox, and K. Results of this study demonstrated the usefulness of a detailed follow-up of the remediation process, not only for the elucidation of the communities gradually switching from autotrophic, oxidizing to heterotrophic and reducing living conditions, but also for the long term management of the remediation

  9. Origin of high Sr/Y magmas from the northern Taihang Mountains: Implications for Mesozoic porphyry copper mineralization in the North China Craton (United States)

    Gao, Yongfeng; Santosh, M.; Wei, Ruihua; Ma, Guoxi; Chen, Zhikuan; Wu, Jinluan


    A number of porphyry Cu deposits have been described from east China which occur in association with Mesozoic high Sr/Y rocks within the continental interior rather than in an arc setting. However, the origin of these high Sr/Y rocks remains controversial. In this study we report precise zircon U-Pb age, as well as major-trace element and Sr-Nd-Pb isotope compositions from the Mujicun Cu mineralized porphyries in the northern Taihang orogen of eastern North China Craton (NCC). LA-ICP-MS zircon U-Pb dating yields an emplacement age of 143 ± 2 Ma, identical to the molybdenite Re-Os isochron ages of 142.5 ± 1.4 Ma for this intrusion. Like most of the Mesozoic adakitic rocks from the eastern NCC, the ore-bearing porphyries and associated volcanic lavas from northern Taihang orogen are rich in large ion lithophile elements and light REE, and have highly differentiated REE patterns. The porphyries and associated volcanic lavas have Sr-Nd-Pb isotopic compositions showing EM1-like isotopic signatures. Such geochemical and isotopic features confirm that the parental magma for these rocks originated from melting of an enriched sub-continental lithospheric mantle source. In comparison to the associated lavas, the ore-bearing porphyries have pronounced low FeO3T, TiO2 and P2O5 contents, and middle-heavy REE (and Y) and Zr concentrations, indicating fractional crystallization of amphibole with the observed accessory mineral assemblage such as Fe-Ti oxides, titanite, zircon and apatite. On the other hand, most of the porphyries exhibit relatively high Al2O3, Ba and Sr concentrations and pronounced positive Eu anomalies, excluding significant plagioclase fractionation due to suppression of the high water content in the magmas. The presence of the contemporary amphibole cumulates regionally exposed in the study area strongly support significant amphibole fractionation during the formation of the Mujicun porphyries. Thus, fractionation of a water-saturated magma is proposed as a

  10. Rb-Sr and Sm-Nd isotopic compositions and Petrogenesis of ore-related intrusive rocks of gold-rich porphyry copper Maherabad prospect area (North of Hanich), east of Iran

    International Nuclear Information System (INIS)

    The Maherabad gold-rich porphyry copper prospect area is located in the eastern part of Lut block, east of Iran. This is the first porphyry Cu-Au prospecting area which is discovered in eastern Iran. Fifteen mineralization-related intrusive rocks range (Middle Eocene 39 Ma) in composition from diorite to monzonite have been distinguished. Monzonitic porphyries had major role in Cu-Au mineralization. The ore bearing porphyries are I-type, meta luminous, high-Kcalc-alkaline to shoshonite intrusive rocks which were formed in island arc setting. These rocks are characterized by average of SiO2> 59 wt %, Al2O3 > 15 wt %, MgO2O> 3 wt %, Sr> 870 ppm, Y 55, moderate Light rare earth elements, relatively low heavy rare earth elements and enrichment LILE (Sr, Cs, Rb, K and Ba) relative to HFSE (Nb, Ta, Ti, Hf and Zr). They are chemically similar to some adakites, but their chemical signatures differ in some ways from normal adakites, including higher K2O contents and K2O/Na2O ratios and lower Mg, (La/Yb)N, (Ce/Yb)N and εNd in Maherabad rocks. Maherabad intrusive rocks are the first K-rich adakites that can be related with subduction zone. Partial melting of mantle hybridized by hydrous, silica-rich slab-derived melts or/and input of enriched mantle-derived ultra-potassic magmas during or prior to the formation and migration of adakitic melts could be explain their high K2O contents and K2O/Na2ratios. Low Mg values and relatively low MgO, Cr and Ni contents imply limited interaction between adakite-like magma and mantle wedge peridotite. The initial 87Sr/86Sr and (143Nd/144Nd)i was recalculated to an age of 39 Ma (unpublished data). Initial 87Sr/86Sr ratios for hornblende monzonite porphyry are 0.7047-0.7048. The (143Nd/144Nd)i isotope composition are 0.512694-0.512713. Initial εNd isotope values 1.45-1.81. These values could be considered as representative of oceanic slab-derived magmas. Source modeling indicates that high-degree of partial melting (relatively up to 50

  11. Andean waterways

    DEFF Research Database (Denmark)

    Rasmussen, Mattias Borg

    Andean Waterways explores the politics of natural resource use in the Peruvian Andes in the context of climate change and neoliberal expansion. It does so through careful ethnographic analysis of the constitution of waterways, illustrating how water becomes entangled in a variety of political...

  12. 遥感技术在格咱岛弧地区斑岩铜矿勘查中的应用%The application of remote sensing technique for porphyry copper exploration in the Gezan arc region

    Institute of Scientific and Technical Information of China (English)

    刘峻杉; 胡滨; 何政伟


    Remote sensing data can be used to extract alteration information,which provides the basis for porphyry copper ore exploration.The study area is located in the Gezan arc region.The level of geological research is low and the metallogenic potential is tremendous.Principal component analyses (PCA)were applied to get the iron-stain alteration and hydroxyl altera-tion information by making use of OLI data.Principal component analyses (PCA)were applied to get sericite information from ASTER data.SWIR band of ASTER data is used to extract sericite information,the method can inhibit the vegetation informa-tion,highlight the mineral information.A porphyry mineralization point was discovered during ground inspection which has confirmed the validity of remote sensing technology.The method can provide a reference for the mineral exploration in Yunnan region.%遥感数据能够提取围岩蚀变信息,为斑岩铜矿的勘查提供依据。研究区地处格咱岛弧地区,地质研究程度较低,成矿潜力巨大。采用主成分分析法处理 OLI 数据得到研究区的铁染和羟基蚀变信息,采用该方法从 ASTER 数据中提取了绢云母信息。利用 ASTER 数据的 SWIR波段来提取绢云母信息,能够抑制植被信息,突出矿物信息。经过野外踏勘发现了斑岩铜矿点,证实了遥感技术的有效性,该方法能够为云南地区斑岩铜矿的勘查提供借鉴。

  13. U-Pb zircon and Re-Os molybdenite geochronology from La Caridad porphyry copper deposit: insights for the duration of magmatism and mineralization in the Nacozari District, Sonora, Mexico (United States)

    Valencia, V. A.; Ruiz, J.; Barra, F.; Geherls, G.; Ducea, M.; Titley, S. R.; Ochoa-Landin, L.


    Uranium-lead zircon (laser ablation multi-collector ICP-MS spot analysis) ages from La Caridad porphyry copper deposit in the Nacozari District, Northeastern Sonora, Mexico, suggest a short period of magmatism, between 55.5 and 52.6 Ma. Two U-Pb ages from the mineralized quartz monzonite unit, showing different textural characteristics, yielded indistinguishable crystallization ages (~54 Ma), and indicate that the intrusion responsible for the mineralization occurred as a single large complex unit, instead of multiple pulses of magmatism. Some zircons analyzed also show inherited ages in cores recording dates of 112-124 Ma, 141-166 Ma and 1.4 Ga. The Re-Os molybdenite ages from the potassic and phyllic hydrothermal alteration veins yielded identical ages within error, 53.6±0.3 Ma and 53.8±0.3 Ma, respectively (weighted average of 53.7±0.21 Ma), supporting a restricted period for the mineralization. The geochronological data thus indicate a short-lived magmatic and hydrothermal system. The inherited zircons of Precambrian and Late Jurassic-Mid Cretaceous age found in the intrusive rocks of La Caridad deposit, can be explained considering two possible scenarios within the tectonic/magmatic evolution of the area. The first scenario considers the presence of a Precambrian anorogenic granitic basement that is intruded by Mesozoic (Jurassic-Cretaceous) units present beneath the La Caridad deposit. The second scenario suggests that the Mesozoic Glance Conglomerate Formation of Arizona underlies the Paleocene volcanic-igneous pile in the La Caridad area.

  14. Influence of backwater on bulk flotation of a porphyry copper-molybdenum ore%某斑岩型铜钼矿尾矿回水对混合浮选的影响

    Institute of Scientific and Technical Information of China (English)

    王怀; 郑晔; 郝福来; 宋超


    为分析某斑岩型铜钼矿尾矿回水对混合浮选的影响,以回水组分为研究对象进行了矿石中铜钼硫矿物可浮性的研究。结果表明:回水导致浮选精矿产率增大,铜、钼可浮性降低,硫被强烈抑制;回水中高浓度钙离子和APAM的联合作用,能有效地抑制矿石中的黄铁矿;浮选药剂以及 APAM 的累积,使浮选矿浆粘度增加,微细粒金属矿物夹杂在絮团之中而未能上浮。%In order to analyze the influence of backwater on bulk flotation of a porphyry copper‐molybdenum ore ,flotation tests were carried out to study the floatability of metallic minerals in the water containing different constituents .The results showed that the concentrate yield increase dramatically ,and the floatability of copper and molybdenum decline significantly under the condition of backwater flotation , however ,the pyrite is strongly inhibited that the high concentrations of calcium and APAM in backwater are the main causes .The slurry viscosity tends to rise with the cumulation of flotation reagents and APAM in backwater ,which lead to the loss of fine‐grained minerals wrapped in floccules .

  15. Zircon and apatite fission track analyses on mineralization ages and tectonic activities of Tuwu-Yandong porphyry copper deposit in northern Xinjiang, China

    Institute of Scientific and Technical Information of China (English)


    The mineralization ages reported in the past in the Tuwu-Yandong copper district not only are different, but also fall into the Hercynian epoch. This study has achieved 9 zircon and 7 apatite fission track analysis results. The zircon fission track ages range from 158 Ma to 289 Ma and the apatite ages are between 64 Ma and 140 Ma. The mineralization accords with the regional tectonics in the copper district. We consider that the zircon fission track age could reveal the mineralization age based on annealing zone temperature of 140-300℃ and retention temperature of ~250℃ for zircon fission track, and metallogenetic temperature of 120-350℃ in this ore district. Total three mineralization epochs have been identified, i.e., 289-276 Ma,232-200 Ma and 165-158 Ma, and indicate occurrence of the mineralization in the Indosinian and Yanshan epochs. Corresponding to apatite fission track ages, the three tectonic-mineralizing epochs are 140-132 Ma, 109-97 Ma and 64 Ma, which means age at about 100℃ after the mineralization. The three epochs lasted 146 Ma, 108 Ma and about 100 Ma from ~250℃ to ~100℃ and trend decrease from early to late. It is shown by the fission track modeling that this district underwent three stages of geological thermal histories, stable in Cretaceous and cooling both before Cretaceous and after 20 Ma.

  16. Magmatic evolution of pre-ore volcanics and porphyry intrusives associated with the Altar Cu-porphyry prospect, Argentina (United States)

    Gatzoubaros, M.; von Quadt, A.; Gallhofer, D.; Rey, R.


    Altar is a Cu-porphyry deposit related to several small plagioclase porphyry intrusions of the late Miocene formed on the margin of the Flat-Slab segment along the Andean Cordillera in north-west Argentina. New stratigraphic and structural mapping supported by geochemistry and geochronology of pre-ore volcanics at Altar has revealed that a period of ˜6-7 Ma of volcanism during the late Oligocene-early Miocene formed ˜4000 m of volcano-stratigraphic succession making up the Pachón Formation. It represents a period dominated by explosive to effusive eruption in a dynamic arc basin with local ash fall and flow deposition in lacustrine and fluvial sites. Volcanism is typified by medium- to high-K calc-alkaline arc magmatism with a shift from mafic compositions at the base to felsic rocks at the top of the formation containing zircons aged 21.9 ± 0.2 Ma (2 Std.Dev, U-Pb). A clear geochemical separation exists between early Miocene pre-ore volcanics that show signatures akin to non-adakitic, normal arc, extensional tectonic settings conducive of chemical differentiation at shallow crustal levels and correlate with intra-regional Abanico and Farellones Formations; and the middle to late-Miocene Cu-mineralised porphyry intrusions. After a break of ˜9 Ma in the geological record at Altar, these Cu-fertile bodies are emplaced entirely within the Pachón Rhyolite and represent adakite-like magmas with fractionation trends evolving from a lower crustal MASH zone. This distinction is controlled by a change from an extensional to compressive tectonic regime in the region during the middle Miocene in which magmas were stalled in the lower crust for an extended period, subsequently became enriched in metals and then formed several Cu-porphyry bodies which were emplaced during a relatively short period towards the late Miocene.

  17. 西藏甲玛超大型铜矿区斑岩脉成岩时代及其与成矿的关系%Zircon SHRIMP U-Pb dating of porphyry vein from the Jiama copper polymetallic deposit in Tibet and its significance

    Institute of Scientific and Technical Information of China (English)

    应立娟; 唐菊兴; 王登红; 郑文宝; 秦志鹏; 张丽


    The Jiama copper polymetallic deposit is an important ore deposit with a super-large scale in the Cangdese metallogenic belt of Tibet Re-Os dating of molybdenites occurred in skarn, porphyry and hornfels has indicated the metallogenic period of Cu-Mo mineralization during 17Ma to 14Ma, whereas the research on its age of diagenesis is rather lack, especially for the porphyry veins as south-north distributed outcrops. In this paper, two samples of slightly mineralized porphyry rocks: granite porphyry (sample JM52-0) and granitic diorite porphyry (sample JM52-46. 7 ) , have been collected from the No. 52 adit in Qianshan of the mining area Through zircon SHRIMP U-Pb dating at the first time, their 206pb/238 U -207 Pb/235 U concord ages are 14. 2 ± 0. 2Ma and 14. 1 ± 0. 3Ma, respectively. The ages from the zircon SHRIMP U-Pb dating in this paper mean the crystallization age of magmatic zircon representing the south-north distributed granite and granitic diorite porphyry outcrops. The diagenesis age of this type porphyry veins is at the same period of ore-bearing porphyry intrusive event related to the south-north normal fault system and rift zone in Gangdese( 18 ~ 12Ma). Diagenesis and mineralization age of the Jiama copper polymetallic deposit shows the similar period for metallogenesis and diagenesis, which is similar to other porphyry-skam type ore deposits in the east part of the Gangdese metallogenic belt with a strong concentration of mineralization during 17 - 14Ma, indicating the magmatic-tectonic events in Miocene in the Gangdese and the genesis relationship between Cu-Mo mineralization and hydrothermal process in Jiama.%甲玛铜多金属矿是冈底斯成矿带上资源储量达到超大型规模的又一个重要矿床,2010年7月已正式投产.产于矽卡岩、斑岩和角岩中的辉钼矿Re-Os定年已表明甲玛矿床的铜钼成矿时代集中于17 ~ 14Ma,而成岩时代的研究相对较少,尤其是矿区及外围大量出露的近南北向

  18. Geochemistry of magnetite from porphyry Cu and skarn deposits in the southwestern United States (United States)

    Nadoll, Patrick; Mauk, Jeffrey L.; LeVeille, Richard A.; Koenig, Alan E.


    A combination of petrographic observations, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and statistical data exploration was used in this study to determine compositional variations in hydrothermal and igneous magnetite from five porphyry Cu–Mo and skarn deposits in the southwestern United States, and igneous magnetite from the unmineralized, granodioritic Inner Zone Batholith, Japan. The most important overall discriminators for the minor and trace element chemistry of magnetite from the investigated porphyry and skarn deposits are Mg, Al, Ti, V, Mn, Co, Zn, and Ga—of these the elements with the highest variance for (I) igneous magnetite are Mg, Al, Ti, V, Mn, Zn, for (II) hydrothermal porphyry magnetite are Mg, Ti, V, Mn, Co, Zn, and for (III) hydrothermal skarn magnetite are Mg, Ti, Mn, Zn, and Ga. Nickel could only be detected at levels above the limit of reporting (LOR) in two igneous magnetites. Equally, Cr could only be detected in one igneous occurrence. Copper, As, Mo, Ag, Au, and Pb have been reported in magnetite by other authors but could not be detected at levels greater than their respective LORs in our samples. Comparison with the chemical signature of igneous magnetite from the barren Inner Zone Batholith, Japan, suggests that V, Mn, Co, and Ga concentrations are relatively depleted in magnetite from the porphyry and skarn deposits. Higher formation conditions in combination with distinct differences between melt and hydrothermal fluid compositions are reflected in Al, Ti, V, and Ga concentrations that are, on average, higher in igneous magnetite than in hydrothermal magnetite (including porphyry and skarn magnetite). Low Ti and V concentrations in combination with high Mn concentrations are characteristic features of magnetite from skarn deposits. High Mg concentrations (magnetite from magnesian skarn and likely reflect extensive fluid/rock interaction. In porphyry deposits, hydrothermal magnetite from different

  19. Geochemical Trace of Silicon Isotopes of Intrusions and Ore Veins Related to Alkali-rich Porphyry Deposits in Western Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    LIU Xianfan; YANG Zhengxi; LIU Jiaduo; WU Dechao; ZHANG Chenjiang; LI Youguo


    Western Yunnan is the well-known polymetallic province in China. It is characterized by copper-gold mineralization related to Cenozoic alkali-rich porphyry. This paper analyzes the silicon isotope data obtained from four typical alkali-rich porphyry deposits based on the dynamic fractionation principle of silicon isotope. The study shows that the ore materials should originate mainly from alkali-rich magmas, together with silicon-rich mineralizing fluids.The process of mineralization was completed by auto-metasomatism, i.e. silicon-rich mineralizing fluids (including alkali-rich porphyry and wall-rock strata) replaced and altered the country rocks and contaminated with crustal rocks during the crystallization of alkali-rich magmas. Such a process is essentially the continuance of the metasomatism of mantle fluids in crust's mineralization. This provides important evidence of silicon isotopic geochemistry for better understanding the mineralization of the Cenozoic alkali-rich porphyry polymetallic deposits

  20. U-Pb geochronology of porphyry bodies of the gold district Vetas California (Depto of Santander, Colombia)

    International Nuclear Information System (INIS)

    Two riodacite porphyry bodies, located in the central sector of the Santander Massif (Cordillera Oriental), were dated by U-Pb method, using the LA-MC-ICPMS technique: Multi collector-Laser Ablation- Inductively Coupled Plasma-Mass Spectrometer. The obtained ages (8.4 ± 0.2 and 9.0 ± 0.2 Ma), evidences a magmatic phase during the Late Miocene (Tortoniano), which took place during the Andean Orogeny. The identification of this magmatic pulse, in addition to provide new information on the geological history of the Santander Massif, deserves special attention, from the point of view of mineral deposit exploration, considering that rocks with the same age and features are related to the formation of important magmatic-hydrothermal deposits, as has been recognized in other regions of the Andean orogenic system.

  1. Fission track thermochronology of Neogene plutons in the Principal Andean Cordillera of central Chile (33-35°S): Implications for tectonic evolution and porphyry Cu-Mo mineralization Termocronología mediante trazas de fision de plutones neógenos en la Cordillera Principal Andina de Chile central (33-35°S): Implicancias para la evolución tectónica y mineralización de pórfidos de Cu-Mo


    Víctor Maksaev; Francisco Munizaga; Marcos Zentilli; Reynaldo Charrier


    Apatite fission track data for Miocene plutons of the western slope of the Principal Andean Cordillera in central Chile (33-35°S) define a distinct episode of enhanced crustal cooling through the temperature range of the apatite partial annealing zone (~125-60°C) from about 6 to 3 Ma. This cooling episode is compatible with accelerated exhumation of the plutons at the time of Pliocene compressive tectonism, and mass wasting on the western slope of the Principal Andean Cordillera in central Ch...

  2. Hydrothermal alteration mapping using ASTER data in Baogutu porphyry deposit, China

    International Nuclear Information System (INIS)

    Remote sensing plays an important role in mineral exploration. One of its proven applications is extracting host-rock lithology and alteration zones that are related to porphyry copper deposits. An Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was used to map the Baogutu porphyry deposit alteration area. A circular alteration mineral zoning pattern was clearly observed in the classification result of potassic, phyllic, argillic, propylitic zones. The potassic is characterized by biotite and anhydrite with an absorption feature centered at 1.94 and 2.1um. The phyllic zone is characterized by illite and sericite that indicates an intense Al-OH absorption feature centered at 2.20um. The narrower argillic zone including kaolinite and alunite displays a secondary Al-OH absorption feature at 2.17 um. The mineral assemblages of the outer propylitic zone are epidote, chlorite and calcite that exhibit absorption features at 2.335um.The performance of Principal Component Analysis(PCA), Minimum Noise Fraction (MNF), band ratio(BR) and Constrained Energy Minimization(CEM) has been evaluated. These techniques identified new prospects of porphyry copper mineralization in the study areas. These results indicate that ASTER is a powerful tool in the initial steps of mineral exploration

  3. Tectonogeochemical features and metallogenic prognosis in the Xiaolongtan copper mining district, Binchuan, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    HE Mingqin; SONG Huanbin; SU Xunqing


    The Xiaolongtan copper mining district is an important area in Dali, West Yunnan, where porphyry copper deposits occur, and copper orebodies are controlled by fault or contact zone structures between porphyry massifs and country rocks. Based on detailed field investigation and deep-going analysis, the authors systematically studied the tectonogeochemical features of this mining district, proposed the principle and foundation of metallogenic prognosis, and delineated the most potential mineralization target area.

  4. Qochas on Andean highlands

    CERN Document Server

    Sparavigna, Amelia Carolina


    On the Andean highlands, the "qochas" are lakes or ponds of natural or artificial origin. An ancient agricultural technique is based on their use. Linked together by a network of canals, qochas form a system of water and soil management, alternately used for crops or pasture. The concave structure of qochas controls the strong evaporation produced by solar radiation and wind blowing. Qochas can be observed in the satellite imagery of Google Maps.

  5. Análisis de inclusiones fluidas en las vetas polimetálicas del pórfiro de Cu-(Mo San Pedro, Mendoza Fluid inclusion analyses in polymetallic veins linked to the San Pedro porphyry copper deposit, Mendoza province, Argentina

    Directory of Open Access Journals (Sweden)

    Lidia I Korzeniewski


    Full Text Available El pórfiro de Cu-(Mo San Pedro, localizado en el cerro homónimo, se ubica en el sector sur del bloque de San Rafael, provincia de Mendoza. Comprende una zona de alteración, con mineralización diseminada, desarrollada en rocas volcánicas pertenecientes al Ciclo Magmático Choiyoi. En sus proximidades, aflora un conjunto de vetas polimetálicas las cuales, basándose en relaciones estratigráficas, han sido genéticamente relacionadas con el pórfiro. Estudios petrográficos y microtermométricos de inclusiones fluidas llevados a cabo en muestras de las vetas permiten confirmar dicha vinculación genética y establecer la existencia de dos etapas en la evolución del sistema hidrotermal. En la primera etapa participan fluidos magmáticos de elevada salinidad (37,5-41 % en peso equivalente NaCl y temperatura (356-389°C que dan origen a la alteración potásica y a la mineralización de Cu y en la segunda etapa participan fluidos magmáticos de bajas temperaturas (176-276°C y salinidades (0,35-8,68 % en peso equivalente NaCl los cuales dan lugar a la alteración fílica.The San Pedro porphyry copper deposit, located in the southern part of the San Rafael, Massif, Mendoza province, Argentina, develops an alteration halo in volcanic rocks of the Choiyoi Magmatic Cycle. Close to this alteration halo a group of polymetallic veins that were genetically linked to the disseminated deposit based on stratigraphic data crops out. Fluid inclusions petrographic and microthermometric studies carried on in samples from these veins confirm this genetic link and allow establishing two stages in the evolution of this hydrothermal system. The first stage with high salinity (37.5-41% and temperature (356-389°C magmatic fluids produce potassic alteration and Cu mineralization. During the second stage diluted magmatic fluids with low temperatures (176-276°C and salinities (0.35-8.68% led to phyllic alteration.

  6. Andean region study

    Energy Technology Data Exchange (ETDEWEB)



    New opportunities for climate change mitigation arising from a higher energy integration among Andean Pact nations were analysed within the framework of the UNEP/GEF Project. Apart from the search for regional mitigation actions, the study was mainly aimed at detecting methodological problems which arise when passing from a strictly national view to the co-ordination of regional actions to deal with climate change. In accordance with the available resources and data, and in view of the mainly methodological nature of the project, it was decided to analyse the opportunities to delve into the energy integration of the Region as regards electricity and natural gas industries and their eventual impact on the emission of greenhouse gases. Although possibilities of setting up electricity and natural gas markets are real, their impacts on GHG emission from the energy system would not prove substantially higher than those which the nations could achieve through the use of their own energy resources, in view that the Andean systems are competitive rather than complementary. More in-depth studies and detail information will be required - unavailable for the present study - to be able to properly evaluate all benefits associated with higher energy integration. Nevertheless, the supply of natural gas to Ecuador seems to be the alternative with the highest impact on GHG emission. If we were to analyse the supply and final consumption of energy jointly, we would most certainly detect additional mitigation options resulting from higher co-operation and co-ordination in the energy field. (EHS)

  7. Understanding microwave induced sorting of porphyry copper ores


    John, R.S.; Batchelor, A.R.; Ivanov, D.; Udoudo, O.B.; Jones, D.A.; Dodds, Chris; Kingman, S. W.


    Global demand for minerals and metals is increasing. It has been established that the impact of mining and mineral processing operations must be reduced to sustainably meet the demands of a low grade future. Successful incorporation of ore sorting in flow sheets has the potential to improve energy efficiency by rejecting non-economic material before grinding. Microwave heating combined with infra-red temperature measurement has been shown to distinguish low and high grade ore fragments from e...


    Institute of Scientific and Technical Information of China (English)

    LIU Xianfan; YANG Zhengxi; LIU Jiaduo; ZHANG Chengjiang; WU Dechao; LI Youguo


    Ultramafic hypoxenoliths found in the alkali-rich porphyry in the Liuhe Village, Heqing, Yunnan,China, are of great significance in understanding the origin and evolution of the porphyry. This paper discusses the mineralogical features of the hypoxenoliths. It shows that the xenoliths are characterized by the upper mantle rocks modified to certain extent by the enriched mantle fluid metasomatism in the mantle environment, with the enriched mantle property of Iow-degree partial melting. This constitutes the important mineralogical evidence for the petrogenesis and mineralization of alkali-rich porphyry.

