Clay squirt: Local flow dispersion in shale-bearing sandstones

DEFF Research Database (Denmark)

Sørensen, Morten Kanne; Fabricius, Ida Lykke

2017-01-01

Dispersion of elastic-wave velocity is common in sandstone and larger in shaly sandstone than in clean sandstone. Dispersion in fluid-saturated shaly sandstone often exceeds the level expected from the stress-dependent elastic moduli of dry sandstone. The large dispersion has been coined clay...... squirt and is proposed to originate from a pressure gradient between the clay microporosity and the effective porosity. We have formulated a simple model that quantifies the clay-squirt effect on bulk moduli of sandstone with homogeneously distributed shale laminae or dispersed shale. The model...... predictions were compared with the literature data. For sandstones with dispersed shale, agreement was found, whereas other sandstones have larger fluid-saturated bulk modulus, possibly due to partially load-bearing shales or heterogeneous shale distribution. The data that agree with the clay-squirt model...

Experimental strain analysis of Clarens Sandstone colonised by endolithic lichens

Directory of Open Access Journals (Sweden)

D. Wessels

1995-08-01

Full Text Available Endolithic lichens occur commonly on Clarens Sandstone in South Africa, where they significantly contribute to the weathering of sandstone by means of mechanical and chemical weathering processes. This preliminary investigation reports on the success- ful use of strain gauges in detecting strain differences between sandstone without epilithic lichens and sandstone colonised by the euendolithic lichen Lecidea aff. sarcogynoides Korb. Mechanical weathering, expressed as strain changes, in Clarens Sandstone was studied during the transition from relatively dry winter to wet summer conditions. Daily weathering of sandstone due to thermal expansion and contraction of colonised and uncolonised sandstone could be shown. Our results show that liquid water in sandstone enhances the mechanical weathering of uncolonised Clarens Sandstone while water in the gaseous phase enhances mechanical weathering of sandstone by euendolithic lichens.

Geothermal characteristics of Buntsandstein sandstone reservoir of Alsace

International Nuclear Information System (INIS)

Haffen, Sebastien

2012-01-01

The Buntsandstein, located in the Upper Rhine Graben, appears to be an easy target for geothermal exploitation, linking sandstone and clay with the regional thermal anomaly. This study aims at characterizing petrophysical characteristics of these sandstones as well as the fracturing affecting them, with the intention of providing a conceptual model of the formation which will act as guide for future exploitation. The sedimentary facies are composed by five petrographical facies (clean sandstones, sandstones with clayey coating, clay matrix sandstones, silicified sandstones and carbonated matrix sandstones) which split with variable proportions and control a part of petrophysical properties measured at matrix scale. The comparison between petrophysical data, macroscopic data from temperature gradient analysis, modelling data and fracturing, allows the building of a Buntsandstein Sandstones fluids circulation conceptual model. This analysis points the role of the damage zone of fault zones for fluids transfer at large scale, but also that of two sedimentary facies: marginal erg and Playa Lake. The analysis of different outcrops shows that the fracturing evolves according to the situation in the sedimentary pile and according to the situation in comparison with major tectonic accidents. (author) [fr

Factors controlling localization of uranium deposits in the Dakota Sandstone, Gallup and Ambrosia Lake mining districts, McKinley County, New Mexico

Science.gov (United States)

Pierson, Charles Thomas; Green, Morris W.

1977-01-01

Geologic studies were made at all of the uranium mines and prospects in the Dakota Sandstone of Early(?) and Late Cretaceous age in the Gallup mining district, McKinley County, New Mexico. Dakota mines in the adjacent Ambrosia Lake mining district were visited briefly for comparative purposes. Mines in the eastern part of the Gallup district, and in the Ambrosia Lake district, are on the Chaco slope of the southern San Juan Basin in strata which dip gently northward toward the central part of the basin. Mines in the western part of the Gallup district are along the Gallup hogback (Nutria monocline) in strata which dip steeply westward into the Gallup sag. Geologic factors which controlled formation of the uranium deposits in the Dakota Sandstone are: (1) a source of uranium, believed to be uranium deposits of the underlying Morrison Formation of Late Jurassic age; (2) the accessibility to the Dakota of uranium-bearing solutions from the Morrison; (3) the presence in the Dakota of permeable sandstone beds overlain by impermeable carbonaceous shale beds; and (4) the occurrence within the permeable Dakota sandstone beds of carbonaceous reducing material as bedding-plane laminae, or as pockets of carbonaceous trash. Most of the Dakota uranium deposits are found in the lower part of the formation in marginal-marine distributary-channel sandstones which were deposited in the backshore environment. However, the Hogback no. 4 (Hyde) Mine (Gallup district) occurs in sandy paludal shale of the backshore environment, and another deposit, the Silver Spur (Ambrosia Lake district), is found in what is interpreted to be a massive beach or barrier-bar sandstone of the foreshore environment in the upper part of the Dakota. The sedimentary depositional environment most favorable for the accumulation of uranium is that of backshore areas lateral to main distributary channels, where levee, splay, and some distributary-channel sandstones intertongue with gray carbonaceous shales and

Responses of soil fungal community to the sandy grassland restoration in Horqin Sandy Land, northern China.

Science.gov (United States)

Wang, Shao-Kun; Zuo, Xiao-An; Zhao, Xue-Yong; Li, Yu-Qiang; Zhou, Xin; Lv, Peng; Luo, Yong-Qing; Yun, Jian-Ying

2016-01-01

Sandy grassland restoration is a vital process including re-structure of soils, restoration of vegetation, and soil functioning in arid and semi-arid regions. Soil fungal community is a complex and critical component of soil functioning and ecological balance due to its roles in organic matter decomposition and nutrient cycling following sandy grassland restoration. In this study, soil fungal community and its relationship with environmental factors were examined along a habitat gradient of sandy grassland restoration: mobile dunes (MD), semi-fixed dunes (SFD), fixed dunes (FD), and grassland (G). It was found that species abundance, richness, and diversity of fungal community increased along with the sandy grassland restoration. The sequences analysis suggested that most of the fungal species (68.4 %) belonged to the phylum of Ascomycota. The three predominant fungal species were Pleospora herbarum, Wickerhamomyces anomalus, and Deconica Montana, accounting for more than one fourth of all the 38 species. Geranomyces variabilis was the subdominant species in MD, Pseudogymnoascus destructans and Mortierella alpine were the subdominant species in SFD, and P. destructans and Fungi incertae sedis were the dominant species in FD and G. The result from redundancy analysis (RDA) and stepwise regression analysis indicated that the vegetation characteristics and soil properties explain a significant proportion of the variation in the fungal community, and aboveground biomass and C:N ratio are the key factors to determine soil fungal community composition during sandy grassland restoration. It was suggested that the restoration of sandy grassland combined with vegetation and soil properties improved the soil fungal diversity. Also, the dominant species was found to be alternative following the restoration of sandy grassland ecosystems.

The Paleozoic-Mesozoic recycling of the Rakaia Terrane, South Island, New Zealand : sandstone clast and sandstone petrology, geochemistry, and geochronology

International Nuclear Information System (INIS)

Wandres, A.M.; Bradshaw, J.D.; Ireland, T.

2005-01-01

The Torlesse terranes - part of the New Zealand Eastern Province - are accretionary complexes that comprise an enormous volume of quartzofeldspathic sandstones and mudstones with subsidiary conglomerates plus minor oceanic assemblages. Two terranes are recognised in the South Island - the Permian to Late Triassic Rakaia Terrane and the Late Jurassic to Early Cretaceous Pahau Terrane. Sandstone clasts from two Rakaia Terrane and two Pahau Terrane conglomerates were collected. We present the first combined detailed information on petrography and geochemistry of Torlesse conglomerate sandstone clasts and use our own and published U-Pb SHRIMP detrital zircon age data to demonstrate the recycling of the Rakaia Terrane into Rakaia strata itself and into Pahau Terrane strata. Sandstone clast major and trace element chemical data largely support petrographic observations derived from thin-section analysis. The similarities of petrographic and geochemical data between sandstone clasts from the Rakaia Terrane and Rakaia sandstones suggest that clasts in the Permian Te Moana and Late Triassic Lake Hill Conglomerates were derived by autocannibalistic reworking of older, consolidated, Rakaia sediments. Data from sandstone clasts from the Pahau Terrane suggest that uplift of the Rakaia Terrane continued into the Cretaceous. These Pahau Terrane clasts indicate that at the time of the Pahau sedimentation Permian to early Late Triassic Rakaia rocks were exposed and recycled into the Pahau Basin. (author). 57 refs., 8 figs., 3 tables

Respirable dust and quartz exposure from three South African farms with sandy, sandy loam, and clay soils.

Science.gov (United States)

Swanepoel, Andrew J; Kromhout, Hans; Jinnah, Zubair A; Portengen, Lützen; Renton, Kevin; Gardiner, Kerry; Rees, David

2011-07-01

To quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and to ascertain whether soil type is a determinant of exposure to respirable quartz. Three farms, located in the Free State and North West provinces of South Africa, had their soil type confirmed as sandy, sandy loam, and clay; and, from these, a total of 298 respirable dust and respirable quartz measurements were collected between July 2006-November 2009 during periods of major farming operations. Values below the limit of detection (LOD) (22 μg · m(-3)) were estimated using multiple 'imputation'. Non-parametric tests were used to compare quartz exposure from the three different soil types. Exposure to respirable quartz occurred on all three farms with the highest individual concentration measured on the sandy soil farm (626 μg · m(-3)). Fifty-seven, 59, and 81% of the measurements on the sandy soil, sandy loam soil, and clay soil farm, respectively, exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25 μg · m(-3). Twelve and 13% of respirable quartz concentrations exceeded 100 μg · m(-3) on the sandy soil and sandy loam soil farms, respectively, but none exceeded this level on the clay soil farm. The proportions of measurements >100 μg · m(-3) were not significantly different between the sandy and sandy loam soil farms ('prop.test'; P = 0.65), but both were significantly larger than for the clay soil farm ('prop.test'; P = 0.0001). The percentage of quartz in respirable dust was determined for all three farms using measurements > the limit of detection. Percentages ranged from 0.5 to 94.4% with no significant difference in the median quartz percentages across the three farms (Kruskal-Wallis test; P = 0.91). This study demonstrates that there is significant potential for over-exposure to respirable quartz in

IMPLEMENTASI SANDI HILL UNTUK PENYANDIAN CITRA

Directory of Open Access Journals (Sweden)

JJ Siang

2002-01-01

Full Text Available Hill's code is one of text encoding technique. In this research, Hill's code is extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used as a key. The results show that Hill's code is suitable for image whose RGB values vary highly. On the contrary, it is not suitable for less varied RGB images since its original pattern is still persisted in encrypted image. Hill's code for image encoding has also disadvantage in the case that the key matrix is not unique. However, for daily application, with good key matrix, Hill's code can be applied to encode image since it's process only deals with simple matrix operation so it become fast. Abstract in Bahasa Indonesia : Sandi Hill merupakan salah satu teknik penyandian teks. Dalam penelitian ini, pemakaian sandi Hill diperluas dari teks ke citra bertipe BMP 24 bit. Matriks yang dipakai berordo 2x2 dan 3x3. Hasil percobaan menunjukkan bahwa sandi Hill cocok untuk enkripsi citra dengan variasi nilai RGB antar piksel berdekatan yang tinggi (seperti foto, tapi tidak cocok untuk citra dengan variasi nilai RGB yang rendah (seperti gambar kartun karena pola citra asli masih tampak dalam citra sandi. Sandi Hill juga memiliki kelemahan dalam hal tidak tunggalnya matriks kunci yang dapat dipakai. Akan tetapi untuk pemakaian biasa, dengan pemilihan matriks kunci yang baik, sandi Hill dapat dipakai untuk penyandian karena hanya melibatkan operasi matriks biasa sehingga prosesnya relatif cepat. Kata kunci: Sandi Hill, Citra, Relatif Prima.

Sandstone Turning by Abrasive Waterjet

Czech Academy of Sciences Publication Activity Database

Hlaváček, Petr; Cárach, J.; Hloch, Sergej; Vasilko, K.; Klichová, Dagmar; Klich, Jiří; Lehocká, D.

2015-01-01

Roč. 48, č. 6 (2015), s. 2489-2493 ISSN 0723-2632 R&D Projects: GA MŠk ED2.1.00/03.0082; GA MŠk(CZ) LO1406 Institutional support: RVO:68145535 Keywords : turning away from the jet * conventional turning towards the jet * sandstone * abrasive water jet Subject RIV: JQ - Machines ; Tools Impact factor: 2.386, year: 2015 http://www.springerprofessional.de/sandstone-turning-by-abrasive-waterjet/6038028.html

Regional distribution regularity of sandstone uranium deposits in Asian continent and prospecting strategy for sandstone uranium deposits in China

International Nuclear Information System (INIS)

Chen Zuyi

2002-01-01

Since the 1980's, after the discovery of numerous sandstone uranium deposits in Middle Asia (Kazakhstan, Uzbekistan) many large sandstone uranium deposits have been found in both Russia and Mongolia. So that Asia has become the most concentrated region of sandstone uranium deposits. The known sandstone uranium deposits occur mostly in a arcual tectonic belt constrained from the north by the Siberian continental block, and the Tarim-North China continental block from the south. This belt is named by Russian geologists as the Central Asian Mobile Belt, and some Chinese geologists call it the 'Mongolian Arc'. A lot of large and super large metallic, non-metallic, gold, polymetallic, porphyry copper and gold, massive sulphide and uranium deposits (of sandstone and volcanic types) with different origin and various types concentrated occur in this belt. The abundant and colourful mineral resources in the region are closely associated with the specific geologic-tectonic evolution of the above belt. It is necessary to strengthen the detailed geologic research and uranium prospecting in the region

Discussion on the origin of bleached sandstone of Qianjiadian uranium deposit

International Nuclear Information System (INIS)

Pang Yaqing; Xiang Weidong; Li Tiangang; Chen Xiaolin; Xia Yuliang

2007-01-01

Qianjiadian uranium deposit is a sandstone-type uranium deposit that has been discovered in Songliao Basin in recent years. Uranium ore bodies are planar or lenticular in shape and under the control of the contact between gray sandstones and bleached sandstones. The bleached sandstone is white in color, cemented loosely, nearly without TOC and pyrite contained and rich in uranium. Geochemical characteristics and types and assemblages of clay minerals of the bleached sandstone reveal that the bleached sandstone is the product of oxidation of the interlayer oxidation zone, and it is a part of the interlayer oxidation zone. The main reasons for white color of the bleached sandstone are transfer of iron ion, oxidation of TOC and kaolinization of sandstone. (authors)

Hurricane Sandy Poster (October 29, 2012)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Sandy poster. Multi-spectral image from Suomi-NPP shows Hurricane Sandy approaching the New Jersey Coast on October 29, 2012. Poster size is approximately...

Sedimentary uranium occurrences in Eastern Europe with special reference to sandstone formations

International Nuclear Information System (INIS)

Barthel, F.; Hahn, L.

1985-01-01

Sedimentary uranium deposits, especially in sandstones, play an important role in uranium mining in Eastern Europe. The paper reviews recent publications on uranium occurrences in sandstone formations in the German Democratic Republic, Poland, CSSR, Hungary, Romania, Bulgaria and Albania. The uranium deposits in sandstones in Yugoslavia are described in a separate paper in this volume. Sandstone deposits of the USSR are not reviewed. Uranium mineralizations occur in sandstones from Ordovician to Tertiary age. Major deposits are developed in Upper Carboniferous sandstones in association with coal (GDR, Poland), in Permian strata (CSSR, Hungary, Romania), in Cretaceous sandstones (GDR, CSSR), and in Tertiary sediments (CSSR). The Permian deposits can be compared with deposits of similar age in Northern Italy and Northern Yugoslavia. Roll-type orebodies are developed in some of the Cenomanian sandstones. Tertiary deposits are mainly associated with lignites. Uranium deposits in sandstones of Albania and Bulgaria are not described in the literature. Geologic similarities with sandstone basins in adjacent countries suggest the presence of uranium mineralizations in Permian, Lower Triassic, and Tertiary sandstones. (author)

Hydro Geo-Electrical Investigation in Gombe Town and Environs ...

African Journals Online (AJOL)

The sandy clay and sandstone constitute the aquifer zones with resistivity range of 28 ohm-m to 84 ohm-m for clay, 240 ohm-m to 501 ohm-m for sandstone, 967 ohm-m to 1008 ohm-m for sandy clay. Others are 2069 ohm-m to 9607 ohm-m for the calcareous and the laterite units and 17456 0hm-m for the compacted sands.

Effect of temperature on sandstone permeability

DEFF Research Database (Denmark)

Rosenbrand, Esther; Kjøller, Claus

Hot water injection in geothermal sandstone aquifers is considered for seasonal energy storage in Denmark. However, an increase in the aquifer temperature might reduce permeability, and thereby increase production costs. An understanding of the factors that control permeability is required in order...... and the Klinkenberg procedure showed the expected correlation between the two measures, however, differences could be around one order of magnitude. In tight gas sandstones, permeability is often sensitive to net stress, which might change due to the pore pressure change in the Klinkenberg procedure. Besides...... affecting the Klinkenberg procedure, the combined effect of slip and changes in permeability would affect production during pressure depletion in tight gas sandstone reservoirs; therefore effects of gas slip and net stress on permeability were combined in a model based on the Klinkenberg equation. A lower...

57Fe Mössbauer and X-ray characterisation of sandstones

International Nuclear Information System (INIS)

Mulaba-Bafubiandi, A. F.; Waanders, F. B.

2013-01-01

Sandstones from the Free State province in South Africa have been mined and processed mainly by small scale and artisanal miners in the rural areas. In the present investigation basic fire proof and water absorption tests, X-ray and γ-ray based characterisation techniques were used to study the sandstones. The collected samples were grouped according to their apparent colour in day light conditions and the elemental analysis showed the presence of a high amount of oxygen (>52%) and silicon (>38%) with Mn, Al, Fe and Ca as major elements in proportions related to the colour distribution of the various sandstones. The uniaxial compressive stress was found to be the highest (56 MPa) for the greyish sandstone and the lowest (8 MPa) for the white sandstone sample, also associated with the lowest (Al+Fe)/Si value of 0.082. The humidity test showed that the 6 % water absorption was lower than the recommended ASTM value of 8 %. The sandstone samples were also subjected to various high temperatures to simulate possible fire conditions and it was found that the non alteration of the mineral species might be one of the reasons why the sandstones are regarded as the most refractory amongst the building materials typically used. Mössbauer spectroscopy revealed that iron is present in all the sandstones, mainly as Fe 3 +  with the black sandstone showing an additional presence of 3 % Fe 2 +  indicating that a higher iron content coupled to higher silicon content, contributes to an increase in the uniaxial compressive strength.

Petrography and geochemistry of Jurassic sandstones from the ...

Indian Academy of Sciences (India)

V Periasamy

On the basis of geochemical results, sandstones are classified into arkose, ..... Geochemical classification diagram of sandstone samples from the Jhuran Formation based on log(SiO2/Al2O3)– ..... 1993) showing single trend for the Jhuran.

Sensing, Measuring and Modelling the Mechanical Properties of Sandstone

Science.gov (United States)

Antony, S. J.; Olugbenga, A.; Ozerkan, N. G.

2018-02-01

We present a hybrid framework for simulating the strength and dilation characteristics of sandstone. Where possible, the grain-scale properties of sandstone are evaluated experimentally in detail. Also, using photo-stress analysis, we sense the deviator stress (/strain) distribution at the micro-scale and its components along the orthogonal directions on the surface of a V-notch sandstone sample under mechanical loading. Based on this measurement and applying a grain-scale model, the optical anisotropy index K 0 is inferred at the grain scale. This correlated well with the grain contact stiffness ratio K evaluated using ultrasound sensors independently. Thereafter, in addition to other experimentally characterised structural and grain-scale properties of sandstone, K is fed as an input into the discrete element modelling of fracture strength and dilation of the sandstone samples. Physical bulk-scale experiments are also conducted to evaluate the load-displacement relation, dilation and bulk fracture strength characteristics of sandstone samples under compression and shear. A good level of agreement is obtained between the results of the simulations and experiments. The current generic framework could be applied to understand the internal and bulk mechanical properties of such complex opaque and heterogeneous materials more realistically in future.

Sandy PMO Disaster Relief Appropriations Act of 2013 Financial Data

Data.gov (United States)

Department of Homeland Security — Sandy PMO: Disaster Relief Appropriations Act of 2013 (Sandy Supplemental Bill) Financial Data. This is the Sandy Supplemental Quarterly Financial Datasets that are...

Elevated Uranium in Aquifers of the Jacobsville Sandstone

Science.gov (United States)

Sherman, H.; Gierke, J.

2003-12-01

The EPA has announced a new standard for uranium in drinking water of 30 parts per billion (ppb). This maximum contaminant level (MCL) takes effect for community water supplies December 2003. The EPA's ruling has heightened awareness among residential well owners that uranium in drinking water may increase the risk of kidney disease and cancer and has created a need for a quantified, scientific understanding of the occurrence and distribution of uranium isotopes in aquifers. The authors are investigating the occurrence of elevated uranium in northern Michigan aquifers of the Middle Proterozoic Jacobsville sandstone, a red to mottled sequence of sandstones, conglomerates, siltstones and shales deposited as basin fill in the 1.1 Ga Midcontinent rift. Approximately 25% of 300 well water samples tested for isotopic uranium have concentrations above the MCL. Elevated uranium occurrences are distributed throughout the Jacobsville sandstone aquifers stretching across Michigan's Upper Peninsula. However, there is significant variation in well water uranium concentrations (from 0.01 to 190 ppb) and neighboring wells do not necessarily have similar concentrations. The authors are investigating hydrogeologic controls on ground water uranium concentrations in the Jacobsville sandstone, e.g. variations in lithology, mineralogy, groundwater residence time and geochemistry. Approximately 2000' of Jacobsville core from the Amoco St. Amour well was examined in conjunction with the spectral gamma ray log run in the borehole. Spikes in equivalent uranium (eU) concentration from the log are frequently associated with clay and heavy mineral layers in the sandstone core. The lithology and mineralogy of these layers will be determined by analysis of thin sections and x-ray diffraction. A portable spectrometer, model GRS-2000/BL, will be used on the sandstone cliffs along Lake Superior to characterize depositional and lithologic facies of the Jacobsville sandstone in terms of

Micropore Structure Representation of Sandstone in Petroleum Reservoirs Using an Atomic Force Microscope

International Nuclear Information System (INIS)

Bai Yong-Qiang; Zhu Xing; Wu Jun-Zheng; Bai Wen-Guang

2011-01-01

The pore structure of sandstone in an oil reservoir is investigated using atomic force microscopy (AFM). At nanoscale resolution, AFM images of sandstone show us the fine structure. The real height data of images display the three-dimensional space structure of sandstone effectively. The three-dimensional analysis results show that the AFM images of sandstone have unique characteristics that, like fingerprints, can identify different structural properties of sandstones. The results demonstrate that AFM is an effective method used to represent original sandstone in petroleum reservoirs, and may help geologists to appreciate the sandstone in oil reservoirs fully. (general)

Transport of silver nanoparticles in single fractured sandstone

Science.gov (United States)

Neukum, Christoph

2018-02-01

Silver nanoparticles (Ag-NP) are used in various consumer products and are one of the most prevalent metallic nanoparticle in commodities and are released into the environment. Transport behavior of Ag-NP in groundwater is one important aspect for the assessment of environmental impact and protection of drinking water resources in particular. Ag-NP transport processes in saturated single-fractured sandstones using triaxial flow cell experiments with different kind of sandstones is investigated. Ag-NP concentration and size are analyzed using flow field-flow fractionation and coupled SEM-EDX analysis. Results indicate that Ag-NP are more mobile and show generally lower attachment on rock surface compared to experiments in undisturbed sandstone matrix and partially fractured sandstones. Ag-NP transport is controlled by the characteristics of matrix porosity, time depending blocking of attachment sites and solute chemistry. Where Ag-NP attachment occur, it is heterogeneously distributed on the fracture surface.

Correlation between landscape fragmentation and sandy desertification: a case study in Horqin Sandy Land, China.

Science.gov (United States)

Ge, Xiaodong; Dong, Kaikai; Luloff, A E; Wang, Luyao; Xiao, Jun; Wang, Shiying; Wang, Qian

2016-01-01

The exact roles of landscape fragmentation on sandy desertification are still not fully understood, especially with the impact of different land use types in spatial dimension. Taking patch size and shape into consideration, this paper selected the Ratio of Patch Size and the Fractal Dimension Index to establish a model that reveals the association between the area of bare sand land and the fragmentation of different land use types adjacent to bare sand land. Results indicated that (1) grass land and arable land contributed the most to landscape fragmentation processes in the regions adjacent to bare sand land during the period 1980 to 2010. Grass land occupied 54 % of the region adjacent to bare sand land in 1980. The Ratio of Patch Size of grass land decreased from 1980 to 2000 and increased after 2000. The Fractal Dimension Index of grass increased during the period 1980 to 1990 and decreased after 1990. Arable land expanded significantly during this period. The Ratio of Patch Size of arable land increased from 1980 to 1990 and decreased since 1990. The Fractal Dimension Index of arable land increased from 1990 to 2000 and decreased after 2000. (2) The Ratio of Patch Size and the Fractal Dimension Index were significantly related to the area of bare sand land. The role of landscape fragmentation was not linear to sandy desertification. There were both positive and negative effects of landscape fragmentation on sandy desertification. In 1980, the Ratio of Patch Size and the Fractal Dimension Index were negatively related to the area of bare sand land, showing that the landscape fragmentation and regularity of patches contributed to the expansion of sandy desertification. In 1990, 2000, and 2010, the Ratio of Patch Size and the Fractal Dimension Index were mostly positively related to the area of bare sand land, showing the landscape fragmentation and regularity of patches contributed to the reversion of sandy desertification in this phase. The absolute values of

INAA and petrological study of sandstones from the Angkor monuments

International Nuclear Information System (INIS)

Kucera, J.; Kranda, K.; Soukal, L.; Novak, J.K.; Lang, M.; Poncar, J.; Krausova, I.; Cunin, O.

2008-01-01

We determined 35 major, minor and trace elements in sandstone samples taken from building blocks of 19 Angkor temples and from an old and a new quarry using INAA. We also characterized the sandstone samples with conventional microscopy and electron microprobe analysis. Using cluster analysis, we found no straightforward correlation between the chemical/petrological properties of the sandstones and a presumed period of individual temples construction. The poor correlation may result either from the inherent inhomogeneity of sandstone or just reflect the diversity of quarries that supplied building blocks for the construction of any particular temple. (author)

INTRODUCTION Sandstone beds within Auchi locality are the ...

African Journals Online (AJOL)

The major framework composition is Q F L which classifies the sandstone as Quartz ... The grains are texturally immature as depicted by their subangular edges but mineralogically ..... Fig 6 : Vertical Section of Bioturbated Sandstone Lithofacies Showing Trace Fossils ..... on Water Quality and Planktonic Production in an.

Formation conditions and prospecting criteria for sandstone uranium deposit of interlayer oxidation type

International Nuclear Information System (INIS)

Huang Shijie

1994-01-01

This paper comprehensively analyses the geotectonic setting and favourable conditions, such as structure of the basin, sedimentary facies and paleogeography, geomorphology and climate, hydrodynamics and hydrogeochemistry, the development of interlayered oxidation etc, necessary for the formation of sandstone uranium deposit of interlayered oxidation type. The following prospecting criteria is proposed, namely: abundant uranium source, arid climate, stable big basin, flat-lying sandstone bed, big alluvial fan, little change in sedimentary facies, intercalation of sandstone and mudstone beds, shallow burying of sandstone bed, well-aquiferous sandstone bed, high permeability of sandstone bed, development of interlayered oxidation, and high content of reductant in sandstone. In addition, the 6 in 1 hydrogenic genetic model is proposed

Channel sandstone and bar morphology of the Beaufort group uranium district near Beaufort West

International Nuclear Information System (INIS)

Stear, W.M.

1980-01-01

Sheet-like and lenticular sandstone bodies in the Lower Beaufort Group (Adelaide Subgroup) uranium district occur in megacyclic repetition as superimposed systems of ephemeral fluvial channels that display characteristics of complex lateral and vertical accretion. Channel sandstone bodies are defined on morphological grounds into two types. Sheet sandstone bodies are the commonest type and comprise the bulk of sandstone packages in arenaceous zones of megacycles. Composite sandstone sheets result from multilateral coalescence of individual sandstone bodies. Isolated lenticular sandstone units in argillaceous zones of megacycles comprise sheet and ribbon sandstone types. Multi-storeying is a prominent feature of most channel sandstone bodies and often results in local sandstone thickening. Bedforms relate to the formation of compound bars and record periods of dynamic accretion and erosion. Rarely preserved palaeosurfaces vividly illustrate the fluctuating hydrodynamic conditions that typified ephemeral fluvial sedimentation in a semi-arid environment during Lower Beaufort times

Channel sandstone and bar morphology of the Beaufort group uranium district near Beaufort West

Energy Technology Data Exchange (ETDEWEB)

Stear, W M

1980-01-01

Sheet-like and lenticular sandstone bodies in the Lower Beaufort Group (Adelaide Subgroup) uranium district occur in megacyclic repetition as superimposed systems of ephemeral fluvial channels that display characteristics of complex lateral and vertical accretion. Channel sandstone bodies are defined on morphological grounds into two types. Sheet sandstone bodies are the commonest type and comprise the bulk of sandstone packages in arenaceous zones of megacycles. Composite sandstone sheets result from multilateral coalescence of individual sandstone bodies. Isolated lenticular sandstone units in argillaceous zones of megacycles comprise sheet and ribbon sandstone types. Multi-storeying is a prominent feature of most channel sandstone bodies and often results in local sandstone thickening. Bedforms relate to the formation of compound bars and record periods of dynamic accretion and erosion. Rarely preserved palaeosurfaces vividly illustrate the fluctuating hydrodynamic conditions that typified ephemeral fluvial sedimentation in a semi-arid environment during Lower Beaufort times.

Strength Characteristics of Reinforced Sandy Soil

OpenAIRE

S. N. Bannikov; Mahamed Al Fayez

2005-01-01

Laboratory tests on determination of reinforced sandy soil strength characteristics (angle of internal friction, specific cohesive force) have been carried out with the help of a specially designed instrument and proposed methodology. Analysis of the obtained results has revealed that cohesive forces are brought about in reinforced sandy soil and an angle of internal soil friction becomes larger in comparison with non-reinforced soil.

ANALYSIS OF OIL-BEARING CRETACEOUS SANDSTONE HYDROCARBON RESERVOIRS, EXCLUSIVE OF THE DAKOTA SANDSTONE, ON THE JICARILLA APACHE INDIAN RESERVATION, NEW MEXICO

International Nuclear Information System (INIS)

Jennie Ridgley

2000-01-01

A goal of the Mesaverde project was to better define the depositional system of the Mesaverde in hopes that it would provide insight to new or by-passed targets for oil exploration. The new, detailed studies of the Mesaverde give us a better understanding of the lateral variability in depositional environments and facies. Recognition of this lateral variability and establishment of the criteria for separating deltaic, strandplain-barrier, and estuarine deposits from each other permit development of better hydrocarbon exploration models, because the sandstone geometry differs in each depositional system. Although these insights will provide better exploration models for gas exploration, it does not appear that they will be instrumental in finding more oil. Oil in the Mesaverde Group is produced from isolated fields on the Chaco slope; only a few wells define each field. Production is from sandstone beds in the upper part of the Point Lookout Sandstone or from individual fluvial channel sandstones in the Menefee. Stratigraphic traps rather than structural traps are more important. Source of the oil in the Menefee and Point Lookout may be from interbedded organic-rich mudstones or coals rather than from the Lewis Shale. The Lewis Shale appears to contain more type III organic matter and, hence, should produce mainly gas. Outcrop studies have not documented oil staining that might point to past oil migration through the sandstones of the Mesaverde. The lack of oil production may be related to the following: (1) lack of abundant organic matter of the type I or II variety in the Lewis Shale needed to produce oil, (2) ineffective migration pathways due to discontinuities in sandstone reservoir geometries, (3) cementation or early formation of gas prior to oil generation that reduced effective permeabilities and served as barriers to updip migration of oil, or (4) erosion of oilbearing reservoirs from the southern part of the basin. Any new production should mimic that of

Landscape Visual Quality and Meiofauna Biodiversity on Sandy Beaches

Science.gov (United States)

Felix, Gabriela; Marenzi, Rosemeri C.; Polette, Marcos; Netto, Sérgio A.

2016-10-01

Sandy beaches are central economic assets, attracting more recreational users than other coastal ecosystems. However, urbanization and landscape modification can compromise both the functional integrity and the attractiveness of beach ecosystems. Our study aimed at investigating the relationship between sandy beach artificialization and the landscape perception by the users, and between sandy beach visual attractiveness and biodiversity. We conducted visual and biodiversity assessments of urbanized and semiurbanized sandy beaches in Brazil and Uruguay. We specifically examined meiofauna as an indicator of biodiversity. We hypothesized that urbanization of sandy beaches results in a higher number of landscape detractors that negatively affect user evaluation, and that lower-rated beach units support lower levels of biodiversity. We found that urbanized beach units were rated lower than semiurbanized units, indicating that visual quality was sensitive to human interventions. Our expectations regarding the relationship between landscape perception and biodiversity were only partially met; only few structural and functional descriptors of meiofauna assemblages differed among classes of visual quality. However, lower-rated beach units exhibited signs of lower environmental quality, indicated by higher oligochaete densities and significant differences in meiofauna structure. We conclude that managing sandy beaches needs to advance beyond assessment of aesthetic parameters to also include the structure and function of beach ecosystems. Use of such supporting tools for managing sandy beaches is particularly important in view of sea level rise and increasing coastal development.

Distinguishing of uranium-bearing sandstone by the geochemical characteristics in northern Sichuan

International Nuclear Information System (INIS)

Wang Wangzhang; Zhang Zhufeng; Wang Yunliang; Sun Shuqin.

1994-01-01

Expounding geochemical characteristics of sandstone-type uranium deposits in northern Sichuan, the authors demonstrate the favourable and unfavourable conditions for enrichment of uranium on the basis of element abundances and ratios of U, Th and K measured by the gamma-ray spectroscopy surveying. The differences between uranium-bearing and non-uranium sandstones and between red sandstone (clay stone) and greenish sandstone can be determined by the gamma-ray spectroscopy (measuring U, Th and K) and XRF analysis (measuring As and Ba). Therefore, the prospecting of the sandstone-type uranium deposits in northern Sichuan can be concentrated in a certain range

Distribution of petrophysical properties for sandy-clayey reservoirs by fractal interpolation

Directory of Open Access Journals (Sweden)

M. Lozada-Zumaeta

2012-04-01

Full Text Available The sandy-clayey hydrocarbon reservoirs of the Upper Paleocene and Lower Eocene located to the north of Veracruz State, Mexico, present highly complex geological and petrophysical characteristics. These reservoirs, which consist of sandstone and shale bodies within a depth interval ranging from 500 to 2000 m, were characterized statistically by means of fractal modeling and geostatistical tools. For 14 wells within an area of study of approximately 6 km², various geophysical well logs were initially edited and further analyzed to establish a correlation between logs and core data. The fractal modeling based on the R/S (rescaled range methodology and the interpolation method by successive random additions were used to generate pseudo-well logs between observed wells. The application of geostatistical tools, sequential Gaussian simulation and exponential model variograms contributed to estimate the spatial distribution of petrophysical properties such as effective porosity (PHIE, permeability (K and shale volume (VSH. From the analysis and correlation of the information generated in the present study, it can be said, from a general point of view, that the results not only are correlated with already reported information but also provide significant characterization elements that would be hardly obtained by means of conventional techniques.