  9. Re-Os molybdenite ages and zircon Hf isotopes of the Gangjiang porphyry Cu-Mo deposit in the Tibetan Orogen (United States)

    Leng, Cheng-Biao; Zhang, Xing-Chun; Zhong, Hong; Hu, Rui-Zhong; Zhou, Wei-De; Li, Chao


    The Miocene porphyry Cu-(Mo) deposits in the Gangdese orogenic belt in southern Tibet were formed in a post-subduction collisional setting. They are closely related to the Miocene adakite-like porphyries which were probably derived from a thickened basaltic lower crust. Furthermore, mantle components have been considered to have played a crucial role in formation of these porphyry deposits (Hou et al. Ore Geol Rev 36: 25-51, 2009; Miner Deposita doi:10.1007/s00126-012-0415-6, 2012). In this study, we present zircon Hf isotopes and molybdenite Re-Os ages on the newly discovered Gangjiang porphyry Cu-Mo deposit in southern Tibet to constrain the magma source of the intrusions and the timing of mineralization. The Gangjiang porphyry Cu-Mo deposit is located in the Nimu ore field in the central Gangdese porphyry deposits belt, southern Tibet. The copper and molybdenum mineralization occur mainly as disseminations and veins in the overlapped part of the potassic and phyllic alteration zones, and are predominantly hosted in the quartz monzonite stock and in contact with the rhyodacite porphyry stock. SIMS zircon U-Pb dating of the pre-mineral quartz monzonite stock and late intra-mineral rhyodacite porphyry yielded ages of 14.73 ± 0.13 Ma (2 σ) and 12.01 ± 0.29 Ma (2 σ), respectively. These results indicate that the magmatism could have lasted as long as about 2.7 Ma for the Gangjiang deposit. The newly obtained Re-Os model ages vary from 12.51 ± 0.19 Ma (2 σ) to 12.85 ± 0.18 Ma (2 σ) for four molybdenite samples. These Re-Os ages are roughly coincident with the rhyodacite porphyry U-Pb zircon age, and indicate a relatively short-lived episode of ore deposition (ca. 0.3 Ma). In situ Hf isotopic analyses on zircons by using LA-MC-ICP-MS indicate that the ɛ Hf( t) values of zircons from a quartz monzonite sample vary from +2.25 to +4.57 with an average of +3.33, while zircons from a rhyodacite porphyry sample vary from +5.53 to +7.81 with an average of +6.64. The

  10. Evidence for extreme partitioning of copper into a magmatic vapor phase

    International Nuclear Information System (INIS)

    The discovery of copper sulfides in carbon dioxide- and chlorine-bearing bubbles in phenocryst-hosted melt inclusions shows that copper resides in a vapor phase in some shallow magma chambers. Copper is several hundred times more concentrated in magmatic vapor than in coexisting pantellerite melt. The volatile behavior of copper should be considered when modeling the volcanogenic contribution of metals to the atmosphere and may be important in the formation of copper porphyry ore deposits

  11. Evidence for extreme partitioning of copper into a magmatic vapor phase

    Energy Technology Data Exchange (ETDEWEB)

    Lowenstern, J.B.; Mahood, G.A. (Stanford Univ., CA (United States)); Rivers, M.L.; Sutton, S.R. (Brookhaven National Lab., Upton, NY (United States))


    The discovery of copper sulfides in carbon dioxide- and chlorine-bearing bubbles in phenocryst-hosted melt inclusions shows that copper resides in a vapor phase in some shallow magma chambers. Copper is several hundred times more concentrated in magmatic vapor than in coexisting pantellerite melt. The volatile behavior of copper should be considered when modeling the volcanogenic contribution of metals to the atmosphere and may be important in the formation of copper porphyry ore deposits.

  12. U-Pb zircon, geochemical and Sr-Nd-Hf-O isotopic constraints on age and origin of the ore-bearing intrusions from the Nurkazgan porphyry Cu-Au deposit in Kazakhstan (United States)

    Shen, Ping; Pan, Hongdi; Seitmuratova, Eleonora; Jakupova, Sholpan


    Nurkazgan, located in northeastern Kazakhstan, is a super-large porphyry Cu-Au deposit with 3.9 Mt metal copper and 229 tonnage gold. We report in situ zircon U-Pb age and Hf-O isotope data, whole rock geochemical and Sr-Nd isotopic data for the ore-bearing intrusions from the Nurkazgan deposit. The ore-bearing intrusions include the granodiorite porphyry, quartz diorite porphyry, quartz diorite, and diorite. Secondary ion mass spectrometry (SIMS) zircon U-Pb dating indicates that the granodiorite porphyry and quartz diorite porphyry emplaced at 440 ± 3 Ma and 437 ± 3 Ma, respectively. All host rocks have low initial 87Sr/86Sr ratios (0.70338-0.70439), high whole-rock εNd(t) values (+5.9 to +6.3) and very high zircon εHf(t) values (+13.4 to +16.5), young whole-rock Nd and zircon Hf model ages, and consistent and slightly high zircon O values (+5.7 to +6.7), indicating that the ore-bearing magmas derived from the mantle without old continental crust involvement and without marked sediment contamination during magma emplacement. The granodiorite porphyry and quartz diorite porphyry are enriched in large ion lithophile elements (LILE) and light rare earth elements (LREE) and depleted in high-field strength elements (HFSE), Eu, Ba, Nb, Sr, P and Ti. The diorite and quartz diorite have also LILE and LREE enrichment and HFSE, Nb and Ti depletion, but have not negative Eu, Ba, Sr, and P anomalies. These features suggest that the parental magma of the granodiorite porphyry and quartz diorite porphyry originated from melting of a lithospheric mantle and experienced fractional crystallization, whereas the diorite and quartz diorite has a relatively deeper lithospheric mantle source region and has not experienced strong fractional crystallization. Based on these, together with the coeval ophiolites in the area, we propose that a subduction of the Balkhash-Junggar oceanic plate took place during the Early Silurian and the ore-bearing intrusions and associated Nurkazgan

  13. Comparative study on the passivation layers of copper sulphide minerals during bioleaching (United States)

    Fu, Kai-bin; Lin, Hai; Mo, Xiao-lan; Wang, Han; Wen, Hong-wei; Wen, Zi-long


    The bioleaching of copper sulphide minerals was investigated by using A. ferrooxidans ATF6. The result shows the preferential order of the minerals bioleaching as djurleite>bornite>pyritic chalcopyrite>covellite>porphyry chalcopyrite. The residues were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It is indicated that jarosite may not be responsible for hindered dissolution. The elemental sulfur layer on the surface of pyritic chalcopyrite residues is cracked. The compact surface layer of porphyry chalcopyrite may strongly hinder copper extraction. X-ray photoelectron spectroscopy (XPS) further confirms that the passivation layers of covellite, pyritic chalcopyrite, and porphyry chalcopyrite are copper-depleted sulphide Cu4S11, S8, and copper-rich iron-deficient polysulphide Cu4Fe2S9, respectively. The ability of these passivation layers was found as Cu4Fe2S9>Cu4S11>S8>jarosite.

  14. Methane origin and oxygen-fugacity evolution of the Baogutu reduced porphyry Cu deposit in the West Junggar terrain, China (United States)

    Shen, Ping; Pan, HongDi


    Most porphyry copper deposits worldwide contain magnetite, hematite, and anhydrite in equilibrium with hypogene copper-iron sulfides (chalcopyrite, bornite) and have fluid inclusions with CO2 >> CH4 that are indicative of high fO2. In contrast, the Baogutu porphyry Cu deposit in the West Junggar terrain (Xinjiang, China) lacks hematite and anhydrite, contains abundant pyrrhotite and ilmenite in equilibrium with copper-iron sulfides (chalcopyrite), and has fluid inclusions with CH4 >> CO2 that are indicative of low fO2. The mineralized intrusive phases at Baogutu include the main-stage diorite stock and minor late-stage diorite porphyry dikes. The main-stage stock underwent fractional crystallization and country-rock assimilation-contamination, and consists of dominant diorite and minor gabbro and tonalite porphyry. The country rocks contain organic carbons (0.21-0.79 wt.%). The δ13CvPDB values of the whole rocks (-23.1 to -25.8 ‰) in the wall rocks suggest a sedimentary organic carbon source. The δ13CvPDB values of CH4 (-28.2 to -36.0 ‰) and CO2 (-6.8 to -20.0 ‰) in fluid inclusions require an organic source of external carbon and equilibration of their Δ13CCO2-CH4 values (8.2-25.0 ‰) at elevated temperatures (294-830 °C) suggesting a significant contribution of thermogenic CH4. Mineral composition data on the main-stage intrusions, such as clinopyroxene, hornblende, biotite, magnetite, ilmenite, sphene, apatite, and pyrrhotite, suggest that the primary magma at Baogutu was oxidized and became reduced after emplacement by contamination with country rocks. Mineral compositions and fluid inclusion gas compositions suggest that the redox state of the system evolved from log fO2 > FMQ + 1 in the magma stage, to log fO2 rocks assimilation-contamination, to log fO2 > FMQ in the hydrothermal stage. Though oxidized magma was emplaced initially, assimilation-contamination of carbonaceous country rocks decreased its fO2 such that exsolved fluids contained

  15. The application of PGNAA borehole logging for copper grade estimation at Chuquicamata mine. (United States)

    Charbucinski, J; Duran, O; Freraut, R; Heresi, N; Pineyro, I


    The field trials of a prompt gamma neutron activation (PGNAA) spectrometric logging method and instrumentation (SIROLOG) for copper grade estimation in production holes of a porphyry type copper ore mine, Chuquicamata in Chile, are described. Examples of data analysis, calibration procedures and copper grade profiles are provided. The field tests have proved the suitability of the PGNAA logging system for in situ quality control of copper ore. PMID:15082058

  16. The application of PGNAA borehole logging for copper grade estimation at Chuquicamata mine

    Energy Technology Data Exchange (ETDEWEB)

    Charbucinski, J. E-mail:; Duran, O.; Freraut, R.; Heresi, N.; Pineyro, I


    The field trials of a prompt gamma neutron activation (PGNAA) spectrometric logging method and instrumentation (SIROLOG) for copper grade estimation in production holes of a porphyry type copper ore mine, Chuquicamata in Chile, are described. Examples of data analysis, calibration procedures and copper grade profiles are provided. The field tests have proved the suitability of the PGNAA logging system for in situ quality control of copper ore.

  17. The application of PGNAA borehole logging for copper grade estimation at Chuquicamata mine

    International Nuclear Information System (INIS)

    The field trials of a prompt gamma neutron activation (PGNAA) spectrometric logging method and instrumentation (SIROLOG) for copper grade estimation in production holes of a porphyry type copper ore mine, Chuquicamata in Chile, are described. Examples of data analysis, calibration procedures and copper grade profiles are provided. The field tests have proved the suitability of the PGNAA logging system for in situ quality control of copper ore

  18. 加权Logistic回归模型在斑岩铜矿预测中的应用——以中—哈边境扎尔—玛萨吾尔成矿带为例%The Application of Weighted Logistic Regression Model in Prediction of Porphyry Copper Deposit——take Zharma-Sawur metallogenic belt, China-Kazakhstan border area, as an example

    Institute of Scientific and Technical Information of China (English)

    努丽曼古·阿不都克力木; 张晓帆; 陈川; 徐仕琪; 赵同阳


    加权Logistic回归是基于GIS成矿预测的主要方法之一,其模型是不同于线性模型的一种类型.它具有强大的空间分析功能、适用性强、不受任何独立条件的约束、预测结果更可靠,因此在矿产资源评价研究中得到了很多地质学家的青睐.以矿床模型和成矿理论为基础,加权Logistic回归分析模型在成矿预测中的应用主要包括三部分:加权Logistic回归模型的建立及其应用、成矿有利度综合评价、成矿远景区圈定.本文以中国—哈萨克斯坦边境地区扎尔玛—萨吾尔成矿带斑岩型铜矿为例,探讨了基于GIS的加权Logistic回归模型在成矿预测中的应用.%Weighted Logistic Regression is one of the main methods of mineral potential mapping. It is different from linear model. Because of its powerful spatial analysis function, strong adaptability, unconstrained by independent conditions, and more reliable prediction results, Weighted Logistic Regression is widely used by many geologists in mineral resources assessment. Based on the mineral deposit model and theory, Weighted Logistic Regression is consists of three parts: (1) Establishment of weighted logistic regression model for mineral potential mapping; (2 ) comprehensive evaluation of favorable degrees; (3 ) mineral potential mapping of study area. By the Weighted Logistic Regression model for mineral potential mapping, Zharma-Sawur Metallogic Belt which across border region of China and Kazakhstan is studied and mineral prospecting area of porphyry copper deposit is mapped. At the end, the availability of Weighted Logistic Regression Model for mineral potential mapping is discussed.

  19. Geochemical, microtextural and petrological studies of the Samba prospect in the Zambian Copperbelt basement: a metamorphosed Palaeoproterozoic porphyry Cu deposit. (United States)

    Master, Sharad; Mirrander Ndhlovu, N.


    Ever since Wakefield (1978, IMM Trans., B87, 43-52) described a porphyry-type meta-morphosed Cu prospect, the ca 50 Mt, 0.5% Cu Samba deposit (12.717°S, 27.833°E), hosted by porphyry-associated quartz-sericite-biotite schists in northern Zambia, there has been controversy about its origin and significance. This is because it is situated in the basement to the world's largest stratabound sediment-hosted copper province, the Central African Copperbelt, which is hosted by rocks of the Neoproterozoic Katanga Supergroup. Mineralization in the pre-Katangan basement has long played a prominent role in ore genetic models, with some authors suggesting that basement Cu mineralization may have been recycled into the Katangan basin through erosion and redeposition, while others have suggested that the circulation of fluids through Cu-rich basement may have leached out the metals which are found concentrated in the Katangan orebodies. On the basis of ca 490-460 Ma Ar-Ar ages, Hitzman et al. (2012, Sillitoe Vol., SEG Spec. Publ., 16, 487-514) suggested that Samba represents late-stage impregnation of copper mineralization into the basement, and that it was one of the youngest copper deposits known in the Central African Copperbelt. If the Samba deposit really is that young, then it would have post-dated regional deformation and metamorphism (560-510 Ma), and it ought to be undeformed and unmetamorphosed. The Samba mineralization consists of chalcopyrite and bornite, occurring as disseminations, stringers and veinlets, found in a zone >1 km along strike, in steeply-dipping lenses up to 10m thick and >150m deep. Our new major and trace element XRF geochemical data (14 samples) show that the host rocks are mainly calc-alkaline metadacites. Cu is correlated with Ag (Cu/Ag ~10,000:1) with no Au or Mo. Our study focused on the microtextures and petrology of the Samba ores. We confirm that there is alteration of similar style to that accompanying classical porphyry Cu mineralization

  20. Relations between A-type granites and copper mineralization as exemplified by the Machangqing Cu deposit

    Institute of Scientific and Technical Information of China (English)


    This paper deals with the relations between the Machangqing rockbody which corresponds to the A-type granites and porphyry copper mineralization in terms of petrochemistry,trace element geochemistry,fluid inclusion geochemistry and isotope geochemistry.The results show that the Machangqing porphyry copper deposit was formed from the fluid predominated by magmatic fluid.This kind of ore-forming fluid was just differentiated from the magma responsible for the A-type granites.Therefore,as viewed from whether they contain water or not,the A-type granites can,at least,be divided into two types:water-bearing and water-free.The water-bearing A-type granites can serve as the host of porphyry copper deposits under certain geological conditions.

  1. Relations between A-type granites and copper mineralization as exemplified by the Machangqing Cu deposit

    Institute of Scientific and Technical Information of China (English)

    毕献武; 胡瑞忠; 叶造军; 邵树勋


    This paper deals with the relations between the Machangqing rockbody which corresponds to the A-type granites and porphyry copper mineralization in terms of petrochemistry, trace element geochemistry, fluid inclusion geochemistry and isotope geochemistry. The results show that the Machangqing porphyry copper deposit was formed from the fluid predominated by mag-matic fluid. This kind of ore-forming fluid was just differentiated from the magma responsible for the A-type granites. Therefore, as viewed from whether they contain water or not, the A-type granites can, at least, be divided into two types: water-bearing and water-free. The water-bearing A-type granites can serve as the host of porphyry copper deposits under certain geological conditions.

  2. Investigation on the age of mineralization in the Sungun porphyry Cu-Mo deposit, NW Iran with a regional metallogenic perspective (United States)

    Simmonds, Vartan; Moazzen, Mohssen; Mathur, Ryan


    The Sungun porphyry copper deposit (PCD) is located in NW Iran, neighbouring several other PCDs and prospects in the region and the Lesser Caucasus (south Armenia). It lies on the Urumieh-Dokhtar magmatic arc (UDMA), which formed through the northeast-ward subduction of the Neo-Tethyan oceanic crust beneath the Central Iranian plate during late-Mesozoic and early-Cenozoic [1], and hosts the porphyry copper metallogenic belt of Iran. The Sungun PCD is the second largest deposit in Iran with ore reserves of about 850 Mt at 0.62 wt% Cu and 0.01 wt% Mo and probable reserves over 1Gt. The monzonitic to quartz monzonitic porphyry stock intruded the upper Cretaceous carbonates and Eocene volcano-sedimentary rocks. It produced a skarn-type mineralization at its contact zone with the carbonate rocks, as well as vast hydrothermal alteration zones and porphyry-type Cu and Mo mineralization. The zircon U-Pb age of the host porphyry stock is about 22.5±0.4 to 20.1±0.4 Ma [2]. Re-Os dating of four molybdenite separates from this PCD shows ages ranging between 22.9±0.2 to 21.7±0.2 Ma, with an average of 22.57±0.2 Ma, corresponding to the early Miocene (Aquitanian). These ages indicate that both the porphyry stock and the Cu-Mo mineralization are post-collisional events, similar to many other deposits and prospects in NW and central Iran and south Armenia, and the mineralization occurred shortly after the emplacement of the host stock, corresponding better to the ages obtained from the marginal parts of the stock. Magmatism and mineralization in Sungun coincides with the third metallogenic epoch in the Lesser Caucasus (Eocene to Miocene; [3]), though it is considerably younger than all of the dated PCDs and prospects in the south Armenia. It also postdates Cu-Mo mineralizations in the Saheb Divan (35 Ma), Qaradagh batholith (31.22±0.28 to 25.19±0.19 Ma), as well as Haft Cheshmeh PCD (28.18±0.42 to 27.05±0.37 Ma) in NW Iran, while it seems to be coeval with the Kighal

  3. Deep xenoliths in alkalic porphyry,liuhe,Yunnan,and implications to petrogenesis of alkalic porphyry and associated mineralizations

    Institute of Scientific and Technical Information of China (English)

    刘显凡; 战新志; 高振敏; 刘家军; 李朝阳; 苏文超


    Na-rich microlite-glass is first discovered in deep-source xenoliths in alkali-rich porphyry, Liuhe village, Heqing County, Yunnan Province. It is shown that the ultramafic xenoliths originated from partial melting of primary mantle and the glass resulted from metasomatism between the xenoliths and mantle fluid derived from mantle degassing. Mantle metasomatism not only resulted in the enrichment of alkaline, large-ion elements, ore metals and volatiles but also created a favorable condition for the generation of alkaline magmas. The mantle xenoliths and their characteristics of mantle metasomatism provide important evidence for a better understanding of the petrogenesis and mineralization of the Cenozoic alkali-rich porphyry in western Yunnan.

  4. Imperial porphyry from Gebel Abu Dokhan, the Red Sea Mountains, Egypt

    DEFF Research Database (Denmark)

    Makovicky, Emil; Frei, Robert; Karup-Møller, Sven;


    The prestigious red Imperial Porphyry was quarried from Mons Porphyrites in the Red Sea Mountains of Egypt. The porphyry, reserved for imperial use in Rome and Constantinople, was widely reused in Romanesque and Renaissance times, and in the Ottoman Empire. At the locality, the rocks vary from da...

  5. Administrative Law in the Andean Community of Nations

    Directory of Open Access Journals (Sweden)

    Jorge Enrique Santos Rodríguez


    Full Text Available One of the contemporary tendencies of Administrative Law is the recognition of its existence beyond the borders of a State. Under such premise, this paper aims to demonstrate that in the Andean Community of Nations sufficient elements to consider the existence of an Andean administrative Law. In the Andean statutes and rules, it is possible to identify an administrative function, as well as an administrative organization inside the Andean Integration System; and a system of Andean administrative rules and an administrative justice system.

  6. Andean highlands: Implications of climate change


    Seth, Anji; Thibeault, J.M.; García, Magali


    This presentation provides background on the SANREM CRSP project "Adapting to Change in the Andean Highlands: Practices and Strategies to Address Climate and Market Risks in Vulnerable Agro-Eco Systems" and discusses the means, variability and projections for the Altiplano climate. available in SANREM office, ESIILTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  7. Geochronological borders of magmatism of Cu-Mo-porphyry Erdenetuin-Obo deposit (Mongolia)

    International Nuclear Information System (INIS)

    Complex study of K-Ar and Rb-Sr methods has been shown that the history of the Erdenetuin-Obo deposit consists of events of varied ranks. The deposit habit was formed under the effect of a great number of discrete pulses including magmatic, hydrothermal, and thermal processes. The age limits of the formation are: the host Selenga granitoids(pluton) 290-260 Ma; ore-bearing complex : 1-rhythm porphyries - 2550240 Ma; 2-rhythm porphyries -230-220 Ma; 3-rhythm porphyries 213-200 Ma; post-ore dikes -185-175 Ma. Hydrothermally-metasomatic formations fall into the age framework of porphyry rhythm. For the investigated magmatic rocks the initial ratio is 0.704-0.7042. 27 refs., 3 figs., 5 tabs

  8. Geochemical constraints on adakites of different origins and copper mineralization (United States)

    Sun, W.-D.; Ling, M.-X.; Chung, S.-L.; Ding, X.; Yang, X.-Y.; Liang, H.-Y.; Fan, W.-M.; Goldfarb, R.; Yin, Q.-Z.


    The petrogenesis of adakites holds important clues to the formation of the continental crust and copper ?? gold porphyry mineralization. However, it remains highly debated as to whether adakites form by slab melting, by partial melting of the lower continental crust, or by fractional crystallization of normal arc magmas. Here, we show that to form adakitic signature, partial melting of a subducting oceanic slab would require high pressure at depths of >50 km, whereas partial melting of the lower continental crust would require the presence of plagioclase and thus shallower depths and additional water. These two types of adakites can be discriminated using geochemical indexes. Compiled data show that adakites from circum-Pacific regions, which have close affinity to subduction of young hot oceanic plate, can be clearly discriminated from adakites from the Dabie Mountains and the Tibetan Plateau, which have been attributed to partial melting of continental crust, in Sr/Y-versus-La/Yb diagram. Given that oceanic crust has copper concentrations about two times higher than those in the continental crust, whereas the high oxygen fugacity in the subduction environment promotes the release of copper during partial melting, slab melting provides the most efficient mechanism to concentrate copper and gold; slab melts would be more than two times greater in copper (and also gold) concentrations than lower continental crust melts and normal arc magmas. Thus, identification of slab melt adakites is important for predicting exploration targets for copper- and gold-porphyry ore deposits. This explains the close association of ridge subduction with large porphyry copper deposits because ridge subduction is the most favorable place for slab melting. ?? 2012 by The University of Chicago.

  9. Mineralization and Geochemical Exploration in Volcanic- Plotonic Area of Halakabad Village (Sabzevar, Regarding to Cu-Porphyry Deposits

    Directory of Open Access Journals (Sweden)

    Panahi Shahri, M.


    Full Text Available The investigated area is located 30 Km south of Sabzevar in Halakabad village. Geological phenomenons in area follow a trend of NW-SE. Mineralization consists of metallic and non-metallic (kaolin mineralization. Disseminated and veinlet mineralization is generally associated with argillic alteration type. Pyrite is the most widespread type of sulfide mineralization in Halakabad occurrences. It usually displays a euhedral habit and have occurred at least in two generations. Calcopyrite is common in veinlets although in minor amounts. Secondary sulfuric acid weathering of the ore has generated huge surficial amounts of oxide and sulfate minerals which of hematite and jarosite are the most abundant. Geochemical exploration was conducted over both drainage geochemistry and rock geochemistry. Results show that some of the stream sediments have higher concentrations of Copper and Zinc than normal. This anomalies maches with monzonite outcrops in area. The chip rock geochemical data shows highest values in west of halakabad mine for Cu and Zn respectively 500 and 900 ppm. These data represents that all samples collected from surficial areas of east of area contain lower concentrations of Copper while sulfide mineralization is more than the other parts. Presence of favorable alteration system in region, presence of monzonite subvolcanic intrusions and regional geological criteria indicates a possible Cu-Au porphyry system in Halakabad area.

  10. Multidimensional study of the trace elements in the American south western prophyry copper type deposits: mineralogy of uranium

    International Nuclear Information System (INIS)

    The use of the spark source masse spectrometry and data treatment methods (principal component analysis and discriminent analysis) allow to describe the trace elements comportments in the porphyry copper type deposits of Arizona (USA) and Sonora (Mexico). The chemical elements are studied in relationship with the alteration zones of these deposits. A electronic microprobe study specifies the uranium bearing minerals

  11. Volcanism and associated hazards: the Andean perspective

    Directory of Open Access Journals (Sweden)

    R. I. Tilling


    Full Text Available Andean volcanism occurs within the Andean Volcanic Arc (AVA, which is the product of subduction of the Nazca Plate and Antarctica Plates beneath the South America Plate. The AVA is Earth's longest but discontinuous continental-margin volcanic arc, which consists of four distinct segments: Northern Volcanic Zone, Central Volcanic Zone, Southern Volcanic Zone, and Austral Volcanic Zone. These segments are separated by volcanically inactive gaps that are inferred to indicate regions where the dips of the subducting plates are too shallow to favor the magma generation needed to sustain volcanism. The Andes host more volcanoes that have been active during the Holocene (past 10 000 years than any other volcanic region in the world, as well as giant caldera systems that have produced 6 of the 47 largest explosive eruptions (so-called "super eruptions" recognized worldwide that have occurred from the Ordovician to the Pleistocene.

    The Andean region's most powerful historical explosive eruption occurred in 1600 at Huaynaputina Volcano (Peru. The impacts of this event, whose eruptive volume exceeded 11 km3, were widespread, with distal ashfall reported at distances >1000 km away. Despite the huge size of the Huaynaputina eruption, human fatalities from hazardous processes (pyroclastic flows, ashfalls, volcanogenic earthquakes, and lahars were comparatively small owing to the low population density at the time. In contrast, lahars generated by a much smaller eruption (<0.05 km3 in 1985 of Nevado del Ruiz (Colombia killed about 25 000 people – the worst volcanic disaster in the Andean region as well as the second worst in the world in the 20th century. The Ruiz tragedy has been attributed largely to ineffective communications of hazards information and indecisiveness by government officials, rather than any major deficiencies in scientific data. Ruiz's disastrous outcome, however, together with responses to subsequent

  12. 75 FR 6679 - Agency Information Collection Activities: Andean Trade Preferences (United States)


    ... Register (74 FR 65543) on December 10, 2009, allowing for a 60- day comment period. This notice allows for... officers to document preferential tariff treatment under the provisions of the Andean Trade Preferences Act... SECURITY U.S. Customs and Border Protection Agency Information Collection Activities: Andean...

  13. 40Ar-39Ar Dating of Albite and Phlogopite from Porphyry Iron Deposits in the Ningwu Basin in East-Central China and Its Significance

    Institute of Scientific and Technical Information of China (English)

    YU Jinjie; MAO Jingwen


    40Ar-39Ar dating of albite from the Meishan and Taocun iron deposits yields plateau ages of 122.90±0.16 Ma and 124.89±0.30 Ma, and isochron ages of 122.60±0.16 Ma and 124.90±0.29 Ma, respectively. Phlogopite from the Zhongshan-Gushan ore field has a plateau age of 126.7±0.17 Ma and an isochron age of 127.21±1.63 Ma. Analysis of regional geodynamic evolution of the middle-lower Yangtze River region suggests that the porphyry iron deposits were formed as a result of large-scale lithosphere delamination and strong sinistral strike-slip movement of the TanchengLujiang fault zone. The copper, molybdenum and gold deposit system in the middle-lower Yangtze River region was formed during the stress transition period of the eastern China continent.

  14. Qian'echong low-F porphyry Mo deposits in the Dabie Mountains, central China (United States)

    Mi, Mei; Li, Cong-ying; Sun, Wei-dong


    The Qian'echong Mo deposit is a large porphyry Mo deposit located in the northwest Dabie Mountains, central China, with proven Mo reserves of 741 Mt at 0.081%. Chondrite-normalized REE patterns of most zircon from samples QEC002, 003, 004 and 011 show HREE enrichment with distinctive positive Ce and moderately negative Eu anomalies, which are typical of magmatic zircon in porphyry deposits. Zircon grains from sample QEC001 are all hydrothermal in origin, whereas there are only several hydrothermal zircons in the other samples. The Ti-in-zircon thermometer yields temperatures of 700-740 °C for the magmatic zircon. The Ce4 +/Ce3 + calculated from the Ce anomaly is a sensitive and robust indicator of magmatic oxidation status. Magmatic zircon have Ce4 +/Ce3 + and (Eu/Eu*)N ratios ranging between 10-577 and 0.2-1.3, respectively. Compared to the Shapinggou deposit (Climax type) also in the Dabie Mountains, the Qian'echong zircon has systematically lower Ce4 +/Ce3 +. Apatite from the Qian'echong deposit belongs to the F-apatite variety, with fluorine concentrations varying between 2.13-4.50% and Cl concentrations between 0.01-0.28%. Whole rock samples of the porphyry from the Qian'echong deposit have F contents of 360-1230 ppm. The porphyry intrusion is consistently associated with calc-alkaline granitic to granodioritic porphyries, with lower F, Nb, and Ta concentrations, and systematically lower Mo contents than the Climax-type deposits. All these characteristics are similar to other low-F porphyry Mo deposits along the eastern Pacific margin. Fluorine is mainly hosted in phengite during plate subduction, which may decompose far beneath the surface of the subduction zone. Therefore, high F deposits may be interpreted as locating the farthermost position reached by the subducting slab. Nevertheless, the F contents of the Qian'echong deposit is much higher than in adjacent barren granites, and may have incorporated additional F from the subduction slab. Given that the

  15. Imperial porphyry from Gebel Abu Dokhan, the Red Sea Mountains, Egypt

    DEFF Research Database (Denmark)

    Makovicky, Emil; Frei, Robert; Karup-Møller, Sven;


    contents, are consistent with crust contamination. Imperial Porphyry erupted during the second Great Oxygenation Event of the Earth atmosphere. Mineralogical observations as well as rock colour and texture, particularly the pleochroic epidote – piemontite, should allow archaeologists to reliably assign.......88 Ga and εNd from +5.1 to +5.7 were inferred. The magmas which led to formation of the Imperial Porphyry appear to be derived from a subduction-modified depleted mantle and underwent only minor contamination by older continental crust. Trace-element features, notably the high Th, U, K, Rb and Cs...

  16. Quinoa trade in Andean countries: opportunities and challenges for family


    Baudoin, Andrea; Lacroix, Pierril; Didier BAZILE; Chia, Eduardo


    Quinoa’s revival has roused much interest in Andean as well as in European and North American countries. This Andean product, formerly denigrated and destined only for self-consumption, has made its way into the diet of the urban populations of Andean countries and has now spread to the United States of America, Europe and other parts of the world. In the Andes, farmgate prices have gone up and the quinoa sector has become attractive to investors. A wide range of products based on this Chenop...

  17. 金平铜厂铜钼矿床赋矿岩体锆石LA-ICP-MS U-Pb年龄及意义%Zircon LA-ICP-MS U-Pb Age of the Jinping-Tongchang Porphyry Associated with Cu-Mo Mineralization and its Geological Implication

    Institute of Scientific and Technical Information of China (English)

    黄波; 梁华英; 莫济海; 谢应雯


    The Jinping-Tongchang Cu-Mo deposit located at the southwestern segment of the Ailao Shan-Red River shear zone,which is in the southern part of the Cenozoic metallogenic belt along the Ailao Shan-Red River shear and its north-em stretching zone in eastern Tibet. The Jinping-Tongchang ore-bearing porphyry is composed of monzogranite porphyries and monzonites. CL photos of the analyzed zircons from the Jinping-Tongchang porphyry are characterized by the well-developed oscillatory zoning, suggesting that the analyzed zircon grains are of magmatic origin. Zircon LA-ICP-MS U-Pb age of the ore-bearing porphyry is 35.1 ±0. 3Ma, with MSWD = 1. 88. Different zoning of the same zircon grain has similar U-Pb age within error. The zircon age of the Jinping-Tongchang ore-bearing porphyry is similar to those of the Machangqing porphyry copper deposit and potassic alkaline rocks along the Ailao Shan-Red River shear zone. It is concluded that the Jinping-Tongchang ore-bearing porphyry has genetic relation to the left-lateral movements of the Ailao Shan-Red River shear zone caused by the collision between the Indian and Asian plates.%金平铜厂铜钼矿床赋矿岩体位于哀牢山-金沙江新生代成矿带南端,红河走滑断裂西侧,赋矿岩体主要由二长花岗斑岩及二长花岗岩组成.岩体锆石阴极发光图(CL)环带构造发育,不同环带U-Pb年龄在误差范围内基本一致.锆石LA-ICP-MS U-Pb年结果表明赋矿岩体主要是35.1±0.3Ma形成的.含矿岩体形成与印度板块与欧亚板块碰撞产生的红河-哀牢山左行走滑断裂活动有关.

  18. The Andean Geotrail (2): An educational project (United States)

    Galland, O.; Sassier, C.; Vial, M.; Thiberge, P.


    The role of Geosciences in our society is of primary importance. Its implications for humanity relate to major challenges such as climate change, managing energy resources, natural hazard mitigation, and water scarcity. Despite these issues being familiar to specialists, this is in general not the case for the public. In a world, where the impact of human activity is beginning to be seen on the environment, knowledge of the Earth and its history is paramount to make informed decisions that will influence our future. The necessity to educate the global population and raise awareness of Geosciences has led UNESCO to designate 2009 the International Year of the Planet Earth. In the framework of the UNESCO International Year of Planet Earth, we performed an educational project in collaboration with primary, secondary and high schools in France and Norway. Geosciences are not usually studied in schools, but this project allowed more than 600 pupils (from 17 schools) aged 8 to 18 years old to share the geological discoveries of our popular science adventure The Andean Geotrail (see Sassier et al., this session). The main educational goal was to promote Geosciences by illustrating in the field what geology is. Our natural laboratory was the spectacular Andean Cordillera. The secondary goal was to promote careers in geology and highlight their variety by allowing the pupils to meet geologists through portraits of geologists. The teachers of the partner schools used our project as a dynamic complement to their theoretical lessons. To set up this partnership, we obtained the support of the pedagogic supervisors of the French Ministry of National Education. The pedagogical project consisted of three steps: (1) Before the expedition (Oct.-Nov. 2008), we visited the pupils of each partner school to present the project, establish personal contact and engage the pupils in our adventure. (2) During The Andean Geotrail itself (Nov. 2008-Aug. 2009), we continuously documented our

  19. Andean Democracies: coming late to the party?

    Directory of Open Access Journals (Sweden)

    Marcelo Coutinho


    Full Text Available After a centuries-long history of oligarchical, populist, and authoritarian institutionality, in recent decades South America has begun the transition to a liberal democratic state model. This new state model harbors the contradiction of being both more democratic and less capable. In other words, it allows public participation and dissent but has less ability to respond, a role that has been largely transferred to the market, which has become globalized and more complex while experiencing difficulties in meeting social demands. The tension between democracy and economic limitations, combined with endogenous institutional problems, has sustained a climate of permanent political instability in parts of South America, reproducing fragmentations and conflicts, which are the focus of this study, a comparative analysis of five Andean countries: Bolivia, Peru, Ecuador, Colombia, and Venezuela.

  20. Andean flat subduction maintained by slab tunneling (United States)

    Schepers, Gerben; van Hinsbergen, Douwe; Kosters, Martha; Boschman, Lydian; McQuarrie, Nadine; Spakman, Wim


    In two segments below the Andean mountain belt, the Nazca Plate is currently subducting sub-horizontally below South America over a distance of 200-300 km before the plate bends into the mantle. Such flat slab segments have pronounced effects on orogenesis and magmatism and are widely believed to be caused by the downgoing plate resisting subduction due to its local positive buoyancy. In contrast, here we show that flat slabs primarily result from a local resistance against rollback rather than against subduction. From a kinematic reconstruction of the Andean fold-thrust belt we determine up to ~390 km of shortening since ~50 Ma. During this time the South American Plate moved ~1400 km westward relative to the mantle, thus forcing ~1000 km of trench retreat. Importantly, since the 11-12 Ma onset of flat slab formation, ~1000 km of Nazca Plate subduction occurred, much more than the flat slab lengths, which leads to our main finding that the flat slabs, while being initiated by arrival of buoyant material at the trench, are primarily maintained by locally impeded rollback. We suggest that dynamic support of flat subduction comes from the formation of slab tunnels below segments with the most buoyant material. These tunnels trap mantle material until tearing of the tunnel wall provides an escape route. Fast subduction of this tear is followed by a continuous slab and the process can recur during ongoing rollback of the 7000 km wide Nazca slab at segments with the most buoyant subducting material, explaining the regional and transient character of flat slabs. Our study highlights the importance of studying subduction dynamics in absolute plate motion context.

  1. Tectonomagmatic Associations on the Central Andean Plateau (United States)

    de Silva, S. L.; Viramonte, J. G.


    The Neogene evolution of the Central Andes is characterized by a strong association between plate convergence, mountain building and plateau formation, and magmatism. Plateau uplift by crustal shortening and thickening in the lower crust is broadly coincident with large scale silicic magmatism defined by the Neogene Central Andean ignimbrite province. Of particular interest here are the spatiotemporal correlations between silicic magmatism and tectonic evolution of the Altiplano-Puna plateau. Although magmatism is driven by the subduction-related flux from mantle to crust, the shift to "crustal" magmatism as indicated by elevated crustal isotopic indices after ~10Ma suggests a link between crustal thickening, plateau formation and silicic magmatism. In particular, elevated geotherms associated with crustal thickening and enhanced mantle flux associated with lithospheric delamination may have played a role in thermally preparing the Central Andean crust for enhanced silicic magma production during the extensive Neogene ignimbrite flare-up. Emplacement of these magmas in the upper crust throughout the Neogene may have fuelled a period of significant interaction between magmatism and tectonism on the plateau. With particular reference to the 21° to 24°S segment of the Central Andes, spatial and structural coincidence of calderas of the Altiplano Puna Volcanic Complex with the NW-SE striking Calama-Olacapata-El Toro fault zone suggests significant tectonomagmatic interaction. Location of calderas suggest that these regional faults focused magma intrusion and storage, while spatially and temporally correlated eruption pulses connote a tectonic control. Indeed, current thermomechanical models of magma chamber development and eruption triggering promote a role for external triggering of "perched" upper crustal magma chambers. This might have been achieved by melt-enhanced deformation, or alternatively, significant uplift (~1km) associated with the development of large

  2. An ontological approach to creating an Andean Weaving Knowledge Base


    Brownlow, Richard; Capuzzi, Stefano; Helmer, Sven; Martins, Luciana; Normann, Immanuel; Poulovassilis, Alexandra


    Andean textiles are products of one of the richest, oldest and continuous weaving traditions in the world. Understanding the knowledge and practice of textile production as a form of cultural heritage is particularly relevant in the Andean context due to erosion of clothing traditions, reuse of traditional textiles on commodities targeted at the tourism market, and loss of knowledge embedded in textile production. ``Weaving Communities of Practice'' was a pilot project that aimed to create a ...

  3. The new Andean Regional Office of Astronomy for Development (ROAD) (United States)

    Char, Farid; Forero-Romero, Jaime


    The Andean Regional Office of Astronomy for Development (ROAD) is a new effort in South America to serve several goals in astronomical development. Six countries (Bolivia, Colombia, Chile, Ecuador, Perú and Venezuela) will work together, representing a common language block in the Andean region and focusing on develop strategies to strengthen the professional research, education and popularization of astronomy. Our current Working Structure comprises a ROAD Coordinator and Coordinators per Task Force, as well as Organizing Committees, Collaborators and Volunteers.The participating institutions of this new ROAD have been involved in many projects involving each of the current OAD’s Task Forces: research, schools and children and public, exploring educational activities/material to be shared among the Andean countries, standardizing the knowledge and creating inspirational experiences. We expect to generate many efforts in order to bring a more homogeneous activity in each Andean country, taking into account the special role of Chile in global astronomy, due to its great conditions for astronomy and the involvement of many professional observatories, universities and astronomy institutions.Our current (and upcoming) most relevant activities includes: Andean Schools on Astronomy, Andean Graduate Program and Massive Open Online Courses (TF1); Virtual Training Sessions and Teaching material for the visually impaired students; Annual TF2 meeting to gather all the collaborators (TF2); Development for planetariums and Communicating Astronomy with the Public (TF3). The Andean region, in the other hand, will also be involved in at least two important events: the CAP Meeting in May 2016 and the XV LARIM in October 2016 (both in Colombia); and Chile will bid to host the XXXI IAU GA in 2021, with the aim of show the great advances in astronomical development from the Andean region and South America.

  4. “三江”地区中旬弧普朗成矿斑岩地球化学特征及其成因%Geochemistry and petrogenesis of Pulang porphyries in Sanjiang region

    Institute of Scientific and Technical Information of China (English)

    任江波; 许继峰; 陈建林; 张世权; 梁华英


    Located in Zhongdian island arc belt in northwestern Yunnan Province, the Pulang super large porphyry copper deposit was formed in late Triassic during the westward subduction of the Ganzi-Litang ocean plate below Zhongdian microplate. The mineralized rocks of the Pulang porphyry copper deposit mainly include quartz dioritic porphyries and quartz monzonitic porphyries in a complex pluton, and economic ores are mainly preserved in the quartz monzonitic porphyries. The quartz dioritic porphyrites were intruded by later quartz monzonitic porphyries, but the two kinds of rocks display similar geochemical characteristics, such as similar REE patterns, incompatible trace element patterns and initial 87Sr/86Sr and Nd/144Nd ratios, suggesting that they were coge-netic products or were derived from similar sources. Geochemically, both kinds of rocks are akin to adakite, as evidenced by such characteristics as high Sr content (289×10-6~l 200×10-6), high La/Yb and Sr/Yb ratios, relatively high MgO and Mg# (>59), depleted Y and Yb, slightly negative Eu anomalies and positive Sranomalies Moreover, the radiogenic Sr [0.705 60 61.0%) and K2O (2.2%~4.4%), while the latter have high SiQ2(> 65.9%) and K2O (3.5%~8.1%). Therefore, the authors hold that the Pulang porphyry copper deposit was probably related to the westward subduction of Ganzhi-Litang oceanic plate during late Triassic. At the early stage of subduction, the quartz dioritic porphyries with subduction-related origin were formed firstly, then increasing adakitic magmas of slab melting were mixed with melts from subducted sediments or arc materials, producing more acid and high oxygen fugacity adakitic magmas, which finally intruded the upper crust below Pulang and promoted the mineralization of the Pulang porphyry copper deposit at the shallow level.%普朗斑岩铜矿床是中国西南“三江”地区新发现的具超大规模的印支期斑岩铜矿床,其成矿岩体的斑岩具有高的Sr含量(289×10-6~1 200

  5. Zircon U-Pb and molybdenite Re-Os dating of the Chalukou porphyry Mo deposit in the northern Great Xing'an Range, China and its geological significance (United States)

    Liu, Jun; Mao, Jingwen; Wu, Guang; Wang, Feng; Luo, Dafeng; Hu, Yanqing


    The newly discovered Chalukou giant porphyry Mo deposit, located in the northern Great Xing'an Range, is the biggest Mo deposit in northeast China. The Chalukou Mo deposit occurs in an intermediate-acid complex and Jurassic volcano-sedimentary rocks, of which granite porphyry, quartz porphyry, and fine-grained granite are closely associated with Mo mineralization. However, the ages of the igneous rocks and Mo mineralization are poorly constrained. In this paper, we report precise in situ LA-ICP-MS zircon U-Pb dates for the monzogranite, granite porphyry, quartz porphyry, fine grained granite, rhyolite porphyry, diorite porphyry, and andesite porphyry in the Chalukou deposit, corresponding with ages of 162 ± 2 Ma, 149 ± 5 Ma, 148 ± 2 Ma, 148 ± 1 Ma, 137 ± 3 Ma, 133 ± 2 Ma, and 132 ± 2 Ma, respectively. Analyses of six molybdenite samples yielded a Re-Os isochron age of 148 ± 1 Ma. These data indicate that the sequence of the magmatic activity in the Chalukou deposit ranges from Jurassic volcano-sedimentary rocks and monzogranite, through late Jurassic granite porphyry, quartz porphyry, and fine-grained granite, to early Cretaceous rhyolite porphyry, diorite porphyry, and andesite porphyry. The Chalukou porphyry Mo deposit was formed in the late Jurassic, and occurred in a transitional tectonic setting from compression to extension caused by subduction of the Paleo-Pacific oceanic plate.

  6. The Andean Geotrail (1): A scientific adventure (United States)

    Sassier, C.; Galland, O.; Raufaste, C.; Mair, K.


    The role of Geosciences in our society is of primary importance. Its implications for humanity relate to major challenges such as climate change, managing energy resources, natural hazard mitigation, and water scarcity. Despite these issues being familiar to specialists, this is in general not the case for the public. In a world, where the impact of human activity is beginning to be seen on the environment, knowledge of the Earth and its history is paramount to make informed decisions that will influence our future. The necessity to educate the global population and raise awareness of Geosciences has led UNESCO to designate 2009 the International Year of the Planet Earth. In this context and with the label of the UNESCO, we organized and performed a popular science adventure that was followed in real time by both school children and many adults around the world. The Andean Geotrail consisted of a cycling expedition through a spectacular geological environment, the Andean Cordillera. During the nine month expedition, we cycled 8000 km and walked 400 km from Ushuaia in the Southern tip of Argentina to Nazca in Peru to encounter a rich variety of geological environments: active volcanoes, earthquakes, mineral and hydrocarbon deposits, and fantastic geological scenery. All this makes the Andes a great pedagogical natural laboratory. During the expedition, we visited spectacular geological localities that illustrate key Earth Science phenomena (such as mines and hydrocarbon deposits, erupting volcanoes and seismogenically active areas, and national parks) and discovered their implications for the local people. Along the way, we interviewed local geologists and scientists who helped us understand the geology of their areas. We gathered our own observations with those of the local specialists and published essays, articles and photographs on our website and blog (, Seventeen schools in France and Norway

  7. Critical Factors Controlling Pd and Pt Potential in Porphyry Cu–Au Deposits: Evidence from the Balkan Peninsula

    Directory of Open Access Journals (Sweden)

    Demetrios G. Eliopoulos


    Full Text Available Porphyry Cu–Au–Pd±Pt deposits are significant Au resources, but their Pd and Pt potential is still unknown. Elevated Pd, Pt (hundreds of ppb and Au contents are associated with typical stockwork magnetite-bornite-chalcopyrite assemblages, at the central parts of certain porphyry deposits. Unexpected high grade Cu–(Pd+Pt (up to 6 ppm mineralization with high Pd/Pt ratios at the Elatsite porphyry deposit, which is found in a spatial association with the Chelopech epithermal deposit (Bulgaria and the Skouries porphyry deposit, may have formed during late stages of an evolved hydrothermal system. Estimated Pd, Pt and Au potential for porphyry deposits is consistent with literature model calculations demonstrating the capacity of aqueous vapor and brine to scavenge sufficient quantities of Pt and Pd, and could contribute to the global platinum-group element (PGE production. Critical requirements controlling potential of porphyry deposits may be from the metals contained in magma (metasomatized asthenospheric mantle wedge as indicated by significant Cr, Co, Ni and Re contents. The Cr content may be an indicator for the mantle input.

  8. Two new Cystoderma species from high Andean Ecuador

    DEFF Research Database (Denmark)

    Saar, I.; Læssøe, Thomas


    ABSTRACT: Two new agaric species, Cystoderma andinum and C. papallactae are described from high Andean Ecuador.......ABSTRACT: Two new agaric species, Cystoderma andinum and C. papallactae are described from high Andean Ecuador....

  9. Architecture of the Northwest Andean Microplates (United States)

    Potts, L. V.; Hernandez, O.; von Frese, R. R.; Schmidt, M.


    Recently revised models on global plate boundary zones show that the North Andes microplate includes a wide distribution of seismicity, volcanic events, active faulting and extreme topography. The current description of the north Andean microplate boundaries is interpreted from a variety of geological and geophysical models including volcanism and seismicity with variable confidence levels. The poorly understood complex structure and geometry of plate boundaries limits the ability of current physical models to predict neotectonic and other effects including intra-plate lithospheric stresses and strain. Together with local surface gravity and topography data, a variety of available space geodetic sensors have substantially improved the modeling of the lithosphere for analyzing subsurface mass dynamics. They include the GPS-derived 3-D crustal velocities, high resolution (90-m) topography, seismic surveys and high resolution gravity models derived from integrated satellite (e.g., CHAMP and GRACE, 200-km resolution) and terrestrial observations (up to ~5 km resolution). Spherical wavelets is a modern tool for a multi-resolution representation of spatially heterogenously distributed gravity (consistent with the generalized boundary value problem) and for topography datasets with the distinct ability to enhance localized signals. Analysis of multi-resolution gravity and topography models combined with GPS velocities provide a unique opportunity to characterize the structure, isostatic conditions, mass dynamics, and intra-plate deformations of the North Andes microplate.

  10. Andean tectonics: Implications for Satellite Geodesy (United States)

    Allenby, R. J.


    Current knowledge and theories of large scale Andean tectonics as they relate to site planning for the NASA Crustal Dynamics Program's proposed high precision geodetic measurements of relative motions between the Nazca and South American plates are summarized. The Nazca Plate and its eastern margin, the Peru-Chile Trench, is considered a prototype plate marked by rapid motion, strong seismicity and well defined boundaries. Tectonic activity across the Andes results from the Nazca Plate subducting under the South American plate in a series of discrete platelets with different widths and dip angles. This in turn, is reflected in the tectonic complexity of the Andes which are a multitutde of orogenic belts superimposed on each other since the Precambrian. Sites for Crustal Dynamics Program measurements are being located to investigate both interplate and extraplate motions. Observing operations have already been initiated at Arequipa, Peru and Easter Island, Santiago and Cerro Tololo, Chile. Sites under consideration include Iquique, Chile; Oruro and Santa Cruz, Bolivia; Cuzco, Lima, Huancayo and Bayovar, Peru; and Quito and the Galapagos Islands, Ecuador. Based on scientific considerations, Santa Cruz, Huancayo (or Lima), Quito and the Galapagos Islands should be replaced by Isla San Felix, Chile; Brazilia or Petrolina, Brazil; and Guayaquil, Ecuador. If resources permit, additional important sites would be Buenaventura and Villavicencio or Puerto La Concordia, Colombia; and Mendoza and Cordoba, Argentina.

  11. Trans-Andean Ancistrus (Siluriformes: Loricariidae). (United States)

    Taphorn, Donald C; Armbruster, Jonathan W; Villa-Navarro, Francisco; Ray, C Keith


    We review the trans-Andean species of Ancistrus from Panama, Colombia and Venezuela. Based on analyses of meristic, morphometric and pigmentation pattern data of preserved specimens, eight of sixteen species reported from this region are considered valid and two new species are described. Here we review Ancistrus chagresi Eigenmann & Eigenmann 1889 from both slopes of central Panama; A. centrolepis Regan 1913 from Pacific slopes of eastern Panama and western Colombia; Ancistrus caucanus Fowler 1943, from the Magdalena River drainage in northern Colombia; Ancistrus martini Schultz 1944, from the Lake Maracaibo Basin of Venezuela and Colombia. Ancistrus galani Pérez & Viloria 1994, from a cave in the Lake Maracaibo Basin of Venezuela is considered valid but was not examined. Ancistrus tolima new species is described from the upper Magdalena River drainage and Ancistrus vericaucanus new species is described from the upper Cauca River drainage. Ancistrus gymnorhynchus Kner 1854 and A. falconensis Taphorn, Armbruster & Rodriguez-O. 2010 were treated previously. One specimen of A. clementinae Rendahl 1937 from the Pacific coast of Ecuador was examined, it is considered a valid species. A key for identification and geographical ranges are provided. PMID:26287090

  12. How to Deepen the Dialogue between the Andean Community and the EU


    Sheila Page


    This paper discusses the European Union trade policy making process and implications for the Andean community. The European Union (EU) divides its agreements with other countries into three types: neighbourhood, trade and development, and is currently classifying the negotiations with the Andean Community as development. The Andean Community must examine how the EU has approached its agreements in the past and what the Andean countries need from an agreement, and decide whether it wants to ne...

  13. On the Nature of Cross-Linguistic Transfer: A Case Study of Andean Spanish (United States)

    Muntendam, Antje G.


    This paper presents the results of a study on cross-linguistic transfer in Andean Spanish word order. In Andean Spanish the object appears in preverbal position more frequently than in non-Andean Spanish, which has been attributed to an influence from Quechua (a Subject-Object-Verb language). The high frequency of preverbal objects could be…

  14. Copper transport. (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N


    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats. PMID:9587137

  15. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P


    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  16. Species richness and indices of abundance of medium-sized mammals in andean forest and reforestations with andean alder: a preliminary analysis




    We studied the species richness and two indices of abundance of medium-sizedmammals in areas with Andean forest and Andean alder (Alnus acuminata)reforestations in a reserve at the Central Andes of Colombia. Since reforested areashave a less complex habitat structure and lower plant diversity than native forests, wepredicted that they have lower richness of mammals than areas with Andean forest.We obtained the indices of abundance from direct contacts in transects and from theuse of track sta...

  17. Porphyry Cu-Au and associated polymetallic Fe-Cu-Au deposits in the Beiya Area, western Yunnan Province, south China (United States)

    Xu, X.-W.; Cai, X.-P.; Xiao, Q.-B.; Peters, S.G.


    The Alkaline porphyries in the Beiya area are located east of the Jinshajiang suture, as part of a Cenozoic alkali-rich porphyry belt in western Yunnan. The main rock types include quartz-albite porphyry, quartz-K-feldspar porphyry and biotite-K-feldspar porphyry. These porphyries are characterised by high alkalinity [(K2O + Na2O)% > 10%], high silica (SiO2% > 65%), high Sr (> 400??ppm) and 87Sr/86Sr (> 0.706)] ratio and were intruded at 65.5??Ma, between 25.5 to 32.5??Ma, and about 3.8??Ma, respectively. There are five main types of mineral deposits in the Beiya area: (1) porphyry Cu-Au deposits, (2) magmatic Fe-Au deposits, (3) sedimentary polymetallic deposits, (4) polymetallic skarn deposits, and (5) palaeoplacers associated with karsts. The porphyry Cu-Au and polymetallic skarn deposits are associated with quartz-albite porphyry bodies. The Fe-Au and polymetallic sedimentary deposits are part of an ore-forming system that produced considerable Au in the Beiya area, and are characterised by low concentrations of La, Ti, and Co, and high concentrations of Y, Yb, and Sc. The Cenozoic porphyries in western Yunnan display increased alkalinity away from the Triassic Jinshajiang suture. Distribution of both the porphyries and sedimentary deposits in the Beiya area are interpreted to be related to partial melting in a disjointed region between upper mantle lithosphere of the Yangtze Plate and Gondwana continent, and lie within a shear zone between buried Palaeo-Tethyan oceanic lithosphere and upper mantle lithosphere, caused by the subduction and collision of India and Asia. ?? 2006 Elsevier B.V. All rights reserved.