Distribution characteristics of Shihongtan uranium deposits calcareous sandstone and discussion on their genesis

International Nuclear Information System (INIS)

Zhu Huanqiao; Jia Heng; Xu Gaozhong; Li Zhanyou

2007-12-01

It is considered that the calcareous sandstone appear at layer along of a bunch of pear lens on and off, localled near up and down surface of sandbody or washed surface, has sandstone of more macro-grain and more gradation through statistics and analysis of calcareous sandstone in goal layer in Shihongtan uranium deposits. The calcareous sandstone accumulation thickness chorogram demonstrated that the calcareous sandstone centralized distribution in the ore body growth area, thus it can be seen, in the oxidation reduction intermediate belt the calcareous sandstone forms with the uranium mine has the certain origin relation. Choropleth map of summed thickness of calcareous sandstone deserves that it mainly appear in area of uranium body and related cause of formation of ore body of interlayer deacidizing--oxidation belt. (authors)

Water Vapor Diffusion and Adsorption of Sandstones: Influence of Rock Texture and Composition

Directory of Open Access Journals (Sweden)

Martin Keppert

2016-01-01

Full Text Available The term sandstone is used for wide range of rocks containing quartz clasts which can be cemented by secondary precipitated quartz or calcite; moreover the space between clasts can be filled by matrix. These facts result in existence of numerous rocks having highly various properties. Sandstones have been used as construction materials due to their good accessibility and workability. Since most of sandstones are porous, water vapor can penetrate through sandstone constructions. The rate of water vapor diffusion, as well as the vapor sorption isotherm, was determined for range of sandstone types. The diffusion resistance factor was found to be dependent on the total porosity of sandstone but the sorption behavior was strongly influenced by nature of the particular sandstone; the specific surface area of stone and presence of clay matrix are determining its sorption isotherm. The published data enable estimating (i diffusion resistance factor of a sandstone via knowledge of its total porosity and (ii the sorption isotherm via knowledge of the stone’s nature and specific surface area. This approach can significantly reduce the time necessary to acquire vapor-related properties of a sandstone.

The ecology of sandy beaches in Natal

African Journals Online (AJOL)

The ecology of sandy beaches in Natal. A.H. Dye, A. Mclachlan and T. Wooldridge. Department of Zoology, University of Port Elizabeth, Port Elizabeth. Data from an ecological survey of four sandy beaches on the. Natal coast of South Africa are presented. Physical para· meters such as beach profile, particle size, moisture, ...

Bibliography of sandy beaches and sandy beach organisms on the African continent

CSIR Research Space (South Africa)

Bally, R

1986-01-01

Full Text Available This bibliography covers the literature relating to sandy beaches on the African continent and outlying islands. The bibliography lists biological, chemical, geographical and geological references and covers shallow marine sediments, surf zones off...

Model projections of atmospheric steering of Sandy-like superstorms.

Science.gov (United States)

Barnes, Elizabeth A; Polvani, Lorenzo M; Sobel, Adam H

2013-09-17

Superstorm Sandy ravaged the eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the Coupled Model Intercomparison Project, phase 5 multimodel ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy's unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

Facies architecture of the Bluejacket Sandstone in the Eufaula Lake area, Oklahoma: Implications for the reservoir characterization of the Bartlesville Sandstone

Energy Technology Data Exchange (ETDEWEB)

Ye, Liangmiao; Yang, Kexian [Univ. of Tulsa, OK (United States)

1997-08-01

Outcrop studies of the Bluejacket Sandstone (Middle Pennsylvanian) provide significant insights to reservoir architecture of the subsurface equivalent Bartlesville Sandstone. Quarry walls and road cuts in the Lake Eufaula area offer excellent exposures for detailed facies architectural investigations using high-precision surveying, photo mosaics. Directional minipermeameter measurements are being conducted. Subsurface studies include conventional logs, borehole image log, and core data. Reservoir architectures are reconstructed in four hierarchical levels: multi-storey sandstone, i.e. discrete genetic intervals; individual discrete genetic interval; facies within a discrete genetic interval; and lateral accretion bar deposits. In both outcrop and subsurface, the Bluejacket (Bartlesville) Sandstone comprises two distinctive architectures: a lower braided fluvial and an upper meandering fluvial. Braided fluvial deposits are typically 30 to 80 ft thick, and are laterally persistent filling an incised valley wider than the largest producing fields. The lower contact is irregular with local relief of 50 ft. The braided-fluvial deposits consist of 100-400-ft wide, 5-15-ft thick channel-fill elements. Each channel-fill interval is limited laterally by an erosional contact or overbank deposits, and is separated vertically by discontinuous mudstones or highly concentrated mudstone interclast lag conglomerates. Low-angle parallel-stratified or trough cross-stratified medium- to coarse-grained sandstones volumetrically dominate. This section has a blocky well log profile. Meandering fluvial deposits are typically 100 to 150 ft thick and comprise multiple discrete genetic intervals.

Elementary analysis on the main factors affecting the permeability of sandstones

International Nuclear Information System (INIS)

Gong Binli

2006-01-01

Researches show that in the early stage of sandstone diagenesis, compaction, pressure solution, cementation and replacement reduce both the porosity and the permeability. The cementation of authigenic kaolinite may preserve the tiny intergranular pore-space, and slightly influence the porosity, and even increase the permeability. During the middle to late stage of diagenesis, the organic matter becomes matured, hydrocarbon and acidic water are produced, which forms secondary porosity by the dissolution and the corrosion, and greatly increases the permeability of sandstones and provides a favorable prerequisite for the formation of sandstone-type uranium deposits. The interlayered oxidation alteration, oil-gas reduction and low-temperature hydrothermal alteration also produce secondary porosity in epigenetic reforming stage, which finally decides the permeability after the formation of sandstone-type uranium deposits. This is an important condition for in-situ leaching of sandstone-type uranium deposit. (authors)

Reservoir architecture patterns of sandy gravel braided distributary channel

Directory of Open Access Journals (Sweden)

Senlin Yin

2016-06-01

Full Text Available The purpose of this study was to discuss shape, scale and superimposed types of sandy gravel bodies in sandy-gravel braided distributary channel. Lithofacies analysis, hierarchy bounding surface analysis and subsurface dense well pattern combining with outcrops method were used to examine reservoir architecture patterns of sandy gravel braided distributary channel based on cores, well logging, and outcrops data, and the reservoir architecture patterns of sandy gravel braided distributary channels in different grades have been established. The study shows: (1 The main reservoir architecture elements for sandy gravel braided channel delta are distributary channel and overbank sand, while reservoir flow barrier elements are interchannel and lacustrine mudstone. (2 The compound sand bodies in the sandy gravel braided delta distributary channel take on three shapes: sheet-like distributary channel sand body, interweave strip distributary channel sand body, single strip distributary channel sand body. (3 Identification marks of single distributary channel include: elevation of sand body top, lateral overlaying, “thick-thin-thick” feature of sand bodies, interchannel mudstone and overbank sand between distributary channels and the differences in well log curve shape of sand bodies. (4 Nine lithofacies types were distinguished in distributary channel unit interior, different channel units have different lithofacies association sequence.

Diagenetic effect on permeabilities of geothermal sandstone reservoirs

DEFF Research Database (Denmark)

Weibel, Rikke; Olivarius, Mette; Kristensen, Lars

The Danish subsurface contains abundant sedimentary deposits, which can be utilized for geothermal heating. The Upper Triassic – Lower Jurassic continental-marine sandstones of the Gassum Formation has been utilised as a geothermal reservoir for the Thisted Geothermal Plant since 1984 extracting...... and permeability is caused by increased diagenetic changes of the sandstones due to increased burial depth and temperatures. Therefore, the highest water temperatures typically correspond with the lowest porosities and permeabilities. Especially the permeability is crucial for the performance of the geothermal......-line fractures. Continuous thin chlorite coatings results in less porosity- and permeability-reduction with burial than the general reduction with burial, unless carbonate cemented. Therefore, localities of sandstones characterized by these continuous chlorite coatings may represent fine geothermal reservoirs...

Characterization of application of acu sandstone in ceramic mass

International Nuclear Information System (INIS)

Nobrega, L.F.P.M.; Souza, M.M.; Gomes, Y.S.; Fernandes, D.L.

2016-01-01

The sandstone is a sedimentary rock formed mainly by quartz grains. In Rio Grande do Norte, there is the Potiguar Basin with the Jandaira and Acu Formations. The latter consists of thick layers of whitish-colored sandstones. It stands out as a water storage facility in the state, but it is also used for building aggregates. This article aimed at the use of the sandstone of this formation in the ceramic mass for coating. Initially, the material was sampled. It went through the comminution process to achieve the required granulometry. After this, three formulations were made to incorporate this new material into the traditional ones. The methods were performed according to ISO 13816. After sintering at 1200 °C, the specimens were subjected to the physical tests. A positive result was obtained for the use of the Acu sandstone in low concentrations. It is clear, therefore, its use in ceramics for coating

Content Analysis of Select YouTube Postings: Comparisons of Reactions to the Sandy Hook and Aurora Shootings and Hurricane Sandy.

Science.gov (United States)

Miller, Eric D

2015-11-01

This study details an innovative and methodical content analysis of 2,207 YouTube comments from four different YouTube videos (e.g., breaking news or memorials) related to the 2012 Sandy Hook Elementary School and Aurora theater mass shootings and the catastrophic Hurricane Sandy. As expected, YouTube comments associated with the Sandy Hook shootings (particularly those from a memorial video) were especially likely to feature compassion and grief with lessened hostility. This study highlights differing online contexts by which individuals show grief and related emotions following man-made and natural calamities and how-even in an online environment-powerful situational contexts greatly guide behavior.

Examples from the 1.6 Ga Chorhat Sandstone, Vindhyan

Indian Academy of Sciences (India)

This paper addresses macroscopic signatures of microbial mat-related structures within the 1.6 Ga-old Chorhat Sandstone of the Semri Group –the basal stratigraphic unit of the Vindhyan succession in Son valley.The Chorhat Sandstone broadly represents a prograding succession of three depositional facies ranging from ...

Trilobites from the Middle Ordovician Stairway Sandstone, Amadeus Basin, central Australia

DEFF Research Database (Denmark)

Jakobsen, Kristian Grube; Nielsen, Arne Thorshøj; Harper, David Alexander Taylor

2014-01-01

During the Middle Ordovician (Darriwilian) sandstones and siltstones were deposited in the epicontinental Larapintine Sea, which covered large parts of central Australia. The Darriwilian Stairway Sandstone has, for the first time, been sampled stratigraphically for macrofossils to track marine...... benthic biodiversity in this clastic-dominated shallow-water palaeoenvironment situated along the margin of northeastern Gondwana. The faunas from the Stairway Sandstone are generally of low diversity and dominated by bivalves but include several animal groups, with trilobites representing 25......% of the entire shelly fauna. Thirteen trilobite taxa are described from the Stairway Sandstone; the fauna displays a high degree of endemism. One new species, Basilicus (Parabasilicus) brumbyensis sp. nov. is described....

Science and Sandy: Lessons Learned

Science.gov (United States)

Werner, K.

2013-12-01

Following Hurricane Sandy's impact on the mid-Atlantic region, President Obama established a Task Force to '...ensure that the Federal Government continues to provide appropriate resources to support affected State, local, and tribal communities to improve the region's resilience, health, and prosperity by building for the future.' The author was detailed from NOAA to the Task Force between January and June 2013. As the Task Force and others began to take stock of the region's needs and develop plans to address them, many diverse approaches emerged from different areas of expertise including: infrastructure, management and construction, housing, public health, and others. Decision making in this environment was complex with many interests and variables to consider and balance. Although often relevant, science and technical expertise was not always at the forefront of this process. This talk describes the author's experience with the Sandy Task Force focusing on organizing scientific expertise to support the work of the Task Force. This includes a description of federal activity supporting Sandy recovery efforts, the role of the Task Force, and lessons learned from developing a science support function within the Task Force.

Uranium distribution and sandstone depositional environments: oligocene and upper Cretaceous sediments, Cheyenne basin, Colorado

International Nuclear Information System (INIS)

Nibbelink, K.A.; Ethridge, F.G.

1984-01-01

Wyoming-type roll-front uranium deposits occur in the Upper Cretaceous Laramie and Fox Hills sandstones in the Cheyenne basin of northeastern Colorado. The location, geometry, and trend of specific depositional environments of the Oligocene White River and the Upper Cretaceous Laramie and Fox Hills formations are important factors that control the distribution of uranium in these sandstones. The Fox Hills Sandstone consists of up to 450 ft (140 m) of nearshore marine wave-dominated delta and barrier island-tidal channel sandstones which overlie offshore deposits of the Pierre Shale and which are overlain by delta-plain and fluvial deposits of the Laramie Formation. Uranium, which probably originated from volcanic ash in the White River Formation, was transported by groundwater through the fluvial-channel deposits of the White River into the sandstones of the Laramie and Fox Hills formations where it was precipitated. Two favorable depositional settings for uranium mineralization in the Fox Hills Sandstone are: (1) the landward side of barrier-island deposits where barrier sandstones thin and interfinger with back-barrier organic mudstones, and (2) the intersection of barrier-island and tidal channel sandstones. In both settings, sandstones were probably reduced during early burial by diagenesis of contained and adjacent organic matter. The change in permeability trends between the depositional strike-oriented barrier sandstones and the dip-oriented tidal-channel sandstones provided sites for dispersed groundwater flow and, as demonstrated in similar settings in other depositional systems, sites for uranium mineralization

Sandstone-filled normal faults: A case study from central California

Science.gov (United States)

Palladino, Giuseppe; Alsop, G. Ian; Grippa, Antonio; Zvirtes, Gustavo; Phillip, Ruy Paulo; Hurst, Andrew

2018-05-01

Despite the potential of sandstone-filled normal faults to significantly influence fluid transmissivity within reservoirs and the shallow crust, they have to date been largely overlooked. Fluidized sand, forcefully intruded along normal fault zones, markedly enhances the transmissivity of faults and, in general, the connectivity between otherwise unconnected reservoirs. Here, we provide a detailed outcrop description and interpretation of sandstone-filled normal faults from different stratigraphic units in central California. Such faults commonly show limited fault throw, cm to dm wide apertures, poorly-developed fault zones and full or partial sand infill. Based on these features and inferences regarding their origin, we propose a general classification that defines two main types of sandstone-filled normal faults. Type 1 form as a consequence of the hydraulic failure of the host strata above a poorly-consolidated sandstone following a significant, rapid increase of pore fluid over-pressure. Type 2 sandstone-filled normal faults form as a result of regional tectonic deformation. These structures may play a significant role in the connectivity of siliciclastic reservoirs, and may therefore be crucial not just for investigation of basin evolution but also in hydrocarbon exploration.

Sandstone-type uranium deposits. Summary and conclusions

International Nuclear Information System (INIS)

Finch, W.I.

1985-01-01

The similarity of most of the deposits described in this report is striking even though they occur in sandstone host rocks ranging in age from Carboniferous to Tertiary and on every continent outside the polar regions. Geologic environments of the uranium deposits consist of distinctive sets of tectonic and sedimentary-depositional systems, all of which have some common threads of favorable geologic processes. In this summary paper it is hoped that this report has sharpened an understanding of the deposit's ''home environment'' that will aid future exploration for these resource-important sandstone-type uranium ores

Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land

Science.gov (United States)

Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.

2016-08-01

A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

Geological principles of exploration for sandstone-hosted uranium deposits

International Nuclear Information System (INIS)

Le Roux, J.P.

1982-10-01

Although the importance of sandstone-hosted uranium deposits has seemingly faded in recent years due to the discovery of large, high -grade deposits elsewhere, a forecasted energy shortage in the near future will probably necessitate a new look at sedimentary basins as a source of uranium. Back-arc basins adjacent to calcalkaline source areas are especially favourable if they are filled with fluvial, post-Devonian sediments. Syn- and post-depositional tectonics play an important role in the sedimentation-mineralisation process and should be investigated. The oxidation-reduction state of the sandstones is a valid prospecting tool. Sedimentological environments govern the permeability and vegetal matter content of sandstones and directly control uranium mineralisation

ANALYSIS OF OIL-BEARING CRETACEOUS SANDSTONE HYDROCARBON RESERVOIRS, EXCLUSIVE OF THE DAKOTA SANDSTONE, ON THE JICARILLA APACHE INDIAN RESERVATION, NEW MEXICO

International Nuclear Information System (INIS)

Jennie Ridgley

2000-01-01

An additional 450 wells were added to the structural database; there are now 2550 wells in the database with corrected tops on the Juana Lopez, base of the Bridge Creek Limestone, and datum. This completes the structural data base compilation. Fifteen oil and five gas fields from the Mancos-ElVado interval were evaluated with respect to the newly defined sequence stratigraphic model for this interval. The five gas fields are located away from the structural margins of the deep part of the San Juan Basin. All the fields have characteristics of basin-centered gas and can be considered as continuous gas accumulations as recently defined by the U.S. Geological Survey. Oil production occurs in thinly interbedded sandstone and shale or in discrete sandstone bodies. Production is both from transgressive and regressive strata as redefined in this study. Oil production is both stratigraphically and structurally controlled with production occurring along the Chaco slope or in steeply west-dipping rocks along the east margin of the basin. The ElVado Sandstone of subsurface usage is redefined to encompass a narrower interval; it appears to be more time correlative with the Dalton Sandstone. Thus, it was deposited as part of a regressive sequence, in contrast to the underlying rock units which were deposited during transgression

Hydrogeology of the Potsdam Sandstone in northern New York

Science.gov (United States)

Williams, John H.; Reynolds, Richard J.; Franzi, David A.; Romanowicz, Edwin A.; Paillet, Frederick L.

2010-01-01

The Potsdam Sandstone of Cambrian age forms a transboundary aquifer that extends across northern New York and into southern Quebec. The Potsdam Sandstone is a gently dipping sequence of arkose, subarkose, and orthoquartzite that unconformably overlies Precambrian metamorphic bedrock. The Potsdam irregularly grades upward over a thickness of 450 m from a heterogeneous feldspathic and argillaceous rock to a homogeneous, quartz-rich and matrix-poor rock. The hydrogeological framework of the Potsdam Sandstone was investigated through an analysis of records from 1,500 wells and geophysical logs from 40 wells, and through compilation of GIS coverages of bedrock and surficial geology, examination of bedrock cores, and construction of hydrogeological sections. The upper several metres of the sandstone typically is weathered and fractured and, where saturated, readily transmits groundwater. Bedding-related fractures in the sandstone commonly form sub-horizontal flow zones of relatively high transmissivity. The vertical distribution of sub-horizontal flow zones is variable; spacings of less than 10 m are common. Transmissivity of individual flow zones may be more than 100 m2/d but typically is less than 10 m2/d. High angle fractures, including joints and faults, locally provide vertical hydraulic connection between flow zones. Hydraulic head gradients in the aquifer commonly are downward; a laterally extensive series of sub-horizontal flow zones serve as drains for the groundwater flow system. Vertical hydraulic head differences between shallow and deep flow zones range from 1 m to more than 20 m. The maximum head differences are in recharge areas upgradient from the area where the Chateauguay and Chazy Rivers, and their tributaries, have cut into till and bedrock. Till overlies the sandstone in much of the study area; its thickness is generally greatest in the western part, where it may exceed 50 m. A discontinuous belt of bedrock pavements stripped of glacial drift extends

Cense Explosion Test Program. Report 1. Cense 1. Explosions in Sandstone

Science.gov (United States)

1977-09-01

series, "Analysis and Summary of CENSE Data." 10 * _ CHAPTER 2 APPROACH 2.1 DESCRIPTION OF TEST SITE An exposed outcrop of Kayenta sandstone with 180...ft/s seismic velocity previously determined (References 12-14) for the unweathered upper zone of the Kayenta sandstone. 16 I The P-wave propagation...Propagation along the horizontal radial was 8400 ft/s. The seismic velocity pre- viously determined for Kayenta sandstone in this area was 7500 ft/s

Sandstone landforms shaped by negative feedback between stress and erosion

Czech Academy of Sciences Publication Activity Database

Bruthans, J.; Soukup, J.; Vaculíková, J.; Filippi, Michal; Schweigstillová, Jana; Mayo, A. L.; Mašín, D.; Kletetschka, Günther; Řihošek, J.

2014-01-01

Roč. 7, č. 8 (2014), s. 597-601 ISSN 1752-0894 R&D Projects: GA ČR GA13-28040S Institutional support: RVO:67985831 ; RVO:67985891 Keywords : sandstone * sandstone landsforms * stress * erosion Subject RIV: DB - Geology ; Mineralogy Impact factor: 11.740, year: 2014

Characterizing flow pathways in a sandstone aquifer: Tectonic vs sedimentary heterogeneities

Science.gov (United States)

Medici, G.; West, L. J.; Mountney, N. P.

2016-11-01

Sandstone aquifers are commonly assumed to represent porous media characterized by a permeable matrix. However, such aquifers may be heavy fractured when rock properties and timing of deformation favour brittle failure and crack opening. In many aquifer types, fractures associated with faults, bedding planes and stratabound joints represent preferential pathways for fluids and contaminants. In this paper, well test and outcrop-scale studies reveal how strongly lithified siliciclastic rocks may be entirely dominated by fracture flow at shallow depths (≤ 180 m), similar to limestone and crystalline aquifers. However, sedimentary heterogeneities can primarily control fluid flow where fracture apertures are reduced by overburden pressures or mineral infills at greater depths. The Triassic St Bees Sandstone Formation (UK) of the East Irish Sea Basin represents an optimum example for study of the influence of both sedimentary and tectonic aquifer heterogeneities in a strongly lithified sandstone aquifer-type. This fluvial sedimentary succession accumulated in rapidly subsiding basins, which typically favours preservation of complete depositional cycles including fine grained layers (mudstone and silty sandstone) interbedded in sandstone fluvial channels. Additionally, vertical joints in the St Bees Sandstone Formation form a pervasive stratabound system whereby joints terminate at bedding discontinuities. Additionally, normal faults are present through the succession showing particular development of open-fractures. Here, the shallow aquifer (depth ≤ 180 m) was characterized using hydro-geophysics. Fluid temperature, conductivity and flow-velocity logs record inflows and outflows from normal faults, as well as from pervasive bed-parallel fractures. Quantitative flow logging analyses in boreholes that cut fault planes indicate that zones of fault-related open fractures characterize 50% of water flow. The remaining flow component is dominated by bed-parallel fractures

Electrokinetic desalination of sandstones for NaCl removal

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Christensen, Iben V.

2012-01-01

of reliable methods to remove the damaging salts in order to stop the decay. Electrokinetic desalination of fired clay bricks have previously shown efficient in laboratory scale and in the present work the method is tested for desalination of Cotta and Posta sandstones, which both have lower porosity than...... each stone, but electroosmosis in the poultices may have caused suction/pressure over the interface between stone and poultice causing the differences in poultice water content. The transport numbers for Cl− and Na+ differed in the two stones and were highest in the most porous Cotta sandstone in spite...... of similar high pore water concentrations and the same applied electric current. The hypotheses is that a layered structure of the sandstones could be the cause for this, as the electric current may preferentially flow in certain paths through the stone, which are thus desalinated first. After...

On the migration of uranium isotopes in sandstone aquifers

International Nuclear Information System (INIS)

Froehlich, K.; Gellermann, R.

1982-01-01

Measurements of natural 238 U and 234 U activity in groundwater of sandstone aquifers have been used to study the migration of these uranium isotopes. Regarding the uranium exchange between liquid phase and rock surface during migration, two different models were applied for evaluating the experimental results. Values of corresponding parameters (retardation factor K, removal rate R) reflecting different behaviour concerning this exchange were determined. For example, the values obtained for 238 U in a Triassic sandstone aquifer of the GDR are K = 8.6 x 10 6 and R = 1.3 x 10 -3 a -1 , respectively. It was found that, under the conditions of the sandstone aquifer concerned, the removal rate model is better suited for calculating uranium-isotope migration in groundwater. (author)

Greybull Sandstone Petroleum Potential on the Crow Indian Reservation, South-Central Montana

Energy Technology Data Exchange (ETDEWEB)

Lopez, David A.

2002-05-13

The focus of this project was to explore for stratigraphic traps that may be present in valley-fill sandstone at the top of the Lower Cretaceous Kootenai Formation. This sandstone interval, generally known as the Greybull Sandstone, has been identified along the western edge of the reservation and is a known oil and gas reservoir in the surrounding region. The Greybull Sandstone was chosen as the focus of this research because it is an excellent, well-documented, productive reservoir in adjacent areas, such as Elk Basin; Mosser Dome field, a few miles northwest of the reservation; and several other oil and gas fields in the northern portion of the Bighorn Basin.

Discussion on distribution characteristics of calcareous sandstone in Shihongtan uranium deposit and its genesis

International Nuclear Information System (INIS)

Zhu Huanqiao; Qiao Haiming; Jia Heng; Xu Gaozhong

2007-01-01

Based on the observation and statistics on the calcareous sandstone in the ore host layer in Shihongtan uranium deposit, this paper finds that the calcareous sandstone occurs on and off near the top or wash surface of the sandbody as beads-strings lens along the layer and concentrates in the area where the ore bodies are rich. In lithology, the calcareous sandstone is of coarse grain and fairly well sorted. According to the analysis on the lithogeochemical features and the carbon and oxygen isotopes of calcareous sandstones, it is realized that there some genetic relation between the formation of calcareous sandstone and uranium mineralization in the oxidation-deoxidation transitional belt, that is the precipitation and enrichment of uranium is accompanied by the deposition of carbonate and formation of calcareous sandstone. (authors)

Operational Group Sandy technical progress report

Science.gov (United States)

,

2013-01-01

Hurricane Sandy made US landfall near Atlantic City, NJ on 29 October 2012, causing 72 direct deaths, displacing thousands of individuals from damaged or destroyed dwellings, and leaving over 8.5 million homes without power across the northeast and mid-Atlantic. To coordinate federal rebuilding activities in the affected region, the President established the cabinet-level Hurricane Sandy Rebuilding Task Force (Task Force). The Task Force was charged with identifying opportunities for achieving rebuilding success while supporting economic vitality, improving public health and safety, protecting and enhancing natural and manmade infrastructure, bolstering resilience, and ensuring appropriate accountability.

A complex investigation of building sandstones from Saxony (Germany)

International Nuclear Information System (INIS)

Goetze, Jens; Siedel, Heiner

2007-01-01

The present paper provides a methodology for the investigation and characterization of building sandstones. This analytical scheme was designed for distinguishing mature arenites, which in general show very similar properties and are difficult to distinguish. This is shown for Cretaceous sandstones from various occurrences in Saxony (Germany), which have been used for centuries as building materials. The procedure is mainly based on the combination of macroscopic rock description, thin section polarizing microscopy (phase composition, texture, grain-size distribution) and cathodoluminescence (CL) microscopy (quartz types, feldspar and kaolinite content) coupled with image analysis, scanning electron microscopy (accessories, pore cement, diagenetic grain surface features), and analysis of pore space data. Sometimes, additional data from X-ray diffraction or chemical analyses (major and trace elements) can be used. Especially in the case of quartz rich arenites, CL is a powerful tool for provenance analysis. The detailed analysis of sandstone material in most cases allows us to assign historically used building material to a specific sandstone occurrence. These results are important for both interpreting the weathering behaviour of the building material and the conservation, reconstruction and stone replacement of historical monuments

The sandy beach meiofauna and free-living nematodes from De Panne (Belgium)

OpenAIRE

Gheskiere, T.; Hoste, E.; Kotwicki, L.; Degraer, S.; Vanaverbeke, J.; Vincx, M.

2002-01-01

Despite their rather barren and arid appearance, European sandy beaches harbour a highly diverse fauna and flora and some of them are even highly productive. In contrast to tropical sandy beaches little is known about the structural and functional diversity of the different benthic components. This study aims to investigate the structural diversity of the meiobenthos, emphasizing on free-living marine nematodes on a Belgian sandy beach.The samples were collected on the sandy beach of De Panne...

Geophysical signature recognition of aquifuge and relatively impermeable interbed in ore-hosting sandstone layer at sandstone-type uranium deposit

International Nuclear Information System (INIS)

Zhao Xigang; Wu Hanning; Bai Guanjun; Zhu Huanqiao; Jia Heng

2006-01-01

Geophysical signature recognition of aquifuge and relatively impermeable interbed in ore-hosting aquifer has been carried out a Shihongtan uranium deposit by using comprehensive logging data. The spatial distribution of above aquifuge and impermeable interbed is discussed, and the relation of these layers to sandstone-type uranium deposit, and their impact to in-situ leach mining technology are discussed. It is suggested that the aquifuge and relatively impermeable interbed bring about significant effect to the formation of interlayer oxidation zone sandstone-type uranium deposit, as well as to in-situ leach mining of the deposit. (authors)

Temperature effect on microstructure and P-wave propagation in Linyi sandstone

International Nuclear Information System (INIS)

Sun, Hui; Sun, Qiang; Deng, Wenni; Zhang, Weiqiang; Lü, Chao

2017-01-01

Highlights: • Mass loss rate, P-wave velocity change rate and damage factor increase exponentially as temperatures rise. • The damage threshold temperature of sandstone samples is 300 °C and limit temperature is 900 °C. • P-wave velocity change rate of sandstone exhibits excellent linearity with mass loss rate. • Damage factor can be well expressed by mass loss rate. - Abstract: In order to study the effect of high temperature on the sandstone, scanning electron microscope (SEM) experiments and primary wave (P-wave) velocity tests have been carried out on sandstone specimens heated to different temperature. The results showed that: (1) the mass loss rate increases exponentially with the increase of temperature and reaches 2.97% at 900 °C; (2) the P-wave velocity change rate increases exponentially with the increase of temperature while there is some fluctuation before 500 °C; (3) the damage threshold temperature of sandstone samples is 300 °C and the limit temperature is 900 °C; (4) there is a good linear relationship between the mass loss rate and the P-wave velocity change rate, and the correlation coefficient (R) of the fitting line is 0.989; (5) the damage caused by high temperature can be reflected better by the mass loss rate than P-wave velocity change rate. The results obtained in this paper will be good for predicting the properties of sandstone when exposed to high temperature.

Desalination of salt damaged Obernkirchen sandstone by an applied DC field

DEFF Research Database (Denmark)

Matyščák, Ondřej; Ottosen, Lisbeth M.; Rörig-Dalgaard, Inge

2014-01-01

Soluble salts are considered as one of the most common causes for decay of building materials. In the present work, an electrokinetic method for desalination of sandstones from a historic warehouse was tested. The sandstones claddings were removed from the warehouse during a renovation action...... in the stones, i.e. the present investigation faces more challenges relevant to a real desalination action. Experiments were conducted with two Obernkirchen sandstones from the same warehouse, but with different levels of salt concentrations and porosity. The investigation includes removal of the most common...... salts: chlorides, nitrates, sulphates. In the experimental setup the electrodes were placed in a clay poultice: a mixture of kaolinite, calcite and distilled water. An electric direct current (DC) field was applied to the sandstone.By applying 2mA for 5–11days it was possible to reduce the chloride...

EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface, Pre-Sandy

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

Characteristics and model of sandstone type uranium deposit in south of Songliao basin

International Nuclear Information System (INIS)

Yu Wenbin; Yu Zhenqing

2010-01-01

Through analyzing the uranium deposit tectonic environment, upper cretaceous sequence stratigraphy, depositional system, evolutionary characteristics of sand bodies, the effect of subsequent transformation and the characteristic of uranium deposit, the sandstone type uranium deposit in southern basin is different from typical interlayer oxidation zone sandstone type uranium deposit. The formation and evolution of sandstone-type uranium deposit are controlled by structure fensters; the favorable sedimentary facies type is braided river facies, and the ore body is braided river sand body. The size of uranium deposits is controlled by the local oxidation zone with the characteristics of sandstone type uranium deposit in partial oxidation zone. Uranium ore bodies which distribute in the roof wings of structure fenstes, and occur in gray layers between the upper and lower oxidation zone, showing tabular, and the plate of uranium ore body is controlled by the local oxidation zone. Based on the geological features of sandstone-type uranium deposits, the metallogenic model of local oxidation zones sandstone-type uranium deposits has been set up in the south of Songliao Baisn. (authors)

Genesis of Hurricane Sandy (2012) Simulated with a Global Mesoscale Model

Science.gov (United States)

Shen, Bo-Wen; DeMaria, Mark; Li, J.-L. F.; Cheung, S.

2013-01-01

In this study, we investigate the formation predictability of Hurricane Sandy (2012) with a global mesoscale model. We first present five track and intensity forecasts of Sandy initialized at 00Z 22-26 October 2012, realistically producing its movement with a northwestward turn prior to its landfall. We then show that three experiments initialized at 00Z 16-18 October captured the genesis of Sandy with a lead time of up to 6 days and simulated reasonable evolution of Sandy's track and intensity in the next 2 day period of 18Z 21-23 October. Results suggest that the extended lead time of formation prediction is achieved by realistic simulations of multiscale processes, including (1) the interaction between an easterly wave and a low-level westerly wind belt (WWB) and (2) the appearance of the upper-level trough at 200 hPa to Sandy's northwest. The low-level WWB and upper-level trough are likely associated with a Madden-Julian Oscillation.

Integrated geomechanical, petrographical and petrophysical study of the sandstones of the Wajid Group, SW Saudi Arabia

Science.gov (United States)

Benaafi, Mohammed; Hariri, Mustafa; Al-Shaibani, Abdulaziz; Abdullatif, Osman; Makkawi, Mohammed

2018-07-01

The Cambro-Permian siliciclastic succession in southwestern Saudi Arabia is represented by the Wajid Group, which consists mainly of fluvial, shallow marine, aeolian, and glacial sandstones. The Wajid Group comprises the Dibsiyah, Sanamah, Qalibah, Khusayyayn, and Juwayl Formations. It is exposed in the Wadi Al-Dawasir area and extends to Najran City. The sandstones of the Wajid Group serve as groundwater aquifers in the Wadi Al-Dawasir and Najran areas and host hydrocarbon (mainly gas) reservoirs in the Rub' Al-Khali Basin. This study aims to characterize the geomechanical properties (rock strength and Young's modulus) of the sandstones of the Wajid Group using field and experimental techniques. A further objective is to investigate the relationships between the geomechanical properties and the petrographical and petrophysical properties of the studied sandstones. The geomechanical properties of the studied sandstones vary from glacial to non-glacial sandstones, as the glacial sandstones display high values of the geomechanical properties with high variability indices. Four geological factors including grain size, cement content, porosity and permeability were observed as the main controls on the geomechanical behaviour of the studied sandstones except for the Khusayyayn sandstone, where the mineral composition was also important. Significant correlations were observed between the petrographical and petrophysical properties and the geomechanical properties of the glacial sandstones. Predictive models of the geomechanical properties (RN, UCS, and E) were generated using regression analysis to account for the glacial sandstones.