  18. Crust-mantle contribution to Andean magmatism

    International Nuclear Information System (INIS)

    There has long been great interest in quantifying the contributions of the continental crust to continental arc magmas, such as those of the Andes using osmium isotopes (Alves et al., 1999; Borg et al., 2000; Brandon et al., 1996; McInnes et al., 1999). In general, Andean volcanic rocks of all compositions show relatively low Sr-isotope ratios and positive to mildly negative epsilon Nd values. Nonetheless, in the Southern Volcanic Zone of central Chile, basalt-andesite-dacite volcanoes along the Quaternary volcanic front were shown (by Hildreth and Moorbath, 1988) to have latitudinally systematic chemical variations, as well as a monotonic increase in 87Sr/Sr86 from ca. 0.7035 to 0.7055 and a decrease in epsilon Nd values from ca. +3 to -1. The isotopic variations correlate with basement elevation of the volcanic edifices and with Bouguer gravity anomalies, both of which are thought to reflect along-arc variations in thickness and average age of the underlying crust. Volcanoes with the most evolved isotopic signatures were fed through the thickest crust. Correlation of chemical and isotopic variations with crustal thickness was interpreted to be caused by Melting (of deep-crustal host rocks), Assimilation, Storage, and Homogenization (MASH) of mantle-derived magmas in long-lived lower-crustal reservoirs beneath each center prior to eruption. We have now determined Os-isotope ratios for a sample suite from these volcanoes (33-36 S lat.), representing a range of crustal thickness from ca. 60-35 km. The samples range in MgO from ca. 8-4% and in SiO2 from 51-57%. The most evolved eruptive products occur above the thickest crust and have 87Sr/86Sr ratios of 0.7054 and epsilon Nd values of -1.5. The 187Os/188Os ratios correlate with the other isotopic systems and with crustal thickness. Volcanoes on the thinnest crust have 187Os/188Os ratios of 0.18-0.21. Those on the thickest crust have 187Os/188Os ratios as high as 0.64. All the Os values are much too radiogenic to

  19. Postmodern Anthropology: Reflections from Andean Ethnohistory

    Directory of Open Access Journals (Sweden)

    Villarías-Robles, Juan J. R.


    Full Text Available The postmodern perspective, which began its influence on studies of Prehispanic Peru in the 1980s, has resulted —as chief positive effect— in reflection and debate concerning the written sources for apprehending such cultural otherness, the so-called “Chronicles of the West Indies”: a perspective accompanied by new editions of these texts. The author of the present article expresses his own reflection on such change in theory and method. He argues that, with regard to self-reflectivity on its epistemological foundations, the new perspective is not entirely original in the long history of Andean ethnohistory; in effect, this approach is almost as old as the field itself. What is indeed original is the cognitive relativism that surfaced in some extreme forms of the discussion. It was an unfortunate development, however: when not denying, as a matter of principle, the very possibility of understanding that cultural otherness, arguments masked actual interpretations or explanations of its features that were protected, ipso facto, from a rigorous process of validation.

    La perspectiva posmoderna, que empezó a ser influyente en los estudios del Perú prehispánico en la década de 1980, ha tenido como principal efecto positivo la reflexión y el debate sobre las fuentes originales de conocimiento de esa alteridad cultural, las llamadas genéricamente “Crónicas de Indias”: una perspectiva acompañada de nuevas ediciones de tales textos. El autor del presente artículo hace aquí su propia reflexión sobre este cambio teórico y metodológico. Plantea que, en lo que tiene de discusión sobre sus bases epistemológicas, no es del todo original en la larga historia de la etnohistoria peruanista. Es, de hecho, casi tan antiguo como ella. Lo que sí ha sido original es el relativismo cognitivo que ha acompañado a algunas expresiones extremas de la discusión. Pero fue ésta una novedad desafortunada: cuando no negaba por principio la

  20. Ornitholimnology: Effects of grazing by the Andean flamingo (Phoenicoparrus andinus). (United States)

    Hurlbert, S H; Chang, C C


    Experimental exclusion of the Andean flamingo (Phoenicoparrus andinus) from shallow water areas of a salt lake in the Bolivian Andes caused large increases in the biomass of microorganisms inhabiting the surface sediments, especially a large diatom (Surirella wetzeli), amebas, ciliates, and nematodes. This is a conservative demonstration of the influences that water birds in general exert on the structure of aquatic ecosystems. PMID:16593350

  1. Ornitholimnology: Effects of grazing by the Andean flamingo (Phoenicoparrus andinus)


    Hurlbert, Stuart H.; Chang, Cecily C. Y.


    Experimental exclusion of the Andean flamingo (Phoenicoparrus andinus) from shallow water areas of a salt lake in the Bolivian Andes caused large increases in the biomass of microorganisms inhabiting the surface sediments, especially a large diatom (Surirella wetzeli), amebas, ciliates, and nematodes. This is a conservative demonstration of the influences that water birds in general exert on the structure of aquatic ecosystems.

  2. Predicting Polylepis distribution: vulnerable and increasingly important Andean woodlands


    Brian R. Zutta; Phillip W. Rundel; Sassan Saatchi; Jorge D. Casana; Paul Gauthier Gauthier; Aldo Soto; Yessenia Velazco; Wolfgang Buermann


    Polylepis woodlands are a vital resource for preserving biodiversity and hydrological functions, which will be altered by climate change and challenge the sustainability of local human communities. However, these highaltitude Andean ecosystems are becoming increasingly vulnerable due to anthropogenic pressure including fragmentation, deforestation and the increase in livestock. Predicting the distribution of native woodlands has become increasingly important to counteract the negative effects...

  3. The Andean Common Market: An Experiment in Regional Cooperation. (United States)

    Carlson, Reynold E.

    The Grupo Andino (GRAN) was formed in 1969 as an effort at economic integration by six Latin American countries (Bolivia, Chile, Columbia, Ecuador, Peru, and Venezuela). It was an outgrowth of its predecessor, the Latin American Free Trade Association (LAFTA), which had been formed in 1960 with eleven member countries. The Andean Group (GRAN) from…

  4. Climate change variability and Andean agriculture: The context


    Valdivia, Corinne


    A presentation by Valdivia from lessons learned in the SANREM CRSP and past research to frame the two day workshop. First session of the workshop: I. Climate Change Variability and Andean Agriculture: The Context Lessons learned from SANREM CRSP on adapting to climate change. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)

  5. Andean shrublands of Moquegua, South Peru: Prepuna plant communities

    NARCIS (Netherlands)

    Montesinos, D.B.; Cleef, A.M.; Sykora, K.V.


    A syntaxonomic overview of shrubland vegetation in the southern Andean regions of Peru is presented. For each plant community, information is given on physiognomy, floristic diversity, ecology and geographical distribution. The shrub vegetation on the slopes of the upper Tambo river valley includes

  6. The astronomy of Andean myth: The history of a cosmology (United States)

    Sullivan, William F.

    It is shown that Andean myth, on one level, represents a technical language recording astronomical observations of precession and, at the same time, an historical record of simultaneous social and celestial transformations. Topographic and architectural terms of Andean myth are interpreted as a metaphor for the organization of and locations on the celestial sphere. Via ethoastronomical date, mythical animals are identified as stars and placed on the celestial sphere according to their topographical location. Tested in the planetarium, these arrays generate cluster of dates - 200 B.C. and 650 A.D. Analysis of the names of Wiraqocha and Manco Capac indicates they represent Saturn and Jupiter and that their mythical meeting represents their conjunction in 650 A.D. The astronomy of Andean myth is then used as an historical tool to examine how the Andean priest-astronomers recorded the simultaneous creation of the avllu and of this distinctive astronomical system about 200 B.C. The idea that the agricultural avllu, with its double descent system stressing the importance of paternity, represents a transformation of society from an earlier matrilineal/horticultural era is examined in light of the sexual imagery employed in myth. Wiraqocha's androgyny and the division of the celestial sphere into male (ecliptic) and female (celestial equator = earth) are interpreted as cosmological validations of the new social structure.

  7. Diversity for cooking time in Andean dry bean (United States)

    A diversity panel of 250 dry bean lines from the Andean gene pool was evaluated for cooking time. Cooking time ranged from 17 to 90 min with an average of 36 min. A faster cooking time was also correlated with a number of other seed characteristics, most notably, higher levels of boron and potassium...

  8. Contribution of mantle components within juvenile lower-crust to collisional zone porphyry Cu systems in Tibet (United States)

    Hou, Zengqian; Zheng, Yuanchuan; Yang, Zhiming; Rui, Zongyao; Zhao, Zhidan; Jiang, Sihong; Qu, Xiaoming; Sun, Qinzhong


    Most porphyry Cu-Mo-Au deposits are found in magmatic arcs worldwide, and are associated with hydrous, high- fO2, calc-alkaline magmas, derived from a mantle wedge that was metasomatized by the fluids from a subducted oceanic slab. Recently, such deposits have been documented as occurring widely in collisional settings, where they are associated with potassic magmas generated during the collisional process, but the genesis of the fertile magmas and the mechanism of metallic enrichment remain controversial. Here we present new geochemical and Sr-Nd-Hf isotopic data from the post-collisional fertile and barren porphyries of the Miocene Gangdese porphyry belt in the Tibetan orogen, an orogen formed by the collision of India and Asia in the early Cenozoic. Both types of porphyry are characterized by high K2O contents, and have geochemical affinities with adakite, but the fertile magmas were most likely derived from the melting of a thickened juvenile mafic lower-crust, formed by the underplating of earlier asthenospheric melts at the base of crust, whereas the derivation of the barren magmas involved variable amounts of old lower-crust in Tibet. The melting of sulfide-bearing phases in the juvenile mantle components of the Tibetan lower-crust probably provided Cu, Au, and S to the fertile magmas. The breakdown of amphibole during melting at the source released the fluids necessary for the formation of the porphyry Cu deposits in Tibet. The thickened crust (up to 70-80 km), due to collision, is thought to be responsible for a decrease in the fO2 of the fertile magmas during their ascent to the upper crust, thus preventing the generation of more porphyry Cu-Au and epithermal Au deposits in this collisional zone.

  9. 大陆碰撞成矿作用:Ⅰ.冈底斯新生代斑岩成矿系统%Metallogenesis of continental collision setting: Part Ⅰ. Gangdese Cenozoic porphyry Cu-Mo systems in Tibet

    Institute of Scientific and Technical Information of China (English)

    侯增谦; 郑远川; 杨志明; 杨竹森


    Giant porphyry deposits are generally found in magmatic arcs and continent collisions] belt. Metallogenic theory, of the porphyry copper deposit under the magmalic arc condition has been well established, while that in the continental collision setting has not been formed. A large number of porphyry deposits were formed in Tibetan plateau as the result of collision between the India and the Lhasa plates. Three different porphyry deposit belts have been found in the Lhasa terrene. The Sharang-type porphyry Mo deposit and the Yaguila-type por-phyry-skarn Pb-Zn-Cu deposit distributed along the north margin of the Gangdese belt (the central Lhasa tcr-rane) were formed in the main-collisional period (65~41 Ma). The Mingze-type porphyry Mo deposit and the Nuri-type porphyry-skarn Cu-Wu-Mo deposit in the central part of the Gangdese belt (southern Lhasa terrane) were formed in late-collisional period (40~26 Ma), whereas the Qulong-type porphyry Cu-Mo deposits developed in the Zedong arc belt was formed in the post-collisional period (25~ 13 Ma). The fertile Gangdese porphyry systems are generally composed of multistage hypergenic intrusive complexes. These complexes are generally characterized by high-K, and most of them are K calc-aikali and shoshonitic in composition- The Cu-bearing porphyries are dominated by monzogranile, and generally show geochemical affinity to adakites, while the Mo-bearing porphyry deposits are mainly associated with granite, which was most likely derived from continental crust. Whole-rock geochemistry and Sr-Nd-Hf isotopic data indicate that the Cu-bearing magmas were most probably derived from the thickened juvenile mafic lower-crust beneath south Tibet. The melting of sul-fide-bearing phases in the juvenile mantle components of the Tibetan lower-crust probably provided parts of Cu, Au and S for the fertile magmas. However, the Mo-bearing magmas were likely derived from partial melting of the ancient Tibetan lower crust, while Mo was also

  10. Barren Miocene granitoids in the Central Andean metallogenic belt, Chile: Geochemistry and Nd-Hf and U-Pb isotope systematics

    International Nuclear Information System (INIS)

    Four Middle-to-Late Miocene barren plutonic complexes that occur between the giant porphyry copper deposits of the central Chilean Andes were selected for U-Pb LA-ICPMS geochronology and Hf-isotope systematics on single zircon grains. Major and trace elements and Sr-Nd-Hf isotope whole rock geochemical studies were undertaken to compare with slightly younger or coeval barren and fertile intrusive rocks between 32o and 34oS. The studied granitoids yield resolvable crystallization ages of 11.3±0.1 Ma (Cerro Meson Alto massif), 10.3±0.2 Ma (La Gloria pluton), 14.9±0.2 Ma/14.9±0.1 Ma (Yerba Loca stock) and 11.2±0.1 Ma/14.7±0.1 Ma (San Francisco Batholith). Major and trace elements discard an adakitic signature as suggested for coeval porphyric intrusions at 32oS, slightly younger mineralized porphyries at Rio Blanco-Los Bronces deposit and other Cenozoic adakites. Volcanic host rocks are less fractionated than the intrusive rock units. The same observation can be made for the unmineralized northern plutons compared to the southern ones. Initial Sr-Nd isotope data show insignificant variation (0.703761-0.704118 and 0.512758- 0.512882), plotting in the mantle array. Trace element enrichment can be explained by addition of subducted-slab fluids and/or terrigenous sediments to the mantle wedge prior to and/or slight crustal input during magma ascent. Zircon grains separated from these barren intrusives share a similar initial εHf-data variation for the younger age group (10-12 Ma; 7.04-9.54) and show a more scattered range for the older one (14-15 Ma; 8.50-15.34); both sets plot between the DM and CHUR evolution lines. There is evidence that magma evolution was slightly distinct through time from older to younger barren magmatism, compared to a few fertile porphyritic rocks from Rio Blanco-Los Bronces porphyry copper deposit. It is suggested that chronological inconsistencies within these complexes might be related to differential shortening across the NE

  11. Active Andean volcanism: its geologic and tectonic setting




    The Andean volcanic arc includes over 200 potentially active Quaternary volcanoes, and at least 12 giant caldera/ignimbrite systems, occurring in four separate segments referred to as the Northern, Central, Southern and Austral Volcanic Zones. Volcanism results from subduction of the Nazca and Antarctic oceanic plates below South America. Active volcanoes occur where the angle of subduction is relatively steep (25°), and active arc segments are separated by regions below which subduction angl...

  12. Trade and infrastructure: evidences from the Andean Community


    Rojas, Gina E. Acosta; CALFAT, Germán; Flôres Junior, Renato Galvão


    This paper presents evidence on the key role of infrastructure in the Andean Community trade patterns. Three distinct but related gravity models of bilateral trade are used. The first model aims at identifying the importance of the Preferential Trade Agreement and adjacency on intra-regional trade, while also checking the traditional roles of economic size and distance. The second and third models also assess the evolution of the Trade Agreement and the importance of sharing a common border, ...

  13. Andean grasslands are as productive as tropical cloud forests


    Oliveras Menor, I.; Girardin, C; Doughty, C. E.; Cahuana, N.; Arenas, C. E.; Oliver, V.; Huaraca Huasco, W.; Malhi, Y.


    We aim to assess net primary productivity (NPP) and carbon cycling in Andean tropical alpine grasslands (puna) and compare it with NPP of tropical montane cloud forests. We ask the following questions: (1) how do NPP and soil respiration of grasslands vary over the seasonal cycle? (2) how do burning and grazing affect puna productivity? (3) if the montane forest expands into the puna, what will be the resulting change in productivity? The study sites are located at the South-eastern Peruvian ...

  14. Climate Change Forces New Ecological States in Tropical Andean Lakes


    Michelutti, Neal; Wolfe, Alexander P.; Cooke, Colin A.; Hobbs, William O.; Vuille, Mathias; John P. Smol


    Air temperatures in the tropical Andes have risen at an accelerated rate relative to the global average over recent decades. However, the effects of climate change on Andean lakes, which are vital to sustaining regional biodiversity and serve as an important water resource to local populations, remain largely unknown. Here, we show that recent climate changes have forced alpine lakes of the equatorial Andes towards new ecological and physical states, in close synchrony to the rapid shrinkage ...

  15. State dilemmas in applying the Previous Consultation Law in the Andean Region

    Directory of Open Access Journals (Sweden)

    Rafael Barrio de Mendoza


    Full Text Available The Peruvian government enacted a new law granting consultation rights to indigenous peoples as a mechanism to enhance social inclusion in the country. The law generated debates about the criteria to identify indigenous population in the Andean region. Why does this law have problems granting consultation rights to Andean people? This paper aims to answer the question by reviewing historically the different Andean identities and analyzing the current international debate on indigenity. Our main argument is that the government intrying to apply the law is structuring a restrictive model that is hardlyable to grasp the complexity and dynamism of Andean identities.

  16. Predicting Polylepis distribution: vulnerable and increasingly important Andean woodlands

    Directory of Open Access Journals (Sweden)

    Brian R. Zutta


    Full Text Available Polylepis woodlands are a vital resource for preserving biodiversity and hydrological functions, which will be altered by climate change and challenge the sustainability of local human communities. However, these highaltitude Andean ecosystems are becoming increasingly vulnerable due to anthropogenic pressure including fragmentation, deforestation and the increase in livestock. Predicting the distribution of native woodlands has become increasingly important to counteract the negative effects of climate change through reforestation and conservation. The objective of this study was to develop and analyze the distribution models of two species that form extensive woodlands along the Andes, namely Polylepis sericea and P. weberbaueri. This study utilized the program Maxent, climate and remotely sensed environmental layers at 1 km resolution. The predicted distribution model for P. sericea indicated that the species could be located in a variety of habitats along the Andean Cordillera, while P. weberbaueri was restricted to the high elevations of southern Peru and Bolivia. For both species, elevation and temperature metrics were the most significant factors for predicted distribution. Further model refinement of Polylepis and other Andean species using increasingly available satellite data demonstrate the potential to help define areas of diversity and improve conservation strategies for the Andes.

  17. Geochronology and geochemistry of the Badaguan porphyry Cu-Mo deposit in Derbugan metallogenic belt of the NE China, and their geological significances (United States)

    Gao, Bingyu; Zhang, Lianchang; Jin, Xindi; Li, Wenjun; Chen, Zhiguang; Zhu, Mingtian


    The Badaguan porphyry Cu-Mo deposit belongs to the Derbugan metallogenic belt, which is located in the Ergun block, NE China. In the mining area, the Cu-Mo mineralization mainly occurs in quartz diorite porphyry and is hosted within silicified-sericitized and sericite alteration zone. Geochemical results of the host porphyry is characterized by high SiO2, high Al2O3, low MgO, weak positive Eu anomalies and clearly HREE depletion, high Sr, low Y and low Yb, similar to those of adakite. The Sr-Nd isotopic composition of the host porphyry displays an initial (87Sr/86Sr)i ratio of 0.7036-0.7055 and positive Nd( t) values of +0.1 to +0.6, which are similar to the OIB, reflecting the source of the host porphyry may derive from subducted ocean slab, and the new lower crust also had some contribution to the magma sources. The SIMS zircon U-Pb age from the host porphyry is 229 ± 2 Ma. The Re-Os isochron age for the molybdenite in the deposit is 225 ± 2 Ma closed to zircon U-Pb age of the host porphyry, indicating that Cu-Mo mineralization event occurred in Triassic. Combining the geology-geochemistry of the host porphyry and the regional tectonic evolution, we infer that the subduction processes of Mongol-Okhotsk oceanic slab under the Ergun block led to the formation of the Badaguan porphyry Cu-Mo deposit during the Triassic.

  18. Ordovician Intrusive-related Gold-Copper Mineralization in West-Central New South Wales, Australia

    Institute of Scientific and Technical Information of China (English)


    Three major types of Ordovician intrusive-related gold-copper deposits are recognized in central-west New South Wales,, Australia: porphyry, skam and high sulphidation epithermal deposits.These deposits are mainly distributed within two Ordovician volcano-intrusive belts of the Lachlan Fold Be1t: the Orange-Wellington Belt and the Parkes-Narromine Belt. Available isotopic age data suggest that mineralization of the three types of deposits is essentially coeval with the Ordovician intrusive rocks (480-430 Ma). Porphyry gold-copper deposits can be further divided into two groups. The first group is associated with monzoniteshowing shoshonitic features represented by Cadia and Goonumbla. The second group is associated with diorite and dacite, including the Copper Hill and Cargo gold-copper deposits. Gold skarn is associated with Late Ordovician (430-439 Ma) monzonitic intrusive complexes in the Junction Reefs area (Sheahan-Grants, Frenchmans, and Cornishmens), Endeavour 6, 7 and 44, Big and Little Cadia. The epithermal gold deposits with high sulphidation including Gidginbung (Temora) and Peak Hill mainly occur within Ordovician andesite and volcaniclastic rocks, and are associated with advanced argillic alteration. Available isotopic age data indicate that both alteration and mineralization of the porphyry, skam and epithermal gold-copper deposits are broadly coeval with the Late Ordovician hoshonitic mangmatism, which is thought to result from the melting of sub-continental lithosphere caused by Palaeozoic subduction events. The Ordovician intrusive-related gold-copper deposits are restricted to two longitudinal parallel volcano-intrusive belts, rarely extending outside them. Diagonal intra-belt trends of mineralization are common, particularly at the intersections of longitudinal and transverse (oblique) fault/fracture zones basedon the authors'review of available geological data. The locations of these gold-copper deposits are obviously influenced by transverse

  19. The magnetic anomaly on the Permian Alcaparrosa porphyry (Argentina). A case of pyrrhotite-remanence-dominated anomaly

    International Nuclear Information System (INIS)

    Complete text of publication follows. The Permian Alcaparrosa porphyry is a small (600 meters in diameter) rhyodacite stock outcropping in the Precordillera geological province, San Juan, Argentina. It developed a 3-kilometers-long, NW-SE-trending alteration halo ('Faja Amarilla', yellow belt) in the host rocks, which is a sequence of Ordovician marine mudstones with interbedded basaltic flows included in the Alcaparrosa Fm. The porphyry-related alteration overprinted a previous low-grade-metamorphic alteration assemblage characteristic of an oceanic floor environment. The aeromagnetic survey revealed a bipolar anomaly in the total magnetic intensity (TMI) coinciding with the outcropping alteration halo. The surrounding Alcaparrosa Fm is non-magnetic and therefore the anomaly is clearly defined in a quiet magnetic zone, showing a minimum to the north, centred on the porphyry, and a semi lunar maximum to the south. The shape of the anomaly is opposed to the expected shape of induced magnetic anomalies in mid latitudes of the southern hemisphere. Available data show that both the Permian porphyry and its alteration halo carry a magnetic remanence with positive inclination (i.e. reversed polarity), probably acquired during the Permo-Carboniferous Reversed Superchron. The Koenigsberger ratio (Q) for the porphyry resulted lower than 1, which means that remanence is not intense enough to control the shape of the magnetic anomaly. On the other side, outcropping rocks of the alteration halo show intense supergene alteration and are non-magnetic. However, relics of phyllic alteration where found relatively preserved of supergene alteration, and they showed monoclinic pyrrhotite as magnetic carrier, and a Q ratio higher than 1. We used those data to model a body carrying a reversed magnetic remanence. The shape and extension of the modelled body seems a good approximation to the possible shape of the sulphide-bearing alteration halo around the rhyodacite porphyry. The

  20. The Laramide Mesa formation and the Ojo de Agua caldera, southeast of the Cananea copper mining district, Sonora, Mexico (United States)

    Cox, Dennis P.; Miller, Robert J.; Woodbourne, Keith L.


    The Mesa Formation extends from Cananea, Mexico, southeast to the Sonora River and is the main host rock of Laramide porphyry copper deposits in the Cananea District and at the Alacran porphyry prospect to the east. The Mesa consists of two members-a lower andesite and an upper dacite. The lowest part of the dacite member is a crystal tuff about 100 m thick. This tuff is the outfall of a caldera centered near the village of Ojo de Agua, dated by 40Ar/39Ar at 65.8 Ma ?0.4. The Ojo de Agua Caldera is about 9 km in diameter and is filled by a light gray biotite dacite tuff with abundant flattened pumice fragments. The volume of the caldera is estimated to be 24 km3.

  1. Geochemical and Sr-Pb-Nd isotopic characteristics of the Shakhtama porphyry Mo-Cu system (Eastern Transbaikalia, Russia) (United States)

    Berzina, A. P.; Berzina, A. N.; Gimon, V. O.


    The Shakhtama Mo-Cu porphyry deposit is located within the eastern segment of the Central Asian Orogenic Belt, bordering the southern margin of the Mongol-Okhotsk suture zone. The deposit includes rocks of two magmatic complexes: the precursor plutonic (J2) and ore-bearing porphyry (J3) complexes. The plutonic complex was emplaced at the final stages of the collisional regime in the region; the formation of the porphyry complex may have overlapped with a transition to extension. The Shakhtama rocks are predominantly metaluminous, I-type high K calc-alkaline to shoshonitic in composition, with relatively high Mg#, Ni, Cr and V. They are characterized by crustal-like ISr (0.70741-0.70782), relatively radiogenic Pb isotopic compositions, ɛNd(T) values close to CHUR (-2.7 to +2.1) and Nd model ages from 0.8 to 1.2 Ga. Both complexes are composed of rocks with K-adakitic features and rocks without adakite trace element signatures. The regional geological setting together with geochemical and isotopic data indicate that both juvenile and old continental crust contributed to their origin. High-Mg# K-adakitic Shakhtama magmas were most likely generated by partial melting of thickened lower crust during delamination and interaction with mantle material, while magmas lacking adakite-like signatures were probably generated at shallower levels of lower crust. The derivation of melts, related to the formation of plutonic and porphyry complexes involved variable amounts of old Precambrian lower crust and juvenile Phanerozoic crust. Isotopic data imply stronger contribution of juvenile mantle-derived material to the fertile magmas of the porphyry complex. Juvenile crust is proposed as an important source of fluids and metals for the Shakhtama ore-magmatic system.

  2. In situ recovery of copper from sulfide ore bodies following nuclear fracturing

    International Nuclear Information System (INIS)

    Leaching now yields about 12 percent of the Nation's annual new copper production. About 200,000 tons of copper a year is being won by heap and vat leaching of ore, dump leaching of waste, and in-place leaching of caved underground workings. Although in-place leaching was practiced as long ago as the 15th century, it is little used and contributes only a few percent of the total leach copper production. Current technology in this area is exemplified by practice at the Miami, Ariz., mine of the Miami Copper Co. Despite its limited use, the concept of extracting copper by in-place leaching without physically mining and transporting the ore continues to present intriguing cost saving possibilities. Project SLOOP has been proposed as an experiment to test the feasibility of nuclear fracturing and acid leaching the oxidized portion of a deep ore body near Safford, Ariz. However, the bulk of the copper in deep ore deposits occurs as sulfide minerals that are not easily soluble in acid solutions. This paper explores the concept of in-place leaching of nuclear fractured, deeply buried copper sulfide deposits. On the assumption that fracturing of rock and solution injection and collection would be feasible, an assessment is made of solution systems that might be employed for the different copper sulfide minerals in porphyry ore bodies. These include the conventional ferric sulfate-sulfuric acid systems and combinations of sulfide mineral oxidants and different acids. (author)

  3. Chemical mining of primary copper ores by use of nuclear technology

    International Nuclear Information System (INIS)

    Chemical mining of primary copper ores, with nuclear explosives to break the ore and in-situ hydrostatic pressure to accelerate dissolution of primary ore minerals, may be feasible. A contained nuclear explosion well below the water table would be used to provide a mass of broken ore in a flooded 'chimney'. The hydrostatic pressure in the chimney should increase the solubility of oxygen in a water-sulfuric acid system enough to allow primary copper minerals such as chalcopyrite and bornite to be dissolved in an acceptably short time. Circulation and collection would be accomplished through drill holes. This method should be especially applicable to the deep portions of porphyry copper deposits that are not economical to mine by present techniques. (author)

  4. Copper Test (United States)

    ... mean? Copper test results must be evaluated in context and are usually compared to ceruloplasmin levels . Abnormal ... Health Professionals ©2001 - by American Association for Clinical Chemistry • Contact Us | Terms of Use | Privacy We comply ...

  5. An orientation soil survey at the Pebble Cu-Au-Mo porphyry deposit, Alaska (United States)

    Smith, Steven M.; Eppinger, Robert G.; Fey, David L.; Kelley, Karen D., (Edited By); Giles, S.A.


    Soil samples were collected in 2007 and 2008 along three traverses across the giant Pebble Cu-Au-Mo porphyry deposit. Within each soil pit, four subsamples were collected following recommended protocols for each of ten commonly-used and proprietary leach/digestion techniques. The significance of geochemical patterns generated by these techniques was classified by visual inspection of plots showing individual element concentration by each analytical method along the 2007 traverse. A simple matrix by element versus method, populated with a value based on the significance classification, provides a method for ranking the utility of methods and elements at this deposit. The interpretation of a complex multi-element dataset derived from multiple analytical techniques is challenging. An example of vanadium results from a single leach technique is used to illustrate the several possible interpretations of the data.

  6. Porphyry copper assessment of northeast Asia: Far East Russia and northeasternmost China: Chapter W in Global mineral resource assessment (United States)

    Mihalasky, Mark J.; Ludington, Stephen; Alexeiev, Dmitriy V.; Frost, Thomas P.; Light, Thomas D.; Briggs, Deborah A.; Hammarstrom, Jane M.; Wallis, John C.; Bookstrom, Arthur A.; Panteleyev, Andre


    The U.S. Geological Survey assesses resources (mineral, energy, water, environmental, and biologic) at regional, national, and global scales to provide science in support of land management and decision making. Mineral resource assessments provide a synthesis of available information about where mineral deposits are known and suspected to be in the Earth’s crust, which commodities may be present, and estimates of amounts of resources in undiscovered deposits.

  7. Porphyry copper assessment of British Columbia and Yukon Territory, Canada: Chapter C in Global mineral resource assessment (United States)

    Mihalasky, Mark J.; Bookstrom, Arthur A.; Frost, Thomas P.; Ludington, Steve


    The U.S. Geological Survey does regional, national, and global assessments of resources (mineral, energy, water, biologic) to provide science in support of land management and decision making. Mineral resource assessments provide a synthesis of available information about where mineral deposits are known and suspected to be in the Earth’s crust, which commodities may be present, and estimates of amounts of resources that may be present in undiscovered deposits.

  8. Pharmaceutical policy of the Andean sub-region. (United States)


    Senior policy makers and health officials from the Andean countries--Bolivia, Colombia, Ecuador, Peru, and Venezuela--have developed a common pharmaceutical policy. The government's role is to assure availability and equal access to effective, quality, and affordable drugs and to safeguard their proper use. The government cannot delegate this role. The availability and accessibility of drugs gauge quality of health services and are social indicators of justice and equity. The public sector must use drugs from the essential drug list. These drugs are also valuable for the private sector. Drugs must not be treated like other merchandise, because the drug market is susceptible to misuse since the consumer cannot select the drug. Commercial advertising strongly influences prescribing of drugs and their use. The 2 major policy points are that promotion of essential drugs is the best approach from a health viewpoint and promotion of generic drug use is the best commercial alternative. The policy calls for the individual countries to pass a comprehensive drug law that reflects commitment to equity and appropriate use and incorporates standardization mechanisms. Criteria for selecting which drugs are allowed on the market include safety, proven efficacy, risk/benefit ratio, and treating the most common health problems at the lowest possible price. The Andean group is working towards harmonization of national essential drugs lists. To assure quality, health authorities must develop the capacity to enforce regulations when situations arise that threaten individual and community health. Supply, marketing, and logistics activities need to be improved and coordinated between the commercial and public sectors. Drug prices are being distanced from administrative control mechanisms and are going to be determined by a dynamic and well-supplied market. Drug information centers and prescription training are needed to achieve rational use of drugs. A joint pharmaceutical market for

  9. Influence of Andean Plateau Rise on South American Climate Dynamics (United States)

    Insel, N.; Poulsen, C. J.; Ehlers, T. A.


    Large mountain ranges exhibit a first-order control on climate. In South America, the modern Andes act as a barrier to atmospheric flow and control regional wind and precipitation patterns. However, it is unclear how climate may have changed over time as Andean topography developed. We present results from a regional general circulation model (RegCM3) to evaluate dynamical and physical atmospheric changes associated with variations in Andean plateau height during the Cenozoic. A series of five experiments were conducted with plateau topography systematically varying between 0 and 100% of the modern. Experiments were performed over a continental-scale domain with 60km horizontal resolution using the MIT-Emanuel convection scheme. Land surface characteristics, sea-surface temperatures and atmospheric boundary conditions were specified from modern NCEP reanalysis data. Model results show that large-scale upper-level (200 mbar) circulation characteristics are only weakly affected by the removal of the Andes with a slight weakening and eastward shift of the high pressure system over Bolivia. However, low-level (800 mbar) wind patterns change significantly and have a direct effect on precipitation in South America. The following features can be observed as the Andean topography decreases: (1) The dominant wind direction in the central Andes reverses with prevailing winds sourced from the Pacific Ocean. The Westerlies are characterized by low moisture content due to the presence of the cold Humboldt current along the west coast of South America. (2) A reduction in the surface pressure gradient between the Andes and the Amazon Basin reduces convergence over the plateau and suppresses the South American low level jet, reducing the southward moisture flux along the eastern flanks of the Andes that is the primary source for precipitation in the Chaco region. These changes lead to declines in precipitation over the Andes and decreased latent heat release. This results in a

  10. Geological characteristics and genetic type of Riabuxi copper-polymetallic deposit in Coqen county,Tibet%西藏自治区措勤县日阿布洗铜多金属矿床地质特征及成因类型

    Institute of Scientific and Technical Information of China (English)

    黄东荣; 杜昌法


    西藏自治区日阿布洗铜多金属矿位于冈底斯山脉北缘斑岩型铜矿成矿带,含矿斑岩体为晚喜山期花岗斑岩,具全岩矿化特征,斑岩体与构造蚀变岩带形成矿床。研究表明,地表和浅部出露含矿斑岩体只是岩枝,矿区剥蚀程度低,主斑岩体尚未出露,深部找矿潜力巨大。经深部钻孔工程及地表槽探验证,矿体品位和厚度沿走向和倾向变化系数较小,伴生组份较多,并对其资源量进行了初步估算。喜山晚期第一阶段花岗斑岩侵入体是主要成矿物质来源,矿床成因类型应为斑岩型铜矿床。%The Riabuxi copper-polymetallic deposit in Coqen county,Tibet,is located in the northern margin of the Gangdise porphyry-type copper metallogenetic belt.The host rocks is the late Himalayan granitic-porphyries which are wholly mineralized.The copper-polymetallic deposit is occured at the contact zones of the porphyries and structural altered rocks.Our study reveals that the ore-bearing porphyries exposed at the surface are only apophyses and dikes,an intense erosion did not take place,indicating a benefit potential for discovering deep-seated porphyry deposits.Verified by deep drilling and surface trenching,it is found that the variation coefficients of grades and thicknesses along strikes and dips of ore bodies are small and associated component contents are relatively great.A preliminary estimate shows that metallogenic materials were originated from the late Himalayan first stage granite-porphyry intrusions,and the deposit belonging to a porphyry-type copper deposit.

  11. Kinetics of Copper Removal from Sulfidized Molybdenite Concentrates by Pressure Leaching (United States)

    Padilla, Rafael; Opazo, Cristian; Ruiz, Maria C.


    Molybdenite concentrates produced from porphyry copper deposits contain copper as an impurity in variable quantities. To produce a high-grade molybdenite concentrate, a chemical purification method is normally practiced. In this paper, a new alternative for the copper elimination from molybdenite concentrates containing chalcopyrite by sulfidation of the molybdenite concentrate and subsequent pressure leaching in sulfuric acid-oxygen media is discussed. The results indicated that copper contained in sulfidized molybdenite concentrates can be dissolved effectively by pressure leaching at low temperature ranging from 373 K to 423 K (100 °C to 150 °C) and low oxygen pressure (303.98 to 1013.25 kPa) with negligible dissolution of molybdenum. The final molybdenite contained less than 0.2 pct Cu which is appropriate for marketing. Temperature and oxygen partial pressure have both significant influence on the copper dissolution. The kinetics of the copper dissolution was analyzed using the shrinking core model with surface chemical control. The calculated activation energy was 51 kJ/mol in the range of 373 K to 423 K (100 °C to 150 °C). The copper dissolution rate is of zero order with respect to hydrogen ion concentration, and first order with respect to oxygen partial pressure.

  12. SENP1, but not fetal hemoglobin, differentiates Andean highlanders with chronic mountain sickness from healthy individuals among Andean highlanders. (United States)

    Hsieh, Matthew M; Callacondo, David; Rojas-Camayo, Jose; Quesada-Olarte, Jose; Wang, Xunde; Uchida, Naoya; Maric, Irina; Remaley, Alan T; Leon-Velarde, Fabiola; Villafuerte, Francisco C; Tisdale, John F


    Chronic mountain sickness (CMS) results from chronic hypoxia. It is unclear why certain highlanders develop CMS. We hypothesized that modest increases in fetal hemoglobin (HbF) are associated with lower CMS severity. In this cross-sectional study, we found that HbF levels were normal (median = 0.4%) in all 153 adult Andean natives in Cerro de Pasco, Peru. Compared with healthy adults, the borderline elevated hemoglobin group frequently had symptoms (headaches, tinnitus, cyanosis, dilatation of veins) of CMS. Although the mean hemoglobin level differed between the healthy (17.1 g/dL) and CMS (22.3 g/dL) groups, mean plasma erythropoietin (EPO) levels were similar (healthy, 17.7 mIU/mL; CMS, 12.02 mIU/mL). Sanger sequencing determined that single-nucleotide polymorphisms in endothelial PAS domain 1 (EPAS1) and egl nine homolog 1 (EGLN1), associated with lower hemoglobin in Tibetans, were not identified in Andeans. Sanger sequencing of sentrin-specific protease 1 (SENP1) and acidic nuclear phosphoprotein 32 family, member D (ANP32D), in healthy and CMS individuals revealed that non-G/G genotypes were associated with higher CMS scores. No JAK2 V617F mutation was detected in CMS individuals. Thus, HbF and other classic erythropoietic parameters did not differ between healthy and CMS individuals. However, the non-G/G genotypes of SENP1 appeared to differentiate individuals with CMS from healthy Andean highlanders. PMID:26952840

  13. Zircon U-Pb geochronology, geochemistry, and Sr-Nd-Hf isotopes of granitoids in the Yulekenhalasu copper ore district, northern Junggar, China: Petrogenesis and tectonic implications (United States)

    Yang, Fuquan; Chai, Fengmei; Zhang, Zhixin; Geng, Xinxia; Li, Qiang


    The Yulekenhalasu porphyry copper deposit is located in the Kalaxiange'er metallogenic belt in northern Junggar, China. We present the results from zircon U-Pb geochronology, and geochemical and Sr-Nd-Hf isotope analyses of the granitoids associated with the ore deposits with a view to constrain their petrogenesis and tectonic setting. The granitoids consist of quartz diorite, diorite porphyry, porphyritic monzonite, and quartz porphyry, emplaced at 382, 379, 375-374, and 348 Ma, respectively, which span Late Devonian to early Carboniferous ages. The ore-bearing intrusion is mainly diorite porphyry, with subordinate porphyritic monzonite. The Late Devonian intrusions are characterized by SiO2 contents of 54.5-64.79 wt.%, Na2O contents of 3.82-8.24 wt.%, enrichment in Na, light rare-earth elements (LREEs), and large ion lithophile elements. They also display relative depletion in Y, Ba, P, Nb, Ta, and Ti, and weak negative Eu anomalies (δEu = 0.6-0.87). The early Carboniferous quartz porphyry is characterized by high SiO2 content (72.26-73.35 wt.%), enrichment in LREEs, K, and Sr, and relative depletion in Y (10.82-12.52 ppm) and Yb (1.06-1.15 ppm). The Late Devonian and early Carboniferous granitoids are characterized by positive ɛNd(t) values (5.2-10.1, one sample at - 1.9), positive ɛHf(t) values (7.46-18.45), low (87Sr/86Sr)i values (0.70363-0.70476), and young crustal residence ages. These data indicate that the sources of the granitoids were mainly mantle-derived juvenile rocks. Geochemical and Nd-Sr-Hf isotopic data demonstrate that the Late Devonian granitoids formed in an oceanic island arc, and they were formed from different sources, among which the mineralized diorite porphyry might have originated from a mixed slab-derived and mantle wedge melt source. The early Carboniferous quartz porphyry was likely emplaced in a mature island arc environment, and was probably derived from juvenile crust.

  14. Climate change forces new ecological states in tropical Andean lakes.

    Directory of Open Access Journals (Sweden)

    Neal Michelutti

    Full Text Available Air temperatures in the tropical Andes have risen at an accelerated rate relative to the global average over recent decades. However, the effects of climate change on Andean lakes, which are vital to sustaining regional biodiversity and serve as an important water resource to local populations, remain largely unknown. Here, we show that recent climate changes have forced alpine lakes of the equatorial Andes towards new ecological and physical states, in close synchrony to the rapid shrinkage of glaciers regionally. Using dated sediment cores from three lakes in the southern Sierra of Ecuador, we record abrupt increases in the planktonic thalassiosiroid diatom Discostella stelligera from trace abundances to dominance within the phytoplankton. This unprecedented shift occurs against the backdrop of rising temperatures, changing atmospheric pressure fields, and declining wind speeds. Ecological restructuring in these lakes is linked to warming and/or enhanced water column stratification. In contrast to seasonally ice-covered Arctic and temperate alpine counterparts, aquatic production has not increased universally with warming, and has even declined in some lakes, possibly because enhanced thermal stability impedes the re-circulation of hypolimnetic nutrients to surface waters. Our results demonstrate that these lakes have already passed important ecological thresholds, with potentially far-reaching consequences for Andean water resources.

  15. Characterization and zircon SHRIMP U-Pb geochronology of the subvolcanic rocks from Yarumalito Porphyry System, Marmato District, Colombia

    International Nuclear Information System (INIS)

    The mining District of Marmato, located in the Central Cordillera, is considered one of the oldest gold districts in Colombia and its exploration dates back to the Inca’s times, being exploited regularly for more than a thousand years. Inserted in this context lies the Yarumalito porphyry system (YPS), characterized to concentrate ore in structure related veins and stockworks. The YPS is related to the Miocene magmatism of the Combia Formation. In this paper, the subvolcanic rocks directly associated with the mineralized zones were described in order to obtain U-Pb ages in zircon to the intrusions. Selected samples from two fertile intrusions, one andesitic (more abundant in the area) and other dioritic (more restricted), were carefully described and dated by SHRIMP. The results points to a very restricted interval for the ages, with weighted average 206Pb/238U varying from 7,00 ± 0,15 Ma for the andesitic porphyry and 6.95 ± 0.16 Ma for the dioritic porphyry. These results constrain the Yarumalito system to the final stages of the Combia magmatism and suggest a brief period for the crystallization of the mineralized subvolcanic rocks in the area and in the Marmato District. (author)

  16. The evolution of witchcraft and the meaning of healing in colonial Andean society. (United States)

    Silverblatt, I


    This paper explores the ways in which traditional beliefs of Andean peoples regarding health and sickness were transformed by the process of Spanish colonization. It also examines how the colonial context devolved new meanings and powers on native curers. The analysis of these transformations in Andean systems of meanings and role structures relating to healing depends on an examination of the European witchcraze of the 16th-17th centuries. The Spanish conquest of the Inca empire in the mid-1500's coincided with the European witch hunts; it is argued that the latter formed the cultural lens through which the Spanish evaluated native religion--the matrix through which Andean concepts of disease and health were expressed--as well as native curers. Andean religion was condemned as heresy and curers were condemned as witches. Traditional Andean cosmology was antithetical to 16th century European beliefs in the struggle between god and the devil, between loyal Christians and the Satan's followers. Consequently, European concepts of disease and health based on the power of witches, Satan's adherents, to cause harm and cure were alien to pre-Columbian Andean thought. Ironically European concepts of Satan and the supposed powers of witches began to graft themselves onto the world view of Andean peoples. The ensuing dialectic of ideas as well as the creation of new healers/witches forged during the imposition of colonial rule form the crux of this analysis. PMID:6362989

  17. Geochemistry and fluid characteristics of the Dalli porphyry Cu-Au deposit, Central Iran (United States)

    Zarasvandi, Alireza; Rezaei, Mohsen; Raith, Johann; Lentz, David; Azimzadeh, Amir-Mortaza; Pourkaseb, Hooshang


    The Miocene Dalli porphyry Cu-Au deposit in the central part of Urumieh-Dokhtar magmatic arc is the first reported Au-rich porphyry Cu deposit in the Zagros orogenic belt. The Cu-Au mineralization is mainly hosted in diorite and quartz diorite intrusions, presenting as numerous veinlets in the altered wall rocks, with potassic, phyllic, and propylitic alteration developed. Based on the mineral assemblages and crosscutting relations of veinlets, hydrothermal mineralization-alteration occurred in at least three stages, characterized by veinlets of (1) Qtz + Kfs + Mag ± Ccp, (2) Qtz + Py + Ccp ± Bn ± Cv ± Cc and, (3) Qtz + Chl + Bt. The ore-bearing intrusions exhibit typical geochemical characteristics of subduction zone magmas, including LREE fractionated pattern, strong enrichment in LILE (Cs, Rb, Ba, Pb, and U), and depletion of HFSE, with marked negative Ti and Nb anomalies. The adakite-like ore-hosting porphyry intrusions are characterized by a systematic gradual decreasing and increasing of Y and Eu/Eu∗ with increasing SiO2 content, respectively. Moreover, they exhibit a significant increasing trend of Sr/Y with decreasing of Y, which indicates progressive hornblende fractionation and suppression of plagioclase fractionation during the evolution toward high water content of parental magma. A relatively flat HREE pattern with low Dyn/Ybn and Nb/Ta values may represent that amphibole played a more important role than garnet in the generation of the adakitic melts in the thickened lower crust. Based on the phase assemblages confirmed by detailed laser Raman spectroscopy analyses and proportion of solid, liquid, and gaseous components, five types of fluid inclusions were recognized, which are categorized as; (1) liquid-rich two phase (liquidH2O + vaporH2O) (IIA), (2) vapor-rich two phase (vaporH2O/CO2 + liquidH2O) (IIB), (3) high saline simple fluids (IIIA; liquidH2O + vaporH2O + Hl), (4) high saline opaque mineral-bearing fluids (IIIB; liquidH2O + vaporH2O

  18. Analysis of the drought resilience of Andosols on southern Ecuadorian Andean páramos


    Iñiguez, V.; O. Morales; Cisneros, F; Bauwens, W; Wyseure, G.


    The neotropical Andean grasslands above 3500 m a.s.l. known as "páramo" offer remarkable ecological services for the Andean region. Most important is the water supply – of excellent quality – to many cities and villages established in the lowlands of the inter-Andean valleys and to the coast. However, the páramo ecosystem is under constant and increased threat by human activities and climate change. In this paper we study the resilience of its soils for drou...

  19. A new Andean species of Philodryas (Dipsadidae, Xenodontinae) from Ecuador. (United States)

    Zaher, Hussam; Arredondo, Juan C; Valencia, Jorge H; Arbeláez, Ernesto; Rodrigues, Miguel T; Altamirano-Benavides, Marco


    We describe a new species of Philodryas from the highlands of southern Ecuador. The new species is distinguished from all known species of Philodryas by a unique combination of coloration, scalation, and hemipenial characters. The new species resembles Philodryas simonsii in color pattern. However, they differ notoriously by their hemipenial morphology. The three other trans-Andean members of the genus (Philodryas simonsii, Philodryas chamissonis, and Philodryas tachymenoides), along with the new species, compose a probably monophyletic group that may be characterized by the presence of ungrooved postdiastemal teeth in the maxilla. Unlike most species of the genus Philodryas, the new species shows a restricted distribution, being apparently endemic to a small region of high-altitude (3150-4450m) grasslands in the southern Andes of Ecuador. PMID:24872238

  20. An Outbreak of Bartonella bacilliformis in an Endemic Andean Community (United States)

    Sanchez Clemente, Nuria; Ugarte-Gil, Cesar; Solorzano, Nelson; Maguiña, Ciro; Moore, David


    Background Bartonellosis affects small Andean communities in Peru, Colombia and Ecuador. Research in this area has been limited. Methods Retrospective review of 191 cases of bartonellosis managed in Caraz District Hospital, Peru, during the last outbreak (2003). Results The majority of cases (65%) were 14 years old and younger. There was a peak in acute cases after the rainy season; chronic cases presented more constantly throughout the year. The sensitivity of blood smear against blood culture in acute disease was 25%. The most commonly used treatment for chronic disease was rifampicin; chloramphenicol was used to treat most acute cases. Complications arose in 6.8% and there were no deaths. Conclusions Diagnostic and treatment algorithms for acute and chronic bartonellosis have been developed without a strong evidence base. Preparation of ready-to-go operational research protocols for future outbreaks would strengthen the evidence base for diagnostic and treatment strategies and enhance opportunities for control. PMID:26991495

  1. Music, movements and colors in Andean fiesta. Bolivian examples

    Directory of Open Access Journals (Sweden)

    Rosalía Martínez


    Full Text Available In the Andean fiesta music is as much intended to be seen as it is to be heard. The multisensorial aspect of musical performance is not just a matter of the juxtaposition of sounds and sights. The analysis of the articulations that indigenous peasants of sucre (Bolivia construct among sounds, movements and colors reveals an original organization of sensitive experience that is as much characterized by its sensory depth as it is by the ways it is linked to other domains of knowledge. The forms of culturally elaborated intersections that occur in the body of the musician lead to new perceptive configurations.

  2. Climate Change Impacts in a Colombian Andean Tropical Basin (United States)

    Ocampo, O. L.; Vélez, J. J.; Londoño, A.


    Climate change and climate variability have a large impact on water resources. Developing regions have less capacity to prepare for, respond to, and recover from climate-related hazards and effects, and then, populations may be disproportionately affected. In Colombia, the geographical location and the marked irregularity in the terrain, give as a result, a complex climate. These factors have contributed to the water supply of the territory. Unfortunately, the visualization of abundant and inexhaustible water resources created a great disregard for them. Besides, the water supply is not distributed uniformly across the country, and then there is water-deficit in some areas as Andean Region, where the largest population and the main development centers are located. In recent decades, water conflicts have emerged locally and regionally, which have generated a crisis in the allocation mechanisms and have improved the understanding of the water situation in Colombia. The Second National Communication to CCMNU alerts on possible future consequences of climate change and the need for regional studies for understanding climate change impacts on the fragile ecosystems of high mountains as paramos and fog forest, which are water production regulators. Colombian water resources are greatly affected by changes in rainfall patterns influenced by El Niño and La Niña. The recent disasters in the 2010-2011 rainy seasons have caught the attention of not only the authorities but from the scientific community to explore strategies to improve water management by tracking, anticipating and responding to climate variability and climate change. Whereas sound water management is built upon long-term, the country is undertaking a pilot exercise for the integrated management of water resources, five Basins are selected, among them, is the Chinchiná River Basin; this Andean tropical Basin is located on the western slopes at the central range in the Andes between 4°48 and 5°12 N

  3. A new minute Andean Pristimantis (Anura: Strabomantidae from Venezuela

    Directory of Open Access Journals (Sweden)

    César L. Barrio-Amorós


    Full Text Available A new species of Pristimantis is described from the Venezuelan Andes. The new species is the smallest in its genus known in Venezuela and belongs to the Pristimantis unistrigatus Group. It differs from the rest of Venezuelan Andean congeners in body size (mean male SVL < 21.3 mm, female SVL < 26.3 mm, expanded discs on fingers and toes, absence of dorsolateral folds, and a distinctivecall consisting in 2–5 cricket-like short notes. The new species inhabits the southwestern part of the Cordillera de Mérida in Venezuela and the Venezuelan side of the Cordillera Oriental deColombia, and could be present on the Colombian portion of the cordillera as well.

  4. Comparing and interpreting three-dimensional fabric results, Henry Mountains porphyry, Utah, U.S.A. (United States)

    Horsman, E.; Ketcham, R. A.


    We compare and interpret results of several rock fabric analysis techniques, as applied to samples of plagioclase-hornblende porphyry from a well-exposed small intrusion in the Henry Mountains of southern Utah, U.S.A. The fabric analysis techniques considered include field measurements of phenocryst shape-preferred orientation, anisotropy of magnetic susceptibility, anisotropy of anhysteric remanent magnetization, high- resolution X-ray computed tomography, and three-dimensional shape-preferred orientation calculated from two- dimensional image analysis. The exceptional exposure of the studied intrusion allows us to confidently infer magma flow kinematics and to estimate the minimum amount of shear strain accommodated by the magma during emplacement. Our study therefore provides an important contrast to most studies, in which flow kinematics and magmatic strain are inferred from rock fabric in incompletely exposed intrusions. We find that observed fabric orientations often closely mimic local intrusion geometry, making it difficult to infer general magmatic flow kinematics from fabric near contacts. At each analysis location, orientation results from each technique generally agree but fabric shape and magnitude parameters vary widely between techniques. Fabric shape may therefore not provide useful information about flow kinematics (e.g. constrictional vs. flattening flow). Similarly, fabric magnitudes plateau at moderate values and do not provide a useful strain gauge. Because each technique provides unique information, it is invariably beneficial to use more than one fabric analysis technique. Failure to check results from one technique against those from another can results in misinterpretation of intrusion flow kinematics.