CO2 Storage Potential of the Eocene Tay Sandstone, Central North Sea, UK

Science.gov (United States)

Gent, Christopher; Williams, John

2017-04-01

Carbon Capture and Storage (CCS) is crucial for low-carbon industry, climate mitigation and a sustainable energy future. The offshore capacity of the UK is substantial and has been estimated at 78 Gt of CO2 in saline aquifers and hydrocarbon fields. The early-mid Eocene Tay Sandstone Member of the Central North Sea (CNS) is a submarine-fan system and potential storage reservoir with a theoretical capacity of 123 Mt of CO2. The Tay Sandstone comprises of 4 sequences, amalgamating into a fan complex 125km long and 40 km at a minimum of 1500 m depth striking NW-SE, hosting several hydrocarbon fields including Gannett A, B, D and Pict. In order to better understand the storage potential and characteristics, the Tay Sandstone over Quadrant 21 has been interpreted using log correlation and 3D seismic. Understanding the internal and external geometry of the sandstone as well as the lateral extent of the unit is essential when considering CO2 vertical and horizontal fluid flow pathways and storage security. 3D seismic mapping of a clear mounded feature has revealed the youngest sequence of the Tay complex; a homogenous sand-rich channel 12 km long, 1.5 km wide and on average 100 m thick. The sandstone has porosity >35%, permeability >5 D and a net to gross of 0.8, giving a total pore volume of 927x106 m3. The remaining three sequences are a series of stacked channels and interbedded mudstones which are more quiescent on the seismic, however, well logs indicate each subsequent sequence reduce in net to gross with age as mud has a greater influence in the early fan system. Nevertheless, the sandstone properties remain relatively consistent and are far more laterally extensive than the youngest sequence. The Tay Sandstone spatially overlaps several other potential storage sites including the older Tertiary sandstones of the Cromarty, Forties and Mey Members and deeper Jurassic reservoirs. This favours the Tay Sandstone to be considered in a secondary or multiple stacked

Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

Science.gov (United States)

Kunz, M.; Mühr, B.; Kunz-Plapp, T.; Daniell, J. E.; Khazai, B.; Wenzel, F.; Vannieuwenhuyse, M.; Comes, T.; Elmer, F.; Schröter, K.; Fohringer, J.; Münzberg, T.; Lucas, C.; Zschau, J.

2013-10-01

At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation) and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

Directory of Open Access Journals (Sweden)

M. Kunz

2013-10-01

Full Text Available At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

On the Impact Angle of Hurricane Sandy's New Jersey Landfall

Science.gov (United States)

Hall, Timothy M.; Sobel, Adam H.

2013-01-01

Hurricane Sandy's track crossed the New Jersey coastline at an angle closer to perpendicular than any previous hurricane in the historic record, one of the factors contributing to recordsetting peak-water levels in parts of New Jersey and New York. To estimate the occurrence rate of Sandy-like tracks, we use a stochastic model built on historical hurricane data from the entire North Atlantic to generate a large sample of synthetic hurricanes. From this synthetic set we calculate that under long-term average climate conditions, a hurricane of Sandy's intensity or greater (category 1+) makes NJ landfall at an angle at least as close to perpendicular as Sandy's at an average annual rate of 0.0014 yr-1 (95% confidence range 0.0007 to 0.0023); i.e., a return period of 714 years (95% confidence range 435 to 1429).

Sandy Hook : alternative access concept plan and vehicle replacement study

Science.gov (United States)

2009-06-01

This study addresses two critical issues of concern to the Sandy Hook Unit of Gateway National : Recreational Area: (1) options for alternative access to Sandy Hook during peak summer season, : particularly when the park is closed to private vehicles...

Preparation of Sandy Soil Stabilizer for Roads Based on Radiation Modified Polymer Composite

International Nuclear Information System (INIS)

Elnahas, H.H.

2016-01-01

Radiation modified polymer composite (RMPC) was studied to build an extremely durable sandy road, construct a trail or bath, or control dust and erosion. A dilute solution of composite binds sandy soil fines through a coagulation bonding process. The result is a dense soil structure that has superior resistance to cracks and water penetration and can also solve erosion control problems. In erosion control applications, diluted composite is merely sprayed into sandy soil without compaction, effectively sealing the surface to prevent air-born dust or deterioration from erosion. The prepared composite has an elastic and melt-able film formation that imparts thermal compacting to the stabilized sandy soil after full dryness for sandy road leveling, repairing and restoration processes. The prepared composite is environmentally economical when compared with traditional sandy soil stabilizing (SSS) or sealing methods.

Deaths associated with Hurricane Sandy - October-November 2012.

Science.gov (United States)

2013-05-24

On October 29, 2012, Hurricane Sandy hit the northeastern U.S. coastline. Sandy's tropical storm winds stretched over 900 miles (1,440 km), causing storm surges and destruction over a larger area than that affected by hurricanes with more intensity but narrower paths. Based on storm surge predictions, mandatory evacuations were ordered on October 28, including for New York City's Evacuation Zone A, the coastal zone at risk for flooding from any hurricane. By October 31, the region had 6-12 inches (15-30 cm) of precipitation, 7-8 million customers without power, approximately 20,000 persons in shelters, and news reports of numerous fatalities (Robert Neurath, CDC, personal communication, 2013). To characterize deaths related to Sandy, CDC analyzed data on 117 hurricane-related deaths captured by American Red Cross (Red Cross) mortality tracking during October 28-November 30, 2012. This report describes the results of that analysis, which found drowning was the most common cause of death related to Sandy, and 45% of drowning deaths occurred in flooded homes in Evacuation Zone A. Drowning is a leading cause of hurricane death but is preventable with advance warning systems and evacuation plans. Emergency plans should ensure that persons receive and comprehend evacuation messages and have the necessary resources to comply with them.

Acidification of sandy grasslands - consequences for plant diversity

DEFF Research Database (Denmark)

Olsson, Pål Axel; Mårtensson, Linda-Maria; Bruun, Hans Henrik

2009-01-01

soil; a number of nationally red-listed species showed a similar pattern. Plant species diversity and number of red-listed species increased with slope. Where the topsoil had been acidified, limestone was rarely present above a depth of 30 cm. The presence of limestone restricts the availability......Questions: (1) Does soil acidification in calcareous sandy grasslands lead to loss of plant diversity? (2) What is the relationship between the soil content of lime and the plant availability of mineral nitrogen (N) and phosphorus (P) in sandy grasslands? Location: Sandy glaciofluvial deposits......). Environmental variables were recorded at each plot, and soil samples were analysed for exchangeable P and N, as well as limestone content and pH. Data were analysed with regression analysis and canonical correspondence analysis. Results: Plant species richness was highest on weakly acid to slightly alkaline...

GREYBULL SANDSTONE PETROLEUM POTENTIAL ON THE CROW INDIAN RESERVATION, SOUTH-CENTRAL MONTANA

Energy Technology Data Exchange (ETDEWEB)

David A. Lopez

2000-12-14

Evaluation of the Lower Cretaceous Greybull Sandstone on the Crow Indian Reservation for potential stratigraphic traps in the valley-fill sandstone was the focus of this project. The Crow Reservation area, located in south-central Montana, is part of the Rocky Mountain Foreland structural province, which is characterized by Laramide uplifts and intervening structural basins. The Pryor and Bighorn mountains, like other foreland uplifts, are characterized by asymmetrical folds associated with basement-involved reverse faults. The reservation area east of the mountains is on the northwestern flank of the Powder River Basin. Therefore, regional dips are eastward and southeastward; however, several prominent structural features interrupt these regional dips. The nearly 4,000 mi{sup 2} reservation is under explored but has strong potential for increased oil and gas development. Oil and gas production is well established in the Powder River Basin of Wyoming to the south as well as in the areas north and west of the reservation. However, only limited petroleum production has been established within the reservation. Geologic relations and trends indicate strong potential for oil and gas accumulations, but drilling has been insufficient for their discovery. The Greybull Sandstone, which is part of the transgressive systems tract that includes the overlying Fall River Sandstone, was deposited on a major regional unconformity. The erosional surface at the base of the Greybull Sandstone is the +100 Ma, late Aptian-Early Albian regional unconformity of Weimer (1984). This lowstand erosional surface was controlled by a basin-wide drop in sea level. In areas where incised Greybull channels are absent, the lowstand erosional unconformity is at the base of the Fall River Sandstone and equivalent formations. During the pre-Greybull lowstand, sediment bypassed this region. In the subsequent marine transgression, streams began to aggrade and deposit sand of the lower Greybull Sandstone

Numerical simulation of roadway support in a sandstone-type uranium mine

International Nuclear Information System (INIS)

Liu Huipeng; Li Yu; Song Lixia

2009-01-01

At present, the most surrounding rocks of sandstone-type uranium mines in China are mudstone, sandstone, pelitic siltstone, and so on. They show the characteristics of soft rock. Such uranium deposit is not fit for in-situ leaching. If the uranium ores are mined by conventional mining method, one of the problems to be solved is the support technique in the soft rock roadway. So, taking a uranium mine in Inner Mongolia as the research object, the support technique in the soft rock roadway of the sandstone-type uranium deposits is studied. Through on-site engineering geological investigation and laboratory test, the main reasons for roadway damage are analyzed. A technique of support in the soft rock roadway of sandstone-type uranium deposits is put forward by drawing on the expericnce of soft rock roadway support in coal mines. The roadway shape and support parameters are optimized by using a numerical simulation method. The results verified the feasibility of the supporting technique. (authors)

Sediment transport direction in fluviatile Karharbari sandstone, Giridih Basin, Bihar

Energy Technology Data Exchange (ETDEWEB)

Tewari, R C; Casshyap, S M

1978-01-01

The sandstone is pebbly, very coarse grained in the lower part, and coarse to medium grained in the upper part. Shale and coal respectively constitute 9 and 5% of the strata Small and large erosional channels and successive sets of large scale cross-bedding characterize the sandstone. Palaeo- currents reveal that the paleodrainage and sediment transport were dominantly directed from SSW to NNE.

Traces of the heritage arising from the Macelj sandstone

Science.gov (United States)

Golež, Mateja

2014-05-01

The landscape of Southeast Slovenia and its stone heritage principally reveal itself through various Miocene sandstones. The most frequently found type on the borderline between Slovenia and Croatia, i.e. east of Rogatec, is the micaceous-quartz Macelj sandstone. This rock ranges in colour from greenish grey to bluish grey and yellowish, depending on the content of glauconite, which colours it green. In its composition, the rock is a heterogeneous mixture of grains of quartz, dolomite, muscovite, microcline, anorthite and glauconite. The average size of grains is 300μm. In cross-section, they are oblong, semi-rounded or round. The mechanical-physical and durability properties of the Macelj sandstone, which have been characterised pursuant to the applicable standards for natural stone, reveal that the rock exhibits poor resistance to active substances from the atmosphere, particularly in the presence of salt. In the surroundings of Rogatec, there are around 45 abandoned quarries of the Macelj sandstone, which are the result of the exploitation of this mineral resource from the 17th century on. The local quarrymen earned their bread until 1957, when the Kambrus quarry industry closed down. From the original use of this mineral resource as construction and decorative material, the useful value of the Macelj sandstone expanded during the development of the metals industry to the manufacture of large and small grindstones for the needs of the domestic and international market. Therefore, traces of quarrying can not only be seen in the disused quarries, but also in the rich architectural heritage of Rogatec and its surroundings, the stone furniture - from portals, window frames, wells, various troughs, pavements to stone walls - and other. The living quarrying heritage slowly passed into oblivion after World War II, although the analysis of the social image of the people residing in Rogatec and its surroundings revealed that there was an average of one stonemason in

Middle Ordovician brachiopods from the Stairway Sandstone, Amadeus Basin, central Australia

DEFF Research Database (Denmark)

Jakobsen, Kristian Grube; Brock, Glenn A.; Nielsen, Arne Thorshøj

2014-01-01

-water palaeoenvironment along the margin of northeastern Gondwana. The brachiopods from the Stairway Sandstone are of low diversity and represent ca 9% of the entire shelly fauna. Five brachiopod taxa are described from the Stairway Sandstone; all are endemic to the Amadeus Basin at species level. Two new species...

Application potential of sequence stratigraphy to prospecting for sandstone-type uranium deposit in continental depositional basins

International Nuclear Information System (INIS)

Li Shengxiang; Chen Zhaobo; Chen Zuyi; Xiang Weidong; Cai Yuqi

2001-01-01

Sequence stratigraphy has been widely used in hydrocarbon exploration and development, and great achievements have been achieved. However, its application to the prospecting for sandstone-type uranium deposits is just beginning. The metallogenic characteristics of sandstone-type uranium deposits and those of oil and gas are compared, and the relationship between sandstone-type uranium metallogenesis and the system tracts of sequence stratigraphy is studied. The authors propose that highest and system tracts are the main targets for prospecting interlayer oxidation zone type sandstone uranium deposits, and the incised valleys of low stand system tracts are favourable places for phreatic oxidation zone type sandstone uranium deposits, and transgressive system tracts are generally unfavorable to the formation of in-situ leachable sandstone-type uranium deposits. Finally, the authors look ahead the application potential of sequence stratigraphy to the prospecting for sandstone-type uranium deposits in continental depositional basins

Rates of Hospitalization for Dehydration Following Hurricane Sandy in New Jersey.

Science.gov (United States)

Swerdel, Joel N; Rhoads, George G; Cosgrove, Nora M; Kostis, John B

2016-04-01

Hurricane Sandy, one of the most destructive natural disasters in New Jersey history, made landfall on October 29, 2012. Prolonged loss of electrical power and extensive infrastructure damage restricted access for many to food and water. We examined the rate of dehydration in New Jersey residents after Hurricane Sandy. We obtained data from 2008 to 2012 from the Myocardial Infarction Data Acquisition System (MIDAS), a repository of in-patient records from nonfederal New Jersey hospitals (N=517,355). Patients with dehydration had ICD-9-CM discharge diagnosis codes for dehydration, volume depletion, and/or hypovolemia. We used log-linear modeling to estimate the change in in-patient hospitalizations for dehydration comparing 2 weeks after Sandy with the same period in the previous 4 years (2008-2011). In-patient hospitalizations for dehydration were 66% higher after Sandy than in 2008-2011 (rate ratio [RR]: 1.66; 95% confidence interval [CI]: 1.50, 1.84). Hospitalizations for dehydration in patients over 65 years of age increased by nearly 80% after Sandy compared with 2008-2011 (RR: 1.79; 95% CI: 1.58, 2.02). Sandy was associated with a marked increase in hospitalizations for dehydration. Reducing the rate of dehydration following extreme weather events is an important public health concern that needs to be addressed, especially in those over 65 years of age.

Hurricane Sandy, Disaster Preparedness, and the Recovery Model.

Science.gov (United States)

Pizzi, Michael A

2015-01-01

Hurricane Sandy was the second largest and costliest hurricane in U.S. history to affect multiple states and communities. This article describes the lived experiences of 24 occupational therapy students who lived through Hurricane Sandy using the Recovery Model to frame the research. Occupational therapy student narratives were collected and analyzed using qualitative methods and framed by the Recovery Model. Directed content and thematic analysis was performed using the 10 components of the Recovery Model. The 10 components of the Recovery Model were experienced by or had an impact on the occupational therapy students as they coped and recovered in the aftermath of the natural disaster. This study provides insight into the lived experiences and recovery perspectives of occupational therapy students who experienced Hurricane Sandy. Further research is indicated in applying the Recovery Model to people who survive disasters. Copyright © 2015 by the American Occupational Therapy Association, Inc.

Discussion on metallogenic prospect of sandstone-type uranium deposit in Yabulai basin

International Nuclear Information System (INIS)

Wang Lianshe; Li Xiangping

2003-01-01

Based on characteristics of initial basin type and tectonic reworking process, this article analyses the distribution features of depositional system and subsequent alteration of the target horizon of sandstone-type uranium deposits in Yabulai basin. Guided by prognostic criteria of sandstone-type uranium deposits, authors suggest that the post-depositional tectonic reworking in the basin was quite intense, and uranium metallogenic prospects are unfavorable. However, the Lower Cretaceous in the paleo-slope at the middle of the basin does show certain metallogenic prospects for sandstone-type uranium deposits

Sedimentological reservoir characteristics of the Paleocene fluvial/lacustrine Yabus Sandstone, Melut Basin, Sudan

Science.gov (United States)

Mahgoub, M. I.; Padmanabhan, E.; Abdullatif, O. M.

2016-11-01

Melut Basin in Sudan is regionally linked to the Mesozoic-Cenozoic Central and Western African Rift System (CWARS). The Paleocene Yabus Formation is the main oil producing reservoir in the basin. It is dominated by channel sandstone and shales deposited in fluvial/lacustrine environment during the third phase of rifting in the basin. Different scales of sedimentological heterogeneities influenced reservoir quality and architecture. The cores and well logs analyses revealed seven lithofacies representing fluvial, deltaic and lacustrine depositional environments. The sandstone is medium to coarse-grained, poorly to moderately-sorted and sub-angular to sub-rounded, arkosic-subarkosic to sublitharenite. On the basin scale, the Yabus Formation showed variation in sandstone bodies, thickness, geometry and architecture. On macro-scale, reservoir quality varies vertically and laterally within Yabus Sandstone where it shows progressive fining upward tendencies with different degrees of connectivity. The lower part of the reservoir showed well-connected and amalgamated sandstone bodies, the middle to the upper parts, however, have moderate to low sandstone bodies' connectivity and amalgamation. On micro-scale, sandstone reservoir quality is directly affected by textures and diagenetic changes such as compaction, cementation, alteration, dissolution and kaolinite clays pore fill and coat all have significantly reduced the reservoir porosity and permeability. The estimated porosity in Yabus Formation ranges from 2 to 20% with an average of 12%; while permeability varies from 200 to 500 mD and up to 1 Darcy. The understanding of different scales of sedimentological reservoir heterogeneities might contribute to better reservoir quality prediction, architecture, consequently enhancing development and productivity.

Multidisciplinary studies on ancient sandstone quarries of Western Sardinia (Italy).

Science.gov (United States)

Grillo, Silvana Maria; Del Vais, Carla; Naitza, Stefano

2013-04-01

The ancient coastal quarries of Mediterranean are increasingly considered geosites of multidisciplinary relevance. They are sites of historical-archaeological interest that show ancient techniques of stone extraction; they are significant for cultural heritage conservation and restoration, as sources of the stones used in ancient buildings and monuments; they are sites of geological relevance, as often retain important stratigraphic sections; they are also useful markers of secular changes in the sea level. A multisciplinary study is in progress on the ancient quarries of the Sinis region (western Sardinia island), integrating archaeological, geological, minero-petrographical data. In Sardinia, coastal quarries have been established from Punic and Roman times. Many of them exploited Quaternary sediments along the southern and western coasts of the island. They consist of middle-late Pleistocene marine conglomerates and carbonate sandstones, and of coastal (aeolian) carbonate sandstones. Sandstone blocks of different sizes have been widely used in ancient cities for buildings, defensive works, harbours, etc. Three main areas of stone extraction (San Giovanni di Sinis, Punta Maimoni, Is Arutas) have been so far recognized in the Sinis. GIS-supported mapping and documentation of the sites includes their geology and stratigraphy, the extension and layout of the quarries, and an evaluation of volumes of extracted rocks. Documented archaeological evidences include ancient extraction fronts, spoil heaps, working areas, working traces in the old fronts, transport routes of blocks, and traces of loading facilities. The study is aimed at reconstructing the relationships of the quarries with the urban areas of Sinis, as the ancient Punic-Roman city of Tharros. Consequently, a minero-petrographical characterization (optical microscopy, XRD) is performed on sandstones sampled in each quarry, and in historical buildings in Tharros and other centres of the region (Cabras

Diagenetic controls on porosity variations within an aeolian sandstone reservoir, borehole Kudu 9A-3

International Nuclear Information System (INIS)

Marot, J.E.B.

1990-01-01

Three boreholes, Kudu 9A-1, 9A-2 and 9A-3, were drilled approximately 125 km west of the Orange River mouth to test a gas-bearing structure of Barremian age. The reservoir interval comprises an upper unit of interbedded shallow marine sandstones, limestones and volcaniclastic mass flow deposits, and a lower non-marine unit of interbedded aeolian sandstones, basaltic lavas and volcaniclastic deposits. Despite the overall good poroperm characteristics of the aeolian sandstone and its apparent mineralogical homogeneity, as implied by a gamma ray trace, the core analysis results show an extreme variation in porosity and permeability values. In order to assist in reservoir quality prediction and to assess the regional prospectivity of the sandstone, it was necessary to explain these variations. The resuls of the study indicate that compositionally and texturally the sandstones are extremely homogeneous. It is concluded that the marked variation in the poroperm characteristics of the aeolian sandstones is a result of a relatively complex diagenesis. A fluctuating water table resulted in the formation of a pattern of calcite, anhydrite and quartz cements within an aeolian dune sandstone. 7 refs., 1 fig

Characteristics of isotope geology of sandstone-type uranium deposit in Turpan-Hami Basin

International Nuclear Information System (INIS)

Liu Hanbin; Xia Yuliang; Lin Jinrong; Fan Guang

2003-01-01

This paper expounds the isotope characteristics of in-situ leachable sandstone-type uranium deposit of Shihongtan in the southwestern part of Turpan-Hami basin. The results suggest that uranium mineralization age of 48 ± 2 Ma and 28 ± 4 Ma are obtained. The ages of the porphyritic granite and gneissic granite from the southwestern area are 422 ± 5 Ma and 268 ± 23 Ma. The U-Pb age of clastic zircons from ore-bearing sandstone is 283 ± 67 Ma, which is corresponding to the age of gneissic granite of the provenance area indicating the material source of uraniferous sandstone.Based. The sources are uraniferous sandstone accumulated during the deposition and the uranium leached from provenance area rocks by weathering. (authors)

Applying reaction condition index to predict sandstone type uranium deposit

International Nuclear Information System (INIS)

Chen Gongxin; Liu Jinhui; Cheng Hai

2002-01-01

On the basic of the explanation of reaction condition index, the deduction of reaction condition index calculation principle, the hydrogeological setting in Gongpoquan basin in Baishan, Gansu province and the study of reaction condition index of its water source point, the north Luotuoquan area in Gongpoquan basin seems to be a favourable place for sandstone type uranium deposit, and the prospect area for sandstone type uranium deposit is delimitated

Superstorm Sandy and the Verdant Power RITE Project

Science.gov (United States)

Corren, D.; Colby, J.; Adonizio, M.

2013-12-01

On October 29, 2012 Superstorm Sandy (formerly Hurricane Sandy) made landfall in New Jersey. One of the deadliest, and second-costliest hurricane in US history, Sandy was the largest Atlantic hurricane on record, with a diameter of 1,800 km. It was this unprecedented size, extreme central low pressure, and full-moon timing that created a storm surge which inundated New York City with record-breaking water levels, resulting in tremendous destruction of buildings and infrastructure. At its RITE (Roosevelt Island Tidal Energy) Project in New York City's East River, Verdant Power has been installing demonstration and commercial turbine systems since 2005, along with performing related environmental monitoring and measurements. The RITE site is located in the East Channel of the East River, on the east side of Roosevelt Island. All along the East River, large areas of the adjacent boroughs were impacted by Sandy, including flooding of the subway tunnels under the river. When Sandy struck, Verdant had recently concluded a two-week in-water test at RITE of a new rotor for its Gen5 KHPS (Kinetic Hydropower System) turbine, with funding assistance by partners NYSERDA and the US Department of Energy. While the turbine had already been removed from its mounting in the river bottom in September, Verdant continued to operate two water measurement instruments in the river. These acoustic Doppler current profilers (ADCPs) measure the 3-D water velocity at various heights in the water column, and are also equipped to provide water level data. Verdant is interested in the effects such an extreme storm could have on turbines and other equipment installed in this river reach, as is planned by Verdant under a 10-year commercial pilot project licensed by the Federal Energy Regulatory Commission (FERC) for up to 30 turbines. Associated equipment includes navigational aids (buoys and signage), which Verdant is required to maintain to exclude vessels from the project boundaries. The East

Hurricane Sandy (New Jersey): Mortality Rates in the Following Month and Quarter.

Science.gov (United States)

Kim, Soyeon; Kulkarni, Prathit A; Rajan, Mangala; Thomas, Pauline; Tsai, Stella; Tan, Christina; Davidow, Amy

2017-08-01

To describe changes in mortality after Hurricane Sandy made landfall in New Jersey on October 29, 2012. We used electronic death records to describe changes in all-cause and cause-specific mortality overall, in persons aged 76 years or older, and by 3 Sandy impact levels for the month and quarter following Hurricane Sandy compared with the same periods in earlier years adjusted for trends. All-cause mortality increased 6% (95% confidence interval [CI] = 2%, 11%) for the month, 5%, 8%, and 12% by increasing Sandy impact level; and 7% (95% CI = 5%, 10%) for the quarter, 5%, 8%, and 15% by increasing Sandy impact level. In elderly persons, all-cause mortality rates increased 10% (95% CI = 5%, 15%) and 13% (95% CI = 10%, 16%) in the month and quarter, respectively. Deaths that were cardiovascular disease-related increased by 6% in both periods, noninfectious respiratory disease-related by 24% in the quarter, infection-related by 20% in the quarter, and unintentional injury-related by 23% in the month. Mortality increased, heterogeneous by cause, for both periods after Hurricane Sandy, particularly in communities more severely affected and in the elderly, who may benefit from supportive services.

Sedimentological Characteristics and Re-interpretation of the Paleoenvironment of Lokoja Sandstone, Southern Bida Basin, Nigeria

International Nuclear Information System (INIS)

Ojo, O. J.; Akande, S. O.

2002-01-01

Detail mapping of the Lokoja Formation consisting predominantly of sandstones exposed along Okene-Abuja highway near the confluence of Rivers Niger and Benue in the southern Bida Basin was undertaken in an attempt to reconstruct their depositional history. The analyses of the lithofacies characteristics, pebble morphogenesis and ichnofossil content of the Lokoja sandstones in the study area reveal their depositional environments which evolved from alluvial fans through braided stream into nearshore shallow marine conditions. The massive, immature, matrix to grain supported conglomerate subfacies can be interpreted as debris flow. The conglomeratic sandstone facies (massive, cross stratified and graded subfacies) reflect deposits of deep braided channels. The bioturbated and herringbone cross stratified conglomeratic sandstones indicate shallowing to marginal marine environments. The fine to medium grained sandstones, siltstones and claystones are interpreted as channel bars and floodplain deposits.Results of pebble morphogenesis analysis indicate predominance of fluvial processes. Minor high energy (probably beach) condition is indicated by some individual clasts from the conglomeratic sandstone facies with sphericity and OP index values less that 0.66 and -1.5 respectively.The study is significant because it represents the first sedimentological evidence of influence of shallow marine in the development of Lokoja sandstones during Campanian-Maastrichtian times

PALEOEVIRONMENT OF NIGERIA'S AJALI SANDSTONES: A ...

African Journals Online (AJOL)

The Ajali Sandstone is a major clastic formation of Campanian-Maastrichtian age occuring within the Anambra Basin, Southeastern Nigeria. ... The result is in line with earlier conclusions of fluvial or fluviodeltaic depositional environment based on analysis of faceis, sedimentary rock which are suitable for morphometrical ...

Family Structures, Relationships, and Housing Recovery Decisions after Hurricane Sandy

Directory of Open Access Journals (Sweden)

Ali Nejat

2016-04-01

Full Text Available Understanding of the recovery phase of a disaster cycle is still in its infancy. Recent major disasters such as Hurricane Sandy have revealed the inability of existing policies and planning to promptly restore infrastructure, residential properties, and commercial activities in affected communities. In this setting, a thorough grasp of housing recovery decisions can lead to effective post-disaster planning by policyholders and public officials. The objective of this research is to integrate vignette and survey design to study how family bonds affected rebuilding/relocating decisions after Hurricane Sandy. Multinomial logistic regression was used to investigate respondents’ family structures before Sandy and explore whether their relationships with family members changed after Sandy. The study also explores the effect of the aforementioned relationship and its changes on households’ plans to either rebuild/repair their homes or relocate. These results were compared to another multinomial logistic regression which was applied to examine the impact of familial bonds on respondents’ suggestions to a vignette family concerning rebuilding and relocating after a hurricane similar to Sandy. Results indicate that respondents who lived with family members before Sandy were less likely to plan for relocating than those who lived alone. A more detailed examination shows that this effect was driven by those who improved their relationships with family members; those who did not improve their family relationships were not significantly different from those who lived alone, when it came to rebuilding/relocation planning. Those who improved their relationships with family members were also less likely to suggest that the vignette family relocate. This study supports the general hypothesis that family bonds reduce the desire to relocate, and provides empirical evidence that family mechanisms are important for the rebuilding/relocating decision

The Bentheim Sandstone: Geology, petrophysics, varieties and it's use as dimension stone

NARCIS (Netherlands)

Dubelaar, C.W.; Nijland, T.G.

2014-01-01

The shallow-marine Bentheim Sandstone was deposited in one of the NW-SE trending basins north of the London-Brabant and Rhenish massifs during the Valanginian (Early Cretaceous). The Bentheim Sandstone forms an important reservoir rock for petroleum, but has also proven itself as a very durable

On the water saturation calculation in hydrocarbon sandstone reservoirs

Energy Technology Data Exchange (ETDEWEB)

Stalheim, Stein Ottar

2002-07-01

The main goal of this work was to identify the most important uncertainty sources in water saturation calculation and examine the possibility for developing new S{sub w} - equations or possibility to develop methods to remove weaknesses and uncertainties in existing S{sub w} - equations. Due to the need for industrial applicability of the equations we aimed for results with the following properties: The accuracy in S{sub w} should increase compared with existing S{sub w} - equations. The equations should be simple to use in petrophysical evaluations. The equations should be based on conventional logs and use as few as possible input parameters. The equations should be numerical stable. This thesis includes an uncertainty and sensitivity analysis of the most common S{sub w} equations. The results are addressed in chapter 3 and were intended to find the most important uncertainty sources in water saturation calculation. To increase the knowledge of the relationship between R{sub t} and S{sub w} in hydrocarbon sandstone reservoirs and to understand how the pore geometry affects the conductivity (n and m) of the rock a theoretical study was done. It was also an aim to examine the possibility for developing new S{sub w} - equations (or investigation an effective medium model) valid inhydrocarbon sandstone reservoirs. The results are presented in paper 1. A new equation for water saturation calculation in clean sandstone oil reservoirs is addressed in paper 2. A recommendation for best practice of water saturation calculation in non water wet formation is addressed in paper 3. Finally a new equation for water saturation calculation in thinly interbedded sandstone/mudstone reservoirs is presented in paper 4. The papers are titled: 1) Is the saturation exponent n a constant. 2) A New Model for Calculating Water Saturation In 3) Influence of wettability on water saturation modeling. 4) Water Saturation Calculations in Thinly Interbedded Sandstone/mudstone Reservoirs. A

The fate of fresh and stored 15N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

DEFF Research Database (Denmark)

Sørensen, P.; Jensen, E.S.

1996-01-01

The fate of nitrogen from N-15-labelled sheep urine and urea applied to two soils was studied under field conditions. Labelled and stored urine equivalent to 204 kg N ha(-1) was either incorporated in soil or applied to the soil surface prior to sowing of Italian ryegrass (Lolium multiflorum L...... and soil was not significantly different for incorporated urine and urea. Almost all the supplied labelled N was accounted for in soil and herbage in the sandy loam soil, whereas 33-34% of the labelled N was unaccounted for in the sandy soil. When the stored urine was applied to the soil surface, 20...... was applied to growing ryegrass at the sandy loam soil, the immobilization of urine-derived N was significantly reduced compared to application prior to sowing. The results indicated that the net mineralization of urine N was similar to that of urea in the sandy soil, but only about 75% of the urine N was net...

Sandy a změna klimatu

Czech Academy of Sciences Publication Activity Database

Pecho, Jozef

2013-01-01

Roč. 92, č. 7 (2013), s. 408-411 ISSN 0042-4544 Institutional support: RVO:68378289 Keywords : hurricanes * climate change Subject RIV: DG - Athmosphere Sciences, Meteorology http://www.vesmir.cz/clanek/sandy-a-zmena-klimatu

Elastic Dispersion and Attenuation in Fully Saturated Sandstones: Role of Mineral Content, Porosity, and Pressures

Science.gov (United States)

Pimienta, Lucas; Borgomano, Jan V. M.; Fortin, Jérôme; Guéguen, Yves

2017-12-01

Because measuring the frequency dependence of elastic properties in the laboratory is a technical challenge, not enough experimental data exist to test the existing theories. We report measurements of three fluid-saturated sandstones over a broad frequency band: Wilkenson, Berea, and Bentheim sandstones. Those sandstones samples, chosen for their variable porosities and mineral content, are saturated by fluids of varying viscosities. The samples elastic response (Young's modulus and Poisson's ratio) and hydraulic response (fluid flow out of the sample) are measured as a function of frequency. Large dispersion and attenuation phenomena are observed over the investigated frequency range. For all samples, the variation at lowest frequency relates to a large fluid flow directly measured out of the rock samples. These are the cause (i.e., fluid flow) and consequence (i.e., dispersion/attenuation) of the transition between drained and undrained regimes. Consistently, the characteristic frequency correlates with permeability for each sandstone. Beyond this frequency, a second variation is observed for all samples, but the rocks behave differently. For Berea sandstone, an onset of dispersion/attenuation is expected from both Young's modulus and Poisson's ratio at highest frequency. For Bentheim and Wilkenson sandstones, however, only Young's modulus shows dispersion/attenuation phenomena. For Wilkenson sandstone, the viscoelastic-like dispersion/attenuation response is interpreted as squirt flow. For Bentheim sandstone, the second effect does not fully follow such response, which could be due to a lower accuracy in the measured attenuation or to the occurence of another physical effect in this rock sample.

Preliminary study on features of mineralogical zoning of epigenetic alteration at sandstone-type uranium deposit, Dongsheng area, Ordos basin

International Nuclear Information System (INIS)

Xiao Xinjian; Li Ziying; Chen Anping

2004-01-01

Sandstone-type uranium deposits located in Dongsheng area, northern Ordos basin, occur in Zhiluo Formation, Middle Jurassic. The Zhiluo Formation is divided into two members. The lower member is further divided into two submembers. The lower submember is dominantly composed of grey sandstone being the ore-hosting horizon; the upper submember consists of grey-green sandstone and mudstone. The upper member of Zhiluo Formation is made of mottled medium-fine grained sandstone and mudstone. Through the microscopic observation and study on sandstones of Zhiluo Formation, authors have established a vertical zonation of epigenetic alteration (from the top to the bottom): the limonitization + clayization + carbonation in the mottled fine-grained sandstone of the upper member of Zhiluo Formation; the green alteration (II) (mainly the chloritization of biotite, as well as the chloritization and epidotization of feldspar) + clayization + carbonation in the grey-green sandstone of the upper submember of the lower member of Zhiluo Formation; and the green alteration (I) (mainly the epidotization of feldspar) + carbonation in grey, grey-white sandstone of the lower submember. The epigenetic alteration basically occurs in grey-green sandstone. The sandstone shows grey-green color because it contains much green biotite (not chlorite). The epigenetic alteration in sandstone layer is closely associated with the uranium ore-formation

New Acid Combination for a Successful Sandstone Acidizing

Science.gov (United States)

Shafiq, M. U.; Mahmud, H. K. B.; Rezaee, R.

2017-05-01

With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

) Sediment petrographic characterisation and diagenetic pathways of the Miocene Agbada sandstone, Niger delta

International Nuclear Information System (INIS)

Akaegbobi, I. M; Gaupp, R.; Fischer, C.

2003-01-01

Combined petrophysical and petrographic investigations of he Agbada sandstone interbeds has been undertaken in order to determine the controlling factors on the reservoir quality of he paralic sandstone facies. Well logs, petrophysical data and a set of core samples from two wells located in the eastern onshore of he Niger delta spanning a depth interval of 3200 to 330m, formed the basic material for the present study. Four sandstone and siltstone facies units ranging form coastal bar sands through transgressive sands to marine claystones were identified based on petrophysical log signatures. Thin section analysis of a selected set of sandstone samples revealed essentially a unimodal, homogeneous grain size distribution of the detrital mineral components. Quantitative assessment of the mineralogical composition using point count method (300 points) revealed the predominance of dring. etrital quartz (85%) over feldspar minerals (9%) and lithic fragments (6%). A database generated from the point counting of the sandstones provided a broad perspective to the relative variations of the intergranular porosities (28%), cementation and matrix. These are remarkable indicators for low compaction. Authigenic kaoline and illite were identified. The partial leaching of detrital feldspars are responsible for the low percentages of intragranular volume (secondary porosity). The main controlling factor on the high porosity can be traced to either low compactional effects (overpressure?) or total leaching of unknown early cements. We suggest that the excellent reservoir properties of the Agbada sandstones are due to under compaction, caused by continuous long-term over pressuring

Heavy mineral sorting in downwards injected Palaeocene sandstone, Siri Canyon, Danish North Sea

DEFF Research Database (Denmark)

Kazerouni, Afsoon Moatari; Friis, Henrik; Svendsen, Johan Byskov

2011-01-01

Post-depositional remobilization and injection of sand are often seen in deep-water clastic systems and has been recently recognised as a significant modifier of deep-water sandstone geometry. Large-scale injectite complexes have been interpreted from borehole data in the Palaeocene Siri Canyon...... of depositional structures in deep-water sandstones, the distinction between "in situ" and injected or remobilised sandstones is often ambiguous. Large scale heavy mineral sorting (in 10 m thick units) is observed in several reservoir units in the Siri Canyon and has been interpreted to represent the depositional...... sorting. In this study we describe an example of effective shear-zone sorting of heavy minerals in a thin downward injected sandstone dyke which was encountered in one of the cores in the Cecilie Field, Siri Canyon. Differences in sorting pattern of heavy minerals are suggested as a tool for petrographic...

A new bee species that excavates sandstone nests.

Science.gov (United States)

Orr, Michael C; Griswold, Terry; Pitts, James P; Parker, Frank D

2016-09-12

Humanity has long been fascinated by animals with apparently unfavorable lifestyles [1]. Nesting habits are especially important because they can limit where organisms live, thereby driving population, community, and even ecosystem dynamics [2]. The question arises, then, why bees nest in active termite mounds [3] or on the rim of degassing volcanoes, seemingly preferring such hardship [4]. Here, we present a new bee species that excavates sandstone nests, Anthophora (Anthophoroides) pueblo Orr (described in Supplemental Information, published with this article online), despite the challenges already inherent to desert life. Ultimately, the benefits of nesting in sandstone appear to outweigh the associated costs in this system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Architecture and quantitative assessment of channeled clastic deposits, Shihezi sandstone (Lower Permian, Ordos Basin, China

Directory of Open Access Journals (Sweden)

Chengye Jia

2017-02-01

Full Text Available Lower Permian Shihezi sandstone in Ordos Basin is the largest gas reservoir in China. Architecture elements of channel, overbank and floodplain facies of braided channel deposits were identified through an outcrops survey, and their proportion of channel facies have been quantitatively estimated from well logging. Characteristics of architecture elements, such as sand thickness, bounding surfaces and lithofacies were investigated through outcrops and core. Petrology of Shihezi sandstone has also been studied in detail. Analysis on sandstone components shows that monocrystalline quartz with approximately 76% bulk volume, and lithic up to 5%–45% bulk volume, are the two main components. Litharenite and lithic quartz sandstone are the main rock types. Compaction is concluded by former researchers as the control factor of low permeability. Examination through thin section reveals that secondary pores developed well in coarse sand. Inter-granular dissolution is included as the positive effect to increasing porosity, and is concluded as the control factor to the generation of net pay. Scale of coarse grained channel fills and channel bar sandstone bodies are quantitatively estimated. Strike-oriented, dip-oriented, and vertical distribution of channel fills and channel bar sandstone bodies have been investigated. The geometry of sand bodies can be depicted as an elongated lens. Subsurface mapping reveals that channel sandstone bodies distribute widely from both lateral and longitudinal cross section profiles, and are poorly connected.

Petrographic study of core plugs from lower goru sandstones

International Nuclear Information System (INIS)

Memon, M.K.; Tunio, A.; Leghari, A.

2008-01-01

Petrographic rock type description is a fundamental component in the reservoir description processes and typically included measurement to identify sediment source, texture, composition and mineralogy. Petroleum workers have long used the Petrographic microscope as an in put device to aid in the study of pore systems. Standard Petrographic thin sections are typically 30 micrometers thick and are usually illuminated by transmitted light. Experienced examiners have trained themselves to see information such as pore size, mineralogy, compaction, etc by disregarding artifacts produced by passing light through a section. This method is adequate for qualitative interpretation of data from thin sections. Rocks in thin section under a microscope display great complexity in pore sizes and shapes. Petrographic study provides measurement on rock texture. Texture deals with the size, shape and arrangement of the component minerals of a rock. It is essentially the micro geometry of the rock. Permeability of collected core plugs of lower Goru sandstones was measured. From this Petrographic study we have identified as the sandstone of Lower Goru constitute almost entirely of quartz. The grains range in size from very fine to medium, moderately well sorted to well sorted and rounded to sub rounded in shape. Particularly attention was paid to mineral content present in Lower Goru Sandstone. The mineral composition from these core plugs of Lower Goru Sandstone as identified contain about 70-80% Quartz with traces of feldspar, muscovite, biotite, Epidote and hornblende. Calcite was present as cementing material and it was about 15 -30% of the total rock. (author)

Abrasive wear based predictive maintenance for systems operating in sandy conditions

NARCIS (Netherlands)

Woldman, M.; Tinga, T.; Heide, E. van der; Masen, M.A.

2015-01-01

Machines operating in sandy environments are damaged by the abrasive action of sand particles that enter the machine and become entrapped between components and contacting surfaces. In the case of the military services the combination of a sandy environment and the wide range of tasks to be

Performance of Different Acids on Sandstone Formations

Directory of Open Access Journals (Sweden)

M. A. Zaman

2013-12-01

Full Text Available Stimulation of sandstone formations is a challenging task, which involves several chemicals and physical interactions of the acid with the formation. Some of these reactions may result in formation damage. Mud acid has been successfully used to stimulate sandstone reservoirs for a number of years. It is a mixture of hydrofluoric (HF and hydrochloric (HCl acids designed to dissolve clays and siliceous fines accumulated in the near-wellbore region. Matrix acidizing may also be used to increase formation permeability in undamaged wells. The change may be up to 50% to 100% with the mud acid. For any acidizing process, the selection of acid (Formulation and Concentration and the design (Pre-flush, Main Acid, After-flush is very important. Different researchers are using different combinations of acids with different concentrations to get the best results for acidization. Mainly the common practice is combination of Hydrochloric Acid – Hydrofluoric with Concentration (3% HF – 12% HCl. This paper presents the results of a laboratory investigation of Orthophosphoric acid instead of hydrochloric acid in one combination and the second combination is Fluoboric and formic acid and the third one is formic and hydrofluoric acid. The results are compared with the mud acid and the results calculated are porosity, permeability, and FESEM Analysis and Strength tests. All of these new combinations shows that these have the potential to be used as acidizing acids on sandstone formations.

Fluvial-deltaic sedimentation and stratigraphy of the ferron sandstone

Science.gov (United States)

Anderson, P.B.; Chidsey, T.C.; Ryer, T.A.

1997-01-01

East-central Utah has world-class outcrops of dominantly fluvial-deltaic Turonian to Coniacian aged strata deposited in the Cretaceous foreland basin. The Ferron Sandstone Member of the Mancos Shale records the influences of both tidal and wave energy on fluvial-dominated deltas on the western margin of the Cretaceous western interior seaway. Revisions of the stratigraphy are proposed for the Ferron Sandstone. Facies representing a variety of environments of deposition are well exposed, including delta-front, strandline, marginal marine, and coastal-plain. Some of these facies are described in detail for use in petroleum reservoir characterization and include permeability structure.

Measuring Sandy Bottom Dynamics by Exploiting Depth from Stereo Video Sequences

DEFF Research Database (Denmark)

Musumeci, Rosaria E.; Farinella, Giovanni M.; Foti, Enrico

2013-01-01

In this paper an imaging system for measuring sandy bottom dynamics is proposed. The system exploits stereo sequences and projected laser beams to build the 3D shape of the sandy bottom during time. The reconstruction is used by experts of the field to perform accurate measurements and analysis...

Age, sedimentary environments, and other aspects of sandstone and related host rocks for uranium deposits

International Nuclear Information System (INIS)

1983-01-01

Project II of the Uranium Geology Working Group was assigned to the study of sedimentary basins and sandstone - type uranium deposits. About 40% of the worlds's uranium resources are contained in sandstone-type deposits, which has led to extensive research. The research was carried out mainly by correspondence, and the results reported by 21 geologists from 10 nations are summarized in this report. It investigated five topics dealing with important aspects of the geology of uranium ores in sandstone host formations: age of host rock; partitioning of uranium between continental and marine sediments; latitude limitation on formation of sandstone deposits; effect of rock formation dip on sandstone ores; usefulness of stable isotope and fluid inclusion studies. The results of studies on these subjects form part of a wider programme of the Working Group, whose final results will be presented at the 27th International Geological Congress in Moscow in 1984

Sandstone Relief Geohazards and their Mitigation: Rock Fall Risk Management in the Bohemian Switzerland National Park

Czech Academy of Sciences Publication Activity Database

Vařilová, Zuzana; Zvelebil, J.

2005-01-01

Roč. 44, - (2005), s. 53-58 ISSN 1682-5519. [Sandstone Landscapes in Europe. Past, Present and Future. International Conference on Sandstone Landscapes /2./. Vianden, 25.05.2005-28.05.2005] Keywords : sandstones * rock-slope instability * rock fall * risk evalution and mitigation * monitoring net * remedial works Subject RIV: DO - Wilderness Conservation

Study of petrological characteristics of uranium-bearing sandstone in the south of ordos basin, China

International Nuclear Information System (INIS)

Tian Cheng; Jia Licheng; Li Song; Zhang Zimin

2007-01-01

This paper discusses the relation between uranium-bearing abundance and texture constituent of sedimentary rock, on the basis of the research of petrological characteristic of sandstone in the south of Ordos basin. The influence of infiltration of sandstone and uranium migration and accumulation by the major diagenesis of compaction and cementation, clay minerals evolution, corrosion and forming of secondary porosity are discussed. Uranium-bearing sandstones are divided into four types and their petrological characteristics are discussed. After mineralization conditions being summed up, the uranium-mineralization model of sandstone-type is built. Reliable petrological evidences for evaluating favourable uranium mineralization rich areas are furnished. (authors)

Transportation during and after Hurricane Sandy.

Science.gov (United States)

2012-11-01

"Hurricane Sandy demonstrated the strengths and limits of the transportation infrastructure in New York City and the surrounding region. As a result of the timely and thorough preparations by New York City and the MTA, along with the actions of city ...

Will the future atmospheric circulation favor the landfall of Sandy-like superstorms? (Invited)

Science.gov (United States)

Barnes, E. A.; Polvani, L. M.; Sobel, A. H.

2013-12-01

Superstorm Sandy ravaged the Eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here, we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the CMIP5 multi-model ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy's unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

Rate type isotach compaction of consolidated sandstone

NARCIS (Netherlands)

Waal, J.A. de; Thienen-Visser, K. van; Pruiksma, J.P.

2015-01-01

Laboratory experiments on samples from a consolidated sandstone reservoir are presented that demonstrate rate type compaction behaviour similar to that observed on unconsolidated sands and soils. Such rate type behaviour can have large consequences for reservoir compaction, surface subsidence and

Migration characteristics of cobalt-60 through sandy soil in high pH solution

International Nuclear Information System (INIS)

Ohnuki, Toshihiko

1992-01-01

Migration characteristics of 60 Co through sandy soil in high pH solution has been investigated by both column and batch techniques. The association of 60 Co with the sandy soil and its components were studied by sequential extraction techniques. The concentration profile of 60 Co in the sandy soil column was composed of two exponential curves showing that 60 Co would consist of immobile and mobile fractions. The immobile 60 Co was retained by the sandy soil and was distributed near the top. Though the mobile 60 Co was little sorbed by soil and migrated through the soil column, maximum concentration of 60 Co in the effluents decreased slightly with increasing path length of the soil column. The sequential extraction of 60 Co from the sandy soil and from its components showed that 60 Co was sorbed by both manganese oxide and clay minerals. And manganese oxide is one of the responsible soil components for the observed decrease in the maximum concentration of 60 Co in the effluents. Although the content of manganese oxide in the sandy soil was 0.13%, manganese oxide is the important component to prevent from the migration of 60 Co in the high pH solution. (author)

EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

Directory of Open Access Journals (Sweden)

Patrick S. Michael

2015-08-01

Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

Fast evolving conduits in clay-bonded sandstone: Characterization, erosion processes and significance for the origin of sandstone landforms

Czech Academy of Sciences Publication Activity Database

Bruthans, J.; Svetlik, D.; Soukup, J.; Schweigstillová, Jana; Válek, Jan; Sedláčková, M.; Mayo, A.L.

2012-01-01

Roč. 177, December (2012), s. 178-193 ISSN 0169-555X R&D Projects: GA AV ČR IAA300130806 Institutional support: RVO:67985891 ; RVO:68378297 Keywords : sandstone * erosion * piping * tensile strength * conduit * landform Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.552, year: 2012

Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms.

Science.gov (United States)

Schwartz, Rebecca M; Gillezeau, Christina N; Liu, Bian; Lieberman-Cribbin, Wil; Taioli, Emanuela

2017-08-24

Hurricane Sandy hit the eastern coast of the United States in October 2012, causing billions of dollars in damage and acute physical and mental health problems. The long-term mental health consequences of the storm and their predictors have not been studied. New York City and Long Island residents completed questionnaires regarding their initial Hurricane Sandy exposure and mental health symptoms at baseline and 1 year later (N = 130). There were statistically significant decreases in anxiety scores (mean difference = -0.33, p Hurricane Sandy has an impact on PTSD symptoms that persists over time. Given the likelihood of more frequent and intense hurricanes due to climate change, future hurricane recovery efforts must consider the long-term effects of hurricane exposure on mental health, especially on PTSD, when providing appropriate assistance and treatment.

33 CFR 80.170 - Sandy Hook, NJ to Tom's River, NJ.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sandy Hook, NJ to Tom's River, NJ. 80.170 Section 80.170 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.170 Sandy Hook, NJ to Tom's River...

Legal Considerations for Health Care Practitioners After Superstorm Sandy.

Science.gov (United States)

Hershey, Tina Batra; Van Nostrand, Elizabeth; Sood, Rishi K; Potter, Margaret

2016-06-01

During disaster response and recovery, legal issues often arise related to the provision of health care services to affected residents. Superstorm Sandy led to the evacuation of many hospitals and other health care facilities and compromised the ability of health care practitioners to provide necessary primary care. This article highlights the challenges and legal concerns faced by health care practitioners in the aftermath of Sandy, which included limitations in scope of practice, difficulties with credentialing, lack of portability of practitioner licenses, and concerns regarding volunteer immunity and liability. Governmental and nongovernmental entities employed various strategies to address these concerns; however, legal barriers remained that posed challenges throughout the Superstorm Sandy response and recovery period. We suggest future approaches to address these legal considerations, including policies and legislation, additional waivers of law, and planning and coordination among multiple levels of governmental and nongovernmental organizations. (Disaster Med Public Health Preparedness. 2016;10:518-524).

A special kind of sandstone-type uranium deposit related to Jurassic palaeochannel systems in the northeastern Ordos Basin, China

International Nuclear Information System (INIS)

Li Ziying; Fang Xiheng; Xia Yuliang; Sun Ye; Jiao Yangquan; Chen Anping; Zhang Ke

2010-01-01

Dongsheng sandstone-type uranium deposit is a large one discovered in recent years in the northeastern Ordos Basin, China. It is a special kind of sandstone-type uranium deposit,different from other ordinary sandstone-type deposits because of its unique signatures. It is generally controlled by a transitional zone between greenish and grayish sandstones, both of those two kinds of sandstones now indicate reduced geochemical environments. The greenish color of the palaeo-oxidized sandstones mainly results from chloritization and epidotization related to oil and gas secondary reduction processes. The deposit genetically is different from ordinary sandstone uranium deposits,which is of more complex origin,undergoing not only palaeo-oxidization mineralization process, but also oil-gas fluid and hydrothermal reworking processes. It is spatially related to Jurassic Zhiluo Formation with braided palaeo channel systems. The uranium mineralization zone with higher grade usually exists in the branching area of the distributary channels of main braided streams, whose sandstone heterogeneity shows a transfer sedimentary facies from the braided stream sedimentary system to the braided delta sedimentary system. Statistical results show that medium and fine-grained sandstones are the most favorable rock types for uranium mineralization. (authors)

Rebuilding Emergency Care After Hurricane Sandy.

Science.gov (United States)

Lee, David C; Smith, Silas W; McStay, Christopher M; Portelli, Ian; Goldfrank, Lewis R; Husk, Gregg; Shah, Nirav R

2014-04-09

A freestanding, 911-receiving emergency department was implemented at Bellevue Hospital Center during the recovery efforts after Hurricane Sandy to compensate for the increased volume experienced at nearby hospitals. Because inpatient services at several hospitals remained closed for months, emergency volume increased significantly. Thus, in collaboration with the New York State Department of Health and other partners, the Health and Hospitals Corporation and Bellevue Hospital Center opened a freestanding emergency department without on-site inpatient care. The successful operation of this facility hinged on key partnerships with emergency medical services and nearby hospitals. Also essential was the establishment of an emergency critical care ward and a system to monitor emergency department utilization at affected hospitals. The results of this experience, we believe, can provide a model for future efforts to rebuild emergency care capacity after a natural disaster such as Hurricane Sandy. (Disaster Med Public Health Preparedness. 2014;0:1-4).

Analysis on metallogenic conditions of paleochannel sandstone type uranium deposits in kelulun region

Energy Technology Data Exchange (ETDEWEB)

Mingyue, Feng [Beijing Research Inst. of Uranium Geology, Beijing (China)

1999-07-01

On the basis of comprehensively analyzing metallogenic conditions of paleochannel sandstone type uranium deposits, the author discusses regional geologic background, characteristics of the basement and sedimentary cover of Kelulun basin and Huchawula-Hulun Lake basin, and the metallogenic potential of paleochannel sandstone type uranium deposits is proposed.

Analysis on metallogenic conditions of paleochannel sandstone type uranium deposits in kelulun region

International Nuclear Information System (INIS)

Feng Mingyue

1999-01-01

On the basis of comprehensively analyzing metallogenic conditions of paleochannel sandstone type uranium deposits, the author discusses regional geologic background, characteristics of the basement and sedimentary cover of Kelulun basin and Huchawula-Hulun Lake basin, and the metallogenic potential of paleochannel sandstone type uranium deposits is proposed

Radionuclide transport in sandstones with WIPP brine

International Nuclear Information System (INIS)

Weed, H.C.; Bazan, F.; Fontanilla, J.; Garrison, J.; Rego, J.; Winslow, A.M.

1981-02-01

Retardation factors (R) have been measured for the transport of 3 H, /sup 95m/Tc, and 85 Sr in WIPP brine using St. Peter, Berea, Kayenta, and San Felipe sandstone cores. If tritium is assumed to have R=1, /sup 95m/Tc has R=1.0 to 1.3 and therefore is essentially not retarded. Strontium-85 has R = 1.0 to 1.3 on St. Peter, Berea, and Kayenta, but R=3 on San Felipe. This is attributed to sorption on the matrix material of San Felipe, which has 45 volume % matrix compared with 1 to 10 volume % for the others. Retardation factors (R/sub s/) for 85 Sr calculated from static sorption measurements are unity for all the sandstones. Therefore, the static and transport results for 85 Sr disagree in the case of San Felipe, but agree for St. Peter, Berea, and Kayenta

Numerical modeling of salt marsh morphological change induced by Hurricane Sandy

Science.gov (United States)

Hu, Kelin; Chen, Qin; Wang, Hongqing; Hartig, Ellen K.; Orton, Philip M.

2018-01-01

The salt marshes of Jamaica Bay serve as a recreational outlet for New York City residents, mitigate wave impacts during coastal storms, and provide habitat for critical wildlife species. Hurricanes have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. In this study, the Delft3D modeling suite was utilized to examine the effects of Hurricane Sandy (2012) on salt marsh morphology in Jamaica Bay. Observed marsh elevation change and accretion from rod Surface Elevation Tables and feldspar Marker Horizons (SET-MH) and hydrodynamic measurements during Hurricane Sandy were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model. The model results agreed well with in situ field measurements. The validated model was then used to detect salt marsh morphological change due to Sandy across Jamaica Bay. Model results indicate that the island-wide morphological changes in the bay's salt marshes due to Sandy were in the range of −30 mm (erosion) to +15 mm (deposition), and spatially complex and heterogeneous. The storm generated paired deposition and erosion patches at local scales. Salt marshes inside the west section of the bay showed erosion overall while marshes inside the east section showed deposition from Sandy. The net sediment amount that Sandy brought into the bay is only about 1% of the total amount of reworked sediment within the bay during the storm. Numerical experiments show that waves and vegetation played a critical role in sediment transport and associated wetland morphological change in Jamaica Bay. Furthermore, without the protection of vegetation, the marsh islands of Jamaica Bay would experience both more erosion and less accretion in coastal storms.

Analysis on depositional system and prospect of sandstone-type uranium deposits of Bayanhua formation in Yilemen basin

International Nuclear Information System (INIS)

Sun Zexuan; Li Guoxin; He Fayang; Wei Yunjie

2002-01-01

Yilemen basin is a typical Mesozoic intra-mountain one. The author analyses characteristics of depositional system and the prospect of sandstone-type uranium deposit in the sedimentary cover of the Bayanhua Formation, Lower Cretaceous. Authors suggest that the conglomerate, sandstone-conglomerate and sandstone beds of braided stream and delta are favourable horizons for locating phreatic and interlayer oxidation zone sandstone-type uranium deposits, i.e. the northwestern side of Dalai uplifted zone, the Chagantaigebuqi narrow sag, and the southern area of Baolinbuqi

Can porosity affect the hyperspectral signature of sandy landscapes?

Science.gov (United States)

Baranoski, Gladimir V. G.; Kimmel, Bradley W.

2017-10-01

Porosity is a fundamental property of sand deposits found in a wide range of landscapes, from beaches to dune fields. As a primary determinant of the density and permeability of sediments, it represents a central element in geophysical studies involving basin modeling and coastal erosion as well as geoaccoustics and geochemical investigations aiming at the understanding of sediment transport and water diffusion properties of sandy landscapes. These applications highlight the importance of obtaining reliable porosity estimations, which remains an elusive task, notably through remote sensing. In this work, we aim to contribute to the strengthening of the knowledge basis required for the development of new technologies for the remote monitoring of environmentally-triggered changes in sandy landscapes. Accordingly, we employ an in silico investigation approach to assess the effects of porosity variations on the reflectance of sandy landscapes in the visible and near-infrared spectral domains. More specifically, we perform predictive computer simulations using SPLITS, a hyperspectral light transport model for particulate materials that takes into account actual sand characterization data. To the best of our knowledge, this work represents the first comprehensive investigation relating porosity to the reflectance responses of sandy landscapes. Our findings indicate that the putative dependence of these responses on porosity may be considerably less pronounced than its dependence on other properties such as grain size and shape. Hence, future initiatives for the remote quantification of porosity will likely require reflectance sensors with a high degree of sensitivity.

Online Media Use and Adoption by Hurricane Sandy Affected Fire and Police Departments

OpenAIRE

Chauhan, Apoorva

2014-01-01

In this thesis work, I examine the use and adoption of online communication media by 840 fire and police departments that were affected by the 2012 Hurricane Sandy. I began by exploring how and why these fire and police departments used (or did not use) online media to communicate with the public during Hurricane Sandy. Results show that fire and police departments used online media during Hurricane Sandy to give timely and relevant information to the public about things such as evacuations, ...

Experimental deformation in sandstone, carbonates and quartz aggregate

Energy Technology Data Exchange (ETDEWEB)

Cheung, Cecilia See Nga [Stony Brook Univ., NY (United States)

2015-05-01

The first part of my thesis is mainly focused on the effect of grain size distribution on compaction localization in porous sandstone. To identify the microstructural parameters that influence compaction band formation, I conducted a systematic study of mechanical deformation, failure mode and microstructural evolution in Bleurswiller and Boise sandstones, of similar porosity (~25%) and mineralogy but different sorting. Discrete compaction bands were observed to develop over a wide range of pressure in the Bleurswiller sandstone that has a relatively uniform grain size distribution. In contrast, compaction localization was not observed in the poorly sorted Boise sandstone. My results demonstrate that grain size distribution exerts important influence on compaction band development, in agreement with recently published data from Valley of Fire and Buckskin Gulch, as well as numerical studies. The second part aimed to improve current knowledge on inelastic behavior, failure mode and brittle-ductile transition in another sedimentary rock, porous carbonates. A micritic Tavel (porosity of ~13%) and an allochemical Indiana (~18%) limestones were deformed under compaction in wet and dry conditions. At lower confining pressures, shear localization occurred in brittle faulting regime. Through transitional regime, the deformation switched to cataclastic flow regime at higher confining pressure. Specifically in the cataclastic regime, the (dry and wet) Tavel and dry Indiana failed by distributed cataclastic flow, while in contrast, wet Indiana failed as compaction localization. My results demonstrate that different failure modes and mechanical behaviors under different deformation regimes and water saturation are fundamental prior to any geophysical application in porous carbonates. The third part aimed to focus on investigating compaction on quartz aggregate starting at low (MPa) using X-ray diffraction. We report the diffraction peak evolution of quartz with increasing

Variations in DNA methylation, acetylated histone H4, and methylated histone H3 during Pinus radiata needle maturation in relation to the loss of in vitro organogenic capability.

Science.gov (United States)

Valledor, Luis; Meijón, Mónica; Hasbún, Rodrigo; Jesús Cañal, Maria; Rodríguez, Roberto

2010-03-15

Needle differentiation is a very complex process associated with the formation of a mature photosynthetic organ. From meristem differentiation to leaf maturation, gene control must play an important role switching required genes on and off to define tissue functions, with the epigenetic code being one of the main regulation mechanisms. In this work, we examined the connections between the variation in the levels of some epigenetic players (DNA methylation, acetylated histone H4 and histone H3 methylation at Lys 4 and Lys 9) at work during needle maturation. Our results indicate that needle maturation, which is associated with a decrease in organogenic capability, is related to an increase in heterochromatin-related epigenetic markers (high DNA methylation and low acetylated histone H4 levels, and the presence of histone H3 methylated at lys 9). Immunohistochemical analyses also showed that the DNA methylation of palisade parenchyma cell layers during the transition from immature to mature scions is associated with the loss of the capacity to induce adventitious organs. Copyright 2009 Elsevier GmbH. All rights reserved.

Emplacement processes of tuffaceous sandstones at IODP Site C0011B, Nankai Trough, derived from modal analysis

Science.gov (United States)

Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.

2011-12-01

Tuffaceous sandstones are characterized by their high amount (25 to 75%) of pyroclasts in their modal composition. During IODP Expedition 322 three interbeds of tuffaceous sandstones have been found within a moderately lithified and bioturbated silty claystone sequence in the late Miocene (>7.07 to ~9.0 Ma) upper part of the middle Shikoku Basin facies. Of the three sandstones, units 1 and 2 are single beds whereas unit 3 is composed of three beds. Modal analyses of 29 sandstone thin sections reveal systematic vertical changes within each bed. Generally low-density pyroclasts are enriched at the top (50-60 vol%) of each sandstone bed whereas dense lithic components (25-30 vol%) and minerals (25-30 vol%) are enriched at the bottom. The vertically varying abundance of various types of lithic fragments (sedimentary, volcanoclastic and metamorphic) suggests that these have also been segregated according to their respective densities. The highest amount of fine-grained matrix glass is found in the middle of each bed. Pumice and lithic fragments in the middle and upper parts of the sandstone beds carry ash coatings. For sandstone package 3, in contrast to 1 and 2, core pictures and thin section analyses indicate a subdivision in three units showing the same significant variations in top to bottom enrichment. This suggests three sedimentation events following each other in short time intervals. Glass and mineral chemistry of each sandstone bed show no significant vertical variations. Specifically the matrix glass-shard major element compositions are identical to the pumice clast composition in each tuffaceous sandstone bed. The compositions of amphibole and pyroxene crystals differ only slightly between the sandstone packages. Application of the Ridolfi et al. (2009) thermobarometric calculations to amphiboles of sandstone packages 1 and 2 suggests that each of these was derived from a volcanic system comprising both a deep and a shallow magma reservoir. Thickness and

Desert and groundwater dynamics of the Jurassic Navajo Sandstone, southeast Utah

Science.gov (United States)

Chan, M. A.; Hasiotis, S. T.; Parrish, J. T.

2017-12-01

The Jurassic Navajo Sandstone of southeastern Utah is a rich archive of a desert complex with an active groundwater system, influenced by climate changes and recharge from the Uncompahgre Uplift of the Ancestral Rocky Mountains. This eastern erg margin was dominated by dune deposits of large (>10 m thick) and small (m-scale) crossbedded sandstone sets. Within these porous deposits, common soft sediment deformation is expressed as contorted and upturned bedding, fluid escape structures, concentrations of clastic pipes with ring faults, and thick intervals of massive sandstone embedded in crossbedded sandstone. Collectively, these deformation features reflect changes and/or overpressure in the groundwater system. Interdune deposits record laterally variable bounding surfaces, resulting from the change in position of and proximity to the water table. Interdune modification by pedogenesis from burrows, roots, and trees suggest stable periods of moisture and water supply, as well as periodic drying expressed as polygonal cracked mud- to sand-cracked layers. Freshwater bedded and platy limestone beds represent lakes of decameter to kilometer extent, common in the upper part of the formation. Some carbonate springs that fed the lakes are preserved as limestone buildups (tufa mounds) with microbial structures. Extradunal deposits of rivers to small ephemeral streams show channelized and lenticular, subhorizontal, cm- to m-scale sandstone bodies with basal scours and rip-up clasts. Proxy records of the active hydrology imply a changing landscape at the Navajo desert's edge, punctuated by periods of significant rainfall, runoff, rivers, lakes, and springs, fed by high water table conditions to sustain periods of flourishing communities of plants, arthropods, reptiles, mammals, and dinosaurs. Strong ground motion perturbations periodically disrupted porous, water-saturated sands with possible surface eruptions, adding to the dynamic activity of the desert regime.

Application status and vistas of sequence stratigraphy to the exploration of sandstone-hosted uranium deposits

International Nuclear Information System (INIS)

Guo Qingyin; Chen Zuyi; Yu Jinshui; Han Shuqin

2008-01-01

Sequence stratigraphy is a newly developed subject based on seismostratigraphy, and has been widely applied in the exploration of hydrocarbon and other sedimentogenic mineral deposits and great achievements have been obtained. However, the application of sequence stratigraphy to the exploration of sandstone-hosted uranium deposits is just at the beginning. In this paper, some primary research achievements of sequence stratigraphy to the exploration of sandstone-hosted uranium deposits are summarized, and problems and their reasons of the application of sequence stratigraphy are discussed. Further more, according to characteristics of sandstone-hosted uranium deposits and the development of sequence stratigraphy, the application vistas of sequence stratigraphy to the exploration of sandstone-hosted uranium deposits are estimated. Finally, application directions are proposed, and some specific suggestions are given. (authors)

Heterotrophic bacterial populations in tropical sandy beaches

Digital Repository Service at National Institute of Oceanography (India)

Nair, S.; LokaBharathi, P.A.

Distribution pattern of heterotrophic bacterial flora of three sandy beaches of the west coast of India was studied. The population in these beaches was microbiologically different. Population peaks of halotolerant and limnotolerant forms were...

Effects of Heating Rate on the Dynamic Tensile Mechanical Properties of Coal Sandstone during Thermal Treatment

Directory of Open Access Journals (Sweden)

Ming Li

2017-01-01

Full Text Available The effects of coal layered combustion and the heat injection rate on adjacent rock were examined in the process of underground coal gasification and coal-bed methane mining. Dynamic Brazilian disk tests were conducted on coal sandstone at 800°C and slow cooling from different heating rates by means of a Split Hopkinson Pressure Bar (SHPB test system. It was discovered that thermal conditions had significant effects on the physical and mechanical properties of the sandstone including longitudinal wave velocity, density, and dynamic linear tensile strength; as the heating rates increased, the thermal expansion of the sandstone was enhanced and the damage degree increased. Compared with sandstone at ambient temperature, the fracture process of heat-treated sandstone was more complicated. After thermal treatment, the specimen had a large crack in the center and cracks on both sides caused by loading; the original cracks grew and mineral particle cracks, internal pore geometry, and other defects gradually appeared. With increasing heating rates, the microscopic fracture mode transformed from ductile fracture to subbrittle fracture. It was concluded that changes in the macroscopic mechanical properties of the sandstone were result from changes in the composition and microstructure.

Quantitative mineralogical analysis of sandstones using x-ray diffraction techniques

International Nuclear Information System (INIS)

Ward, C.R.; Taylor, J.C.

1999-01-01

Full text: X-ray diffraction has long been used as a definitive technique for mineral identification based on the measuring the internal atomic or crystal structures present in powdered rocks; soils and other mineral mixtures. Recent developments in data gathering and processing, however, have provided an improved basis for its use as a quantitative tool, determining not only the nature of the minerals but also the relative proportions of the different minerals present. The mineralogy of a series of sandstone samples from the Sydney and Bowen Basins of eastern Australia has been evaluated by X-ray diffraction (XRD) on a quantitative basis using the Australian-developed SIROQUANT data processing technique. Based on Rietveld principles, this technique generates a synthetic X-ray diffractogram by adjusting and combining full-profile patterns of minerals nominated as being present in the sample and interactively matches the synthetic diffractogram under operator instructions to the observed diffractogram of the sample being analysed. The individual mineral patterns may be refined in the process, to allow for variations in crystal structure of individual components or for factors such as preferred orientation in the sample mount. The resulting output provides mass percentages of the different minerals in the mixture, and an estimate of the error associated with each individual percentage determination. The chemical composition of the mineral mixtures indicated by SIROQUANT for each individual sandstone studied was estimated using a spreadsheet routine, and the indicated proportion of each oxide in each sample compared to the actual chemical analysis of the same sandstone as determined independently by X-ray fluorescence spectrometry. The results show a high level of agreement for all major chemical constituents, indicating consistency between the SIROQUANT XRD data and the whole-rock chemical composition. Supplementary testing with a synthetic corundum spike further

2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

Current status and prospects of uranium geology developments of foreign in-situ leachable sandstone type uranium deposits

International Nuclear Information System (INIS)

Wang Zhengbang

2002-01-01

Firstly, with emphasis on in-situ leachable sandstone-type uranium deposits, the prospecting history of uranium deposits worldwide and its scientific research development are generally reviewed in four steps, and their basic historical experience is also summarized. Secondly, based on the detailed description of current development status of uranium geology of foreign in-situ leachable sandstone-type uranium deposits the important strategic position of sandstone-type uranium deposits in overall uranium resources all-over-the-world and its classification, spatial-temporal distribution and regulation, and metallogenic condition of sandstone-type uranium deposits are analysed thoroughly in five aspects: techtonics, paleo-climate, hydrogeology, sedimentary facies and lithology, as well as uranium sources: Afterwards, evaluation principles of three type of hyper-genic, epigenetic infiltrated sandstone-type uranium deposits are summarized. Based on sandstone-type uranium deposits located two important countries: the United States and Russia, the current development status of prospecting technology for in-situ leachable sandstone-type uranium deposits in foreign countries is outlined. Finally, according to the prospects of supply-demand development of global uranium resources, the author points out seriously that Chinese uranium geology is faced with a severe challenge, and proposes directly four strategic measures that should be taken

Nodular features from Proterozoic Sonia Sandstone, Jodhpur Group ...