  5. Central Andean crustal structure from receiver function analysis (United States)

    Ryan, Jamie; Beck, Susan; Zandt, George; Wagner, Lara; Minaya, Estela; Tavera, Hernado


    The Central Andean Plateau (15°-27°S) is a high plateau in excess of 3 km elevation, associated with thickened crust along the western edge of the South America plate, in the convergent margin between the subducting Nazca plate and the Brazilian craton. We have calculated receiver functions using seismic data from a recent portable deployment of broadband seismometers in the Bolivian orocline (12°-21°S) region and combined them with waveforms from 38 other stations in the region to investigate crustal thickness and crust and mantle structures. Results from the receiver functions provide a more detailed map of crustal thickness than previously existed, and highlight mid-crustal features that match well with prior studies. The active volcanic arc and Altiplano have thick crust with Moho depths increasing from the central Altiplano (65 km) to the northern Altiplano (75 km). The Eastern Cordillera shows large along strike variations in crustal thickness. Along a densely sampled SW-NE profile through the Bolivian orocline there is a small region of thin crust beneath the high peaks of the Cordillera Real where the average elevations are near 4 km, and the Moho depth varies from 55 to 60 km, implying the crust is undercompensated by ~ 5 km. In comparison, a broader region of high elevations in the Eastern Cordillera to the southeast near ~ 20°S has a deeper Moho at ~ 65-70 km and appears close to isostatic equilibrium at the Moho. Assuming the modern-day pattern of high precipitation on the flanks of the Andean plateau has existed since the late Miocene, we suggest that climate induced exhumation can explain some of the variations in present day crustal structure across the Bolivian orocline. We also suggest that south of the orocline at ~ 20°S, the thicker and isostatically compensated crust is due to the absence of erosional exhumation and the occurrence of lithospheric delamination.

  6. Genetic diversity of Phytophthora infestans in the Northern Andean region

    Directory of Open Access Journals (Sweden)

    Grünwald Niklaus J


    Full Text Available Abstract Background Phytophthora infestans (Mont. de Bary, the causal agent of potato late blight, is responsible for tremendous crop losses worldwide. Countries in the northern part of the Andes dedicate a large proportion of the highlands to the production of potato, and more recently, solanaceous fruits such as cape gooseberry (Physalis peruviana and tree tomato (Solanum betaceum, all of which are hosts of this oomycete. In the Andean region, P. infestans populations have been well characterized in Ecuador and Peru, but are poorly understood in Colombia and Venezuela. To understand the P. infestans population structure in the Northern part of the Andes, four nuclear regions (ITS, Ras, β-tubulin and Avr3a and one mitochondrial (Cox1 region were analyzed in isolates of P. infestans sampled from different hosts in Colombia and Venezuela. Results Low genetic diversity was found within this sample of P. infestans isolates from crops within several regions of Colombia and Venezuela, revealing the presence of clonal populations of the pathogen in this region. We detected low frequency heterozygotes, and their distribution patterns might be a consequence of a high migration rate among populations with poor effective gene flow. Consistent genetic differentiation exists among isolates from different regions. Conclusions The results here suggest that in the Northern Andean region P. infestans is a clonal population with some within-clone variation. P. infestans populations in Venezuela reflect historic isolation that is being reinforced by a recent self-sufficiency of potato seeds. In summary, the P. infestans population is mainly shaped by migration and probably by the appearance of variants of key effectors such as Avr3a.

  7. [Elaboration and evaluation of infant food based on Andean crops]. (United States)

    Repo-Carrasco, R; Hoyos, N L


    The Andes mountain range of South America is one of the most important centres for crop domestication, potato, corn, and lesser known grains such as quinua, cañihua, kiwicha and tarwi are indigenous of these highlands. These Andean grains have adapted perfectly to the climatic and geographical conditions present, whereas other grains have not been able to survive. In addition to their hardiness, they also have a high nutritional value. Bearing in mind on one hand, the high nutritional value of these indegenous products, and on the other hand the high rate of child malnutrition prevalent in the population, it was considered important to look for new variations in their processing which would facilitate their consumption by the poor working classes, especially the children. Accordingly three different flour mixtures were developed based on these Andean grains, the mixtures were then subjected to bromatological and biological analysis. The three new flour mixtures were: Quinua-Cañihua-Broad Bean (Q-C-B), Quinua-Kiwicha-Bean (Q-K-B) and Kiwicha-Rice (K-R). The protein content of these mixtures varied between 11.35-15.46 g/100g, the mixture K-R having the lowest protein level and the Q-C-B having the highest. The Q-K-B mixture had the highest chemical score, PER and NPU value. This PER value of 2.59 was higher than the value of casein which was 2.50. In addition this mixture had a chemical score of 0.94 and a NPU value of 59.38. The Q-C-B mixture had a chemical score of 0.88 and its PER, NPU and Digestibility values were 2.36, 47.24 and 79.2 respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7826191

  8. Heavy Metals in Sediments and Soils Around the Buchim Copper Mine Area

    International Nuclear Information System (INIS)

    In frame of this paper are given the results and findings from the research performed for determination of metal pollution around the porphyry copper deposit Buchim., After the analysis and interpretation of data were confirmed the assumptions for increased values of the the following metals: Cu, Fe, Zn, Pb, Mn, Ni, Cd, Ag, As and Co. Since the Buchim Mine is a mine for copper exploitation, especially interesting were the results for Cu that reached 17.5 - 153541.0 mg/kg in sediments and 35.0 - 4248.0 mg/kg in soils. The increase of metal concentration was determined in all of the analyzed media: sediment and soil. Increased concentrations of metals quite often were of several times magnitude over the maximal allowed standards. The increase of metals concentration of metals in sediments and soils was highest in the area of the tailing dam and below the studied watercourses. (Author)

  9. Watershed-based natural research management: Lessons from projects in the Andean region


    Sowell, A.R.


    This Undergraduate Honors Thesis focuses on how different factors affect the success of a watershed management project and lessons learned from projects in the Andean Region. LTRA-3 (Watershed-based NRM for Small-scale Agriculture)

  10. Farmers' participation and breeding for durable disease resistance in the Andean region

    NARCIS (Netherlands)

    Danial, D.L.; Parlevliet, J.E.; Almekinders, C.J.M.; Thiele, G.


    In the Andean region, the Preduza project and its partners combined breeding for durable disease resistance using locally adapted cultivars and farmer participatory methods. The approach taken resembles participatory variety selection (PVS). Farmers participated in the selection of advanced material

  11. Sediment budget in the Ucayali River basin, an Andean tributary of the Amazon River


    W. Santini; Martinez, J. -M.; Espinoza-Villar, R.; G. Cochonneau; Vauchel, P.; Moquet, J.-S.; Baby, P.; Espinoza, J.-C.; Lavado, W.; Carranza, J.; Guyot, J.-L.


    Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in the upper Ucayali basin are rapid, favoured by a marked seasonality in this region and extreme precipitation cells above sedimentary strata, uplifted...

  12. 40Ar/39Ar Dating of the Shaxi Porphyry Cu-Au Deposit in the Southern Tan-Lu Fault Zone, Anhui Province

    Institute of Scientific and Technical Information of China (English)

    YANG Xiaoyong; ZHENG Yongfei; XIAO Yilin; DU Jianguo; SUN Weidong


    Four samples of plagioclase and biotite from the Shaxi porphyry in the lower part of the Yangtze metallogenic belt were analyzed for age determination with the 40Ar/39Ar method. The results yield reproducible ages of 126 Ma to 135 Ma with a high level of confidence according to the agreement between isochron and plateau ages. The four Ar-Ar ages are relatively consistent within the analytical error. These ages are also consistent with, but more precise than, previous K-Ar and Rb-Sr ages and thus provide better constraints on the time of porphyry formation and associated Cu-Au mineralization along the middle to lower part of the Yangtze metallogenic belt. The ages of 126 to 135 Ma are interpreted to represent the intrusive time of the Shaxi porphyry, so that the Cu-Au mineralization should have occurred later due to the post-magmatic hydrothermal event.

  13. Geologic and geochemical insights into the formation of the Taiyangshan porphyry copper–molybdenum deposit, Western Qinling Orogenic Belt, China (United States)

    Kun-Feng Qiu; Taylor, Ryan D.; Yao-Hui Song; Hao-Cheng Yu; Kai-Rui Song; Nan Li


    Taiyangshan is a poorly studied copper–molybdenum deposit located in the Triassic Western Qinling collisional belt of northwest China. The intrusions exposed in the vicinity of the Taiyangshan deposit record episodic magmatism over 20–30 million years. Pre-mineralization quartz diorite porphyries, which host some of the deposit, were emplaced at 226.6 ± 6.2 Ma. Syn-collisional monzonite and quartz monzonite porphyries, which also host mineralization, were emplaced at 218.0 ± 6.1 Ma and 215.0 ± 5.8 Ma, respectively. Mineralization occurred during the transition from a syn-collisional to a post-collisional setting at ca. 208 Ma. A barren post-mineralization granite porphyry marked the end of post-collisional magmatism at 200.7 ± 5.1 Ma. The ore-bearing monzonite and quartz monzonite porphyries have a εHf(t) range from − 2.0 to + 12.5, which is much more variable than that of the slightly older quartz diorite porphyries, with TDM2 of 1.15–1.23 Ga corresponding to the positive εHf(t) values and TDM1 of 0.62–0.90 Ga corresponding to the negative εHf(t) values. Molybdenite in the Taiyangshan deposit with 27.70 to 38.43 ppm Re suggests metal sourced from a mantle–crust mixture or from mafic and ultramafic rocks in the lower crust. The δ34S values obtained for pyrite, chalcopyrite, and molybdenite from the deposit range from + 1.3‰ to + 4.0‰, + 0.2‰ to + 1.1‰, and + 5.3‰ to + 5.9‰, respectively, suggesting a magmatic source for the sulfur. Calculated δ18Ofluid values for magmatic K-feldspar from porphyries (+ 13.3‰), hydrothermal K-feldspar from stockwork veins related to potassic alteration (+ 11.6‰), and hydrothermal sericite from quartz–pyrite veins (+ 8.6 to + 10.6‰) indicate the Taiyangshan deposit formed dominantly from magmatic water. Hydrogen isotope values for hydrothermal sericite ranging from − 85 to − 50‰ may indicate that magma degassing progressively depleted residual liquid in

  14. Variation of molybdenum isotopes in molybdenite from porphyry and vein Mo deposits in the Gangdese metallogenic belt, Tibetan plateau and its implications (United States)

    Wang, Yong; Zhou, Lian; Gao, Shan; Li, Jian-Wei; Hu, Zhi-Fang; Yang, Lu; Hu, Zhao-Chu


    We present Mo isotopic ratios of molybdenite from five porphyry molybdenum deposits (Chagele, Sharang, Jiru, Qulong, and Zhuonuo) and one quartz-molybdenite vein-type deposit (Jigongcun) along the Gangdese metallogenic belt in the Tibetan Plateau. These deposits represent a sequence of consecutive events of the India-Asia collision at different periods. Additional molybdenite samples from the Henderson Mo deposit (USA), the oceanic subduction-related El Teniente (Chile), and Bingham (USA) porphyry Cu-(Mo) deposits were analyzed for better understanding the controls on the Mo isotope systematics of molybdenite. The results show that molybdenite from Sharang, Jiru, Qulong, and Zhuonuo deposits have similar δ97Mo (˜0 ‰), in agreement with the values of the Henderson Mo deposit (-0.10 ‰). In contrast, samples from the Changle and Jigongcun deposit have δ97Mo of 0.85 ‰ to 0.88 ‰ and -0.48 %, respectively. Molybdenite from the El Teniente and Bingham deposits yields intermediate δ97Mo of 0.27 and 0.46 ‰, respectively. The Mo isotopes, combined with Nd isotope data of the ore-bearing porphyries, indicate that source of the ore-related magmas has fundamental effects on the Mo isotopic compositions of molybdenite. Our study indicates that molybdenite related to crustal-, and mantle-derived magmas has positive or negative δ97Mo values, respectively, whereas molybdenite from porphyries formed by crust-mantle mixing has δ97Mo close to 0 ‰. It is concluded that the Mo isotope composition in the porphyry system is a huge source signature, without relation to the tectonic setting under which the porphyry deposits formed.

  15. Sr–Nd–Pb–Hf isotope systematics of the Hugo Dummett Cu–Au porphyry deposit (Oyu Tolgoi, Mongolia)


    A. Dolgopolova; R. Seltmann; Armstrong, R.; Belousova, E.; Pankhurst, R.J.; Kavalieris, I.


    Major and trace element geochemistry including Sr–Nd–Pb–Hf isotopic data are presented for a representative sample suite of Late Devonian to Early Carboniferous plutonic and volcanic rocks from the Hugo Dummett deposit of the giant Oyu Tolgoi porphyry Cu–Au district in South Gobi, Mongolia. Sr and Nd isotopes (whole-rock) show restricted ranges of initial compositions, with positive εNdt mainly between + 3.4 and + 7.4 and (87Sr/86Sr)t predominantly between 0.7037 and 0.7045 reflecting magma g...

  16. Cretaceous subduction-related magmatism and associated porphyry-type Cu-Mo prospects in the Eastern Pontides, Turkey: New constraints from geochronology and geochemistry (United States)

    Delibaş, Okan; Moritz, Robert; Ulianov, Alexey; Chiaradia, Massimo; Saraç, Cem; Revan, Kemal M.; Göç, Deniz


    This study focuses on the Elbeyli-Ordu, Emeksen-Giresun, Güzelyayla-Trabzon and Ulutaş-Ispir porphyry-type prospects located in the Eastern Pontides, Turkey. Our new LA-ICP-MS U-Pb zircon age data reveal that the Elbeyli-Ordu Mo-Cu mineralization is hosted by a 77.0 ± 1.3 Ma-old monzonite/monzodiorite with a shoshonitic character. The Emeksen Mo mineralization, located ~ 40 km southeast of the Elbeyli-Ordu prospect, consists of NW- and NE-striking quartz veins crosscutting a high-K calc-alkaline to shoshonitic granite dated at 78.5 ± 0.8 Ma, a granodiorite dated at 78.7 ± 0.5 Ma and porphyry granite dated at 77.7 ± 0.5 Ma. The Güzelyayla porphyry Cu-Mo prospect consists of a stockwork-type Cu-Mo mineralization crosscutting a calc-alkaline 81.4 ± 1.1 Ma-old dacite porphyry and Late Cretaceous calc-alkaline andesite. The Ispir-Ulutaş mineralization is hosted within a highly sericitized 131.1 ± 0.9 Ma-old quartz-porphyry that intruded into a 132.9 ± 0.6 Ma-old calc-alkaline granite porphyry. Our new U-Pb zircon ages, lithogeochemical and radiogenic isotopic data of the host rocks associated with the porphyry-type prospects in the Eastern Pontides indicate that they formed in an arc-related environment during Cretaceous subduction of the Neotethys Ocean, and the Ispir-Ulutaş prospect is attributed to the main stage of the northward subduction of the Neotethys during the Early Cretaceous. We conclude that the Güzelyayla and Emeksen hydrothermal systems were formed during a transitional compressional to extensional tectonic evolution, whereas the Late Cretaceous Elbeyli hydrothermal system was emplaced during an extensional arc magmatic event. Highly-oxidized, high-K calc-alkaline to shoshonitic magmas at Emeksen and Elbeyli were derived from a metasomatized, heterogeneous and enriched lithospheric mantle, with variable degrees of partial melting of the mantle wedge and variable crustal contamination. Mixing/mingling processes between mafic magmas derived

  17. 新疆东戈壁斑岩型钼矿床之斑岩体特征%Geological and Geochemical Characteristics of Ore-forming Granite Porphyry in East Gobi Porphyry Molybdenum Deposit in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    杨志强; 吴邦友; 郑松森; 安金亮; 常勇强


    East Gobi porphyry molybdenum deposit which locates at south of Hami(about 110 km away),Xinjiang province,is in the Jueluotage polymetallic metallogenic belt of Eastern Tianshan Mt..Three type magmatic rocks,pale red porphyritic granite,granite prophyry vein and fine-grained granite vein are distributed in East Gobi Mo deposit,while ore-bodies are mainly occurred in the outer contact zone of Late Hercynian intruded porphyritic granite and low-metamorphic clastic rock.The petrological and geochemical feature of ore-bearing porphyry in East Gobi Mo deposit is comparison with the porphyry in other porphyry-type Mo deposits,which indicated that the porphyritic granite is with higher SiO2 content and belongs to calc alkali S-type granite.East Gobi porphyry Mo deposit is the first discovered super-large Mo deposit in Xinjiang province,this research may be very valuable for prospecting the similar deposit in this area.%新疆东戈壁斑岩型钼矿床位于哈密市南110 km,为荒漠戈壁区,隶属于东天山觉罗塔格多金属成矿带。钼矿体赋存于斑状花岗岩体的外接触带浅变质碎屑岩中;侵入岩主要有浅肉红色斑状花岗岩(隐伏岩体)、花岗斑岩脉、细粒花岗岩脉三种,控矿岩体为隐伏斑状花岗岩,属华力西晚期第二次侵入。本文对东戈壁矿区岩体的岩石学、岩石化学、岩石地球化学特征进行了较详细研究,并与国内的斑岩型钼矿岩体的岩石化学、岩石地球化学特征进行了对比,其主要结论是东戈壁矿区斑状花岗岩SiO2含量偏高,属钙碱性岩,侵入岩成因分类属陆壳重熔S型花岗岩。该矿床为新疆发现的第一个特大型钼矿床,此项研究对在区域上寻找同类型矿床具有重要的借鉴意义。

  18. Changing Hydrology in Glacier-fed High Altitude Andean Peatbogs (United States)

    Slayback, D. A.; Yager, K.; Baraer, M.; Mohr, K. I.; Argollo, J.; Wigmore, O.; Meneses, R. I.; Mark, B. G.


    Montane peatbogs in the glacierized Andean highlands of Peru and Bolivia provide critical forage for camelids (llama and alpaca) in regionally extensive pastoral agriculture systems. During the long dry season, these wetlands often provide the only available green forage. A key question for the future of these peatbog systems, and the livelihoods they support, is the impact of climate change and glacier recession on their hydrology, and thus forage production. We have already documented substantial regional glacier recession, of, on average, approximately 30% of surface area over the past two decades. As glaciers begin to retreat under climate change, there is initially a period of increased meltwater outflow, culminating in a period of "peak water", and followed by a continual decline in outflows. Based on previous work, we know that some glaciers in the region have already passed peak water conditions, and are now declining. To better understand the impacts of these processes on peatbog hydrology and productivity, we have begun collecting a variety of surface data at several study sites in both Bolivia and Peru. These include precipitation, stream flow, water levels, water chemistry and isotope analyses, and peatbog biodiversity and biomass. These measurements will be used in conjunction with a regional model driven by satellite data to predict likely future impacts. We will present the results from these initial surface measurements, and an overview of satellite datasets to be used in the regional model.

  19. Storage of carbon in natural grasses high andean

    Directory of Open Access Journals (Sweden)

    Raúl Marino Yaranga Cano


    Full Text Available The aim of the study was to determine the capacity of storage of carbon in species of grasses natural of high andean, between January of 2012 and March of 2013. They were defined two sampling areas in the districts of Huasicancha and Chicche of the county of Huancayo, Junín. The first of the areas was located in the place Pumahuasi (18L 466456E 8628580N and the second in Vista Alegre (18L 464886E 8642964N, between 3 845 and 3 870 meters of altitude. 10 plants per species were collected at random, between April and May, considering the moment of maximum growth of the plants. The samples were washed and dried off to the atmosphere during 15 days, being completed the drying in a stove to 60 °C, during 48 hours. The determination of the percentage of dry matter of the samples was carried out by the difference between the initial and final weights. While that the determination of the percentage of carbon was carried out through the method of Walkley-Black. The results of the correlation of weight between air biomass and biomass radicular were highly significant r = 0.9856 ** and b = 3.4507. The percentage of the weight of the root regarding that of the air biomass oscillated between 27.93% and 30.20%, respectively. The content of carbon expressed as percentage varied according to the part of the plant and the origin place.

  20. Antwerp Copper Plates

    DEFF Research Database (Denmark)

    Wadum, Jørgen


    In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes.......In addition to presenting a short history of copper paintings, topics detail artists’ materials and techniques, as well as aspects of the copper industry, including mining, preparation and trade routes....

  1. Andean subduction orogeny: feedbacks between tectonics, relief evolution and global climate (United States)

    Lacassin, Robin; Armijo, Rolando; Coudurier-Curveur, Aurélie; Carrizo, Daniel


    The Andean subduction margin, largest tectonic relief on the Earth (13 km vertically from the trench to the Altiplano) has a stepped morphology, which results of the evolution over the past 50 Myr of two parallel flat-ramp thrust systems, at the - previously unidentified - West Andean Thrust (WAT), and at the subduction interface. The evolution of those thrusts appears concomitant with increasing aridity in the Atacama Desert, which keeps a large-scale record of interplaying tectonics and Cenozoic climate change. The coastal morphology is dominated by the Atacama Bench, a giant uplifted terrace at 1-2km asl. Geomorphic and climatic data, numerical experiments of drainage formation are consistent with the development of a flat Atacama morphology close to sea level, interrupted at ≤10 Ma by tectonic uplift prevailing to the present. This suggests recent trench-ward relief growth by incorporation of the coastal Atacama Bench to the Andes reliefs. Thrust splay structures and other complexities above the subduction interface may explain this relief growth, as well as the distribution of asperities under the oceanward forearc, and the down-dip segmentation of coupling and seismicity on the megathrust. Combining those results with geological knowledge at the scale of the whole Central Andes, we show that the Andean orogeny results from protracted processes of bivergent crustal shortening in a wide region squeezed between the rigid Marginal Block and the S America Plate. The overall growth curve of Andean orogeny over the past 50 Myr appears synchronous with the onset of the "ramp-shaped" temperature decrease since the Early Eocene climatic optimum. Andean growth and global cooling may have operated under the same forcing mechanism at plate-scale, involving viscous flow in the mantle. But Andean growth appears modulated by climatic feedbacks causative of stepwise reductions of erosive power over the Andean margin. The first of such events is coeval with Late Eocene

  2. Geochronology and geochemistry constraints of the Early Cretaceous Taibudai porphyry Cu deposit, northeast China, and its tectonic significance (United States)

    Zhou, Zhen-Hua; Mao, Jing-Wen; Wu, Xin-Li; Ouyang, Hen-Gen


    The southern Great Xing'an Range (SGXR), located in the southeastern part of Inner Mongolia, China, shows intense Mesozoic tectono-magmatic activity and hosts economically important polymetallic (Cu-Pb-Zn-Sn-Fe-Ag-Au-Mo) mineralization. Here, we present new zircon U-Pb ages, whole-rock geochemical data, Nd-Sr-Hf isotopic data and Re-Os ages for the Taibudai deposit in the SGXR. The Taibudai granitoids show high SiO2 (70.62-72.13 wt.%) and alkali (Na2O + K2O = 7.04-8.60 wt.%) concentrations, low MgO (0.89-1.37 wt.%) and Al2O3 (∼14 wt.%), ASI ratios geology, tectonic evolution, and age data from the literature, suggests that the Early Cretaceous (∼140 Ma) was the peak metallogenic epoch for the Great Xing'an Range, and the mineralization in this period generally takes the form of porphyry, skarn, or hydrothermal polymetallic ore deposits in an active extensional continental margin environment. The Taibudai porphyry and associated mineralization provides a typical example of magmatism and metallogeny associated with a Paleo-Pacific plate subduction, continental margin, back-arc extensional setting.

  3. Using a titanium-in-quartz geothermometer for crystallization temperature estimation of the Palaeoproterozoic Suursaari quartz porphyry

    Directory of Open Access Journals (Sweden)

    Kairi Ehrlich


    Full Text Available The Suursaari volcanic sequence represents volcanic activity related to Wiborg Batholith rapakivi intrusions in the southern part of the Fennoscandian Shield. The estimated pressure conditions for batholith granitic rocks are 1–5 kbar and crystallization temperatures range from 670 to 890 °C. To describe the temperature regime of the Suursaari volcanic system, a rock sample was taken from the Mäkiinpäällys Mountain outcrop and analysed with laser ablation inductively coupled plasma mass spectrometry. Sample spots were selected from quartz phenocrysts and groundmass. Quartz crystallization temperatures were calculated by the Ti-in-quartz method that takes into account rutile equilibrium and Ti activity in each phase. The calculated crystallization temperatures of the Suursaari quartz porphyry are in the range of 647–738 °C. The results show that the Suursaari quartz porphyry contains two generations of quartz which can be distinguished on the basis of crystallization temperatures: phenocrysts crystallized at higher and groundmass quartz at lower temperature.

  4. Separation of copper-64 from copper phthalocyanine

    International Nuclear Information System (INIS)

    The separation of copper-64 from irradiated copper phthalocyanine by Szilard-Chalmers effect is studied. Two methods of separation are used: one of them is based on the dissolution of the irradiated dry compound in concentrated sulfuric acid following its precipitation in water. In the other one the compound is irradiated with water in paste form following treatment with water and hydrochloric acid. The influence of the crystal form of the copper phthalocyanine on the separation yield of copper-64 is shown. Preliminary tests using the ionic exchange technique for purification and changing of copper-64 sulfate to chloride form are carried out. The specific activity using the spectrophotometric technique, after the determination of the copper concentration in solution of copper-64, is calculated. (Author)

  5. Adakite-like granitoid porphyries in the Eastern Pontides, NE Turkey: Potential parental melts and geodynamic implications (United States)

    Karsli, Orhan; Ketenci, Murat; Uysal, İbrahim; Dokuz, Abdurrahman; Aydin, Faruk; Chen, Bin; Kandemir, Raif; Wijbrans, Jan


    The tectonic setting of the Eastern Pontides during the late Mesozoic to early Cenozoic remains a subject of debate. Petrogenesis of adakite-like granitoid porphyries plays a critical role in determining the nature of the lower continental crust and mantle dynamics during orogenic processes in the region. Here we describe, for the first time, the late Paleocene to early Eocene adakite-like granitoid porphyries from the northern part of the Eastern Pontides although their counterparts in the southern part have recently been found. The adakitic porphyries, which emplaced into the subduction-related Turonian-Santonian volcanics from northern part of the region, consist of I-type calc-alkaline quartz monzonite-tonalite (SiO2 = 62.89-65.07 wt.%) and high-K calc-alkaline granodiorite-granite associations (SiO2 = 69.06-70.43 wt.%). The former displays peraluminous to metaluminous signatures, whereas the latter shows peraluminous geochemical character. The granite-granodiorite porphyries have high K2O (3.32-3.84 wt.%), and low Na2O (3.48-4.61 wt.%) and MgO (0.91-1.04 wt.%) relative to the quartz monzonite-tonalite association (K2O = 1.50-1.92 wt.%; Na2O = 4.08-6.45 wt.%; MgO = 1.44-2.07 wt.%). Ar-Ar geochronology studies on the amphibole separates reveal that the adakite-like porphyries have a crystallization ages of 51.34 ± 0.27 to 53.55 ± 0.34 Ma. Here, we contend that these rocks were formed by partial fusion of a mafic lower continental crust in a collisional phase but not in a subduction setting. All the samples exhibit the typical geochemical characteristics of adakite, that is, high Sr (250-1141 ppm), high Sr/Y ratios (16-147), low Y (6.8-14.8 ppm) and low HREE concentrations; they are similar to adakites formed by slab melting associated with the subduction zone. However, the rocks exhibit heterogeneity in isotopic composition, with ISr ranging from 0.70554 to 0.70986, εNd (51 Ma) from -8.5 to -0.9 and Nd model ages from 0.72 to 1.26 Ga. The samples are

  6. Copper Metabolism of Astrocytes


    Ralf Dringen; Scheiber, Ivo F.; Julian FB Mercer


    This short review will summarize the current knowledge on the uptake, storage, and export of copper ions by astrocytes and will address the potential roles of astrocytes in copper homeostasis in the normal and diseased brain. Astrocytes in culture efficiently accumulate copper by processes that include both the copper transporter Ctr1 and Ctr1-independent mechanisms. Exposure of astrocytes to copper induces an increase in cellular glutathione (GSH) content as well as synthesis of metallothion...