Indian Academy of Sciences (India)

Corresponding author. e-mail: parthageology@gmail.com. The Sonia ..... cement variety in the form of dispersed dark brown clots and .... content within the nodule sandstones bear sig- nature in ..... Carbonates and Evaporites 21 133–143.

Geohydrology of the Navajo sandstone in western Kane, southwestern Garfield, and southeastern Iron counties, Utah

Science.gov (United States)

Freethey, G.W.

1988-01-01

The upper Navajo and Lamb Point aquifers in the Navajo Sandstone are the principal source of water for the city of Kanab, irrigation, stock, and for rural homes in the study area. Well logs and outcrop descriptions indicate the Navajo Sandstone consists of the Lamb Point Tongue and an unnamed upper member that are separated by the Tenney Canyon Tongue of the Kayenta Formation. The main Kayenta Formation underlies the Lamb Point Tongue. The Lamb Point Tongue and the upper member of the Navajo Sandstone are saturated and hydraulically connected through the Tenney Canyon Tongue. Available data indicate that precipitation percolates to the groundwater reservoir where the Navajo Sandstone crops out. Estimates of the rate of recharge at the outcrop range from 0.1 to as much as 2.8 in/yr. Water level data indicate that water moves from the upper member of the Navajo Sandstone, through the Tenney Canyon Tongue, and into the Lamb Point Tongue. Lateral flow is generally from the outcrop areas toward the incised canyons formed by tributaries of Kanab Creek and Johnson Wash. Direction and rate of groundwater movement and the location and character of the natural hydrologic boundaries in the northern part of the area where the Navajo Sandstone is buried cannot be determined conclusively without additional water level data. (Author 's abstract)

A New Multichelating Acid System for High-Temperature Sandstone Reservoirs

Directory of Open Access Journals (Sweden)

Nianyin Li

2015-01-01

Full Text Available Sandstone reservoir acidizing is a complex and heterogeneous acid-rock reaction process. If improper acid treatment is implemented, further damage can be induced instead of removing the initial plug, particularly in high-temperature sandstone reservoirs. An efficient acid system is the key to successful acid treatment. High-temperature sandstone treatment with conventional mud acid system faces problems including high acid-rock reaction rate, short acid effective distance, susceptibility to secondary damage, and serious corrosion to pipelines. In this paper, a new multichelating acid system has been developed to overcome these shortcomings. The acid system is composed of ternary weak acid, organic phosphonic chelating agent, anionic polycarboxylic acid chelating dispersant, fluoride, and other assisted additives. Hydrogen ion slowly released by multistage ionization in ternary weak acid and organic phosphonic within the system decreases the concentration of HF to achieve retardation. Chelating agent and chelating dispersant within the system inhibited anodic and cathodic reaction, respectively, to protect the metal from corrosion, while chelating dispersant has great chelating ability on iron ions, restricting the depolarization reaction of ferric ion and metal. The synergic effect of chelating agent and chelating dispersant removes sulfate scale precipitation and inhibits or decreases potential precipitation such as CaF2, silica gel, and fluosilicate. Mechanisms of retardation, corrosion-inhibition, and scale-removing features have been discussed and evaluated with laboratory tests. Test results indicate that this novel acid system has good overall performance, addressing the technical problems and improving the acidizing effect as well for high-temperature sandstone.

Architecture of an Upper Jurassic barrier island sandstone reservoir, Danish Central Graben:

DEFF Research Database (Denmark)

Johannessen, Peter N.; Nielsen, Lars H.; Nielsen, Lars

2010-01-01

An unusually thick (c. 88 m), transgressive barrier island and shoreface sandstone succession characterizes the Upper Jurassic Heno Formation reservoir of the Freja oil field situated on the boundary of Denmark and Norway. The development and preservation of such thick transgressive barrier island...... sands is puzzling since a barrier island typically migrates landwards during transgression and only a thin succession of back-barrier and shoreface sands is preserved. Investigation of the development and geometry of the Freja reservoir sandstones is problematic since the reservoir is buried c. 5 km...... and seismic resolution is inadequate for architectural analysis. Description of the reservoir sandstone bodies is thus based on sedimentological interpretation and correlation of seven wells, of which five were cored. Palaeotopography played a major role in the position and preservation of the thick reservoir...

Research on geochronology and uranium source of sandstone-hosted uranium ore-formation in major uranium-productive basins, Northern-China

International Nuclear Information System (INIS)

Xia Yuliang; Liu Hanbin; Lin Jinrong; Fan Guang; Hou Yanxian

2004-12-01

A method is developed for correcting uranium content in uranium ore samples by considering the U-Ra equilibrium coefficient, then a U-Pb isochron is drawn up. By performing the above correction ore-formation ages of sandstone-hosted uranium mineralization which may be more realistic have been obtained. The comparative research on U-Pb isotopic ages of detritic zircon in ore-hosting sandstone and zircon in intermediate-acid igneous rocks in corresponding provenance area indicates that the ore-hosting sandstone is originated from the erosion of intermediate-acid igneous rocks and the latters are the material basis for the formation of the uranium-rich sandstone beds. On the basis of the study on U-Pb isotopic system evolution of the provenance rocks and sandstones from ore-hosting series, it is verified that the uranium sources of the sandstone-hosted uranium deposit are: the intermediate-acid igneous rocks with high content of mobile uranium, and the sandstone bodies pre-concentrated uranium. (authors)

Study on U-Ra equilibrium coefficient of the in-situ leaching sandstone-type uranium deposits: A case study of Qianjiadian uranium deposit

International Nuclear Information System (INIS)

Xia Yuliang; Xiu Qunye; Han Jun; Li Linqiang; Zheng Jiwei

2013-01-01

This paper investigated the U-Ra equilibrium coefficient (K-p) of mineralized sandstone and mudstone, and unmineralized sandstone and mudstone for the in-situ leaching sandstone-type uranium deposits. It is surprised that all of the mineralized sandstone and mudstone are both relatively to be partial to uranium, but all of the unmineralized sandstone and mudstone are both relatively to be partial to radium. Meanwhile the uranium in mineralized mudstone is relatively richer than that in mineralized sandstone, and the radium in unmineralized mudstone is relatively richer than that in unmineralized sandstone. It is suggested that mudstones were permeable at the uranium mineralized phase and the unmineralized mudstone and sandstone could serve as important mineralized uranium source. (authors)

Mapping Bedrock Topography using Electromagnetic Profiling ...

African Journals Online (AJOL)

Mapping Bedrock Topography using Electromagnetic Profiling. ... will be constructed The area under study is within the Abakaliki Shales Geologic Formation. ... micaceous sandstone; micaceous siltstone, sandy shales and shelly limestone.

Measurement of biological oxygen demand sandy beaches

African Journals Online (AJOL)

Measurements of biological oxygen demand in a sandy beach using conventional .... counting the cells present in a sample of aged seawater and comparing this with .... This activity peaked at 71 % above the undisturbed level after 16 hours.

Integrated prediction based on GIS for sandstone-type uranium deposits in the northwest of Ordos Basin

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Hu Shuiqing; Guo Qingyin; Hou Huiqun

2005-01-01

The integrated prediction model of sandstone-type uranium deposits and its integrated evaluation methods as well as flow of the work based on GIS are studied. A software for extracting metallogenic information is also developed. A multi-source exploring information database is established in the northwest of Ordos Basin, and an integrated digital mineral deposit prospecting model of sandstone-type uranium deposits is designed based on GIS. The authors have completed metallogenic information extraction and integrated evaluation of sandstone-type uranium deposits based on GIS in the study area. Research results prove that the integrated prediction of sandstone-type uranium deposits based on GIS may further delineate prospective target areas rapidly and improve the predictive precision. (authors)

Application research on remote sensing geology of sandstone-type uranium deposit in Yili basin

International Nuclear Information System (INIS)

Wang Huaiwu

2002-01-01

Based on remote sensing images and practical materials, and new ideas of laying particular emphasis on the research of regional geologic structures, and large in-situ leachable sandstone-type uranium deposits, applying the theory of plate tectonics, the author makes a comprehensive analysis on the uranium metallogenic environments, characteristics of regional geologic structures, the ore-controlling mechanism and factors, and uranium metallogeny. Authors propose that large interlayer oxidation zone sandstone-type uranium deposits are controlled by the combination of the stable block in Meso-Cenozoic compressive-shearing faulted subsided basin on the Yili multiphase massif in Tianshan paleo-island arc system, and the specific paleo-geographic environments and its' structural terrace'. The origin of hydrogenic sandstone-type uranium deposits is summarized by the authors as the 'mixing and neutralization' genetic model, and the 'eight ore-controlling factors merge into an organic whole' prospecting model. The above mentioned provides clear prospecting direction and new ideas for the forecasting direction for prospecting large sandstone-type uranium deposits

Study on integrated evaluation of sandstone-hosted uranium metallogenic potential in southern Yili basin

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Xu Jianguo; Zheng Enjiu; Li Shengxiang

2008-01-01

Plenty of geological data have been accumulated during mineral resource survey in China; under the guidance of new metallogenic theories, it is an important task of how to use these data most effectively for the new cycle uranium survey. In this paper, the flow of establishing the integrated mineral deposits prospecting model for sandstone-hosted uranium deposits is put forward. Based on studying geologic, hydrogeologic and regional geophysical field characteristics of representative uranium deposits No. 512 in southern Yili basin, its multi-source information descriptive model has been established, from which 512-type integrated prospecting models of sandstone-hosted uranium orefield and deposits are summarized. According to the established integrated prospecting models, the metallogenic information extraction of sandstone-hosted uranium deposits has completed in the study area. Finally, the integrated quantitative evaluation of sandstone-hosted uranium metallogenic potential is performed by using the evidence weighing method to integrate middle scale multi-source metallogenic information in the southern Yili basin, and good prediction effect is obtained. (authors)

Experimental and Numerical Investigations on Strength and Deformation Behavior of Cataclastic Sandstone

Science.gov (United States)

Zhang, Y.; Shao, J. F.; Xu, W. Y.; Zhao, H. B.; Wang, W.

2015-05-01

This work is devoted to characterization of the deformation and strength properties of cataclastic sandstones. Before conducting mechanical tests, the physical properties were first examined. These sandstones are characterized by a loose damaged microstructure and poorly cemented contacts. Then, a series of mechanical tests including hydrostatic, uniaxial, and triaxial compression tests were performed to study the mechanical strength and deformation of the sandstones. The results obtained show nonlinear stress-strain responses. The initial microcracks are closed at hydrostatic stress of 2.6 MPa, and the uniaxial compressive strength is about 0.98 MPa. Under triaxial compression, there is a clear transition from volumetric compressibility to dilatancy and a strong dependency on confining pressure. Based on the experimental evidence, an elastoplastic model is proposed using a linear yield function and a nonassociated plastic potential. There is good agreement between numerical results and experimental data.

The controlling role of positive structures over the metallogenesis and emplacement of inter layer oxidation sandstone type uranium deposits

International Nuclear Information System (INIS)

Gu Kangheng; Chen Zuyi

2010-01-01

The positive structures in this paper mean the geological structures related to the occurrence of U-metallogenic zones or U-deposit such as anticlines, uplifts and uplifted fault-blocks. Occurrence features of interlayer oxidation sandstone type deposit at the southern margin of Yili basin and southwestern margin of Turpan-Hami basin, the northeastern margin of Jiudong basin illustrate that the sandstone-hosted uranium deposits, the U-mineralized sections and the uranium occurrences are always selectively emplaced on/in positive structures. The reasons for this lie in the formation mechanism of sandstone-hosted U-deposits. The positive structures raised the elevation of ore-hosting sandstone horizon and make it close to ground surface or exposed at the ground surface, which result in the infiltration of uranium and oxygen bearing groundwater from recharge area into host sandstone horizon, and the interlayer oxidation of host sandstone, as well as the dissolution and the migration of uranium in host sandstone, and the reduction mineralization at the oxidation-reduction interface. Sufficient attention should be paid to the controlling role of positive structures over the metallogenesis and emplacement of sandstone-hosted uranium deposits. They could act as an important criterion for recognizing and prognosticating potential uranium mineralized areas in uranium metallogenic zones or uranium-productive sedimentary basins. (authors)

The sedimentology of uranium-bearing sandstones on the farm Ryst Kuil 351 Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1979-06-01

A study of the sedimentology of some uranium-bearing sandstones on the farm Ryst Kuil 351 was made in order to assess possible relationships between the mineralisation and the sedimentary facies and/or the palaeo-environment. Use was made of 6 vertical profiles, derived from horizontal traverses. 12 sedimentary facies were recognised according to grain-size and sedimentary structure. The transitions between these facies, as derived from the vertical profiles, were subjected to Markov analysis. Only 3 Markov-dependent transitions were derived, but several facies transitions and associations occurred with greater than random frequency. These, together with the vertical profiles, were used to interpret the palaeo-environmental succession. This succession is fluvial meandering and two sub-environments - channel and flood plain - were delineated according to the prevalence of sandstone or mudstone facies. The uranium-bearing sandstones occur in the lower part of a thick (29 - 46m) multistorey point bar sequence within the channel sub-environment. The mineralisation is associated with koffieklip and is restricted to two sedimentary facies - massive very fine-to-finegrained sandstone and horizontally bedded, very fine- to fine-grained sandstone. The mineralisation normally occurs near the bases of the point bars

Quantifying the effect of squirt flow dispersion from compliant clay porosity in clay bearing sandstones

DEFF Research Database (Denmark)

Sørensen, Morten Kanne; Fabricius, Ida Lykke

2013-01-01

Compliant porosity in the form of cracks is known to cause significant attenuation and velocity dispersion through pore pressure gradients and consequent relaxation, dubbed squirt flow. Squirt flow from cracks vanish at high confining stress due to crack closing. Studies on clay bearing sandstones......-squirt flow on the bulk modulus of a clay bearing sandstone. The predicted magnitude of the clay-squirt effect on the bulk modulus is compared with experimental data. The clay-squirt effect is found to possibly account for a significant portion of the deviances from Gassmann fluid substitution in claybearing...... sandstones....

Multielement statistical evidence for uraniferous hydrothermal activity in sandstones overlying the Phoenix uranium deposit, Athabasca Basin, Canada

Science.gov (United States)

Chen, Shishi; Hattori, Keiko; Grunsky, Eric C.

2018-04-01

The Phoenix U deposit, with indicated resources of 70.2 M lb U3O8, occurs along the unconformity between the Proterozoic Athabasca Group sandstones and the crystalline basement rocks. Principal component analysis (PCA) is applied to the compositions of sandstones overlying the deposit. Among PCs, PC1 accounts for the largest variability of U and shows a positive association of U with rare earth elements (REEs) + Y + Cu + B + Na + Mg + Ni + Be. The evidence suggests that U was dispersed into sandstones together with these elements during the uraniferous hydrothermal activity. Uranium shows an inverse association with Zr, Hf, Th, Fe, and Ti. Since they are common in detrital heavy minerals, such heavy minerals are not the major host of U. The elements positively associated with U are high in concentrations above the deposit, forming a "chimney-like" or "hump-like" distribution in a vertical section. Their enrichment patterns are explained by the ascent of basement fluids through faults to sandstones and the circulation of basinal fluids around the deposit. The Pb isotope compositions of whole rocks are similar to expected values calculated from the concentrations of U, Th, and Pb except for sandstones close to the deposit. The data suggest that in situ decay of U and Th is responsible for the Pb isotope compositions of most sandstones and that highly radiogenic Pb dispersed from the deposit to the proximal sandstones long after the mineralization. This secondary dispersion is captured in PC8, which has low eigenvalue. The data suggests that the secondary dispersion has minor effect on the overall lithogeochemistry of sandstones.

Controls on the variability of net infiltration to desert sandstone

Science.gov (United States)

Heilweil, Victor M.; McKinney, Tim S.; Zhdanov, Michael S.; Watt, Dennis E.

2007-01-01

As populations grow in arid climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and then develops an empirical equation for its spatial quantification at the watershed scale using linear least squares inversion methods for evaluating controlling parameters (independent variables) based on estimated net infiltration rates (dependent variables). Net infiltration rates used for this regression analysis were calculated from environmental tracers in boreholes and more than 3000 linear meters of vadose zone excavations in an upland basin in southwestern Utah underlain by Navajo sandstone. Soil coarseness, distance to upgradient outcrop, and topographic slope were shown to be the primary physical parameters controlling the spatial variability of net infiltration. Although the method should be transferable to other desert sandstone settings for determining the relative spatial distribution of net infiltration, further study is needed to evaluate the effects of other potential parameters such as slope aspect, outcrop parameters, and climate on absolute net infiltration rates.

INAA and petrological study of sandstones from Khmer temples in Angkor

International Nuclear Information System (INIS)

Kucera, J.; Kranda, K.; Novak, J.K.; Poncar, J.; Krausova, I.; Soukal, L.

2009-01-01

INAA was used to determine 35 major, minor and trace elements in sandstone samples taken from building blocks of 21 Khmer temples in Angkor, Cambodia. The sandstone samples were also characterized by conventional optical microscopy, X-ray diffraction analysis and electron microprobe analysis. The aim of this work was to examine the hypothesis that a particular elemental and/or mineral composition of the building materials can be characteristic of a particular architectural style/building period in the history of constructing the Angkor monuments. Preliminary results of this study are presented

Epidemic gasoline exposures following Hurricane Sandy.

Science.gov (United States)

Kim, Hong K; Takematsu, Mai; Biary, Rana; Williams, Nicholas; Hoffman, Robert S; Smith, Silas W

2013-12-01

Major adverse climatic events (MACEs) in heavily-populated areas can inflict severe damage to infrastructure, disrupting essential municipal and commercial services. Compromised health care delivery systems and limited utilities such as electricity, heating, potable water, sanitation, and housing, place populations in disaster areas at risk of toxic exposures. Hurricane Sandy made landfall on October 29, 2012 and caused severe infrastructure damage in heavily-populated areas. The prolonged electrical outage and damage to oil refineries caused a gasoline shortage and rationing unseen in the USA since the 1970s. This study explored gasoline exposures and clinical outcomes in the aftermath of Hurricane Sandy. Prospectively collected, regional poison control center (PCC) data regarding gasoline exposure cases from October 29, 2012 (hurricane landfall) through November 28, 2012 were reviewed and compared to the previous four years. The trends of gasoline exposures, exposure type, severity of clinical outcome, and hospital referral rates were assessed. Two-hundred and eighty-three gasoline exposures were identified, representing an 18 to 283-fold increase over the previous four years. The leading exposure route was siphoning (53.4%). Men comprised 83.0% of exposures; 91.9% were older than 20 years of age. Of 273 home-based calls, 88.7% were managed on site. Asymptomatic exposures occurred in 61.5% of the cases. However, minor and moderate toxic effects occurred in 12.4% and 3.5% of cases, respectively. Gastrointestinal (24.4%) and pulmonary (8.4%) symptoms predominated. No major outcomes or deaths were reported. Hurricane Sandy significantly increased gasoline exposures. While the majority of exposures were managed at home with minimum clinical toxicity, some patients experienced more severe symptoms. Disaster plans should incorporate public health messaging and regional PCCs for public health promotion and toxicological surveillance.

Recent exploration progresses on sandstone-hosted uranium deposits in north-western China

International Nuclear Information System (INIS)

Li, Z.

2014-01-01

The metallogenic target selection using multiple exploration techniques and drilling program for sandstone-hosted uranium deposits have been intensively carried out for recent years, and big progresses on new discoveries of uranium reserve/resource have been made in the Mesozoic sedimentary basins such as in Yili, Ordos etc. in North-western China The Yili basin is a depression one within the Tianshan Mountain belt in the western part of China. Its basement is composed of Proterozoic-Paleozoic metamorphic and sedimentary rocks, and covers of Mesozoic sediments. The early-middle Jurassic Shuixigou Group is major uranium-productive beds which are composed of three Formations such as Badaowan, Sangonghe, Xisanyao and eight sedimentary cycles. Uranium deposits are found in the south margin of the Basin and controlled by the redox zone. The combined exploration techniques of detailed sedimentary facies study, Rn-survey, high-precision magnetic and soil geochemical and seismic surveys have been successfully used to have locate the potential targets and mineralization zones. The enlargement of uranium reserve/resources in the known deposits and new resources in the selected new targets and cycles have been achieved through further drilling programs. The Ordos basin is a large Meso-Cenozoic basin developed in North China Platform, with its size of approximately 250,000 km"2 and is well known as an important “energy resources basin” because of abundance of coal, oil and gas deposits. The Dongsheng sandstone type uranium deposit is a large one discovered in recent years in northeastern Ordos basin. It is a special kind of sandstone type uranium deposit, different from other ordinary sandstone type deposits because of its unique signatures. It is generally controlled by a transitional zone between greenish and grayish sandstones, both of those two kinds of sandstones now indicate reduced geochemical environments. The greenish color of the paleooxidized sandstones mainly

A new bee species that excavates sandstone nests

Science.gov (United States)

Many wonder why animals act in seemingly injurious ways. Understanding the behavior of pollinators such as bees is especially important because of the necessary ecosystem service they provide. The new species Anthophora pueblo, discovered excavating sandstone nests, provides a model system for addre...

Mechanical Behavior of Red Sandstone under Incremental Uniaxial Cyclical Compressive and Tensile Loading

Directory of Open Access Journals (Sweden)

Baoyun Zhao

2017-01-01

Full Text Available Uniaxial experiments were carried out on red sandstone specimens to investigate their short-term and creep mechanical behavior under incremental cyclic compressive and tensile loading. First, based on the results of short-term uniaxial incremental cyclic compressive and tensile loading experiments, deformation characteristics and energy dissipation were analyzed. The results show that the stress-strain curve of red sandstone has an obvious memory effect in the compressive and tensile loading stages. The strains at peak stresses and residual strains increase with the cycle number. Energy dissipation, defined as the area of the hysteresis loop in the stress-strain curves, increases nearly in a power function with the cycle number. Creep test of the red sandstone was also conducted. Results show that the creep curve under each compressive or tensile stress level can be divided into decay and steady stages, which cannot be described by the conventional Burgers model. Therefore, an improved Burgers creep model of rock material is constructed through viscoplastic mechanics, which agrees very well with the experimental results and can describe the creep behavior of red sandstone better than the Burgers creep model.

78 FR 7780 - Sunshine Act Meeting; FCC Announces Further Details for the First Post-Superstorm Sandy Field...

Science.gov (United States)

2013-02-04

... First Post-Superstorm Sandy Field Hearing, Tuesday, February 5, 2013 AGENCY: Federal Communications Commission. ACTION: Sunshine notice. SUMMARY: In the wake of Superstorm Sandy, Federal Communications... focusing on the impact of Superstorm Sandy, and help inform recommendations and actions to strengthen wired...

The Upper Permian sandstones of Mountains Mecsek: form elements of uranium ore mineralization and facies relations Pt. 2

International Nuclear Information System (INIS)

Vincze, Janos; Somogyi, Janos

1984-01-01

The ore mineralization in the Upper Permian sandstones of Mountais Mecsek, Hungary, was brought about at the oxidation-reduction front between the grey and red sandstones; the predominant rock colour here is green. The sandstones of different colour are oxidation-reduction species. The formation is a megacycle containing in its core grey sandstones of reduced state with coalified plant remains and in its mantle oxidized red sandstones. Uranium accumulates mainly in the transitional green facies. Uranium content gets enriched to a commercial concentration only if the difference in potential of neighbouring beds is in the range of 400-480 mV. The relationship between organic matter and uranium content in the individual facies is shown. The principles of oxidation-reduction processes in the formation of boundary facies are discussed. (V.N.)

The effects of impure CO2 on reservoir sandstones: results from mineralogical and geomechanical experiments

Science.gov (United States)

Marbler, H.; Erickson, K. P.; Schmidt, M.; Lempp, Ch.; Pöllmann, H.

2012-04-01

An experimental study of the behaviour of reservoir sandstones from deep saline aquifers during the injection and geological storage of CO2 with the inherent impurities SOX and NOX is part of the German national project COORAL*. Sample materials were taken from outcrops of possible reservoir formations of Rotliegend and Bunter Sandstones from the North German Basin. A combination of mineralogical alteration experiments and geomechanical tests was carried out on these rocks to study the potential effects of the impurities within the CO2 pore fluid. Altered rock samples after the treatment with CO2 + SOX/NOX in an autoclave system were loaded in a triaxial cell under in-situ pressure and temperature conditions in order to estimate the modifications of the geomechanical rock properties. Mineralogical alterations were observed within the sandstones after the exposure to impure supercritical (sc)CO2 and brine, mainly of the carbonatic, but also of the silicatic cements, as well as of single minerals. Besides the partial solution effects also secondary carbonate and minor silicate mineral precipitates were observed within the pore space of the treated sandstones. These alterations affect the grain structure of the reservoir rock. Results of geomechanical experiments with unaltered sandstones show that the rock strength is influenced by the degree of rock saturation before the experiment and the chemical composition of the pore fluid (scCO2 + SOX + NOX). After long-term autoclave treatment with impure scCO2, the sandstone samples exhibit modified strength parameters and elastic deformation behaviour as well as changes in porosity compared to untreated samples. Furthermore, the injected fluid volume into the pore space of sandstones from the same lithotype varies during triaxial loading depending on the chemistry of the pore fluid. CO2 with NOX and SOX bearing fluid fills a significantly larger proportion of the sandstone pore space than brine with pure scCO2. * The

Near-real-time Forensic Disaster Analysis: experiences from hurricane Sandy

Science.gov (United States)

Kunz, Michael; Mühr, Bernhard; Schröter, Kai; Kunz-Plapp, Tina; Daniell, James; Khazai, Bijan; Wenzel, Friedemann; Vannieuwenhuyse, Marjorie; Comes, Tina; Münzberg, Thomas; Elmer, Florian; Fohringer, Joachim; Lucas, Christian; Trieselmann, Werner; Zschau, Jochen

2013-04-01

Hurricane Sandy was the last tropical cyclone of the 2012 Northern Atlantic Hurricane season that made landfall. It moved on an unusual track from the Caribbean to the East Coast of the United States from 24 to 30 October as a Category 1 and 2 Hurricane according to the Saffir-Simpson Scale. Along its path, the severe storm event caused widespread damage including almost 200 fatalities. In the early hours of 30 October, Sandy made landfall near Atlantic City, N.J. Sandy was an extraordinary event due to its multihazard nature and several cascading effects in the aftermath. From the hydro-meteorological perspective, most unusual was the very large spatial extent of up to 1,700 km. High wind speeds were associated with record breaking storm surges at the U.S. Mid- Atlantic and New England Coast during high (astronomical) tide, leading to widespread flooding. Though Sandy was not the most severe storm event in terms of wind speed and precipitation, the impact in the U.S. was enormous with total damage estimates of up to 90 billion US (own estimate from Dec. 2012). Although much better data emerge weeks after such an event, the Forensic Disaster Analysis (FDA) Task Force of the Center for Disaster Management and Risk Reduction Technology (CEDIM) made an effort to obtain a comprehensive and holistic overview of the causes, hazardous effects and consequences associated with Sandy immediately after landfall at the U.S. coast on 30 October 2012. This was done in an interdisciplinary way by collecting and compiling scattered and distributed information from available databases and sources via the Internet, by applying own methodologies and models for near-real time analyses developed in recent years, and by expert knowledge. This contribution gives an overview about the CEDIM-FDA analyses' results. It describes the situation that led to the extraordinary event, highlights the interaction of the tropical cyclone with other hydro-meteorological events, and examines the

Coastal dune facies, Permian Cutler Formation (White Rim Sandstone), Capitol Reef National Park area, southern Utah

Science.gov (United States)

Kamola, Diane L.; Chan, Marjorie A.

1988-04-01

The Permian Cutler Formation (White Rim Sandstone) in the Capitol Reef National Park area in southern Utah is an excellent example of a coastal dune complex subjected to periodic flooding by marine waters. Wind-ripple, grainfall and grainflow laminae compose the cross-sets deposited by eolian dunes. However, wave-reworked structures such as oscillation ripples, the occurrence of the characteristically marine trace fossils Thalassinoides and Chondrites, and interfingering marine carbonate beds of the Kaibab Formation collectively indicate marine interaction with the eolian environment. Four facies are distinguished: cross-stratified sandstone, burrowed to bioturbated sandstone, brecciated and deformed sandstone, and ripple-laminated sandstone and thin carbonate beds. One unusual aspect of the cross-stratified sandstone facies is the abundance of coarse-grained sand. Coarse-grained sand is atypical in many ancient eolian slipface deposits, but occurs here in large slipface foresets as both grainflow and wind-ripple deposits. No water-laid structures are found in these slipface deposits. Coarse-grained sand was probably transported to the Cutler shoreline by fluvial systems draining the Uncompahgre Uplift to the east, and then concentrated as coarse-grained ripples in interdune areas. Some of these coarse-grained ripples migrated up the stoss side of the dunes and accumulations of coarse-grained sand avalanched down the crest to form grainflow deposits. An extensive amount of soft-sediment deformation is indicated by the presence of convolute bedding and brecciation. These features occur near the zone of interfingering with marine carbonate beds of the Kaibab Formation. The water-saturated and moist conditions required for extensive deformation may have been controlled by the proximity of these sandstones to the shoreline, and fluctuations in the associated groundwater table.

The sedimentology of uranium-bearing sandstones on the farm Riet Kuil 307, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1980-10-01

The sedimentology of four sandstones was studied in outcrop and in the subsurface on the farm Riet Kuil 307, near Beaufort West. Only two of these sandstones are mineralised. These are four surface and two subsurface uranium anomalies and one surface uranium anomaly. The sedimentological study was made by means of 47 vertical profiles measured across and adjacent to the surface anomalies as well as 11 core-logs, which intersected the subsurface anomalies. The unmineralised sandstones are included in this study. A total of 19 sedimentary facies was recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structure. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation is almost entirely confined to the coarser-grained sedimentary facies, which probably acted as suitable aquifers for the transport of uraniferous solutions prior to the precipitation of the uranium. Horizontally bedded sandstone facies comprises 60 per cent of the total cumulative thickness of mineralisation. The nature of the bedding of this facies may have provided a more effective permeability zone for the transport of uraniferous solutions. This facies contains an abundance of carbonaceous material which acted as an important indirect reductant for the precipitation of uranium from solution. The direct reductant was most probably H 2 S produced by enaerobic bacteria acting on this carbonaceous material shortly after deposition of the sediments. Carbonaceous material also occurs in the other mineralised facies and is considered to be the major control on the mineralisation in the uranium-bearing sandstones

[Fish community structure and its seasonal change in subtidal sandy beach habitat off southern Gouqi Island].

Science.gov (United States)

Wang, Zhen-Hua; Wang, Kai; Zhao, Jing; Zhang, Shou-Yu

2011-05-01

To understand the characteristics of fish community structure in sandy beach habitats of island reef water areas, and to evaluate the potential capacity of these habitats in local fish stock maintenance, fishes were monthly collected with multi-mesh trammel nets in 2009 from the subtidal sandy beach habitat off southern Gouqi Island, taking the adjacent rocky reef habitat as the control. alpha and beta species diversity indices, index of relative importance (IRI), relative catch rate, and dominance curve for abundance and biomass (ABC curve) were adopted to compare the fish species composition, diversity, and community pattern between the two habitats, and multivariate statistical analyses such as non-metric multidimensional scaling (nMDS) and cluster were conducted to discuss the fish assemblage patterns. A total of 63 fish species belonging to 11 orders, 38 families, and 56 genera were collected, of which, 46 fish species were appeared in the two habitats. Due to the appearance of more warm water species in sandy bottom, the fishes in subtidal sandy beach habitat showed much higher richness, and the abundance catch rate (ACR) from May to July was higher than that in rocky reef habitat. In most rest months, the ACR in subtidal sandy beach habitat also showed the similar trend. However, the species richness and diversity in spring and summer were significantly lower in subtidal sandy beach habitat than in rocky reef habitat, because of the high species dominance and low evenness in the sandy beach habitat. Japanese tonguefish (Paraplagusia japonica) was the indicator species in the sandy beach habitat, and dominated in early spring, later summer, autumn, and winter when the fishing pressure was not strong. In sandy bottom, a unique community structure was formed and kept in dynamic, due to the nursery use of sandy beach by Japanese anchovy (Engraulis japonicus) from May to July, the gathering of gray mullet (Mugil cephalus) in most months for feeding, and the large

Contribution To The Sedimentology Of The Bahariya Formation Of Gebel El-Dist, Bahariya Oasis, Western Desert, Egypt

OpenAIRE

Hilmy, M. E. [محمد عز الدين حلمي; Saad, N.; Abu-Zeid, M. M.

1983-01-01

Combined microscopic, grain-size and heavy-mineral analyses were carried out on the Bahariya Formation at Gebel El-Dist (type section), Bahariya Oasis. These studies revealed that the formation is composed of moderately poorly-sorted silty sandstones and sandy siltstones with few intercalations of sandstones, siltstones and clayey siltstones. The heavy-mineral suite is composed of (in order of decreasing abundance): opaques, zircon, rutile. staurolite, tourmaline, kyanite, garnet and bioti...

Experimental Investigation on Shock Mechanical Properties of Red Sandstone under Preloaded 3D Static Stresses

Directory of Open Access Journals (Sweden)

Niu Yong

2015-11-01

Full Text Available Triaxial impact mechanical performance experiment was performed to study the mechanical properties of red sandstone subjected to three-dimensional (3D coupled static and dynamic loads, i.e., three confining pressures (0, 5, and 10 MPa and three axial pressures (11, 27, and 43 MPa. A modified 3D split Hopkinson pressure bar testing system was used. The change trend in the deformation of red sandstone and the strength and failure modes under axial pressures and confining pressures were analyzed. Results show that, when the confining pressure is constant, the compressive strength, secant modulus, and energy absorbed per unit volume of red sandstone initially increases and subsequently decreases, whereas the average strain rate exhibits an opposite trend. When the axial pressure is constant, both the compressive strength and secant modulus of red sandstone are enhanced, but the average strain rate is decreased with increasing confining pressure. The energy absorbed per unit volume is initially increased and subsequently decreased as the confining pressure increases. Red sandstone exhibits a cone-shaped compression–shear failure mode under the 3D coupled static and dynamic loads. The conclusions serve as theoretical basis on the mechanical properties of deep medium-strength rock under a high ground stress and external load disturbance condition

Electrical Spectroscopy of Permo-Triassic Sandstone From the United Kingdom

Science.gov (United States)

Scott, J.; Barker, R.

2003-12-01

Electrical spectroscopy measurements in the range of mHz to kHz have been made on the dominantly red Permo-Triassic sandstone from the United Kingdom. Samples have been selected from borehole cores from all of the main outcrop areas of sandstone and represent a wide variety of lithologies. This sandstone is an important aquifer for several major cities including Manchester and Birmingham. The samples have been fully saturated with sodium chloride brines and a synthetic groundwater solution that is higher in calcium and magnesium ions than sodium and which closely matches the cation concentrations of the groundwater at Birmingham. Electrical measurements were made using a four-electrode arrangement of silver-silver chloride electrodes. Most of the electrical spectra show a clear, slightly asymmetric, electrical relaxation phenomenon with relaxation peaks in the range of 0.001 Hz to 20 Hz. These relaxation phenomena can be fitted very well by a generalised Cole-Cole model. The relaxation time from this model is found to correlate closely with the dominant pore-throat size from mercury injection. Normalising the chargeability, Cole-Cole m parameter, by the conductivity gives a polarisation magnitude which correlates well with the pore surface to volume ratio (SPOR) for sandstone samples with an even distribution of surface coating clays. The information obtained from the electrical spectra is very useful. The pore-throat size is important in controlling the permeability and in particular the flow of non-aqueous phase fluids. The pore surface area has links to the sorbtion properties of the rock, which are important in estimating contaminant transport. The electrical spectra also provide a useful fingerprint of individual lithologies which could be used for correlation between boreholes or outcrops.

Application of Rock-Eval pyrolysis to the detection of hydrocarbon property in sandstone-type uranium deposits

International Nuclear Information System (INIS)

Sun Ye; Li Ziying; Guo Qingyin; Xiao Xinjian

2006-01-01

Rock-Eval pyrolysis is introduced into the research of uranium geology by means of oil-gas geochemical evaluation. Hydrocarbon (oil-gas) components in DS sandstone-type uranium deposit are detected quantitatively. Through analyzing the oil-gas bearing categories of the uranium-bearing sandstones, the internal relationships between the uranium deposit and the oil-gas are revealed. Rock-Eval pyrolysis is an effective method to study the interaction between inorganic and organic matters, and should be extended to the study of sandstone-type uranium deposits. (authors)

Different effects of temperature and salinity on permeability reduction by fines migration in Berea sandstone

DEFF Research Database (Denmark)

Rosenbrand, Esther; Kjøller, Claus; Riis, Jacob Fabricius

2015-01-01

Hot water injection into geothermal aquifers is considered in order to store energy seasonally. Berea sandstone is often used as a reference formation to study mechanisms that affect permeability in reservoir sandstones. Both heating of the pore fluid and reduction of the pore fluid salinity can...

An analysis of the synoptic and dynamical characteristics of hurricane Sandy (2012)

Science.gov (United States)

Varlas, George; Papadopoulos, Anastasios; Katsafados, Petros

2018-01-01

Hurricane Sandy affected the Caribbean Islands and the Northeastern United States in October 2012 and caused 233 fatalities, severe rainfalls, floods, electricity blackouts, and 75 billion U.S. dollars in damages. In this study, the synoptic and dynamical characteristics that led to the formation of the hurricane are investigated. The system was driven by the interaction between the polar jet displacement and the subtropical jet stream. In particular, Sandy was initially formed as a tropical depression system over the Caribbean Sea and the unusually warm sea drove its intensification. The interaction between a rapidly approaching trough from the northwest and the stagnant ridge over the Atlantic Ocean drove Sandy to the northeast coast of United States. To better understand the dynamical characteristics and the mechanisms that triggered Sandy, a non-hydrostatic mesoscale model has been used. Model results indicate that the surface heat fluxes and the moisture advection enhanced the convective available potential energy, increased the low-level convective instability, and finally deepened the hurricane. Moreover, the upper air conditions triggered the low-level frontogenesis and increased the asymmetry of the system which finally affected its trajectory.

Telehealth at the US Department of Veterans Affairs after Hurricane Sandy.

Science.gov (United States)

Der-Martirosian, Claudia; Griffin, Anne R; Chu, Karen; Dobalian, Aram

2018-01-01

Background Like other integrated health systems, the US Department of Veterans Affairs has widely implemented telehealth during the past decade to improve access to care for its patient population. During major crises, the US Department of Veterans Affairs has the potential to transition healthcare delivery from traditional care to telecare. This paper identifies the types of Veterans Affairs telehealth services used during Hurricane Sandy (2012), and examines the patient characteristics of those users. Methods This study conducted both quantitative and qualitative analyses. Veterans Affairs administrative and clinical data files were used to illustrate the use of telehealth services 12 months pre- and 12 months post- Hurricane Sandy. In-person interviews with 31 key informants at the Manhattan Veterans Affairs Medical Center three-months post- Hurricane Sandy were used to identify major themes related to telecare. Results During the seven-month period of hospital closure at the Manhattan Veterans Affairs Medical Center after Hurricane Sandy, in-person patient visits decreased dramatically while telehealth visits increased substantially, suggesting that telecare was used in lieu of in-person care for some vulnerable patients. The most commonly used types of Veterans Affairs telehealth services included primary care, triage, mental health, home health, and ancillary services. Using qualitative analyses, three themes emerged from the interviews regarding the use of Veterans Affairs telecare post- Hurricane Sandy: patient safety, provision of telecare, and patient outreach. Conclusion Telehealth offers the potential to improve post-disaster access to and coordination of care. More information is needed to better understand how telehealth can change the processes and outcomes during disasters. Future studies should also evaluate key elements, such as adequate resources, regulatory and technology issues, workflow integration, provider resistance, diagnostic fidelity and

Low field NMR surface relaxivity studies of chalk and argillaceous sandstones

DEFF Research Database (Denmark)

Katika, Konstantina; Fordsmand, Henrik; Fabricius, Ida Lykke

2017-01-01

the accuracy of predictions of petrophysical properties of various rocks with the use of NMR spectrometry. We perform laboratory transverse relaxation (T2) measurements on water saturated Gorm field chalk, Stevns Klint chalk, Solsort field greensand and Berea sandstone. These rocks are of particular interest...... field chalk and Solsort field greensand have higher ρ at higher Larmor frequency. By contrast, ρ of the purely calcitic Stevns chalk and quartzitic Berea sandstone proved not to be affected by the changes in frequency. T2 distributions at temperatures ranging from 10 °C to 60 °C provided comparison...

Lessons from Hurricane Sandy for port resilience.

Science.gov (United States)

2013-12-01

New York Harbor was directly in the path of the most damaging part of Hurricane Sandy causing significant impact on many of the : facilities of the Port of New York and New Jersey. The U.S. Coast Guard closed the entire Port to all traffic before the...

Effect Of Hot Water Injection On Sandstone Permeability

DEFF Research Database (Denmark)

Rosenbrand, Esther; Fabricius, Ida Lykke

2012-01-01

of published results regarding the effect of temperature on sandstone permeability. These tests are performed with mineral oil, nitrogen gas, distilled water and solutions of NaCl, KCl, CaCl2 as well as brines that contain a mixture of salts. Thirteen sandstone formations, ranging from quartz arenites...... to formations with a significant fraction of fine particles including clay minerals are investigated. The porosities range from 0.10 to 0.30 and permeabilities span the range from 1 to 1000 md. To compare different rock types, specific surface is determined from permeability and porosity using Kozeny’s equation...... not account for all the permeability reductions observed. Permeablity reduction occurs both when distilled water is the saturating fluid as well as in tests with NaCl, KCl or CaCl2 solutions, however, this is not the case in tests with mineral oil or nitrogen gas. The formation of a filter cake or influx...

The experimental modeling of gas percolation mechanisms in a coal-measure tight sandstone reservoir: A case study on the coal-measure tight sandstone gas in the Upper Triassic Xujiahe Formation, Sichuan Basin, China

Directory of Open Access Journals (Sweden)

Shizhen Tao

2016-12-01

Full Text Available Tight sandstone gas from coal-measure source rock is widespread in China, and it is represented by the Xujiahe Formation of the Sichuan Basin and the Upper Paleozoic of the Ordos Basin. It is affected by planar evaporative hydrocarbon expulsion of coal-measure source rock and the gentle structural background; hydrodynamics and buoyancy play a limited role in the gas migration-accumulation in tight sandstone. Under the conditions of low permeability and speed, non-Darcy flow is quite apparent, it gives rise to gas-water mixed gas zone. In the gas displacing water experiment, the shape of percolation flow curve is mainly influenced by core permeability. The lower the permeability, the higher the starting pressure gradient as well as the more evident the non-Darcy phenomenon will be. In the gas displacing water experiment of tight sandstone, the maximum gas saturation of the core is generally less than 50% (ranging from 30% to 40% and averaging at 38%; it is similar to the actual gas saturation of the gas zone in the subsurface core. The gas saturation and permeability of the core have a logarithm correlation with a correlation coefficient of 0.8915. In the single-phase flow of tight sandstone gas, low-velocity non-Darcy percolation is apparent; the initial flow velocity (Vd exists due to the slippage effect of gas flow. The shape of percolation flow curve of a single-phase gas is primarily controlled by core permeability and confining pressure; the lower the permeability or the higher the confining pressure, the higher the starting pressure (0.02–0.08 MPa/cm, whereas, the higher the quasi-initial flow speed, the longer the nonlinear section and the more obvious the non-Darcy flow will be. The tight sandstone gas seepage mechanism study shows that the lower the reservoir permeability, the higher the starting pressure and the slower the flow velocity will be, this results in the low efficiency of natural gas migration and accumulation as well as

The influence of climate on early and burial diagenesis of Triassic and Jurassic sandstones from the Norwegian – Danish Basin

DEFF Research Database (Denmark)

Weibel, Rikke; Olivarius, Mette; Kjøller, Claus

2017-01-01

Climate changes preserved in sandstones are documented by comparing the sediment composition and early diagenetic changes in sandstones deposited during arid to semi-arid conditions, the Skagerrak Formation, with sandstones of the Gassum Formation deposited in a humid well-vegetated environment...

Possible application of underground leaching of uranium in ''sandstone'' deposits by drilling method

International Nuclear Information System (INIS)

Bareja, E.

1988-01-01

Underground leaching as the method for excavation of uranium from its sandstone deposits is applied in many countries. A preliminary examination of a possible use of this method to sandstone deposits in Poland suggests it to be analysed against the uranium mineralization, noted within sediments of the Lower Triassic age in the Peribaltic Syneclise in the Krynica Morska - Paslek area. Before a definite decision on such exploitation of uranium, geologic and hydrogeologic conditions should be studied of individual uranium-bearing beds, particularly their permeability and insulation by impermeable claystone series as well as extraction of uranium from its bearing sandstones. The depth at which uranium-bearing beds occur, forms a very important item. The depth at which uranium ores described in literature and exploited by this method occur, does not exceed 700 m. 7 refs. (author)

Quantifying the Digital Traces of Hurricane Sandy on Flickr

Science.gov (United States)

Preis, Tobias; Moat, Helen Susannah; Bishop, Steven R.; Treleaven, Philip; Stanley, H. Eugene

2013-11-01

Society's increasing interactions with technology are creating extensive ``digital traces'' of our collective human behavior. These new data sources are fuelling the rapid development of the new field of computational social science. To investigate user attention to the Hurricane Sandy disaster in 2012, we analyze data from Flickr, a popular website for sharing personal photographs. In this case study, we find that the number of photos taken and subsequently uploaded to Flickr with titles, descriptions or tags related to Hurricane Sandy bears a striking correlation to the atmospheric pressure in the US state New Jersey during this period. Appropriate leverage of such information could be useful to policy makers and others charged with emergency crisis management.

Stable isotopic mass balance in sandstone-shale couplets. An example from the Neogene Pannonian Basin

International Nuclear Information System (INIS)

Matyas, J.; Geologisches Institut.

1996-01-01

Oxygen isotopic ratios of carbonate cements in the Neogene sandstones of the Pannonian Basin show distinct variations: early calcites 3-6 per mille lighter than the late calcites from the same location and depth. This shift is thought to be related to the isotopically heavy oxygen released from the mixed-layer illite/smectite during illitisation. For sandstones dominated by compactional flow, closed system mass balance calculations predict an isotopic shift comparable to that deducted from petrographic and geochemical observations. The model suggests that variations of geothermal gradient has little effect on isotopic evolution; much more significant is the sandstone: shale ratio in the couplets. (author)

Spatial patterns and natural recruitment of native shrubs in a semi-arid sandy land.

Science.gov (United States)

Wu, Bo; Yang, Hongxiao

2013-01-01

Passive restoration depending on native shrubs is an attractive approach for restoring desertified landscapes in semi-arid sandy regions. We sought to understand the relationships between spatial patterns of native shrubs and their survival ability in sandy environments. Furthermore, we applied our results to better understand whether passive restoration is feasible for desertified landscapes in semi-arid sandy regions. The study was conducted in the semi-arid Mu Us sandy land of northern China with the native shrub Artemisia ordosica. We analyzed population structures and patterns of A. ordosica at the edges and centers of land patches where sand was stabilized by A. ordosica-dominated vegetation. Saplings were more aggregated than adults, and both were more aggregated at the patch edges than at the patch centers. At the patch edges, spatial association of the saplings with the adults was mostly positive at distances 0.3-6.6 m, and turned from positive to neutral, and even negative, at other distances. At the patch centers, the saplings were spaced almost randomly around the adults, and their distances from the adults did not seem to affect their locations. A greater number of A. ordosica individuals emerged at the patch edges than at the patch centers. Such patterns may have resulted from their integrative adjustment to specific conditions of soil water supply and sand drift intensity. These findings suggest that in semi-arid sandy regions, native shrubs that are well-adapted to local environments may serve as low-cost and competent ecological engineers that can promote the passive restoration of surrounding patches of mobile sandy land.

Regional diagenesis of sandstone in the Upper Jurassic Morrison Formation, San Juan Basin, New Mexico and Colorado

International Nuclear Information System (INIS)

Hansley, P.L.

1990-01-01

The author reports that early authigenic mineral assemblages and vitroclastic textures are very well preserved in upper sandstones of the Upper Jurassic Morrison Formation. The distributions of the authigenic minerals were controlled, in part, by chemical gradients in a large saline, alkaline lake (Lake T'oo'dichi) that existed in late Morrison time. Sandstones on lake margins were cemented by smectite and silica, whereas sandstones nearer the lake center, in which waters were most saline and alkaline, were cemented by zeolites. Diagenetic alterations in sandstones were promoted by alkaline interstitial waters that emanated from adjacent fine-grained, tuffaceous lake beds. Metastable phases that precipitated first were replaced relatively quickly by more stable, ordered phases in the geochemically favorable environment of the closed basin setting. Elevation of temperatures above the geothermal gradient was proved by the influx of warm, deep-basin waters that locally modified early diagenetic assemblages during burial diagenesis. In organic- (and commonly also uranium ore-) bearing sandstones located primarily in the southern part of the basin, complex diagenetic assemblages resulted from water/rock reactions involving soluble organic complexes

THE PROBLEMATIC OF SANDY LANDS IN PARANAVAI MUNICIPALITY –PR

Directory of Open Access Journals (Sweden)

Marcelo Eduardo Freres Stipp

2005-05-01

Full Text Available The sandy lands are a process of scouring with sand forming a sandy area, which correspondsto a reworking of the sands due its constant mobility, involving the transformation of notsolids deposits is sandy areas. This work tried to establish the characterization of thisphenomenon of scouring with sand in a local level, occurring in arenaceous areas in theNortheast of the state of Paraná, specifically in the urban site of Paranavaí. It was also madean evaluation of the environmental degradation as well as different causes for what provokedthese sandy areas. Being an area with a high level of soil decomposition with the highwaysroutes crossing it, it was necessary, besides bibliographic data that allowed a theoretical basis,a research applied in order to supply subsides for future planning related to the spaceorganization. The evolution of the use and soil occupation in this area has been processedwithin an urban planning which considered by no account neither soil characteristic, thevegetation nor the predominant climate in that region. The mechanisms of region atmospherecirculation were analyzed, the alterations or attributes of the climate as well, aiming toidentify the genesis of the erosion sandy and possible time and space distribution. Initially, themain characteristics of the region were collected, components e processes working on the landmodel. It was observed how it worked and the use and occupation of the soil in past times andcurrently. During 2004, using the Environmental Fragility Letter, the areas of erosion wereidentified, ravines and strong erosion that compounds the first stages of the focused problem.The sandy land is a process that involves erosion, transport, e accumulation, meaning most oftimes the loosing of Biosphere productivity. For monitoring these risk areas some measuringcanes were made to measure the soil loss, which were used in several spots of erosion in theurban area in Paranavaí. The measurement happened in

Properties and durability assessment of glauconitic sandstone: A case study on Zamel sandstone from Bohemian Cretaceous Basin (Czech Republic)

Czech Academy of Sciences Publication Activity Database

Martinec, Petr; Vavro, M.; Ščučka, Jiří; Mašláň, M.

2010-01-01

Roč. 115, 3/4 (2010), s. 175-181 ISSN 0013-7952 R&D Projects: GA ČR GP101/07/P512; GA ČR(CZ) GA103/07/1662 Institutional research plan: CEZ:AV0Z30860518 Keywords : building stone * sandstone * physical properties Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.442, year: 2010 http://www.sciencedirect.com/science

Migration of cesium-137 through sandy soil layer effect of fine silt on migration

International Nuclear Information System (INIS)

Ohnuki, Toshihiko; Wadachi, Yoshiki

1983-01-01

The migration of 137 Cs through sandy soil layer was studied with consideration of the migration of fine silt by column method. It was found that a portion of fine silt migrated through the soil layer accompanying with 137 Cs. The mathematical migration model of 137 Cs involved the migration of fine silt through such soil layer was presented. This model gave a good accordance between calculated concentration distribution curve in sandy soil layer and effluent curve and observed those. So, this model seems to be advanced one for evaluating migration of 137 Cs in sandy soil layer with silt. (author)

Distribution of K, Na, Th and U in sandstones and shales from western Shikoku, Japan

International Nuclear Information System (INIS)

Ishihara, Shunso; Sakamaki, Yukio; Mochizuki, Tsunekazu; Terashima, Shigeru; Endo, Yuji

1981-01-01

The regional variation of K, Na, Th and U distributions was studied on 58 sandstones, 81 shales and 3 green schists from the sedimentary terrains across western Shikoku. The geological structure of the studied district is explained. The regional characteristics of the sedimentary rocks are best demonstrated in the composition of the sandstones. The sandstones, in the source areas of which granitic and rhyolitic rocks exist and which have been deposited rapidly, were rich in K, whereas those derived mainly from mafic volcanic areas showed high Na content. The sandstones of the Shimanto Supergroup had the intermediate values, and K and K + Na contents became low in the south where the younger Upper Shimanto Group is exposed. Th and U in both sandstones and shales were highest in the Izumi Group, and generally low in the Shimanto Supergroup. The black shales of the Shimanto Supergroup did not show U-anomaly. In each group, highly matured rocks gave slightly higher Th/U ratio. Highly matured polycyclic sediments contained the least amount of radioactive elements. The radioactive anomaly due to the anomalous K contained in sericite, and that due to U in black shale were found in Chichibu and Sambosan belts. Similar anomaly was discovered in the foot wall of Mn deposits in the same zone. The possibility of anomalous U may be the least in the Shimanto Supergroup. (Kako, I.)

Analysis of storm-tide impacts from Hurricane Sandy in New York

Science.gov (United States)

Schubert, Christopher E.; Busciolano, Ronald J.; Hearn, Paul P.; Rahav, Ami N.; Behrens, Riley; Finkelstein, Jason S.; Monti, Jack; Simonson, Amy E.

2015-07-21

The hybrid cyclone-nor’easter known as Hurricane Sandy affected the mid-Atlantic and northeastern United States during October 28-30, 2012, causing extensive coastal flooding. Prior to storm landfall, the U.S. Geological Survey (USGS) deployed a temporary monitoring network from Virginia to Maine to record the storm tide and coastal flooding generated by Hurricane Sandy. This sensor network augmented USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent monitoring sites that also documented storm surge. Continuous data from these networks were supplemented by an extensive post-storm high-water-mark (HWM) flagging and surveying campaign. The sensor deployment and HWM campaign were conducted under a directed mission assignment by the Federal Emergency Management Agency (FEMA). The need for hydrologic interpretation of monitoring data to assist in flood-damage analysis and future flood mitigation prompted the current analysis of Hurricane Sandy by the USGS under this FEMA mission assignment.

An Effective Acid Combination for Enhanced Properties and Corrosion Control of Acidizing Sandstone Formation

International Nuclear Information System (INIS)

Shafiq, Mian Umer; Mahmud, Hisham Khaled Ben

2016-01-01

To fulfill the demand of the world energy, more technologies to enhance the recovery of oil production are being developed. Sandstone acidizing has been introduced and it acts as one of the important means to increase oil and gas production. Sandstone acidizing operation generally uses acids, which create or enlarge the flow channels of formation around the wellbore. In sandstone matrix acidizing, acids are injected into the formation at a pressure below the formation fracturing pressure, in which the injected acids react with mineral particles that may restrict the flow of hydrocarbons. Most common combination is Hydrofluoric Acid - Hydrochloric with concentration (3% HF - 12% HCl) known as mud acid. But there are some problems associated with the use of mud acid i.e., corrosion, precipitation. In this paper several new combinations of acids were experimentally screened to identify the most effective combination. The combinations used consist of fluoboric, phosphoric, formic and hydrofluoric acids. Cores were allowed to react with these combinations and results are compared with the mud acid. The parameters, which are analyzed, are Improved Permeability Ratio, strength and mineralogy. The analysis showed that the new acid combination has the potential to be used in sandstone acidizing. (paper)

Endolithic algae of semi-desert sandstones: systematic, biogeographic and ecophysiologic investigations

International Nuclear Information System (INIS)

Bell, R.A.

1986-01-01

Investigations were conducted into the ecology of an unusual algal community in northern Arizona. These microorganisms are called endolithic algae because they occur beneath the surface of rocks. Eighteen taxa, including representatives of both eukaryotic and prokaryotic genera, were isolated from below the surface of eight sandstones in four semi-desert and cold temperate biomes of the Colorado Plateau. As the macroclimate of the area changes from cold temperature desert scrub to cold temperate forest the taxonomic composition of the endolithic algal communities shifts from domination by coccoid blue-green algae to domination by coccoid and sarcinoid green algae. The algal communities varied in generic composition, chlorophyll a content, and in their location within the different sandstones. Investigations into the microclimate of the endolithic algal zone in two adjacent but differently-colored sections (white and brown) of Coconino sandstone have demonstrated differences between the environment above the rock surface and that just beneath the surface. In seasonal samples of the Coconino sandstone, chlorophyll a content ranged from 50 to 100 mg x m -2 in the white rock and 8 to 45 mg x m -2 in the brown rock. Primary production (as measured by 14 CO 2 incorporation) displayed marked seasonal patterns that appear to be correlated to the environmental conditions within the rocks as opposed to those outside the rocks. The widespread distribution of certain algae in the endolithic habitats of the Colorado Plateau and their presence in rocks at quite distant locations suggests that the endolithic habitat may be utilized by algae whenever it provides more favorable conditions than the surrounding surfaces

The ecology of sandy beaches in Transkei

African Journals Online (AJOL)

Data from an ecological survey of three sandy beaches in. Transkei and from Gulu beach on the eastern Cape coast,. South Africa, are presented. Physical parameters such as beach profile, sand particle size, Eh and carbonate content, as well as abundance, composition, biomass and distribution of the macrofauna and ...

The Collyhurst Sandstone as a secondary storage unit for CCS in the East Irish Sea Basin (UK)

Science.gov (United States)

Gamboa, D.; Williams, J. D. O.; Kirk, K.; Gent, C. M. A.; Bentham, M.; Schofield, D. I.

2016-12-01

Carbon Capture and Storage (CCS) is key technology for low-carbon energy and industry. The UK hosts a large CO2 storage potential offshore with an estimated capacity of 78 Gt. The East Irish Sea Basin (EISB) is the key area for CCS in the western UK, with a CO2 storage potential of 1.7 Gt in hydrocarbon fields and in saline aquifers within the Triassic Sherwood Sandstone Formation. However, this theoretical storage capacity does not consider the secondary storage potential in the lower Permian Collyhurst Sandstone Formation. 3D seismic data were used to characterise the Collyhurst Sandstone Formation in the EISB. On the southern basin domain, numerous fault-bound blocks limit the lateral continuity of the sandstone strata, while on the northern domain the sandstones are intersected by less faults. The caprock for the Collyhurst sandstones is variable. The Manchester Marls predominate in the south, transitioning to the St. Bees evaporites towards the north. The evaporites in the EISB cause overburden faults to terminate or detach along Upper Permian strata, limiting the deformation of the underlying reservoir units. Five main storage closures have been identified in the Permian strata. In the southern and central area these are predominantly fault bounded, occurring at depths over 1000m. Despite the higher Collyhurst sandstone thickness in the southern IESB, the dolomitic nature of the caprock constitutes a storage risk in this area. Closures in the northern area are deeper (around 2000-2500m) and wider, reaching areas of 34Km2, and are overlain by evaporitic caprocks. The larger Collyhurst closures to the north underlie large Triassic fields with high storage potential. The spatial overlap favours storage plans including secondary storage units in the EISB. The results of this work also expand the understanding of prospective areas for CO2 sequestration in the East Irish Sea Basin in locations where the primary Sherwood Sandstone Formation is either too shallow

An experimental study of the response of the Galesville sandstone to simulated CAES conditions

Energy Technology Data Exchange (ETDEWEB)

Erikson, R L; Stottlemyre, J A; Smith, R P

1980-07-01

The objective of this experimental study was to determine how the mineralogical and physical characteristics of host rock formations are affected by environmental conditions anticipated for compressed air energy storage (CAES) in porous, permeable rock. In this study, Galesville sandstone cores were reacted in autoclave pressure vessels supporting one of four environments: dry air; heated, air-water vapor; heated, nitrogen-water vapor mixtures; and heated, compressed, liquid water. The simulated CAES environments were maintained in autoclave pressure vessels by controlling the following independent variables: temperature, pressure, time, oxygen content, carbon dioxide content, nitrogen content, and liquid volume. The dependent variables studied were: apparent porosity, gas permeability, water permeability, and friability. These variables were measured at ambient temperature and pressure before and after each sandstone sample was reacted in one of the CAES environments. The experiments gave the following results: the Galesville sandstone exhibited excellent stability in dry air at all temperatures tested (50/sup 0/ to 300/sup 0/C); and significant physical alterations occurred in sandstone samples exposed to liquid water above 150/sup 0/C. Samples shielded from dripping water exhibited excellent stability to 300/sup 0/C; sandstone may be a suitable storage media for heated, humid air provided elevated temperature zones are relatively free of mobile liquid water; and observed changes in the physical properties of the rock may have been caused, in part, by the lack of confining stress on the sample. The inability to apply confining pressure is a severe limitation of autoclave experiments.

Remote sensing information acquisition of paleo-channel sandstone-type uranium deposit in Nuheting area

International Nuclear Information System (INIS)

Liu Jianjun

2000-01-01

The author briefly describes the genesis and ore-formation mechanism of paleo-channel sandstone-type uranium deposit in Nuheting area. Techniques such as remote sensing digital image data processing and data enhancement, as well as 3-dimension quantitative analysis of drill hole data are applied to extract information on metallogenic environment of paleo-channel sandstone-type uranium deposit and the distribution of paleo-channel

Temperature Effects on Stiffness Moduli of Reservoir Sandstone from the Deep North Sea

DEFF Research Database (Denmark)

Orlander, Tobias; Andreassen, Katrine Alling; Fabricius, Ida Lykke

We investigate effect of testing temperature on the dynamic frame stiffness of quartz-bearing North Sea sandstone from depths of 5 km. We show that at low stress levels, the rock frame stiffens with increasing temperature and we propose an explanation for the controlling mechanisms. While...... temperature. This is unfortunate and hence, we designed a testing program with the intension of separating and quantifying effects of temperature and stress, specifically for the sandstone material subject to this study....

Structural stability and hydraulic conductivity of Nkpologu sandy ...

African Journals Online (AJOL)

vincent

mean weight diameter (MWD), water dispersible silt (WDSi), aggregate size distributions (> 2 mm, 1-0.5 mm and < 0.25 ... above sea level. ... and red to brownish red and derived from sandy ... where Q = steady state volume of outflow from the.

Lessons from Hurricane Sandy: a community response in Brooklyn, New York.

Science.gov (United States)

Schmeltz, Michael T; González, Sonia K; Fuentes, Liza; Kwan, Amy; Ortega-Williams, Anna; Cowan, Lisa Pilar

2013-10-01

The frequency and intensity of extreme weather events have increased in recent decades; one example is Hurricane Sandy. If the frequency and severity continue or increase, adaptation and mitigation efforts are needed to protect vulnerable populations and improve daily life under changed weather conditions. This field report examines the devastation due to Hurricane Sandy experienced in Red Hook, Brooklyn, New York, a neighborhood consisting of geographically isolated low-lying commercial and residential units, with a concentration of low-income housing, and disproportionate rates of poverty and poor health outcomes largely experienced by Black and Latino residents. Multiple sources of data were reviewed, including street canvasses, governmental reports, community flyers, and meeting transcripts, as well as firsthand observations by a local nonprofit Red Hook Initiative (RHI) and community members, and social media accounts of the effects of Sandy and the response to daily needs. These data are considered within existing theory, evidence, and practice on protecting public health during extreme weather events. Firsthand observations show that a community-based organization in Red Hook, RHI, was at the center of the response to disaster relief, despite the lack of staff training in response to events such as Hurricane Sandy. Review of these data underscores that adaptation and response to climate change and likely resultant extreme weather is a dynamic process requiring an official coordinated governmental response along with on-the-ground volunteer community responders.

The effect of hot water injection on sandstone permeability

DEFF Research Database (Denmark)

Rosenbrand, Esther; Haugwitz, Christian; Jacobsen, Peter Sally Munch

2014-01-01

Seasonal energy storage can be achieved by hot water injection in geothermal sandstone aquifers. We present an analysis of literature data in combination with new short-term flow through permeability experiments in order to address physical and physico-chemical mechanisms that can alter...

Influence of fluvial sandstone architecture on geothermal energy production

NARCIS (Netherlands)

Willems, C.J.L.; Maghami Nick, Hamidreza M.; Weltje, G.J.; Donselaar, M.E.; Bruhn, D.F.

2015-01-01

Fluvial sandstone reservoirs composed of stacked meander belts are considered as potential geothermal resources in the Netherlands. Net-to-gross, orientation and stacking pattern of the channel belts is of major importance for the connectivity between the injection and production well in such

Experimental Study of Cement - Sandstone/Shale - Brine - CO2 Interactions.

Science.gov (United States)

Carroll, Susan A; McNab, Walt W; Torres, Sharon C

2011-11-11

Reactive-transport simulation is a tool that is being used to estimate long-term trapping of CO2, and wellbore and cap rock integrity for geologic CO2 storage. We reacted end member components of a heterolithic sandstone and shale unit that forms the upper section of the In Salah Gas Project carbon storage reservoir in Krechba, Algeria with supercritical CO2, brine, and with/without cement at reservoir conditions to develop experimentally constrained geochemical models for use in reactive transport simulations. We observe marked changes in solution composition when CO2 reacted with cement, sandstone, and shale components at reservoir conditions. The geochemical model for the reaction of sandstone and shale with CO2 and brine is a simple one in which albite, chlorite, illite and carbonate minerals partially dissolve and boehmite, smectite, and amorphous silica precipitate. The geochemical model for the wellbore environment is also fairly simple, in which alkaline cements and rock react with CO2-rich brines to form an Fe containing calcite, amorphous silica, smectite and boehmite or amorphous Al(OH)3. Our research shows that relatively simple geochemical models can describe the dominant reactions that are likely to occur when CO2 is stored in deep saline aquifers sealed with overlying shale cap rocks, as well as the dominant reactions for cement carbonation at the wellbore interface.

Lattice strain measurements on sandstones under load using neutron diffraction

Science.gov (United States)

Frischbutter, A.; Neov, D.; Scheffzük, Ch.; Vrána, M.; Walther, K.

2000-11-01

Neutron diffraction methods (both time-of-flight- and angle-dispersive diffraction) are applied to intracrystalline strain measurements on geological samples undergoing uniaxial increasing compressional load. The experiments were carried out on Cretaceous sandstones from the Elbezone (East Germany), consisting of >95% quartz which are bedded but without crystallographic preferred orientation of quartz. From the stress-strain relation the Young's modulus for our quartz sample was determined to be (72.2±2.9) GPa using results of the neutron time-of-flight method. The influence of different kinds of bedding in sandstones (laminated and convolute bedding) could be determined. We observed differences of factor 2 (convolute bedding) and 3 (laminated bedding) for the elastic stiffness, determined with angle dispersive neutron diffraction (crystallographic strain) and with strain gauges (mechanical strain). The data indicate which geological conditions may influence the stress-strain behaviour of geological materials. The influence of bedding on the stress-strain behaviour of a laminated bedded sandstone was indicated by direct residual stress measurements using neutron time-of-flight diffraction. The measurements were carried out six days after unloading the sample. Residual strain was measured for three positions from the centre to the periphery and within two radial directions of the cylinder. We observed that residual strain changes from extension to compression in a different manner for two perpendicular directions of the bedding plane.

Cathodoluminescence, fluid inclusions and trace element data for the syntaxial quartz cementation in the sandstones of Ora Formation, northern Iraq

DEFF Research Database (Denmark)

Omer, Muhamed Fakhri; Friis, Henrik

2018-01-01

Quartz cements of the quartz arenitic sandstones from the Chalky Nasara and Ora section of the (Devonian-Carboniferous) Ora Formation in northern Iraq have been studied. A combination of Hot-Cathodoluminescence (CL), LA-ICP-MS and fluid inclusions microthermometry revealed three syntaxial quartz......-bedded sandstones than in the6 thickly-bedded sandstones filling most of remaining pore space during mesogenesis. The Q3 was formed during early telogenesis stage fully cementing the sandstones and the fractures were filled by hydrothermal chlorite and sulfides. Significant amount of trace elements Al, Li, Ge...

Nivelstein sandstone, weakly lithified pure silica sands from the Dutch-German border area, intermittently used in architecture for two millennia

Science.gov (United States)

Nijland, Timo G.; Wim Dubelaar, C.

2017-04-01

The current paper provides a concise overview of the geological setting of the Nivelstein sandstone in broad sense, its petrographic and physical characteristics, and its use as natural stone. Miocene pure silica sands occur around Heerlen in the southeastern part of the Dutch province of Limburg and Herzogenrath in adjacent Germany, as well as in the Belgian province of Limburg near Opgrimbie. In Dutch Limburg and in Germany are three large active exploitations, quarrying the sands for industrial purposes. On top of the unconsolidated sands in the Herzogenrath quarry, lithified banks of sandstone occur, known as Nivelstein (or more rarely Herzogenrath) sandstone. This sandstone has been used as dimension stone and ornamental stone since Roman times. In the 11th century the quarry was reopened and after a long period of disuse sandstone blocks were again quarried in the second half of the 19th century. The lithification of the Nivelstein sandstone usually is very weak, with grain to grain contacts and some newly formed quartz rims only. The clay content is extremely low and is restricted to tiny booklets of kaolinite. Despite the weak cementation the Nivelstein sandstone has proved to be very time-resistant building stone that forms a major element in the stone cultural heritage of the Dutch- German border area.