  7. Seed production differences of the Andean oak Quercus Humboldtii Bonpl. in two Andean forests of the Colombian Eastern Cordillera

    International Nuclear Information System (INIS)

    Knowledge of mechanisms of tree species reproduction under natural situations including fruit and seed production patterns is very important for forest management strategies. Considering the influence of abiotic factors such as soil characteristics, humidity and rainfall on fruiting phenology, we studied fruit production patterns of the Andean oak (Quercus humboldtii: Fagaceae) in two forest sites of the Colombian Eastern Cordillera (Cachalu and Patios Altos), under contrasting environmental conditions. At both sites, we monitored monthly fruit production of 15 trees in Cachalu and 11 in Patios Altos using fruit/seed traps placed under the tree crowns. In each site soil cores were extracted below the litter layer 20 cm depth, and soil characteristics and nutrients were analyzed. In general, trees in Cachalu produced more fruits than in Patios Altos, as well as mean fruit mass (wet and dry weight) was significantly higher in Cachalu. At both sites, oak fruiting peaked from April to May, when the highest rainfall occurs. We found positive correlations between fruit production and rainfall one month prior. High phosphorus (P) and potassium (K) were the main variables for explaining the high production. In contrast, high aluminum (Al) contents explained the low production found in Patios Altos. We discuss the importance of including fruit production for oak management strategies, such as restoration and reforestation programs.

  8. Early Paleozoic magmatism and metallogeny in Northeast China: a record from the Tongshan porphyry Cu deposit (United States)

    Hu, Xinlu; Yao, Shuzhen; Ding, Zhenju; He, Mouchun


    The Tongshan Cu deposit is located in the northern segment of the Great Xing'an Range and represents one of the few early Paleozoic porphyry Cu deposits in northeastern China. The granitic rocks in the Tongshan Cu deposit include concealed granodiorite and exposed tonalite, which yield LA-ICP-MS zircon U-Pb ages of 478 ± 3 Ma and 214 ± 3 Ma, respectively. The granodiorite has relatively high SiO2 (60.5-63.5 wt%) and Sr (596-786 ppm) contents, low Yb (1.21-1.53 ppm) and Y (9.81-13.0 ppm) contents, and initial 87Sr/86Sr ratios (0.7038-0.7040), suggesting adakitic affinity. Combined with its positive ɛNd(t) values (3.5-5.4), low Mg# values (41-50), and low contents of Cr (18.6-29.0 ppm) and Ni (7.3-9.1 ppm), we propose an origin by partial melting of a juvenile mafic lower crust in a post-collisional setting after the amalgamation of the Erguna and Xing'an Blocks. The tonalite is characterized by high SiO2 (63.1-65.9 wt%) and Al2O3 (16.0-16.3 wt%) contents, low (87Sr/86Sr) i ratios (0.7041-0.7042), positive ɛNd(t) values (2.6-3.0), along with LILE and LREE enrichments and Nb-Ta-Ti depletions, suggesting an origin by partial melting of juvenile mafic lower crust, coupled with fractional crystallization, in a post-orogenic setting after the collision between the Xing'an and Songnen Blocks. The δD values of ore-forming fluids range from -100 to -93 ‰, and the δ18O values calculated from hydrothermal quartz are between -3 and 10 ‰. The δ34S values of sulfides vary from -2.6 to -1.1 ‰. Field observations, as well as the geochronological and H-O-S isotopic data, suggest that the Cu mineralization at Tongshan was genetically linked with the granodiorite.

  9. Ultraviolet-B-driven pigmentation and genetic diversity of benthic macroinvertebrates from high-altitude Andean streams

    NARCIS (Netherlands)

    R.A. Loayza Muro; J.K. Marticorena-Ruíz; E.J. Palomino; C Merrit; J.A.J. Breeuwer; P. Kuperus; M.H.S. Kraak; W. Admiraal


    Photoprotective pigments in benthic macroinvertebrates may reduce the damage caused by the blistering UV-B radiation in Andean high-altitude streams above 3500 m. The aim of this study was therefore to determine whether melanisation in macroinvertebrates inhabiting high-altitude Andean streams is an

  10. Variations in magnetic anisotropy and opaque mineralogy along a kilometer deep profile within a vertical dyke of the syenogranite porphyry at Cínovec (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Hrouda, F.; Chlupáčová, M.; Novák, Jiří Karel


    Roč. 113, 1/2 (2002), s. 37-47. ISSN 0377-0273 R&D Projects: GA ČR GA205/95/0149; GA ČR GA205/96/0272; GA AV ČR IAA3013903 Keywords : magnetic anisotropy * syenogranite porphyry * Bohemian Massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.974, year: 2002

  11. Sediment budget in the Ucayali River basin, an Andean tributary of the Amazon River (United States)

    Santini, W.; Martinez, J.-M.; Espinoza-Villar, R.; Cochonneau, G.; Vauchel, P.; Moquet, J.-S.; Baby, P.; Espinoza, J.-C.; Lavado, W.; Carranza, J.; Guyot, J.-L.


    Formation of mountain ranges results from complex coupling between lithospheric deformation, mechanisms linked to subduction and surface processes: weathering, erosion, and climate. Today, erosion of the eastern Andean cordillera and sub-Andean foothills supplies over 99% of the sediment load passing through the Amazon Basin. Denudation rates in the upper Ucayali basin are rapid, favoured by a marked seasonality in this region and extreme precipitation cells above sedimentary strata, uplifted during Neogene times by a still active sub-Andean tectonic thrust. Around 40% of those sediments are trapped in the Ucayali retro-foreland basin system. Recent advances in remote sensing for Amazonian large rivers now allow us to complete the ground hydrological data. In this work, we propose a first estimation of the erosion and sedimentation budget of the Ucayali River catchment, based on spatial and conventional HYBAM Observatory network.

  12. Transference of some microsatellite molecular markers from Fabaceae family to Andean Lupin (Lupinus mutabilis Sweet

    Directory of Open Access Journals (Sweden)

    Michelle C. Chirinos-Arias


    Full Text Available In order to analyze transferibility of 15 microsatellite primers from Fabaceae family to Lupinus mutabilis Sweet "andean lupine" chosen to present transferability between species and genera, by its high rate of polymorphic content (PIC and high degree of observed and expected heterozygosity. DNA was extracted of 300 andean lupines plants, PCR conditions were standardized by gradients of master mix components. Primers for screening were run on 3% agarose gel with some samples. Finally population was amplified and run on 6% polyacrylamide gel for its highest resolution. Only 6.67% of primers were amplified, but they were monomorphic, so they cannot be used for molecular characterization. We proposed eight microsatellite primers for andean lupin wich should be probed in laboratory conditions.

  13. Microsatellite characterization of Andean races of common bean (Phaseolus vulgaris L.). (United States)

    Blair, M W; Díaz, J M; Hidalgo, R; Díaz, L M; Duque, M C


    The Andean gene pool of common bean (Phaseolus vulgaris L.) has high levels of morphological diversity in terms of seed color and size, growth habit and agro-ecological adaptation, but previously was characterized by low levels of molecular marker diversity. Three races have been described within the Andean gene pool: Chile, Nueva Granada and Peru. The objective of this study was to characterize a collection of 123 genotypes representing Andean bean diversity with 33 microsatellite markers that have been useful for characterizing race structure in common beans. The genotypes were from both the primary center of origin as well as secondary centers of diversity to which Andean beans spread and represented all three races of the gene pool. In addition we evaluated a collection of landraces from Colombia to determine if the Nueva Granada and Peru races could be distinguished in genotypes from the northern range of the primary center. Multiple correspondence analyses of the Andean race representatives identified two predominant groups corresponding to the Nueva Granada and Peru races. Some of the Chile race representatives formed a separate group but several that had been defined previously as from this race grouped with the other races. Gene flow was more notable between Nueva Granada and Peru races than between these races and the Chile race. Among the Colombian genotypes, the Nueva Granada and Peru races were identified and introgression between these two races was especially notable. The genetic diversity within the Colombian genotypes was high, reaffirming the importance of this region as an important source of germplasm. Results of this study suggest that the morphological classification of all climbing beans as Peru race genotypes and all bush beans as Nueva Granada race genotypes is erroneous and that growth habit traits have been mixed in both races, requiring a re-adjustment in the concept of morphological races in Andean beans. PMID:17924092

  14. Diverging Responses of Tropical Andean Biomes under Future Climate Conditions (United States)

    Tovar, Carolina; Arnillas, Carlos Alberto; Cuesta, Francisco; Buytaert, Wouter


    Observations and projections for mountain regions show a strong tendency towards upslope displacement of their biomes under future climate conditions. Because of their climatic and topographic heterogeneity, a more complex response is expected for biodiversity hotspots such as tropical mountain regions. This study analyzes potential changes in the distribution of biomes in the Tropical Andes and identifies target areas for conservation. Biome distribution models were developed using logistic regressions. These models were then coupled to an ensemble of 8 global climate models to project future distribution of the Andean biomes and their uncertainties. We analysed projected changes in extent and elevational range and identified regions most prone to change. Our results show a heterogeneous response to climate change. Although the wetter biomes exhibit an upslope displacement of both the upper and the lower boundaries as expected, most dry biomes tend to show downslope expansion. Despite important losses being projected for several biomes, projections suggest that between 74.8% and 83.1% of the current total Tropical Andes will remain stable, depending on the emission scenario and time horizon. Between 3.3% and 7.6% of the study area is projected to change, mostly towards an increase in vertical structure. For the remaining area (13.1%–17.4%), there is no agreement between model projections. These results challenge the common believe that climate change will lead to an upslope displacement of biome boundaries in mountain regions. Instead, our models project diverging responses, including downslope expansion and large areas projected to remain stable. Lastly, a significant part of the area expected to change is already affected by land use changes, which has important implications for management. This, and the inclusion of a comprehensive uncertainty analysis, will help to inform conservation strategies in the Tropical Andes, and to guide similar assessments for

  15. [Structural recovering in Andean successional forests from Porce (Antioquia, Colombia)]. (United States)

    Yepes, Adriana P; del Valle, Jorge I; Jaramillo, Sandra L; Orrego, Sergio A


    Places subjected to natural or human disturbance can recover forest through an ecological process called secondary succession. Tropical succession is affected by factors such as disturbances, distance from original forest, surface configuration and local climate. These factors determine the composition of species and the time trend of the succession itself. We studied succession in soils used for cattle ranching over various decades in the Porce Region of Colombia (Andean Colombian forests). A set of twenty five permanent plots was measured, including nine plots (20 x 50 m) in primary forests and sixteen (20 x 25 m) in secondary forests. All trees with diameter > or =1.0 cm were measured. We analyzed stem density, basal area, above-ground biomass and species richness, in a successional process of ca. 43 years, and in primary forests. The secondary forests' age was estimated in previous studies, using radiocarbon dating, aerial photographs and a high-resolution satellite image analysis (7 to >43 years). In total, 1,143 and 1,766 stems were measured in primary and secondary forests, respectively. Basal area (5.7 to 85.4 m2 ha(-1)), above-ground biomass (19.1 to 1,011.5 t ha(-1)) and species richness (4 to 69) directly increased with site age, while steam density decreased (3,180 to 590). Diametric distributions were "J-inverted" for primary forests and even-aged size-class structures for secondary forests. Three species of palms were abundant and exclusive in old secondary forests and primary forests: Oenocarpus mapora, Euterpe precatoria and Oenocarpus bataua. These palms happened in cohorts after forest disturbances. Secondary forest structure was 40% in more than 43 years of forest succession and indicate that many factors are interacting and affecting the forests succession in the area (e.g. agriculture, cattle ranching, mining, etc.). PMID:20411733

  16. Andean grasslands are as productive as tropical cloud forests (United States)

    Oliveras, I.; Girardin, C.; Doughty, C. E.; Cahuana, N.; Arenas, C. E.; Oliver, V.; Huaraca Huasco, W.; Malhi, Y.


    We aim to assess net primary productivity (NPP) and carbon cycling in Andean tropical alpine grasslands (puna) and compare it with NPP of tropical montane cloud forests. We ask the following questions: (1) how do NPP and soil respiration of grasslands vary over the seasonal cycle? (2) how do burning and grazing affect puna productivity? (3) if the montane forest expands into the puna, what will be the resulting change in productivity? The study sites are located at the South-eastern Peruvian Andes; one grassland site and the forest sites are in Wayqecha biological station, and another grassland site in Manu National Park. At each grassland site, we selected a burnt and an unburnt area, installed unfenced and fenced transects in each area, and monitored above-ground productivity (NPPAG), below-ground productivity (NPPBG) and soil respiration (Rs) for 2 yr. In the forest, we monitored NPPAG, NPPBG and Rs for 2-4 yr. Grassland NPP varied between 4.6 ± 0.25 (disturbed areas) to 15.3 ± 0.9 Mg C ha-1 yr-1 (undisturbed areas) and cloud forest NPP was between 7.05 ± 0.39 and 8.0 ± 0.47 Mg C ha-1 yr-1, while soil carbon stocks were in the range of 126 ± 22 to 285 ± 31 Mg C ha-1. There were no significant differences on NPP between the puna and forest sites. The most undisturbed site had significantly higher NPP than other grassland sites, but no differences were found when relating grazing and fire at other sites. There were lower residence times of above-ground biomass compared to below-ground biomass. There was a strong seasonal signal on grassland NPPAG and NPPBG, with a shift on allocation at the beginning of the austral summer. High elevation tropical grasslands can be as productive as adjacent cloud forests, but have very different carbon cycling and retention properties than cloud forests.

  17. Sediment-hosted stratabound copper deposit model: Chapter M in Mineral deposit model for resource assessment (United States)

    Hayes, Timothy S.; Cox, Dennis P.; Bliss, James D.; Piatak, Nadine M.; Seal, Robert R., II


    This report contains a descriptive model of sediment-hosted stratabound copper (SSC) deposits that supersedes the model of Cox and others (2003). This model is for use in assessments of mineral resource potential. SSC deposits are the second most important sources of copper in the world behind porphyry copper deposits. Around 20 percent of the copper in the world is produced from this class of deposits. They are also the most important sources of cobalt in the world, and they are fourth among classes of ore deposits in production of silver. SSC deposits are the basis of the economies of three countries: Democratic Republic of Congo, Poland, and Zambia. This report provides a description of the key features of SSC deposits; it identifies their tectonic-sedimentary environments; it illustrates geochemical, geophysical, and geoenvironmental characteristics of SSC deposits; it reviews and evaluates hypotheses on how these deposits formed; it presents exploration and assessment guides; and it lists some gaps in our knowledge about the SSC deposits. A summary follows that provides overviews of many subjects concerning SSC deposits.

  18. Two new cis-Andean species of the South American catfish genus Megalonema allied to trans-Andean Megalonema xanthum, with description of a new subgenus (Siluriformes: Pimelodidae)


    Lundberg, John G.; Dahdul, Wasila M.


    A revised diagnosis of the pimelodid catfish genus Megalonema is given based on synapomorphic features of the Weberian complex and gas bladder. Megalonema xanthum from the Magdalena River is redescribed. Two new cis-Andean species of Megalonema are described, M. amaxanthum n. sp. from the Amazon River basin, and M. orixanthum n. sp. from the Orinoco River basin. These three species are differentially diagnosed by shape and size of the supraoccipital posterior process, adipose-fin shape, verte...

  19. Copper partitioning between felsic melt and H2O-CO2 bearing saline fluids (United States)

    Tattitch, Brian C.; Candela, Philip A.; Piccoli, Philip M.; Bodnar, Robert J.


    Analysis of fluid inclusions from porphyry copper deposits reveals that magmatic vapor and brine are vital for the removal of copper from arc magmas and its transport to the site of ore deposition. Experiments in melt-vapor-brine systems allow for investigation of the partitioning of copper between silicate melts and volatile phases at magmatic conditions. The presence of CO2 affects both the pressure at which a melt saturates with respect to volatile phases. Therefore, the partitioning of copper among felsic (rhyolitic) melt, vapor and brine in CO2-bearing experiments was examined to provide insights into copper partitioning and the generation of porphyry copper and related deposits. We present results from experiments performed at 800 °C and 100 MPa in CO2-bearing melt-vapor-brine systems with XCO2v+b = 0.10 and 0.38. The compositions of vapor and brine inclusions, and run-product glasses, were determined during the course of this investigation. Microthermometric measurements of fluid inclusions show an increase in the salinity of the magmatic brine (∼65 to ∼70 wt% NaCleq) and decrease in the salinity of the vapor (∼3.5 to ∼1 wt% NaCleq) as XCO2 is increased from 0.10 to 0.38. The partitioning of copper between brine and vapor (DCub/v ± 2 σ) increases from 25 (±6) at XCO2 = 0.10, to 100 (±30) at XCO2 = 0.38 . The partitioning of copper between vapor and melt (DCuv/m ± 2 σ) decreases from 9.6 (±3.3) at XCO2 = 0.10 , to 2 (±0.8) at XCO2 = 0.38 . These data demonstrate that copper partitioning in sulfur-free, CO2-bearing systems is controlled by the changes in the salinity of the vapor and brine that, in turn, are functions of XCO2 . No change in the apparent equilibrium constants for Cu-Na exchange was observed in Fe-bearing experiments which supports a salinity-dependent model for copper partitioning. An existing model (MVPart) for ore metal partitioning between melt and volatile phases was modified to incorporate partitioning data from CO2

  20. USGS exploration geochemistry studies at the Pebble porphyry Cu-Au-Mo deposit, Alaska-pdf of presentation (United States)

    Eppinger, Robert G.; Kelley, Karen D.; Fey, David L.; Giles, Stuart A.; Minsley, Burke J.; Smith, Steven M.


    From 2007 through 2010, scientists in the U.S. Geological Survey (USGS) have been conducting exploration-oriented geochemical and geophysical studies in the region surrounding the giant Pebble porphyry Cu-Au-Mo deposit in southwestern Alaska. The Cretaceous Pebble deposit is concealed under tundra, glacial till, and Tertiary cover rocks, and is undisturbed except for numerous exploration drill holes. These USGS studies are part of a nation-wide research project on evaluating and detecting concealed mineral resources. This report focuses on exploration geochemistry and comprises illustrations and associated notes that were presented as a case study in a workshop on this topic. The workshop, organized by L.G. Closs and R. Glanzman, is called 'Geochemistry in Mineral Exploration and Development,' presented by the Society of Economic Geologists at a technical conference entitled 'The Challenge of Finding New Mineral Resources: Global Metallogeny, Integrative Exploration and New Discoveries,' held at Keystone, Colorado, October 2-5, 2010.

  1. Timing of porphyry (Cu-Mo) and base metal (Zn-Pb-Ag-Cu) mineralisation in a magmatic-hydrothermal system—Morococha district, Peru (United States)

    Catchpole, Honza; Kouzmanov, Kalin; Bendezú, Aldo; Ovtcharova, Maria; Spikings, Richard; Stein, Holly; Fontboté, Lluís


    The Morococha district in central Peru is characterised by economically important Cordilleran polymetallic (Zn-Pb-Ag-Cu) vein and replacement bodies and the large Toromocho porphyry Cu-Mo deposit in its centre. U-Pb, Re-Os, and 40Ar/39Ar geochronology data for various porphyry-related hydrothermal mineralisation styles record a 3.5-Ma multi-stage history of magmatic-hydrothermal activity in the district. In the late Miocene, three individual magmatic-hydrothermal centres were active: the Codiciada, Toromocho, and Ticlio centres, each separated in time and space. The Codiciada centre is the oldest magmatic-hydrothermal system in the district and consists of a composite porphyry stock associated with anhydrous skarn and quartz-molybdenite veins. The hydrothermal events are recorded by a titanite U-Pb age at 9.3 ± 0.2 Ma and a molybdenite Re-Os age at 9.26 ± 0.03 Ma. These ages are indistinguishable from zircon U-Pb ages for porphyry intrusions of the composite stock and indicate a time span of 0.2 Ma for magmatic-hydrothermal activity. The small Ticlio magmatic-hydrothermal centre in the west of the district has a maximum duration of 0.3 Ma, ranging from porphyry emplacement to porphyry mineralisation at 8.04 ± 0.14 Ma (40Ar/39Ar muscovite cooling age). The Toromocho magmatic-hydrothermal centre has a minimum of five recorded porphyry intrusions that span a total of 1.3 Ma and is responsible for the formation of the giant Toromocho Cu-Mo deposit. At least two hydrothermal pulses are identified. Post-dating a first pulse of molybdenite mineralisation, wide-spread hydrous skarn covers an area of over 6 km2 and is recorded by five 40Ar/39Ar cooling ages at 7.2-6.8 Ma. These ages mark the end of the slowly cooling and long-lived Toromocho magmatic-hydrothermal centre soon after last magmatic activity at 7.26 ± 0.02 Ma. District-wide (50 km2) Cordilleran base metal vein and replacement bodies post-date the youngest recorded porphyry mineralisation event at Toromocho

  2. Hydrothermal Evolution of the Giant Cenozoic Kadjaran porphyry Cu-Mo deposit, Tethyan metallogenic belt, Armenia, Lesser Caucasus: mineral paragenetic, cathodoluminescence and fluid inclusion constraints (United States)

    Hovakimyan, Samvel; Moritz, Robert; Tayan, Rodrik; Rezeau, Hervé


    The Lesser Caucasus belongs to the Central segment of the Tethyan metallogenic belt and it is a key area to understand the metallogenic evolution between the Western & Central parts of the Tethyan belt and its extension into Iran. Zangezur is the most important mineral district in the southernmost Lesser Caucasus. It is a component of the South Armenian block, and it was generated during the convergence and collision of the southern margin of the Eurasian plate and the northern margin of the Arabian plate, and terranes of Gondwana origin (Moritz et al., in press). The Zangezur ore district consists of the Tertiary Meghri-Ordubad composite pluton, which is characterized by a long-lasting Eocene to Pliocene magmatic, tectonic and metallogenic evolution. It hosts major porphyries Cu-Mo and epithermal Au - polymetallic deposits and occurrences, including the giant world class Kadjaran porphyry Cu-Mo deposit (2244 Mt reserves, 0.3% Cu, 0.05% Mo and 0.02 g/t Au). The Kadjaran deposit is hosted by a monzonite intrusion (31.83±0.02Ma; Moritz et al., in press). Detailed field studies of the porphyry stockwork and veins of the different mineralization stages, their crosscutting and displacement relationships and the age relationship between different paragenetic mineral associations were the criteria for distinction of the main stages of porphyry mineralization at the Kadjaran deposit. The economic stages being: quartz- molybdenite, quartz-molybdenite-chalcopyrite, and quartz-chalcopyrite. The main paragenetic association of the Kadjaran porphyry deposit includes pyrite, molybdenite, chalcopyrite, bornite, chalcocite, pyrrhotite, covellite, sphalerite, and galena. Recent field observations in the Kadjaran open pit revealed the presence of epithermal veins with late vuggy silica and advanced argillic alteration in the north-eastern and eastern parts of the deposit. They are distributed as separate veins and have also been recognized in re-opened porphyry veins and in

  3. Characterization of Two Microbial Isolates from Andean Lakes in Bolivia (United States)

    Demergasso, C.; Blamey, J.; Escudero, L.; Chong, G.; Casamayor, E. O.; Cabrol, N. A.; Grin, E. A.; Hock, A.; Kiss, A.; Borics, G.


    We are currently investigating the biological population present in the highest and least explored perennial lakes on earth in the Bolivian and Chilean Andes, including several volcanic crater lakes of more than 6000 m elevation, in combination of microbiological and molecular biological methods. Our samples were collected in saline lakes of the Laguna Blanca Laguna Verde area in the Bolivian Altiplano and in the Licancabur volcano crater (27 deg. 47 min S/67 deg. 47 min. W) in the ongoing project studying high altitude lakes. The main goal of the project is to look for analogies with Martian paleolakes. These Bolivian lakes can be described as Andean lakes following the classification of Chong. We have attempted to isolate pure cultures and phylogenetically characterize prokaryotes that grew under laboratory conditions. Sediment samples taken from the Licancabur crater lake (LC), Laguna Verde (LV), and Laguna Blanca (LB) were analyzed and cultured using enriched liquid media under both aerobic and anaerobic conditions. All cultures were incubated at room temperature (15 to 20 C) and under light exposure. For the reported isolates, 36 hours incubation were necessary for reaching optimal optical densities to consider them viable cultures. Ten serial dilutions starting from 1% inoculum were required to obtain a suitable enriched cell culture to transfer into solid media. Cultures on solid medium were necessary to verify the formation of colonies in order to isolate pure cultures. Different solid media were prepared using several combinations of both trace minerals and carbohydrates sources in order to fit their nutrient requirements. The microorganisms formed individual colonies on solid media enriched with tryptone, yeast extract and sodium chloride. Cells morphology was studied by optical and electronic microscopy. Rodshape morphologies were observed in most cases. Total bacterial genomic DNA was isolated from 50 ml late-exponential phase culture by using the CTAB

  4. Andean grasslands are as productive as tropical cloud forests

    International Nuclear Information System (INIS)

    We aim to assess net primary productivity (NPP) and carbon cycling in Andean tropical alpine grasslands (puna) and compare it with NPP of tropical montane cloud forests. We ask the following questions: (1) how do NPP and soil respiration of grasslands vary over the seasonal cycle? (2) how do burning and grazing affect puna productivity? (3) if the montane forest expands into the puna, what will be the resulting change in productivity? The study sites are located at the South-eastern Peruvian Andes; one grassland site and the forest sites are in Wayqecha biological station, and another grassland site in Manu National Park. At each grassland site, we selected a burnt and an unburnt area, installed unfenced and fenced transects in each area, and monitored above-ground productivity (NPPAG), below-ground productivity (NPPBG) and soil respiration (Rs) for 2 yr. In the forest, we monitored NPPAG, NPPBG and Rs for 2–4 yr. Grassland NPP varied between 4.6 ± 0.25 (disturbed areas) to 15.3 ± 0.9 Mg C ha−1 yr−1 (undisturbed areas) and cloud forest NPP was between 7.05 ± 0.39 and 8.0 ± 0.47 Mg C ha−1 yr−1, while soil carbon stocks were in the range of 126 ± 22 to 285 ± 31 Mg C ha−1. There were no significant differences on NPP between the puna and forest sites. The most undisturbed site had significantly higher NPP than other grassland sites, but no differences were found when relating grazing and fire at other sites. There were lower residence times of above-ground biomass compared to below-ground biomass. There was a strong seasonal signal on grassland NPPAG and NPPBG, with a shift on allocation at the beginning of the austral summer. High elevation tropical grasslands can be as productive as adjacent cloud forests, but have very different carbon cycling and retention properties than cloud forests. (paper)

  5. Genetic admixture and lineage separation in a southern Andean plant (United States)

    Morello, Santiago; Sede, Silvana M.