PETROFACIES CHARACTERISTICS OF THE SANDSTONES OF THE UPPER MIOCENELOWER PLIOCENE AGED IN THE ULUMUHSİNE-TATKÖY (KONYA AREA

Directory of Open Access Journals (Sweden)

A. Müjdat ÖZKAN

2000-03-01

Full Text Available In the study area, Upper Miocene-Lower Pliocene aged Ulumuhsine formation, was formed in a shallow, open lake and river environment. The lithologies of this formation are thin-medium bedded, laminated and fossil rich limestone, thin-thick bedded mudstone, thin-thick bedded marl, thin-thick bedded dolomite with stromatolite interbedded limestone, tuffite, chert bands and coal-rich levels. In addition, it includes conglomerates and sandstones of underwater distrubution channels in lacustrine, and channel and bar sediments in stream environments. Red, gray, rarely green colored sandstones are thin-thick bedded, and in some levels well sorting, in some levels proorly sorting. They present sedimentary structures, as graded, herringbone cross-bedding, symmetric ripple-marks, and laminate. Sandstones are named lithic arenite and lithic graywacke and litharenite, feldspathic litharenite and sublithic arenite. These sandstones are rich rock fragments and quartzs, in addition they contain plagioclase, biotite, muskovite, opaque mineral and epidote. Binding materials of sandstones are mainly calcite cements and clay matrix, and iron oxide cement in little amount. From the mineralogical and textural point of view. As a tectonic environment, the main source of sandstones are recycled orogen (thrust, collision and land uplift and recyded lithic fragments.

provenance of sandstone on the western flank of anambra basin

African Journals Online (AJOL)

HP

GLOBAL JOURNAL OF GEOLOGICAL SCIENCES VOL. 14, 2016: 13-21. COPYRIGHT© ... from Fugar locality. The sandstones each classify as quartz arenites and sublitharenites. ... Tectonic movement in the Santonian times resulted in the ...

Discussion on several problems on the mineralization of paleo-channel sandstone type uranium deposits

International Nuclear Information System (INIS)

Huang Shijie

1997-01-01

On the basis of comprehensively analyzing paleo-channel sandstone type uranium deposits at home and abroad, the author discusses the division of mineralization types of paleo-channel sandstone type uranium deposits, and analyzes the metallogenic geologic conditions such as regional geologic background, climatic and geomorphological conditions, basement and sedimentary cover, characteristics of paleo-valley and paleo-channel, mineralization features as well as epigenetic metallogenic process. Future prospecting direction is also proposed

Vulnerable, But Why? Post-Traumatic Stress Symptoms in Older Adults Exposed to Hurricane Sandy.

Science.gov (United States)

Heid, Allison R; Christman, Zachary; Pruchno, Rachel; Cartwright, Francine P; Wilson-Genderson, Maureen

2016-06-01

Drawing on pre-disaster, peri-disaster, and post-disaster data, this study examined factors associated with the development of post-traumatic stress disorder (PTSD) symptoms in older adults exposed to Hurricane Sandy. We used a sample of older participants matched by gender, exposure, and geographic region (N=88, mean age=59.83 years) in which one group reported clinically significant levels of PTSD symptoms and the other did not. We conducted t-tests, chi-square tests, and exact logistic regressions to examine differences in pre-disaster characteristics and peri-disaster experiences. Older adults who experienced PTSD symptoms reported lower levels of income, positive affect, subjective health, and social support and were less likely to be working 4 to 6 years before Hurricane Sandy than were people not experiencing PTSD symptoms. Those developing PTSD symptoms reported more depressive symptoms, negative affect, functional disability, chronic health conditions, and pain before Sandy and greater distress and feelings of danger during Hurricane Sandy. Exact logistic regression revealed independent effects of preexisting chronic health conditions and feelings of distress during Hurricane Sandy in predicting PTSD group status. Our findings indicated that because vulnerable adults can be identified before disaster strikes, the opportunity to mitigate disaster-related PTSD exists through identification and resource programs that target population subgroups. (Disaster Med Public Health Preparedness. 2016;10:362-370).

The impact of Hurricane Sandy on the mental health of New York area residents.

Science.gov (United States)

Schwartz, Rebecca M; Sison, Cristina; Kerath, Samantha M; Murphy, Lisa; Breil, Trista; Sikavi, Daniel; Taioli, Emanuela

2015-01-01

To evaluate the long-term psychological impact of Hurricane Sandy on New York residents. Prospective, cross-sectional study. Community-based study. From October 2013 to February 2015, 669 adults in Long Island, Queens, and Staten Island completed a survey on their behavioral and psychological health, demographics, and hurricane impact (ie, exposure). Depression, anxiety, and post-traumatic stress disorder (PTSD). Using multivariable logistic regression models, the relationships between Hurricane Sandy exposure and depression, anxiety, and PTSD were examined. Participants experienced an average of 3.9 exposures to Hurricane Sandy, most of which were related to property damage/loss. Probable depression was reported in 33.4 percent of participants, probable anxiety in 46 percent, and probable PTSD in 21.1 percent. Increased exposure to Hurricane Sandy was significantly associated with a greater likelihood of depression (odds ratio [OR] = 1.09, 95% confidence interval [CI]: 1.04-1.14), anxiety (OR = 1.08, 95% CI: 1.03-1.13), and probable PTSD (OR = 1.32, 95% CI: 1.23-1.40), even after controlling for demographic factors known to increase susceptibility to mental health issues. Individuals affected by Hurricane Sandy reported high levels of mental health issues and were at an increased risk of depression, anxiety, and PTSD in the years following the storm. Recovery and prevention efforts should focus on mental health issues in affected populations.

Clay minerals in sandstone uranium deposits: radwaste applications

International Nuclear Information System (INIS)

Brookins, D.G.

1990-01-01

Clay minerals play an important role in the genesis of uranium deposits in sandstones. They incorporate the rate earths (REE), U, Sb, Th, Cs, Rb, Sr, Y, Ba, and even small amounts of chalcophiles. These minerals possess analog elements for many of the radwaste fission products as well as actinides and some actinide daughters. In sandstone uranium deposits, clay minerals are also associated with sulfide minerals, usually pyrite, and organic carbonaceous matter. The primary clay minerals are usually smectites, illites, chlorites and mixed layer varieties. The integrity of these clay minerals is demonstrated by their retention of formational-mineralization ages determined by Rb-Sr geochronologic investigation of the Grants Mineral Belt of the United States. The importance of the clay minerals as analog for parts of the multi-barrier concept in radwaste disposal is their ability to impede water penetration into - and movement of key elements out of uranium rich zones. The clay minerals further sorb and in other ways incorporate into their structures many fission products and actinide analogs from man-made nuclear wastes. 22 refs., 1 fig., 3 tabs

Modelling of a diffusion-sorption experiment on sandstone

International Nuclear Information System (INIS)

Smith, P.A.

1989-11-01

The results of a diffusion-sorption experiment on a sample of Darley Dale sandstone, using simulated groundwater spiked with a mixture of 125 I, 85 Sr and 137 Cs, are modelled by a one-dimensional porous medium approach in which sorption is described by Freundlich isotherms. The governing equations are solved analytically for the special case of a linear isotherm, and numerically using the computer code RANCHDIFF for non-linear isotherms. A set of time-dependent, ordinary differential equations is obtained using the Lagrange interpolation technique and integrated by Gear's variable order predictor-corrector method. It is shown that the sorption behaviour of 85 Sr can be modelled successfully by a linear isotherm, using a sorption parameter consistent with batch-sorption tests. The behaviour of 137 Cs may be modelled by a non-linear isotherm, but the amount of 137 Cs sorbed is less than that anticipated from batch-sorption tests. 125 I is assumed to be non-sorbing and is used to determine the porosity of the sandstone. (author) 10 figs., 4 tabs., 6 refs

Metallogenic characteristics, model and exploration prospect for the paleo-interlayer-oxidation type sandstone-hosted uranium deposits in China

International Nuclear Information System (INIS)

Huang Jingbai; Li Shengxiang

2007-01-01

In this paper, the paleo-interlayer-oxidation type sandstone-hosted uranium deposits occurred in the Meso-Cenozoic continental basins in China are divided into 3 subtype, they are stratum over lapping buried subtype, structure-uplifting destroy subtype and faulted-folding conserved subtype. The metallogenic characteristics, metallogenic model and exploration prospect for these 3 subtypes uranium deposits are discussed. It is proposed that the paleo-interlayer-oxidation type sandstone-hosted uranium deposits, besides the recent interlayer oxidation type sandstone-hosted uranium deposits, are of great prospecting potential in the Meso-Cenozoic continental basins in China. Therefore, the metallogenic theory of these types uranium deposits should be conscientiously summarized and replenished continuously so as to propel forward the exploration of the sandstone-hosted uranium deposits in China. (authors)

Preliminary research on finite difference method to solve radon field distribution over sandstone-type uranium ore body

International Nuclear Information System (INIS)

Li Bihong; Shuang Na; Liu Qingcheng

2006-01-01

The principle of finite difference method is introduced, and the radon field distribution over sandstone-type uranium deposit is narrated. The radon field distribution theory equation is established. To solve radon field distribution equation using finite difference algorithm is to provide the value computational method for forward calculation about radon field over sandstone-type uranium mine. Study on 2-D finite difference method on the center of either high anomaly radon fields in view of the character of radon field over sandstone-type uranium provide an algorithm for further research. (authors)

CHARACTERIZATION OF SANDSTONE RESERVOIRS FOR ENHANCED OIL RECOVERY: THE PERMIAN UPPER MINNELUSA FORMATION, POWDER RIVER BASIN, WYOMING.

Science.gov (United States)

Schenk, C.J.; Schmoker, J.W.; Scheffler, J.M.

1986-01-01

Upper Minnelusa sandstones form a complex group of reservoirs because of variations in regional setting, sedimentology, and diagenetic alteration. Structural lineaments separate the reservoirs into northern and southern zones. Production in the north is from a single pay sand, and in the south from multi-pay sands due to differential erosion on top of the Upper Minnelusa. The intercalation of eolian dune, interdune, and sabkha sandstones with marine sandstones, carbonates, and anhydrites results in significant reservoir heterogeneity. Diagenetic alterations further enhance heterogeneity, because the degree of cementation and dissolution is partly facies-related.

Uranium-series disequilibria as a means to study recent migration of uranium in a sandstone-hosted uranium deposit, NW China

International Nuclear Information System (INIS)

Min Maozhong; Peng Xinjian; Wang Jinping; Osmond, J.K.

2005-01-01

Uranium concentration and alpha specific activities of uranium decay series nuclides 234 U, 238 U, 230 Th, 232 Th and 226 Ra were measured for 16 oxidized host sandstone samples, 36 oxic-anoxic (mineralized) sandstone samples and three unaltered primary sandstone samples collected from the Shihongtan deposit. The results show that most of the ores and host sandstones have close to secular equilibrium alpha activity ratios for 234 U/ 238 U, 230 Th/ 238 U, 230 Th/ 234 U and 226 Ra/ 230 Th, indicating that intensive groundwater-rock/ore interaction and uranium migration have not taken place in the deposit during the last 1.0 Ma. However, some of the old uranium ore bodies have locally undergone leaching in the oxidizing environment during the past 300 ka to 1.0 Ma or to the present, and a number of new U ore bodies have grown in the oxic-anoxic transition (mineralized) subzone during the past 1.0 Ma. Locally, uranium leaching has taken place during the past 300 ka to 1.0 Ma, and perhaps is still going on now in some sandstones of the oxidizing subzone. However, uranium accumulation has locally occurred in some sandstones of the oxidizing environment during the past 1 ka to 1.0 Ma, which may be attributed to adsorption of U(VI) by clays contained in oxidized sandstones. A recent accumulation of uranium has locally taken place within the unaltered sandstones of the primary subzone close to the oxic-anoxic transition environment during the past 300 ka to 1.0 Ma. Results from the present study also indicate that uranium-series disequilibrium is an important tool to trace recent migration of uranium occurring in sandstone-hosted U deposits during the past 1.0 Ma and to distinguish the oxidation-reduction boundary

Electrofacies vs. lithofacies sandstone reservoir characterization Campanian sequence, Arshad gas/oil field, Central Sirt Basin, Libya

Science.gov (United States)

Burki, Milad; Darwish, Mohamed

2017-06-01

The present study focuses on the vertically stacked sandstones of the Arshad Sandstone in Arshad gas/oil field, Central Sirt Basin, Libya, and is based on the conventional cores analysis and wireline log interpretation. Six lithofacies types (F1 to F6) were identified based on the lithology, sedimentary structures and biogenic features, and are supported by wireline log calibration. From which four types (F1-F4) represent the main Campanian sandstone reservoirs in the Arshad gas/oil field. Lithofacies F5 is the basal conglomerates at the lower part of the Arshad sandstones. The Paleozoic Gargaf Formation is represented by lithofacies F6 which is the source provenance for the above lithofacies types. Arshad sediments are interpreted to be deposited in shallow marginal and nearshore marine environment influenced by waves and storms representing interactive shelf to fluvio-marine conditions. The main seal rocks are the Campanian Sirte shale deposited in a major flooding events during sea level rise. It is contended that the syn-depositional tectonics controlled the distribution of the reservoir facies in time and space. In addition, the post-depositional changes controlled the reservoir quality and performance. Petrophysical interpretation from the porosity log values were confirmed by the conventional core measurements of the different sandstone lithofacies types. Porosity ranges from 5 to 20% and permeability is between 0 and 20 mD. Petrophysical cut-off summary of the lower part of the clastic dominated sequence (i. e. Arshad Sandstone) calculated from six wells includes net pay sand ranging from 19.5‧ to 202.05‧, average porosity from 7.7 to 15% and water saturation from 19 to 58%.

Simulation of forced convection in non-Newtonian fluid through sandstones

Science.gov (United States)

Gokhale, M. Y.; Fernandes, Ignatius

2017-11-01

Numerical simulation is carried out to study forced convection in non-Newtonian fluids flowing through sandstones. Simulation is carried out using lattice Boltzmann method (LBM) for both shear-thinning and shear-thickening, by varying the power law index from 0.5 to 1.5 in Carreau-Yasuda model. Parameters involved in LBM and Carreau model are identified to achieve numerical convergence. Permeability and porosity are varied in the range of 10-10-10-6 and 0.1-0.7, respectively, to match actual geometrical properties of sandstone. Numerical technology is validated by establishing Darcy's law by plotting the graph between velocity and pressure gradient. Consequently, investigation is carried out to study the influence of material properties of porous media on flow properties such as velocity profiles, temperature profiles, and Nusselt number.

Prospect analysis for sandstone-type uranium mineralization in the northern margin of Qaidam basin

International Nuclear Information System (INIS)

Liu Lin; Song Xiansheng; Feng Wei; Song Zhe; Li Wei

2010-01-01

Affected by the regional geological structural evolution, a set of sedimentary structure, i.e. the construction of coal-bearing classic rocks which is in favor of the sandstone-type uranium mineralization has deposited in the northern margin of Qaidam Basin since Meso-Cenozoic. A NWW thrust nappe tectonic belt, i.e. the ancient tectonic belt which is the basis for the development of ancient interlayer oxidation zone formed by the tectonic reverse in late Jurassic and Cretaceous. The Mid and late Jurassic layer was buried by the weak extension in Paleogene and the depression in early Neogene. The extrusion reversal from late Neogene to Quaternary made the basin into the development era of the modern interlayer oxidation zone. It can be concluded that the layer of the northern margin of Qaidam Basin has the premise for the formation of sandstone-type uranium ore. Based on the analysis of the characteristics of the thrust belt, the structure of the purpose layer, the sand body, the hydrogeology, the interlayer oxidation zone and uranium mineralization, the results indicated that the ancient interlayer oxidation zone is the prospecting type of sandstone-type uranium ore. Beidatan and the east of Yuqia are the favorable prospective area of sandstone-type uranium mineralization. (authors)

The migration of uranium through sandstone

International Nuclear Information System (INIS)

Bennett, D.G.; Read, D.; Lawless, T.A.; Sims, R.J.

1992-01-01

Three column experiments are described in which the migration of uranium through Clashach Sandstone was studied. A priori predictions of uranium migration in the experiments were made using an equilibrium chemical transport model. The experimental results showed that, even under oxidising conditions, the migration of uranium is strongly retarded owing to the affinity of uranium for mineral surfaces. For the relatively simple chemical system investigated, the chemical transport model was successful in predicting the migration of uranium and its distribution along the column. (author)

Reviews on the metallogenic and geological features of sandstone-type uranium deposits in Japan

International Nuclear Information System (INIS)

Pei Chengkai; Huang Xianfang; Zhang Baoju

2006-01-01

Regional geologic settings of sandstone-type uranium deposits in Japan are firstly analyzed. The regional tectonic evolution characteristics of 'Green tuff region' and 'Non green tuff region' and their relationship with uranium mineralization are elaborated in depth. Based on those mentioned above, the uranium sources of sandstone-type uranium deposits in Japan are discussed deeply and the most favorable uranium sources are considered to come from the basement and the surrounding granites. Their intrusive epochs range from Later Cretaceous to Palaeogene (about 60 to 70 Ma ago). The characteristics of ore-bearing host rocks, matter compositions of the deposits, ore formation enrichment factors, the hydrogeologic conditions and so on are described by taking Ningyo-Toge and Tono deposits as examples. Finally, the prospecting measures for the palaeo-channel sandstone-type uranium deposits (basal type) are reviewed. (authors)

Petrographic characteristic of the sandstones of the upper paleocene-middle eocene aged in the Yildizli-Aydinkent (Ereğli-Konya area

Directory of Open Access Journals (Sweden)

A. Müjdat Özkan

2002-03-01

Full Text Available In the study area, Upper Paleocene - Middle Eocene aged Halkapınar formation, was formed in a shallow and deep marine environment. The lithologies of this formation are medium - thick bedded conglomerate, thin - thick bedded sandstone, thin - very thick bedded shale, thin - medium bedded marl with chert nodules and bands. In addition olistolithes of ophiolitic melange are found at the top of the sandstones, which includes basalt interbands. Yellowish gray, greenish gray, beige, gray colored sandstones include some sedimentary structures, namely ripple - marks, graded bedding, laminate, convolute lamination, current ripple, tool marks. Constituents of the sandstones are quartz, plagioclase, sanidine, orthoclase, fragments of sedimentary and methamorphic rocks, biotite, muscovite, opaque mineral and glauconite. The sandstones, which are not matured in terms of mineralogy and texture, are mainly cemented by calcite, clay matrix and minor iron oxide and glauconite matrix. The sandstones are named lithic arenite, lithic graywacke, feldspathic litharenite and litharenite.

The effects of Hurricane Sandy on trauma center admissions.

Science.gov (United States)

Curran, T; Bogdanovski, D A; Hicks, A S; Bilaniuk, J W; Adams, J M; Siegel, B K; DiFazio, L T; Durling-Grover, R; Nemeth, Z H

2018-02-01

Hurricane Sandy was a particularly unusual storm with regard to both size and location of landfall. The storm landed in New Jersey, which is unusual for a tropical storm of such scale, and created hazardous conditions which caused injury to residents during the storm and in the months following. This study aims to describe differences in trauma center admissions and patterns of injury during this time period when compared to a period with no such storm. Data were collected for this study from patients who were admitted to the trauma center at Morristown Medical Center during Hurricane Sandy or the ensuing cleanup efforts (patients admitted between 29 October 2012 and 27 December 2012) as well as a control group consisting of all patients admitted to the trauma center between 29 October 2013 and 27 December 2013. Patient information was collected to compare the admissions of the trauma center during the period of the storm and cleanup to the control period. A total of 419 cases were identified in the storm and cleanup period. 427 were identified for the control. Striking injuries were more common in the storm and cleanup group by 266.7% (p = 0.0107); cuts were more common by 650.8% (p = 0.0044). Medical records indicate that many of these injuries were caused by Hurricane Sandy. Self-inflicted injuries were more common by 301.3% (p = 0.0294). There were no significant differences in the total number of patients, mortality, or injury severity score between the two cohorts. The data we have collected show that the conditions caused by Hurricane Sandy and the following cleanup had a significant effect on injury patterns, with more patients having been injured by being struck by falling or thrown objects, cut while using tools, or causing self-inflicted injuries. These changes, particularly during the cleanup period, are indicative of environmental changes following the storm which increase these risks of injury.

Radon emanation coefficients in sandy soils

International Nuclear Information System (INIS)

Holy, K.; Polaskova, A.; Baranova, A.; Sykora, I.; Hola, O.

1998-01-01

In this contribution the results of the study of an influence of the water content on the emanation coefficient for two sandy soil samples are reported. These samples were chosen on the because of the long-term continual monitoring of the 222 Rn concentration just in such types of soils and this radon concentration showed the significant variations during a year. These variations are chiefly given in connection with the soil moisture. Therefore, the determination of the dependence of the emanation coefficient of radon on the water content can help to evaluate the influence of the soil moisture variations of radon concentrations in the soil air. The presented results show that the emanation coefficient reaches the constant value in the wide interval of the water content for both sandy soil samples. Therefore, in the common range of the soil moisture (5 - 20 %) it is impossible to expect the variations of the radon concentration in the soil air due to the change of the emanation coefficient. The expressive changes of the radon concentration in the soil air can be observed in case of the significant decrease of the emanation coefficient during the soil drying when the water content decreases under 5 % or during the complete filling of the soil pores by the water. (authors)

Fine natural aggregate replacement for sandy residue from itabirite exploitation in Portland cement mortar

International Nuclear Information System (INIS)

Melo, V.A.R.; Freire, C.B.; Pereira Junior, S.S.; Lameiras, F.S.; Tello, C.C.O.

2011-01-01

The fine natural aggregates are a material largely used by the civil construction for mortar and concrete production. Due to tightening legal restrictions imposed on their extraction, alternative materials are being considered. The use of sandy residue from BIF (banded iron formations) exploitation was investigated. It requires their grinding and flotation to concentrate iron oxides. Large amounts of sandy residue composed of quartz and iron oxides are generated in this process. The sandy residue was characterized relative to mineralogical composition, particle size distribution, presence of organic impurities, and particle shape. Mortar formulations were prepared by varying the type of cement, the cement to aggregate proportion and the water/cement ratio (a/c). The results of viscosity and density of fresh mortar, setting time, and compressive strength are presented. Compressive strength up to 19.5 MPa at 28 days were achieved with the use of cement CPV, a/c ratio of 0.80 and cement:aggregate proportion of 1:2. The results demonstrate the technical feasibility of using sandy residue as fine aggregate. (author)

Caulogenic induction in cotyledons of stone pine (Pinus pinea): relationship between organogenic response and benzyladenine trends in selected families.

Science.gov (United States)

Cuesta, Candela; Rodríguez, Ana; Centeno, María Luz; Ordás, Ricardo J; Fernández, Belén

2009-07-15

Adventitious bud formation in stone pine cotyledons cultured in the presence of benzyladenine (BA) has been proposed as a model for the study of in vitro shoot organogenesis in conifers. This is because of its advantageous characteristics including the requirement of only one plant growth regulator (BA), the synchronous fashion of its induction, and the homogeneity and low degree of differentiation of cotyledons. Although optimal culture conditions have been developed and are currently in use, we still lack data for BA dynamics in cotyledons cultured under these conditions, and the morphological description of the early induction stages has not, until now, been approached from a histological perspective. Consequently, this is the focus of the present report. Additionally, we examined uptake and metabolism of BA in cotyledons from two selected families, previously characterized by, and selected for, the difference in the magnitude of their organogenic response. Media transfer experiments established that cotyledons should be in contact with 44.4 microM BA for at least 6h to obtain any caulogenic response (minimum shoot-induction period). Histological observations, carried out here for the first time in this species, determined that meristemoid structures had already begun to appear in explants within 12 h of culture. Moreover, results from the BA uptake and metabolism experiments indicated that the point at which explants reached the maximum concentration of active forms of BA (276.60 microM at 6 h) and the onset of the determination phase of shoot organogenesis were directly related. A direct relationship was also observed between the intensity of the caulogenic response in cotyledons from families 36 and 61 and the endogenous concentration of BA and its riboside at the start of the induction phase. Hence, family 36, characterized by its higher bud production, reached concentrations of 251.56 microM, while family 61, selected for its low bud-producing trait, only

Diagenesis and reservoir quality of the Lower Cretaceous Quantou Formation tight sandstones in the southern Songliao Basin, China

Science.gov (United States)

Xi, Kelai; Cao, Yingchang; Jahren, Jens; Zhu, Rukai; Bjørlykke, Knut; Haile, Beyene Girma; Zheng, Lijing; Hellevang, Helge

2015-12-01

The Lower Cretaceous Quantou Formation in the southern Songliao Basin is the typical tight oil sandstone in China. For effective exploration, appraisal and production from such a tight oil sandstone, the diagenesis and reservoir quality must be thoroughly studied first. The tight oil sandstone has been examined by a variety of methods, including core and thin section observation, XRD, SEM, CL, fluorescence, electron probing analysis, fluid inclusion and isotope testing and quantitative determination of reservoir properties. The sandstones are mostly lithic arkoses and feldspathic litharenites with fine to medium grain size and moderate to good sorting. The sandstones are dominated by feldspar, quartz, and volcanic rock fragments showing various stages of disintegration. The reservoir properties are quite poor, with low porosity (average 8.54%) and permeability (average 0.493 mD), small pore-throat radius (average 0.206 μm) and high displacement pressure (mostly higher than 1 MPa). The tight sandstone reservoirs have undergone significant diagenetic alterations such as compaction, feldspar dissolution, quartz cementation, carbonate cementation (mainly ferrocalcite and ankerite) and clay mineral alteration. As to the onset time, the oil emplacement was prior to the carbonate cementation but posterior to the quartz cementation and feldspar dissolution. The smectite to illite reaction and pressure solution at stylolites provide a most important silica sources for quartz cementation. Carbonate cements increase towards interbedded mudstones. Mechanical compaction has played a more important role than cementation in destroying the reservoir quality of the K1q4 sandstone reservoirs. Mixed-layer illite/smectite and illite reduced the porosity and permeability significantly, while chlorite preserved the porosity and permeability since it tends to be oil wet so that later carbonate cementation can be inhibited to some extent. It is likely that the oil emplacement occurred

Tertiary lithofacies and paleo-geographic framework and interlayer oxidation zone sandstone uranium deposits in Longjiang-Zhaozhou area

International Nuclear Information System (INIS)

Zhang Zhenqiang

2003-01-01

The main points of views for the experiment are: (1) Yi'an formation is mainly composed of limnetic facies of siltstone and fine sandstone, due to weak surface water, limited sedimentation and simple material source; (2) strengthened surface water and enormous material brought from north and west-north and enlarged sedimentation from north to south, the major deposition during Da'an period are channel facies of conglomerate and river bed facies of sandstone; (3) stronger surface water during Taikang period, led alluvial-flood plain facies brown-yellow conglomerate to develop along western margin of the basin, the channel facies of conglomerate and river bed facies of grey-green sandstone, pelitic siltstone were widely formed southward and eastward; (4) according to the lithofacies criterion for in-situ leachable sandstone uranium ore, Taikang formation is an ideal horizon, river bed facies is suitable for interlayer oxidation type uranium deposit. (author)

Experimental Investigation on Hydraulic Properties of Granular Sandstone and Mudstone Mixtures

Directory of Open Access Journals (Sweden)

Dan Ma

2018-01-01

Full Text Available The caved zone during longwall mining has high permeability, resulting in a mass of groundwater storage which causes a threat of groundwater inrush hazard to the safe mining. To investigate the hazard mechanism of granular sandstone and mudstone mixture (SMM in caved zone, this paper presents an experimental study on the effect of sandstone particle (SP and mudstone particle (MP weight ratio on the non-Darcy hydraulic properties evolution. A self-designed granular rock seepage experimental equipment has been applied to conduct the experiments. The variation of particle size distribution was induced by loading and water seepage during the test, which indicated that the particle crushing and erosion properties of mudstone were higher than those of sandstone. Porosity evolution of SMM was strongly influenced by loading (sample height and SP/MP weight ratio. The sample with higher sample height and higher weight ratio of SP achieved higher porosity value. In particular, a non-Darcy equation, for hydraulic properties (permeability κ and non-Darcy coefficient ζ calculation, was sufficient to fit the relation between the hydraulic gradient and seepage velocity. The test results indicated that, due to the absence and narrowing of fracture and void during loading, the permeability κ decreases and the non-Darcy coefficient ζ increases. The variation of the hydraulic properties of the sample within the same particle size and SP/MP weight ratio indicated that groundwater inrush hazard showed a higher probability of occurrence in sandstone strata and crushed zone (e.g., faults. Moreover, isolated fractures and voids were able to achieve the changeover from self-extension to interconnection at the last loading stage, which caused the fluctuation tendency of κ and ζ. Fluctuation ability in mudstone was higher than that in sandstone. The performance of an empirical model was also investigated for the non-Darcy hydraulic properties evolution prediction of

Hurricane Sandy: Rapid Response Imagery of the Surrounding Regions

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of Hurricane Sandy. The aerial photography missions were conducted by the NOAA Remote Sensing Division. The images were acquired...

2014 USGS CMGP Lidar: Sandy Restoration (Delaware and Maryland)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Extent: SANDY_Restoration_DE_MD_QL2 Area of Interest covers approximately 3.096 square miles. Lot #5 contains the full project area Dataset Description:...

Fine-scale spatial distribution of plants and resources on a sandy soil in the Sahel

NARCIS (Netherlands)

Rietkerk, M.G.; Ouedraogo, T.; Kumar, L.; Sanou, S.; Langevelde, F. van; Kiema, A.; Koppel, J. van de; Andel, J. van; Hearne, J.; Skidmore, A.K.; Ridder, N. de; Stroosnijder, L.; Prins, H.H.T.

2002-01-01

We studied fine-scale spatial plant distribution in relation to the spatial distribution of erodible soil particles, organic matter, nutrients and soil water on a sandy to sandy loam soil in the Sahel. We hypothesized that the distribution of annual plants would be highly spatially autocorrelated

Aspects of the sedimentology of some uranium-bearing sandstones in the Beaufort West area, Cape Province

International Nuclear Information System (INIS)

Cole, D.I.

1980-01-01

The sedimentology of some uranium-bearing sandstones from the Beaufort Group in the Beaufort West area was studied by use of some 116 vertical profiles measured across and adjacent to 14 mineralized deposits. The vertical profiles consist of 91 field sections and 25 borehole logs. The sandstones are usually multistorey and alternate with a mudstone and/or siltstone succession. The vertical profiles basically consist of a succession of facies. Some 19 facies were recognised within the sandstones on the basis of texture and sedimentary structure. The facies transitions within the sandstone sequence were subjected to a one-step Markov chain analysis. The cumulative thickness of uranium mineralization for each sedimentary facies within the sandstone sequence was measured. Some 99 per cent of the total cumulative thickness occurs within the coarser-grained facies (grain sizes in excess of very fine), which suggests that permeability was an important control on the mineralization. The coarser-grained facies, which mostly represent lower point bar or channel bar deposits near the base of each storey, probably acted as suitable aquifers for the transport of uraniferous solutions. Irregularities in the base of each storey may have interrupted the flow of these solutions and allowed sufficient time for precipitation of the uranium. Carbonaceous debris is frequently associated with the mineralized deposits and most likely acted as an indirect reductant for this precipitation. Mineralization decreases upwards in the sandstone sequence and some 40 per cent of the total cumulative thickness is restricted to the initial storey. The horizontally bedded facies contain a high proportion of the total cumulative thickness of mineralization (45 per cent) and this again may be related to a more abundant content of carbonaceous debris

National uranium resource evaluation. Geology and recognition criteria for sandstone uranium deposits of the salt wash type, Colorado Plateau Province. Final report

International Nuclear Information System (INIS)

Thamm, J.K.; Kovschak, A.A. Jr.; Adams, S.S.

1981-01-01

The uranium-vanadium deposits of the Salt Wash Member of the Morrison Formation in the Colorado Plateau are similar to sandstone uranium deposits elsewhere in the USA. The differences between Salt Wash deposits and other sandstone uranium deposits are also significant. The Salt Wash deposits are unique among sandstone deposits in that they are dominantly vanadium deposits with accessory uranium. The Salt Wash ores generally occur entirely within reduced sandstone, without adjacent tongues of oxidized sandstone. They are more like the deposits of Grants, which similarly occur in reduced sandstones. Recent studies of the Grants deposits have identified alteration assemblages which are asymmetrically distributed about the deposits and provide a basis for a genetic model for those deposits. The alteration types recognized by Shawe in the Slick Rock district may provide similar constraints on ore formation when expanded to broader areas and more complete chemical analyses

A Coordinated USGS Science Response to Hurricane Sandy

Science.gov (United States)

Jones, S.; Buxton, H. T.; Andersen, M.; Dean, T.; Focazio, M. J.; Haines, J.; Hainly, R. A.

2013-12-01

In late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection and Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term networks and rapid-deployment real-time streamgages and water-quality monitors tracked river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm-related information from many agencies on the Internet on a daily basis. Immediately following Hurricane Sandy the USGS developed a science plan, 'Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-A U.S. Geological Survey Science Plan for Support of Restoration and Recovery'. The plan will ensure continuing coordination of internal USGS activities as well as

The effect of grain size and cement content on index properties of weakly solidified artificial sandstones

Science.gov (United States)

Atapour, Hadi; Mortazavi, Ali

2018-04-01

The effects of textural characteristics, especially grain size, on index properties of weakly solidified artificial sandstones are studied. For this purpose, a relatively large number of laboratory tests were carried out on artificial sandstones that were produced in the laboratory. The prepared samples represent fifteen sandstone types consisting of five different median grain sizes and three different cement contents. Indices rock properties including effective porosity, bulk density, point load strength index, and Schmidt hammer values (SHVs) were determined. Experimental results showed that the grain size has significant effects on index properties of weakly solidified sandstones. The porosity of samples is inversely related to the grain size and decreases linearly as grain size increases. While a direct relationship was observed between grain size and dry bulk density, as bulk density increased with increasing median grain size. Furthermore, it was observed that the point load strength index and SHV of samples increased as a result of grain size increase. These observations are indirectly related to the porosity decrease as a function of median grain size.