    Mountain uplifts have generated new ecologic opportunities for plants, and triggered evolutionary processes, favouring an increase on the speciation rate in all continents. Moreover, mountain ranges may act as corridors or barriers for plant lineages and populations. In South America a high rate of diversification has been linked to Andean orogeny during Pliocene/Miocene. More recently, Pleistocene glacial cycles have also shaped species distribution and demography. The endemic genus Escallonia is known to have diversified in the Andes. Species with similar morphology obscure species delimitation and plants with intermediate characters occur naturally. The aim of this study is to characterize genetic variation and structure of two widespread species of Escallonia: E. alpina and E. rubra. We analyzed the genetic variation of populations of the entire distribution range of the species and we also included those with intermediate morphological characters; a total of 94 accessions from 14 populations were used for the Amplified Fragment Length Polymorphism (AFLP) analysis. Plastid DNA sequences (trnS-trnG, 3′trnV-ndhC intergenic spacers and the ndhF gene) from sixteen accessions of Escallonia species were used to construct a Statistical Parsimony network. Additionally, we performed a geometric morphometrics analysis on 88 leaves from 35 individuals of the two E. alpina varieties to further study their differences. Wright’s Fst and analysis of molecular variance tests performed on AFLP data showed a significant level of genetic structure at the species and population levels. Intermediate morphology populations showed a mixed genetic contribution from E. alpina var. alpina and E. rubra both in the Principal Coordinates Analysis (PCoA) and STRUCTURE. On the other hand, E. rubra and the two varieties of E. alpina are well differentiated and assigned to different genetic clusters. Moreover, the Statistical Parsimony network showed a high degree of divergence between the

  6. Copper Bioleaching in Chile


    Juan Carlos Gentina; Fernando Acevedo


    Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first...

  7. Forests of the tropical eastern Andean flank during the middle Pleistocene

    NARCIS (Netherlands)

    M.L. Cárdenas; W.D. Gosling; R.T. Pennington; I. Poole; S.C. Sherlock; P. Mothes


    Inter-bedded volcanic and organic sediments from Erazo (Ecuador) indicate the presence of four different forest assemblages on the eastern Andean flank during the middle Pleistocene. Radiometric dates (40Ar-39Ar) obtained from the volcanic ash indicate that deposition occurred between 620,000 and 19

  8. Marcos Zapata's "Last Supper": a feast of European religion and Andean culture. (United States)

    Zendt, Christina


    In Marcos Zapata's 1753 painting of the Last Supper in Cuzco, Peru, Christian symbolism is filtered through Andean cultural tradition. Zapata was a late member of the Cuzco School of Painting, a group comprised of few European immigrants and handfuls of mestizo and Indian artists. The painters in Cuzco learned mostly from prints of European paintings, and their style tends to blend local culture into the traditional painting of their conquistadors. Imagery was the most successful tool used by the Spaniards in their quest to Christianize the Andean population. By teaching locals to paint Christian subjects, they were able to infuse Christianity into Andean traditions. Zapata's rendering of the Last Supper utilizes this cultural blending while staying true to the Christian symbolism within the subject. Instead of the traditional lamb, Zapata's Last Supper features a platter of cuy, or guinea pig, an Andean delicacy stocked with protein as well as cultural significance. Cuy was traditionally a sacrificial animal at Inca agricultural festivals and in this way it offers poignant parallel to the lamb, as a traditional Christian sacrificial animal. PMID:21568039

  9. The abiotic and biotic drivers of rapid diversification in Andean bellflowers (Campanulaceae). (United States)

    Lagomarsino, Laura P; Condamine, Fabien L; Antonelli, Alexandre; Mulch, Andreas; Davis, Charles C


    The tropical Andes of South America, the world's richest biodiversity hotspot, are home to many rapid radiations. While geological, climatic, and ecological processes collectively explain such radiations, their relative contributions are seldom examined within a single clade. We explore the contribution of these factors by applying a series of diversification models that incorporate mountain building, climate change, and trait evolution to the first dated phylogeny of Andean bellflowers (Campanulaceae: Lobelioideae). Our framework is novel for its direct incorporation of geological data on Andean uplift into a macroevolutionary model. We show that speciation and extinction are differentially influenced by abiotic factors: speciation rates rose concurrently with Andean elevation, while extinction rates decreased during global cooling. Pollination syndrome and fruit type, both biotic traits known to facilitate mutualisms, played an additional role in driving diversification. These abiotic and biotic factors resulted in one of the fastest radiations reported to date: the centropogonids, whose 550 species arose in the last 5 million yr. Our study represents a significant advance in our understanding of plant evolution in Andean cloud forests. It further highlights the power of combining phylogenetic and Earth science models to explore the interplay of geology, climate, and ecology in generating the world's biodiversity. PMID:26990796

  10. A novel cold active esterase derived from Colombian high Andean forest soil metagenome

    NARCIS (Netherlands)

    Jiménez, Diego Javier; Montaña, José Salvador; Alvarez, Diana; Baena, Sandra


    In order to search new lipolytic enzymes and conduct bioprospecting of microbial communities from high Andean forest soil, a metagenomic library of approximately 20,000 clones was constructed in Escherichia coli using plasmid p-Bluescript II SK+. The library covered 80 Mb of the metagenomic DNA main

  11. Taxonomic and functional assignment of cloned sequences from high Andean forest soil metagenome

    NARCIS (Netherlands)

    Montaña, José Salvador; Jiménez Avella, Diego; Angel, Tatiana; Hernández, Mónica; Baena, Sandra


    Total metagenomic DNA was isolated from high Andean forest soil and subjected to taxonomical and functional composition analyses by means of clone library generation and sequencing. The obtained yield of 1.7 μg of DNA/g of soil was used to construct a metagenomic library of approximately 20,000 clon

  12. The electronic procurement in the framework of the Andean Community. State of the art


    William David Hernández Martínez


    The article is structured as a brief survey of the academic and policy approach on the unification or harmonization of regulations about electronic commerce, specifically relating the electronic contracts, in Latin America, with special emphasis on the Andean Community of Nations as a proposed work on the development of modern trends of international trade law.

  13. Synopsis of Central Andean Orthalicoid land snails (Gastropoda, Stylommatophora), excluding Bulimulidae


    Abraham S.H. Breure; Avila, Valentín Mogollón


    Abstract A faunal overview is presented of the molluscan families Amphibulimidae , Megaspiridae , Odontostomidae , Orthalicidae , Simpulopsidae in Bolivia, Ecuador, and Peru. These Central Andean countries are known for their biodiverse malacofauna, of which the superfamily Orthalicoidea takes relatively a large share. In this paper the five families containing 103 (sub)species, for which systematic information (original publication, type locality, type depository, summarizing literature) and...

  14. Persistence of chironomids in metal polluted Andean high altitude streams: does melanin play a role?

    NARCIS (Netherlands)

    R.A. Loayza Muro; J.K. Marticorena-Ruíz; E.J. Palomino; C. Merritt; M.L. de Baat; M. van Gemert; R.A. Verweij; M.H.S. Kraak; W. Admiraal


    In high altitude Andean streams an intense solar radiation and coinciding metal pollution allow the persistence of only a few specialized taxa, including chironomids. The aim of the present study was therefore to determine the mechanisms underlying the persistence of chironomids under these multiple

  15. Phylogeny and historical biogeography of trans-Andean cichlid fishes (Teleostei: Cichlidae)

    Czech Academy of Sciences Publication Activity Database

    Musilová, Zuzana; Říčan, O.; Říčanová, Š.; Janšta, P.; Gahura, O.; Novák, J.


    Roč. 65, č. 3 (2015), s. 333-350. ISSN 1864-5755 R&D Projects: GA MŠk LC06073 Institutional support: RVO:67985904 Keywords : Andean uplift * Andinoacara * Mesoheros Subject RIV: EG - Zoology Impact factor: 0.593, year: 2014

  16. 76 FR 8766 - Agency Information Collection Activities: Andean Trade Preference Act (United States)


    ... Register (75 FR 73118) on November 29, 2010, allowing for a 60-day comment period. This notice allows for... Preference Act AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION: 30-Day... accordance with the Paperwork Reduction Act: Andean Trade Preference Act. This is a proposed extension of...

  17. Copper Metabolism of Astrocytes

    Directory of Open Access Journals (Sweden)

    Ralf eDringen


    Full Text Available This short review will summarize the current knowledge on the uptake, storage and export of copper ions by astrocytes and will address the potential roles of astrocytes in copper homeostasis in the normal and diseased brain. Astrocytes in culture efficiently accumulate copper by processes that include both the copper transporter Ctr1 and Ctr1-independent mechanisms. Exposure of astrocytes to copper induces an increase in cellular glutathione (GSH content as well as synthesis of metallothioneins, suggesting that excess of copper is stored as complex with GSH and in metallothioneins. Furthermore, exposure of astrocytes to copper accelerates the release of GSH and of glycolytically generated lactate. Astrocytes are able to export copper and express the Menkes protein ATP7A. This protein undergoes reversible, copper-dependent trafficking between the trans-Golgi network and vesicular structures. The ability of astrocytes to efficiently take up, store and export copper suggests that astrocytes play a key role in the supply of neurons with copper and that astrocytes should be considered as target for therapeutic inventions that aim to correct disturbances in brain copper homeostasis.

  18. Geological, geochronological, geochemical, and Sr-Nd-O-Hf isotopic constraints on origins of intrusions associated with the Baishan porphyry Mo deposit in eastern Tianshan, NW China (United States)

    Wang, Yinhong; Xue, Chunji; Liu, Jiajun; Zhang, Fangfang


    The Baishan porphyry Mo deposit (0.72 Mt; 0.06 % Mo) is located in the interior of the eastern Tianshan orogenic belt in Xinjiang, NW China. The deposit comprises 15 orebodies that are associated with monzogranite and granite porphyry stocks and are structurally controlled by roughly EW-trending faults. Secondary ion mass spectrometry (SIMS) zircon U-Pb dating of the monzogranite and granite porphyry yielded the Middle Triassic age (228 ± 2 to 227 ± 2 Ma), which coincide with the molybdenite Re-Os model ages ranging from 226 ± 3 to 228 ± 3 Ma. The Triassic monzogranite and granite porphyry belong to high-K calc-alkaline series and are characterized by high SiO2 and Al2O3 and low MgO, TiO2, and P2O5 concentrations, with negative Eu anomalies (δEu = 0.55-0.91). The least-altered monzogranite and granite porphyry yield uniform ɛ Nd(t) values from +1.6 to +3.6, and wide (87Sr/86Sr) i ratios ranging between 0.7035 and 0.7071, indicating that they were derived from the lower crust. In situ O-Hf isotopic analyses on zircon using SIMS and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) indicate that the δ18O and ɛ Hf(t) values of zircon from a monzogranite sample vary from 6.1 to 7.3 ‰ and +8.0 to +11.7, respectively, whereas zircon from a granite porphyry sample vary from 6.2 to 6.9 ‰ and +7.3 to +11.2, respectively. The geochemical and isotopic data imply that the primary magmas of the Baishan granite were likely derived from partial melts from the lower crust involving some mantle components. The Baishan Mo deposit and granitic emplacement were proposed to be most likely related to post-orogenic lithospheric extension and magmatic underplating. An extensional event coupled with the rising of hot mantle-derived melts triggered partial melting of the lower crust, as well as provided metals (Mo).

  19. Shifts in leaf litter breakdown along a forest-pasture-urban gradient in Andean streams. (United States)

    Iñiguez-Armijos, Carlos; Rausche, Sirkka; Cueva, Augusta; Sánchez-Rodríguez, Aminael; Espinosa, Carlos; Breuer, Lutz


    Tropical montane ecosystems of the Andes are critically threatened by a rapid land-use change which can potentially affect stream variables, aquatic communities, and ecosystem processes such as leaf litter breakdown. However, these effects have not been sufficiently investigated in the Andean region and at high altitude locations in general. Here, we studied the influence of land use (forest-pasture-urban) on stream physico-chemical variables (e.g., water temperature, nutrient concentration, and pH), aquatic communities (macroinvertebrates and aquatic fungi) and leaf litter breakdown rates in Andean streams (southern Ecuador), and how variation in those stream physico-chemical variables affect macroinvertebrates and fungi related to leaf litter breakdown. We found that pH, water temperature, and nutrient concentration increased along the land-use gradient. Macroinvertebrate communities were significantly different between land uses. Shredder richness and abundance were lower in pasture than forest sites and totally absent in urban sites, and fungal richness and biomass were higher in forest sites than in pasture and urban sites. Leaf litter breakdown rates became slower as riparian land use changed from natural to anthropogenically disturbed conditions and were largely determined by pH, water temperature, phosphate concentration, fungal activity, and single species of leaf-shredding invertebrates. Our findings provide evidence that leaf litter breakdown in Andean streams is sensitive to riparian land-use change, with urban streams being the most affected. In addition, this study highlights the role of fungal biomass and shredder species (Phylloicus; Trichoptera and Anchytarsus; Coleoptera) on leaf litter breakdown in Andean streams and the contribution of aquatic fungi in supporting this ecosystem process when shredders are absent or present low abundance in streams affected by urbanization. Finally, we summarize important implications in terms of managing of

  20. Andean Condor (Vultur gryphus) in Ecuador: Geographic Distribution, Population Size and Extinction Risk. (United States)

    Naveda-Rodríguez, Adrián; Vargas, Félix Hernán; Kohn, Sebastián; Zapata-Ríos, Galo


    The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation. PMID:26986004

  1. Adaptation and mal-adaptation to ambient hypoxia; Andean, Ethiopian and Himalayan patterns.

    Directory of Open Access Journals (Sweden)

    Guoqiang Xing

    Full Text Available The study of the biology of evolution has been confined to laboratories and model organisms. However, controlled laboratory conditions are unlikely to model variations in environments that influence selection in wild populations. Thus, the study of "fitness" for survival and the genetics that influence this are best carried out in the field and in matching environments. Therefore, we studied highland populations in their native environments, to learn how they cope with ambient hypoxia. The Andeans, African highlanders and Himalayans have adapted differently to their hostile environment. Chronic mountain sickness (CMS, a loss of adaptation to altitude, is common in the Andes, occasionally found in the Himalayas; and absent from the East African altitude plateau. We compared molecular signatures (distinct patterns of gene expression of hypoxia-related genes, in white blood cells (WBC from Andeans with (n = 10, without CMS (n = 10 and sea-level controls from Lima (n = 20 with those obtained from CMS (n = 8 and controls (n = 5 Ladakhi subjects from the Tibetan altitude plateau. We further analyzed the expression of a subset of these genes in Ethiopian highlanders (n = 8. In all subjects, we performed the studies at their native altitude and after they were rendered normoxic. We identified a gene that predicted CMS in Andeans and Himalayans (PDP2. After achieving normoxia, WBC gene expression still distinguished Andean and Himalayan CMS subjects. Remarkably, analysis of the small subset of genes (n = 8 studied in all 3 highland populations showed normoxia induced gene expression changes in Andeans, but not in Ethiopians nor Himalayan controls. This is consistent with physiologic studies in which Ethiopians and Himalayans show a lack of responsiveness to hypoxia of the cerebral circulation and of the hypoxic ventilatory drive, and with the absence of CMS on the East African altitude plateau.

  2. Reconciling Local and Global Agendas in Sustainable Development: Participatory Research with Indigenous Andean Communities

    Institute of Scientific and Technical Information of China (English)

    Robert E. Rhoades; Virginia Nazarea


    This paper discusses participatory research in the Andes and presents a case study in Cotacachi, Ecuador, where sustainability scientists and indigenous people seek common ground in their respective but drastically different research and social agendas. Participatory research based on Andean experiences pre-dated and inspired much of the later international movement in agriculture, health, and conservation. Andean communities have a long history in demanding that outsiders address the needs of the community as a condition for carrying out scientific or applied activities. What an Andean community, however, sees as relevant may or may not practiced throughout much of the world. In fact,overzealous participatory researchers are just as bothersome as their predecessors bearing long questionnaires. More important to Andean people is an equitable relationship with researchers and developers in which exchanges of value are made. A research is drawn. In the case of the SANREM project in Cotacachi, Ecuador, scientists carried out enriching research activities of interest to local people as a way to generate social capital for conducting basic research which does not have an obvious, immediate local benefit. The requested research did not have a conventional participatory methodology but provided valuable products (educational opportunity,germplasm, community visualization tools, and information) to the indigenous community in exchange for time and resources to conduct research on more basic natural resource questions. We argue that in the Andean context the key to reconciling the needs of scientists and of local needs is seeking new forms of equitable collaboration which reach beyond the present and now somewhat tired discourse of ‘participation'.

  3. Formation of the giant Chalukou porphyry Mo deposit in northern Great Xing'an Range, NE China: Partial melting of the juvenile lower crust in intra-plate extensional environment (United States)

    Li, Zhen-Zhen; Qin, Ke-Zhang; Li, Guang-Ming; Ishihara, Shunso; Jin, Lu-Ying; Song, Guo-Xue; Meng, Zhao-Jun


    The Chalukou porphyry Mo deposit (2.46 Mt @ 0.087% Mo), located in the northern Great Xing'an Range, NE China, is the largest Mo deposit discovered in China so far. The host rocks consist of aplite porphyry, granite porphyry and quartz porphyry, and are intruded into Lower Ordovician intermediate-felsic volcanic-sedimentary rocks and pre-ore monzogranite and are cut by post-ore feldspar porphyry, diorite porphyry and quartz monzonite porphyry. Here, we present the zircon U-Pb ages, whole-rock geochemistry, Sr-Nd isotopic and zircon Hf isotopic data for the pre-ore, syn-ore and post-ore intrusive rocks. The Chalukou ore-forming porphyries intruded during 147-148 Ma and have high-silica, alkali-rich, metaluminous to slightly peraluminous compositions and are oxidized. They are enriched in large ion lithophile elements (e.g. K, Rb, U and Th), light REE and depleted in high-field strength elements (e.g. Nb, P and Ti). Depletions in Eu, Ba, Sr, Nb, Ta, P and Ti suggest that they have experienced strong fractional crystallization of plagioclase, biotite, hornblende and accessory minerals. The pre-ore monzogranite (~ 172 Ma) also belongs to the high-K calc-alkaline series. Highly fractionated REE patterns ((La/Yb) N = 19.6-21.7), high values of Sr/Y (54-69) and La/Yb (29-32), are adakite-like geochemical features. The post-ore rocks (~ 141-128 Ma) have similar geochemical characteristics with ore-forming porphyries except that quartz monzonite porphyry shows no Ba-Sr negative anomaly. All intrusive rocks have relative low initial 87Sr/86Sr (0.705413-0.707889) and εNd (t) values (- 1.28 to + 0.92), positive εHf (t) values (+ 2.4 to + 10.1) and young two-stage Nd and Hf model ages (TDM2 (Nd) = 863-977 Ma, TDM2 (Hf) = 552-976 Ma). These geochemical and isotopic data are interpreted to demonstrate that the ore-forming porphyries formed by partial melting of the juvenile lower crust caused by underplating of mafic magmas in an intra-plate extensional setting. The pre

  4. Copper Bioleaching in Chile

    Directory of Open Access Journals (Sweden)

    Juan Carlos Gentina


    Full Text Available Chile has a great tradition of producing and exporting copper. Over the last several decades, it has become the first producer on an international level. Its copper reserves are also the most important on the planet. However, after years of mineral exploitation, the ease of extracting copper oxides and ore copper content has diminished. To keep the production level high, the introduction of new technologies has become necessary. One that has been successful is bioleaching. Chile had the first commercial operation in the world exclusively via bioleaching copper sulfides. Nowadays, all bioleaching operations run in the country contribute to an estimated 10% of total copper production. This article presents antecedents that have contributed to the development of copper bioleaching in Chile.

  5. Helium isotope characteristics of Andean geothermal fluids and lavas (United States)

    Hilton, D. R.; Hammerschmidt, K.; Teufel, S.; Friedrichsen, H.


    The first comprehensive helium isotope survey of the Andes is reported here. We have sampled geothermal fluids and phyric lava flows from the Southern (svz) and Central (cvz) Volcanic Zones, the volcanically active Puna region and the Precordillera, Salta Basin, Longitudinal Valley and the aseismic region between the two volcanic zones. Although the active areas are characterized by significant differences in crustal age and thickness, the svz, cvz and Puna are characterized by a wide and overlapping range in He-3/He-4 ratios (for fluids and phenocrysts) from predominantly radiogenic values to close to the Mid-Ocean Ridge Basalt (MORB) ratio. The measured ranges in He-3/He-4 ratios (R) (reported normalised to the air He-3/He-4 -- R(sub A)) are: svz (0.18 less than R/R(sub A) less than 6.9); cvz (0.82 less than R/R(sub A) less than 6.0); and Puna (1.8 less than R/R(sub A) less than 5.4). Modification of magmatic He-3/He-4 ratios by water/rock interactions (fluids) or post-eruptive grow-in of radiogenic He-4 or preferential diffusive loss of He-3 (phenocrysts) is considered unlikely; this means that the wide range reflects the helium isotope characteristics of magma bodies in the Andean crust. The mechanism controlling the He-3/He-4 ratios appears to be a mixing between mantle (MORB-like) helium and a radiogenic helium component derived from radioactive decay within the magma (magma aging) and/or interaction with He-4-rich country rock: a process expected to be influenced by pre-eruptive degassing of the mantle component. Assimilation of lower crust is also capable of modifying He-3/He-4 ratios, albeit to a much lesser extent. However, it is possible that the highest measured values in each zone were established by the addition of lower crustal radiogenic helium to MORB helium. In this case, the higher 'base level' ratios of the svz would reflect the younger crustal structure of this region. In contrast to helium, there is no overlap in the Sr or Pb isotope

  6. Sr and O isotopic characteristics of porphyries in the Qinling molybdenum deposit belt and their implication to genetic mechanism and type

    Institute of Scientific and Technical Information of China (English)

    陈衍景; 李超; 张静; 李震; 王海华


    A great deal of Mesozoic hypobatholithic granites and hypabyssal porphyries develop in the Qinling Mountains. The former has long been regarded as transformation type (or S-type), and the latter associated with Mo-mineralization regarded as syntexis type (or l-type) granitoids. Statistics show that Sr, andδ18O of hypabyssal porphyries respectively range from 0.705 to 0.714, and from 7.2‰ to 12.1‰, agreeing with those of hypobatholithes (Sr1=0.705-0.710, δ18O = 6.1‰-10.4‰), which indicates that they share similar material sources and petrogenic mechanism. Based on analysis of lithological, mineralogical and geochemical characteristics of these granitoids and on study of their petrogenic tectonic background and regional geophysical data, we argue that both the shallow-seated porphyries and deep-seated batholithes were the products of Mesozoic collision between South China and North China paleocontinents. Subsequently, all these granti-toids should be attributed to collision type.

  7. Regional Trade Agreements: Effects of the Andean and Mercosur Packs on the Venezuelan Soybean Trade and U.S. Exports


    Reeder, John; Torene, Jillian A.; Jabara, Cathy L.; Babula, Ronald A.


    Since the mid-1990s, the two regional trade agreements in South America, the southern Mercosur Pact (among Brazil, Argentina, Paraguay and Uruguay), and the northern Andean Pact (among Venezuela, Colombia, Ecuador, Bolivia, and Peru) noticeably affected certain trade patterns between the two pacts' members and with the United States for various reasons discussed herein. The effect of trade diversion owing to the Andean Pact with its common external tariff and price band system against non-And...

  8. Plant-water relations in an Andean landscape: Modeling the effect of irrigation on upland crop production


    Zehetner, Franz; Miller, W.


    In the inter-Andean valleys of northern Ecuador, irrigation systems have long been used to minimize drought risk and secure the production of food crops during dry periods. However, not all Andean communities have access to irrigation water. Increasing population pressure has forced many peasant farmers to move higher up the volcanic slopes and cultivate more marginal land under rainfed conditions. In the SANREM CRSP research site of Cotacachi, local community members and officials of the loc...

  9. Determination of copper isotope ratios by LA-MC-ICP-MS

    International Nuclear Information System (INIS)

    Full text: The stable isotope ratios of metals commonly found in sulphide ore deposits (e.g., Cu, Zn. Fe, Sb, Ag) may be fractionated significantly during ore-forming processes (redox reactions, etc.) and thus provide important information on the source, transport and depositional mechanisms of these metals. However, little work has been done on these isotopic systems because of past analytical difficulties in making precise measurements. Recently developed laser ablation (LA)-multi-collector (MC)-ICP-MS technology now allows routine rapid, in situ determination of the isotope ratios of these metals. This study reports on: (a) the development of an analytical protocol for the measurement of the 65Cu/63Cu ratio of chalcopyrite, (b) preliminary data for samples from a wide range of copper-bearing mineral deposits, and (c) a preliminary study of the spatial distribution of Cu isotope ratios within the Cadia Hill porphyry Cu-Au deposit. The instrumentation used in this study was a Merchantek LUV266 laser sampler operated with either Ar or He as the sample carrier gas. The ablated material was transported into a Plasma MC-ICP-MS for isotopic determination. Instrumental mass bias was corrected using the measured 66Zn/64Zn ratio of a Zn-bearing aerosol added continuously to the ablated sample carrier gas flow via a T-junction. The isotopes of copper (and other metals) are fractionated significantly by volatilisation and condensation processes operative during the laser sampling/transport processes, both of which favour depletion of 65Cu relative to 63Cu in the transported material. This fractionation may be reduced by using high laser pulse energies, low repetition rates and, most significantly, by ablation in He, which reduces dramatically the condensation blanket of sulphidic material around the ablation site. Using these conditions, relatively stable Cu isotope ratios may be maintained over a long ablation period (up to 4 minutes). However, absolute ratios are still

  10. Study on the origin of the Hongshan brecciated copper deposit in Huichang County,Jiangxi Province, China

    Institute of Scientific and Technical Information of China (English)


    The Hongshan copper deposit is a typical cryptoexplosive breccia-type deposit, which occurs in a Metamorphic rock series of the Mesoproterozoic Taoxiyuan Formation. Orebodies are distributed inside and outside porphyry-cryptoexplosive breccia pipes. The isotope geochemistry of the deposit is consistent with the origin of porphyry breccia: the δ18OH2O values ranging from 1.2‰ to 6.1‰ and the δ34S values varying from 0 to 2.5‰.206Pb/204Pb,207Pb/204Pb and 208Pb/204Pb ratios of pyrite, which coexists with ore minerals, indicate it was derived from the orogenic belt. Thermodynamic analysis indicates that the main metals were deposited largely as a result of the decreasing of proton concentrations associated with H2S and CO2 exsolution during exploslon and temperature dropping.Based on K-Ar dating of quartz coexisting with ore minerals,the age of mineralization was estimated to be 97.1-98.8 Ma,which suggests that mineralization occurred between the Early and Late Cretaceous. According to the relevant informtion obtained,a diagenetic and metallogenic pattern in the area has been presented in this paper.