The sedimentology of uranium-bearing sandstones on the farm Kaffersfontein 328, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1979-10-01

The sedimentology of uranium-bearing sandstones on the farm Kaffersfontein 328 was studied by use of 23 vertical profiles measured across and adjacent to 3 mineralised deposits. The profiles consist of 18 field sections and 5 borehole logs. The vertical profiles basically consist of a succession of sedimentary facies. A total of 18 facies were recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structures. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation coincides with areas of thicker sandstone, usually where channel over-deepening has taken place. It always occurs above the base of a channel, which often marks the base of the fluvial sandstone sequence. Irregularities in the base of the channel probably caused interruptions to the flow of uraniferous solutions and allowed sufficient time for the precipitation of the uranium. Carbonaceous debris is always associated with the mineralisation and most likely acted as an indirect reductant for the precipitation of uranium from solution. The direct reductant was most probably H 2 S produced by anaerobic bacteria acting on the carbonaceous debris. The mineralisation is confined to the coarser-grained sedimentary facies, which suggests that permeability was an important control on the mineralisation. These facies probably acted as suitable aquifers for the transport of uraniferous solutions. Horizontally bedded sandstone facies comprises 41 per cent of the total cumulative thickness of mineralisation. This facies represents a higher stream power and may consequently contain more carbonaceous material derived from plants, which were eroded from upstream areas. The nature of the bedding may also have provided a more effective permeability zone for the transport of uraniferous solutions prior to precipitation of the uranium

Diagenetic history of the Surma Group sandstones (Miocene) in the Surma Basin, Bangladesh

Science.gov (United States)

Rahman, M. Julleh Jalalur; McCann, Tom

2012-02-01

This study examines the various diagenetic controls of the Miocene Surma Group sandstones encountered in petroleum exploration wells from the Surma Basin, which is situated in the northeastern part of the Bengal Basin, Bangladesh. The principal diagenetic minerals/cements in the Surma Group sandstones are Fe-carbonates (with Fe-calcite dominating), quartz overgrowths and authigenic clays (predominantly chlorite, illite-smectite and minor kaolin). The isotopic composition of the carbonate cement revealed a narrow range of δ 18O values (-10.3‰ to -12.4‰) and a wide range of δ 13C value (+1.4‰ to -23.1‰). The δ 13C VPDB and δ 18O VPDB values of the carbonate cements reveal that carbon was most likely derived from the thermal maturation of organic matter during burial, as well as from the dissolution of isolated carbonate clasts and precipitated from mixed marine-meteoric pore waters. The relationship between the intergranular volume (IGV) versus cement volume indicates that compaction played a more significant role than cementation in destroying the primary porosity. However, cementation also played a major role in drastically reducing porosity and permeability in sandstones with poikilotopic, pore-filling blocky cements formed in early to intermediate and deep burial areas. In addition to Fe-carbonate cements, various clay minerals including illite-smectite and chlorite occur as pore-filling and pore-lining authigenic phases. Significant secondary porosity has been generated at depths from 2500 m to 4728 m. The best reservoir rocks found at depths of 2500-3300 m are well sorted, relatively coarse grained; more loosely packed and better rounded sandstones having good porosities (20-30%) and high permeabilities (12-6000 mD). These good quality reservoir rocks are, however, not uniformly distributed and can be considered to be compartmentalized as a result of interbedding with sandstone layers of low to moderate porosities, low permeabilities owing to poor

Remote detection of fluid-related diagenetic mineralogical variations in the Wingate Sandstone at different spatial and spectral resolutions

Science.gov (United States)

Okyay, Unal; Khan, Shuhab D.

2016-02-01

Well-exposed eolian units of the Jurassic system on the Colorado Plateau including the Wingate Sandstone, show prominent color variations throughout southeastern Utah due to diagenetic changes that include precipitation and/or removal of iron oxide, clay, and carbonate cement. Spatially variable characteristic diagenetic changes suggest fluid-rock interactions through the sandstone. Distinctive spectral signatures of diagenetic minerals can be used to map diagenetic mineral variability and possibly fluid-flow pathways. The main objective of this work was to identify characteristic diagenetic minerals, and map their spatial variability from regional to outcrop scale in Wingate Sandstone exposures of Lisbon Valley, Utah. Laboratory reflectance spectroscopy analysis of the samples facilitated identification of diagnostic spectral characteristics of the common diagenetic minerals and their relative abundances between altered and unaltered Wingate Sandstone. Comparison of reflectance spectroscopy with satellite, airborne, and ground-based imaging spectroscopy data provided a method for mapping and evaluating spatial variations of diagenetic minerals. The Feature-oriented Principal Component Selection method was used on Advanced Spaceborne Thermal Emission and Reflection Radiometer data so as to map common mineral groups throughout the broader Wingate Sandstone exposure in the area. The Minimum Noise Fraction and Spectral Angle Mapper methods were applied on airborne HyMap and ground-based hyperspectral imaging data to identify and map mineralogical changes. The satellite and airborne data showed that out of 25.55 km2 total exposure of Wingate Sandstone in Lisbon Valley, unaltered sandstone cover 12.55 km2, and altered sandstone cover 8.90 km2 in the northwest flank and 5.09 km2 in the southern flank of the anticline. The ground-based hyperspectral data demonstrated the ability to identify and map mineral assemblages with two-dimensional lateral continuity on near

Structural Stability and Hydraulic Conductivity Of Nkpologu Sandy ...

African Journals Online (AJOL)

Studies were conducted in the runoff plots at the University of Nigeria Nsukka Teaching and Resesarch Farm in 2010 and 2011 to monitor the changes in structural stability and saturated hydraulic conductivity (Ksat) of Nkpologu sandy loam soil under different cover management practices. The management practices were ...

Application of base-level cycles to sandstone-type uranium deposit: taking Dongsheng uranium deposits as an example

International Nuclear Information System (INIS)

Yang Renchao; Han Zuozhen; Fan Aiping; Chang Xiangchun

2006-01-01

High-resolution sequence stratigraphy taking base-level cycles as interface of reference was developed rapidly in recent years. Its greatest predominance lies in that it can be applied to multi-controled continental sedimentary basins and can effectively improve accuracy and distinguishability of sequence stratigraphy analysis. Principles of base-level cycles can also be applied to the research and practice of the exploration and exploitation of sandstone-type uranium deposits as they control the spatial distribution, porosity, the permeability and the sealing ability of sandstone and mudstone, and stacking patterns of strata configuration. Taking Dongsheng uranium deposits as an example, the application of base-level cycles to exploration and exploitation of sandstone uranium deposits was analyzed. It is suggested that favorable strata framework of sandstone and mudstone was developed very well in the fluctuation of base-level cycles. Sand bodies were provided with good connectedness, coarse granularity, high debris content, low matrix content and good porosity-permeability becoming the most important uranium hosted strata. (authors)

Water-borne radon and hydrogeochemical based uranium exploration in Rajamundry sandstone, W. Godavari district, Andhra Pradesh

International Nuclear Information System (INIS)

Jeyagopal, A.V.; Rajaraman, H.S.; Som, Anjan

2010-01-01

The lithology and sedimentary structures of the Rajamundry Formation of the Mio-Pliocene age covering an area of 1100 sq.km. indicate that it may be a typical valley fill sediment. It is about 600 m thick comprising sandstone and clay with lignite as the main lithounits. It is continental in onshore and marine in the offshore and is in contact with Gondwana sediments and Rajamundry traps. Tertiary sandstones are important hosts for uranium mineralisation. The reducing gas (Methane or other volatile hydrocarbon) moving to uraniferous oxidising water has precipitated uranium in the sediments in South Texas and Northwest Colorado, USA: (a) along faults, (b) above petroliferous aquifers, (c) vertically above hydrocarbon accumulations and (d) oil-water interface at hydrocarbon accumulations i.e., at the points of introduction of reducent into oxidising ground waters. In this context, Rajamundry sandstone lying above the natural gas and petroleum bearing Krishna Godavari basin with faults is an important geological setting for uranium mineralisation. The exploration strategies of hydrogeochemical survey and water-borne Radon (Rn) surveys were selected in this soil-covered area. Hydrogeochemical survey carried out in the Rajamundry sandstone has brought out four hydro-uranium anomalous zones with water samples (10-45ppb) falling around Kadiyadda, Madhavaram, Erramalla and Chinna Malapalle areas of West Godavari district, Andhra Pradesh. The zones vary from 9 to 24 sq km area. Water-borne Radon was utilized as a tool for exploration of uranium in this soil covered terrain. Rn contours cluster around two zones around Kadiyadda and SW of Gollagudem wherein the Rn value is >60 counts/50 sec/500 ml. These Rn anomalies fall within the above mentioned hydrouranium anomalous zones. Gamma-ray logging of private bore wells has recorded relatively higher radioactivity in Kommugudem, which also falls in the high hydrouranium - high waterborne radon zone. These data and

How Pore Filling Shale Affects Elastic Wave Velocities in Fully and Partially Saturated Sandstone: Characterization, Measurement, and Modelling

DEFF Research Database (Denmark)

Sørensen, Morten Kanne; Fabricius, Ida Lykke

2017-01-01

The elastic bulk modulus of a sandstone is affected by the fluid saturation as compression induces a pressure in the fluid thus increasing the bulk modulus of the sandstone as a whole. Assuming a uniform induced pressure and no interaction between the saturating fluid and the solid rock the fluid...... contribution to the elastic bulk modulus is quantified by Gassmann's equations. Experimental measurements of the fluid contribution to the elastic moduli are, however often much larger than predicted within the assumptions of Gassmann. Clay-rich low-mobility sandstones are especially prone to having elastic...... moduli highly sensitive to the fluid saturation. The presence of clay in a sandstone can affect two of the underlying assumptions to Gassmann's equations: decreased fluid mobility can cause pressure gradients and fluid-clay interactions are common. The elastic and petrophysical properties of clay...

Permeability in Rotliegend gas sandstones to gas and brine as predicted from NMR, mercury injection and image analysis

DEFF Research Database (Denmark)

Rosenbrand, Esther; Fabricius, Ida Lykke; Fisher, Quentin

2015-01-01

Permeability characterisation of low permeability, clay-rich gas sandstones is part of production forecasting and reservoir management. The physically based Kozeny (1927) equation linking permeability with porosity and pore size is derived for a porous medium with a homogeneous pore size, whereas...... the pore sizes in tight sandstones can range from nm to μm. Nuclear magnetic resonance (NMR) transverse relaxation was used to estimate a pore size distribution for 63 samples of Rotliegend sandstone. The surface relaxation parameter required to relate NMR to pore size is estimated by combination of NMR...

The sedimentology of uranium-bearing sandstones on the Waterval portion of the farm Brandewyns Gat 214, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1980-08-01

The sedimentology of two uranium-bearing sandstones on the Waterval portion of the farm Brandewyns Gat 214 was studied by means of 36 vertical profiles measured across, through and adjacent to 4 mineralised deposits. The vertical profiles basically consist of a succession of sedimentary facies. A total of 19 facies was recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structure. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation occurs mostly within the lower half of the fluvial sandstone sequence and is confined to the coarser-grained sedimentary facies. These facies probably acted as suitable aquifers for the transport of uraniferous solutions and permeability differences between the sandstone and the underlying mudstone and siltstone must have restricted these solutions to the lower half of the channel sandstone. The massive mudstone facies contains 13 per cent of the total cumulative thickness of mineralisation. This mineralisation probably originated from synchronously deposited tuffaceous material. Subsequent migration of uraniferous solutions may have concentrated the uranium

Towards a typology of the mares sandstone of Mallorca Concept, characterization and stratigraphy

International Nuclear Information System (INIS)

Mas Gornals, C.

2017-01-01

The mares sandstone has traditionally been the most representative and characteristic building stone on the island of Mallorca, used practically exclusively as construction material for centuries, since the abandonment of stone-and-mortar walls, until its progressive disuse with the appearance of the re-enforced concrete, which finally eclipsed its use. Such emblematic buildings for the island, as Bellver Castle, the Cathedral, La Lonja or the old city walls of Palma, bear witness to this. In Mallorca, the mares sandstone is quarried in the open air or in subterranean galleries. Vernacular architecture has always used the most accessible appropriate materials, and in the case of the mares sandstone, its abundance, sufficient softness, which facilitates its extraction, Together with sufficient hardness to confer solidity and durability in constructions, converge. The lack of specific scientific and geological data published about the different types of mares in Mallorca, added to the recent resurgence of technical, applied and landscape interest in this stone, have made a revision of its definition, characterization and classification necessary. [es

2014 USGS CMGP Lidar: Post Sandy (Long Island, NY)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Long Island New York Sandy LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00296 Woolpert...

Hurricane Sandy science plan: coastal impact assessments

Science.gov (United States)

Stronko, Jakob M.

2013-01-01

Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: coastal topography and bathymetry, impacts to coastal beaches and barriers, impacts of storm surge, including disturbed estuarine and bay hydrology, impacts on environmental quality and persisting contaminant exposures, impacts to coastal ecosystems, habitats, and fish and wildlife. This fact sheet focuses assessing impacts to coastal beaches and barriers.

Rapid Assessment of Anthropogenic Impacts of Exposed Sandy ...

African Journals Online (AJOL)

We applied a rapid assessment methodology to estimate the degree of human impact of exposed sandy beaches in Ghana using ghost crabs as ecological indicators. The use of size ranges of ghost crab burrows and their population density as ecological indicators to assess extent of anthropogenic impacts on beaches ...

Estimation of uranium migration parameters in sandstone aquifers.

Science.gov (United States)

Malov, A I

2016-03-01

The chemical composition and isotopes of carbon and uranium were investigated in groundwater samples that were collected from 16 wells and 2 sources in the Northern Dvina Basin, Northwest Russia. Across the dataset, the temperatures in the groundwater ranged from 3.6 to 6.9 °C, the pH ranged from 7.6 to 9.0, the Eh ranged from -137 to +128 mV, the total dissolved solids (TDS) ranged from 209 to 22,000 mg L(-1), and the dissolved oxygen (DO) ranged from 0 to 9.9 ppm. The (14)C activity ranged from 0 to 69.96 ± 0.69 percent modern carbon (pmC). The uranium content in the groundwater ranged from 0.006 to 16 ppb, and the (234)U:(238)U activity ratio ranged from 1.35 ± 0.21 to 8.61 ± 1.35. The uranium concentration and (234)U:(238)U activity ratio increased from the recharge area to the redox barrier; behind the barrier, the uranium content is minimal. The results were systematized by creating a conceptual model of the Northern Dvina Basin's hydrogeological system. The use of uranium isotope dating in conjunction with radiocarbon dating allowed the determination of important water-rock interaction parameters, such as the dissolution rate:recoil loss factor ratio Rd:p (a(-1)) and the uranium retardation factor:recoil loss factor ratio R:p in the aquifer. The (14)C age of the water was estimated to be between modern and >35,000 years. The (234)U-(238)U age of the water was estimated to be between 260 and 582,000 years. The Rd:p ratio decreases with increasing groundwater residence time in the aquifer from n × 10(-5) to n × 10(-7) a(-1). This finding is observed because the TDS increases in that direction from 0.2 to 9 g L(-1), and accordingly, the mineral saturation indices increase. Relatively high values of R:p (200-1000) characterize aquifers in sandy-clayey sediments from the Late Pleistocene and the deepest parts of the Vendian strata. In samples from the sandstones of the upper part of the Vendian strata, the R:p value is ∼ 24, i.e., sorption processes are

Trap architecture of the Early Cretaceous Sarir Sandstone in the eastern Sirt Basin, Libya

Energy Technology Data Exchange (ETDEWEB)

Gras, R. [Schlumberger GeoQuest, Cedex (France); Thusu, B. [Arabian Gulf Oil Company, Benghazi (Libyan Arab Jamahiriya)

1998-12-31

The Sarir Sandstone is the principal reservoir for oil accumulations in the eastern Sirt Basin in Libya. The main phase of the rifting in this area took place in the Late Jurassic-Early Cretaceous, during which time the Sarir Sandstone was deposited as a non-marine, intra-continental clastic syn-rift sequence. Although successfully explored from 1959 onwards, the prolific eastern Sirt Basin is in a relatively immature stage of exploration regarding wildcat drilling and 3D seismic data acquisition. The most recent phase of exploration, utilizing 3D seismic techniques, revealed a complex structural development. The trap geometries are often related to E-W trending, basement-controlled fault systems, oblique to the NNW-SSE Sirt Basin trend. The fault systems were active during the Sarir Sandstone deposition, giving rise to structural as well as combined structural-traps. An increased understanding of trap architecture has led to both re-evaluation of older fields and new discoveries. (author)

Study of lixiviant damage of a sandstone deposit during in-situ leaching of uranium

International Nuclear Information System (INIS)

Liao Wensheng; Wang Limin; Jiang Yan; Jiang Guoping; Tan Yahui

2014-01-01

The permeability of sandstone deposit is a key factor for economical uranium recovery during in-situ leaching uranium. Low permeability sandstone uranium deposits behave low push-pull capacity, and show formation damage in leaching operations. It is important to study formation damage of permeability, therefore, and to stabilize even improve the push-pull power of drillholes during in-situ leaching. In this paper, formation damage caused by lixiviants was investigated based on a low permeability sandstone uranium deposit. The resulted showed that, under the conditions of in-situ leaching, the salinity of leaching fluid has no harm to formation permeability, on the contrary, the increment of salinity of lixiviant during in-situ leaching improve the permeability of the deposit. The alkalinity, hydrogen peroxide and productivity of the lixiviant cause no significant formation damage. But the fine particles in the lixiviant shows formation damage significantly, and the quantity of the particles should be controlled during production. (authors)

Prediction of calcite Cement Distribution in Shallow Marine Sandstone Reservoirs using Seismic Data

Energy Technology Data Exchange (ETDEWEB)

Bakke, N.E.

1996-12-31

This doctoral thesis investigates how calcite cemented layers can be detected by reflection seismic data and how seismic data combined with other methods can be used to predict lateral variation in calcite cementation in shallow marine sandstone reservoirs. Focus is on the geophysical aspects. Sequence stratigraphy and stochastic modelling aspects are only covered superficially. Possible sources of calcite in shallow marine sandstone are grouped into internal and external sources depending on their location relative to the presently cemented rock. Well data and seismic data from the Troll Field in the Norwegian North Sea have been analysed. Tuning amplitudes from stacks of thin calcite cemented layers are analysed. Tuning effects are constructive or destructive interference of pulses resulting from two or more closely spaced reflectors. The zero-offset tuning amplitude is shown to depend on calcite content in the stack and vertical stack size. The relationship is found by regression analysis based on extensive seismic modelling. The results are used to predict calcite distribution in a synthetic and a real data example. It is found that describing calcite cemented beds in shallow marine sandstone reservoirs is not a deterministic problem. Hence seismic inversion and sequence stratigraphy interpretation of well data have been combined in a probabilistic approach to produce models of calcite cemented barriers constrained by a maximum amount of information. It is concluded that seismic data can provide valuable information on distribution of calcite cemented beds in reservoirs where the background sandstones are relatively homogeneous. 63 refs., 78 figs., 10 tabs.

A method for automatic grain segmentation of multi-angle cross-polarized microscopic images of sandstone

Science.gov (United States)

Jiang, Feng; Gu, Qing; Hao, Huizhen; Li, Na; Wang, Bingqian; Hu, Xiumian

2018-06-01

Automatic grain segmentation of sandstone is to partition mineral grains into separate regions in the thin section, which is the first step for computer aided mineral identification and sandstone classification. The sandstone microscopic images contain a large number of mixed mineral grains where differences among adjacent grains, i.e., quartz, feldspar and lithic grains, are usually ambiguous, which make grain segmentation difficult. In this paper, we take advantage of multi-angle cross-polarized microscopic images and propose a method for grain segmentation with high accuracy. The method consists of two stages, in the first stage, we enhance the SLIC (Simple Linear Iterative Clustering) algorithm, named MSLIC, to make use of multi-angle images and segment the images as boundary adherent superpixels. In the second stage, we propose the region merging technique which combines the coarse merging and fine merging algorithms. The coarse merging merges the adjacent superpixels with less evident boundaries, and the fine merging merges the ambiguous superpixels using the spatial enhanced fuzzy clustering. Experiments are designed on 9 sets of multi-angle cross-polarized images taken from the three major types of sandstones. The results demonstrate both the effectiveness and potential of the proposed method, comparing to the available segmentation methods.

Carbon dioxide/brine wettability of porous sandstone versus solid quartz: An experimental and theoretical investigation.

Science.gov (United States)

Alnili, Firas; Al-Yaseri, Ahmed; Roshan, Hamid; Rahman, Taufiq; Verall, Michael; Lebedev, Maxim; Sarmadivaleh, Mohammad; Iglauer, Stefan; Barifcani, Ahmed

2018-08-15

Wettability plays an important role in underground geological storage of carbon dioxide because the fluid flow and distribution mechanism within porous media is controlled by this phenomenon. CO 2 pressure, temperature, brine composition, and mineral type have significant effects on wettability. Despite past research on this subject, the factors that control the wettability variation for CO 2 /water/minerals, particularly the effects of pores in the porous substrate on the contact angle at different pressures, temperatures, and salinities, as well as the physical processes involved are not fully understood. We measured the contact angle of deionised water and brine/CO 2 /porous sandstone samples at different pressures, temperatures, and salinities. Then, we compared the results with those of pure quartz. Finally, we developed a physical model to explain the observed phenomena. The measured contact angle of sandstone was systematically greater than that of pure quartz because of the pores present in sandstone. Moreover, the effect of pressure and temperature on the contact angle of sandstone was similar to that of pure quartz. The results showed that the contact angle increases with increase in temperature and pressure and decreases with increase in salinity. Copyright © 2018 Elsevier Inc. All rights reserved.

Concurrent nitrate and Fe(III) reduction during anaerobic biodegradation of phenols in a sandstone aquifer

DEFF Research Database (Denmark)

Broholm, Mette; Crouzet, C.; Arvin, Erik

2000-01-01

The biodegradation of phenols (similar to 5, 60, 600 mg 1(-1)) under anaerobic conditions (nitrate enriched and unamended) was studied in laboratory microcosms with sandstone material and groundwater from within an anaerobic ammonium plume in an aquifer, The aqueous phase was sampled and analyzed...... for phenols and selected redox sensitive parameters on a regular basis. An experiment with sandstone material from specific depth intervals from a vertical profile across the ammonium plume was also conducted. The miniature microcosms used in this experiment were sacrificed for sampling for phenols...... and selected redox sensitive parameters at the end of the experiment. The sandstone material was characterized with respect to oxidation and reduction potential and Fe(II) and Fe(III) speciation prior to use for all microcosms and at the end of the experiments for selected microcosms. The redox conditions...

A method of quantitative prediction for sandstone type uranium deposit in Russia and its application

International Nuclear Information System (INIS)

Chang Shushuai; Jiang Minzhong; Li Xiaolu

2008-01-01

The paper presents the foundational principle of quantitative predication for sandstone type uranium deposits in Russia. Some key methods such as physical-mathematical model construction and deposits prediction are described. The method has been applied to deposits prediction in Dahongshan region of Chaoshui basin. It is concluded that the technique can fortify the method of quantitative predication for sandstone type uranium deposits, and it could be used as a new technique in China. (authors)

Studies on Thiobacilli spp. isolated from sandy beaches of Kerala

Digital Repository Service at National Institute of Oceanography (India)

Gore, P.S.; Raveendran, O.; Unnithan, R.V.

Occurrence, isolation and oxidative activity of Thiobacilli spp. from some sandy beaches of Kerala are reported. These organisms were encountered in polluted beaches and were dominant during monsoon in all the beaches...

Edegbai and Emofurieta (12).cdr

African Journals Online (AJOL)

Timothy Ademakinwa

ABSTRACT. 131. INTRODUCTION. The Maastrichtian Mamu Formation has been described as a cyclotherm comprising Dark Shale, sandstones and sandy shales (with coal beds at various stratigraphic levels) deposited in a marginal marine environment (tidal flat - estuarine setting; Ladipo, 1988).This Formation exhibits.

Geology and potential of the formation of sandstone type uranium mineralization at Hatapang region, North Sumatera

International Nuclear Information System (INIS)

Ngadenin

2013-01-01

The Study based on geological setting of Hatapang region, North Sumatera, identified as a favourable area to the formation of sandstone type uranium mineralization. This characterized by the occurred of anomalous radioactivity, uranium contents of the upper cretaceous granite intrusions and radioactivity anomalous of tertiary sedimentary rocks deposited in terrestrial environments. The study is objective to find out the potential formation of sandstone type-uranium mineralization within tertiary sedimentary rocks based on data’s studies of geological, geochemical, mineralogy, radioactivity of rocks. Stratigraphy of Hatapang area of the oldest to youngest are quartz units (permian-carboniferous), sandstone units (upper Triassic), granite (upper cretaceous), conglomerate units (Lower –middle Miocene) and tuff units (Pleistocene). Hatapang’s granite is S type granite which is not only potential as source of radioactive minerals, particularly placer type monazite, but also potential as source rocks of sandstone type-uranium mineralization on lighter sedimentary rocks. Sedimentary rock of conglomerate units has potential as host rock, even though uranium did not accumulated in its rocks since the lack number of carbon as precipitant material and dissolved U"+"6 in water did not reduced into U"+"4 caused the uranium mineralization did not deposited. (author)

Storm Impact and Depression Among Older Adults Living in Hurricane Sandy-Affected Areas.

Science.gov (United States)

Sirey, Jo Anne; Berman, Jacquelin; Halkett, Ashley; Giunta, Nancy; Kerrigan, Janice; Raeifar, Elmira; Artis, Amanda; Banerjee, Samprit; Raue, Patrick J

2017-02-01

Research on the impact of natural disasters on the mental health of older adults finds both vulnerabilities and resilience. We report on the rates of clinically significant depression among older adults (aged ≥60 years) living in areas affected by Hurricane Sandy in 2012 and the factors associated with mental health need. The Sandy Mobilization, Assessment, Referral and Treatment for Mental Health (SMART-MH) program integrates community outreach and needs assessments to identify older adults with mental health and aging service needs. Older adults with significant anxiety or depressive symptoms were offered short-term psychotherapy. Social service referrals were made directly to community agencies. All SMART-MH activities were offered in Spanish, Russian, Mandarin/Cantonese, and English. Across the full sample, 14% of participants screened positive for depression. Hurricane Sandy stressors predicted increased odds of depression, including storm injury, post-storm crime, and the total count of stressors. Outcomes varied significantly by age group, such that all Sandy-related variables remained significant for younger-old adults (aged 60-74 years), whereas only the loss of access to medical care was significant for older-old adults (aged ≥75 years). Storm-affected communities show higher rates of depressive symptoms than seen in the general population, with storm stressors affecting mental health needs differentially by age group. (Disaster Med Public Health Preparedness. 2017;11:97-109).

Development and Application of Syndromic Surveillance for Severe Weather Events Following Hurricane Sandy.

Science.gov (United States)

Tsai, Stella; Hamby, Teresa; Chu, Alvin; Gleason, Jessie A; Goodrow, Gabrielle M; Gu, Hui; Lifshitz, Edward; Fagliano, Jerald A

2016-06-01

Following Hurricane Superstorm Sandy, the New Jersey Department of Health (NJDOH) developed indicators to enhance syndromic surveillance for extreme weather events in EpiCenter, an online system that collects and analyzes real-time chief complaint emergency department (ED) data and classifies each visit by indicator or syndrome. These severe weather indicators were finalized by using 2 steps: (1) key word inclusion by review of chief complaints from cases where diagnostic codes met selection criteria and (2) key word exclusion by evaluating cases with key words of interest that lacked selected diagnostic codes. Graphs compared 1-month, 3-month, and 1-year periods of 8 Hurricane Sandy-related severe weather event indicators against the same period in the following year. Spikes in overall ED visits were observed immediately after the hurricane for carbon monoxide (CO) poisoning, the 3 disrupted outpatient medical care indicators, asthma, and methadone-related substance use. Zip code level scan statistics indicated clusters of CO poisoning and increased medicine refill needs during the 2 weeks after Hurricane Sandy. CO poisoning clusters were identified in areas with power outages of 4 days or longer. This endeavor gave the NJDOH a clearer picture of the effects of Hurricane Sandy and yielded valuable state preparation information to monitor the effects of future severe weather events. (Disaster Med Public Health Preparedness. 2016;10:463-471).

Brazilian sandy beaches: characteristics, ecosystem services, impacts, knowledge and priorities

Directory of Open Access Journals (Sweden)

Antonia Cecília Zacagnini Amaral

Full Text Available ABSTRACT Sandy beaches constitute a key ecosystem and provide socioeconomic goods and services, thereby playing an important role in the maintenance of human populations and in biodiversity conservation. Despite the ecological and social importance of these ecosytems, Brazilian sandy beaches are significantly impacted by human interference, chemical and organic pollution and tourism, as well as global climate change. These factors drive the need to better understand the environmental change and its consequences for biota. To promote the implementation of integrated studies to detect the effects of regional and global environmental change on beaches and on other benthic habitats of the Brazilian coast, Brazilian marine researchers have established The Coastal Benthic Habitats Monitoring Network (ReBentos. In order to provide input for sample planning by ReBentos, we have conducted an intensive review of the studies conducted on Brazilian beaches and summarized the current knowledge about this environment. In this paper, we present the results of this review and describe the physical, biological and socioeconomics features of Brazilian beaches. We have used these results, our personal experience and worldwide literature to identify research projects that should be prioritized in the assessment of regional and global change on Brazilian sandy beaches. We trust that this paper will provide insights for future studies and represent a significant step towards the conservation of Brazilian beaches and their biodiversity.

77 FR 74891 - Order Granting Exemptions From Certain Rules of Regulation SHO Related to Hurricane Sandy

Science.gov (United States)

2012-12-18

... Client Update on Superstorm Sandy--Current and Ongoing Operations as Markets Re-Open; Physical.../downloads/legal/imp_notices/2012/dtcc/z0033.pdf ; ``DTCC Client Update on Superstorm Sandy--Physical...://www.dtcc.com/downloads/legal/imp_notices/2012/dtcc/z0035.pdf ; ``DTCC Client Update on Superstorm...

Hydrological modelling in sandstone rocks watershed

Science.gov (United States)

Ponížilová, Iva; Unucka, Jan

2015-04-01

The contribution is focused on the modelling of surface and subsurface runoff in the Ploučnice basin. The used rainfall-runoff model is HEC-HMS comprising of the method of SCS CN curves and a recession method. The geological subsurface consisting of sandstone is characterised by reduced surface runoff and, on the contrary, it contributes to subsurface runoff. The aim of this paper is comparison of the rate of influence of sandstone on reducing surface runoff. The recession method for subsurface runoff was used to determine the subsurface runoff. The HEC-HMS model allows semi- and fully distributed approaches to schematisation of the watershed and rainfall situations. To determine the volume of runoff the method of SCS CN curves is used, which results depend on hydrological conditions of the soils. The rainfall-runoff model assuming selection of so-called methods of event of the SCS-CN type is used to determine the hydrograph and peak flow rate based on simulation of surface runoff in precipitation exceeding the infiltration capacity of the soil. The recession method is used to solve the baseflow (subsurface) runoff. The method is based on the separation of hydrograph to direct runoff and subsurface or baseflow runoff. The study area for the simulation of runoff using the method of SCS CN curves to determine the hydrological transformation is the Ploučnice basin. The Ploučnice is a hydrologically significant river in the northern part of the Czech Republic, it is a right tributary of the Elbe river with a total basin area of 1.194 km2. The average value of CN curves for the Ploučnice basin is 72. The geological structure of the Ploučnice basin is predominantly formed by Mesozoic sandstone. Despite significant initial loss of rainfall the basin response to the causal rainfall was demonstrated by a rapid rise of the surface runoff from the watershed and reached culmination flow. Basically, only surface runoff occures in the catchment during the initial phase of

Selected trace and minor elements in sandstones from Paraguay

International Nuclear Information System (INIS)

Facetti-Masulli, J.F.; Gonzalez, E.; Kump, P.

2010-01-01

Selected trace and minor elements analyzed by XRF in sandstone samples were Rb-Sr-Zr-Nb-Ba-La-Ce-Nd as well as Ti-Mn-Fe with which they are often correlated. Refractory elements like REE are considered useful indicators of geochemical processes and, in this case, of provenance. Usually they maintain their original relationships and are transferred almost directly into sediments. The values here found, absolute and normalized, show correlations among the samples, allowing the establishment of their origin. Most of them in the spidergram patterns display positive spikes of Zr, and negative anomalies at Nb, Sr, Ti: differences in their height/depth could be in relation with the different Series or Formations. Strikingly, spidergrams of samples collected from the Patino Formation show marked negative anomalies interalia of Ba, as well as positive spikes of Nb and Zr, very similar to those found in magmatic specimens from Misiones, Carapegua-Acahay and Alto Paraguay Province and quite different from the other analyzed samples. In addition a remarkable presence of Precambrian signatures were found in the analyzed sandstones from the Paleozoic. (orig.)

Selected trace and minor elements in sandstones from Paraguay

Energy Technology Data Exchange (ETDEWEB)

Facetti-Masulli, J.F.; Gonzalez, E. [Hydroconsult SRL, Asuncion (Paraguay); Kump, P. [J. Stefan Inst., Ljubljana (Slovenia)

2010-07-01

Selected trace and minor elements analyzed by XRF in sandstone samples were Rb-Sr-Zr-Nb-Ba-La-Ce-Nd as well as Ti-Mn-Fe with which they are often correlated. Refractory elements like REE are considered useful indicators of geochemical processes and, in this case, of provenance. Usually they maintain their original relationships and are transferred almost directly into sediments. The values here found, absolute and normalized, show correlations among the samples, allowing the establishment of their origin. Most of them in the spidergram patterns display positive spikes of Zr, and negative anomalies at Nb, Sr, Ti: differences in their height/depth could be in relation with the different Series or Formations. Strikingly, spidergrams of samples collected from the Patino Formation show marked negative anomalies interalia of Ba, as well as positive spikes of Nb and Zr, very similar to those found in magmatic specimens from Misiones, Carapegua-Acahay and Alto Paraguay Province and quite different from the other analyzed samples. In addition a remarkable presence of Precambrian signatures were found in the analyzed sandstones from the Paleozoic. (orig.)

Bacterial polyextremotolerant bioemulsifiers from arid soils improve water retention capacity and humidity uptake in sandy soil

KAUST Repository

Raddadi, Noura

2018-05-31

Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils.From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls.Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.

Bacterial polyextremotolerant bioemulsifiers from arid soils improve water retention capacity and humidity uptake in sandy soil

KAUST Repository

Raddadi, Noura; Giacomucci, Lucia; Marasco, Ramona; Daffonchio, Daniele; Cherif, Ameur; Fava, Fabio

2018-01-01

Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils.From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls.Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.

Bacterial polyextremotolerant bioemulsifiers from arid soils improve water retention capacity and humidity uptake in sandy soil.

Science.gov (United States)

Raddadi, Noura; Giacomucci, Lucia; Marasco, Ramona; Daffonchio, Daniele; Cherif, Ameur; Fava, Fabio

2018-05-31

Water stress is a critical issue for plant growth in arid sandy soils. Here, we aimed to select bacteria producing polyextremotolerant surface-active compounds capable of improving water retention and humidity uptake in sandy soils. From Tunisian desert and saline systems, we selected eleven isolates able to highly emulsify different organic solvents. The bioemulsifying activities were stable with 30% NaCl, at 4 and 120 °C and in a pH range 4-12. Applications to a sandy soil of the partially purified surface-active compounds improved soil water retention up to 314.3% compared to untreated soil. Similarly, after 36 h of incubation, the humidity uptake rate of treated sandy soil was up to 607.7% higher than untreated controls. Overall, results revealed that polyextremotolerant bioemulsifiers of bacteria from arid and desert soils represent potential sources to develop new natural soil-wetting agents for improving water retention in arid soils.

Sediment Chemistry and Toxicity in Barnegat Bay, New Jersey: Pre- and Post- Hurricane Sandy, 2012-2013.

Science.gov (United States)

Romanok, Kristin M.; Szabo, Zoltan; Reilly, Timothy J.; Defne, Zafer; Ganju, Neil K.

2016-01-01

Hurricane Sandy made landfall in Barnegat Bay, October, 29, 2012, damaging shorelines and infrastructure. Estuarine sediment chemistry and toxicity were investigated before and after to evaluate potential environmental health impacts and to establish post-event baseline sediment-quality conditions. Trace element concentrations increased throughout Barnegat Bay up to two orders of magnitude, especially north of Barnegat Inlet, consistent with northward redistribution of silt. Loss of organic compounds, clay, and organic carbon is consistent with sediment winnowing and transport through the inlets and sediment transport modeling results. The number of sites exceeding sediment quality guidance levels for trace elements tripled post-Sandy. Sediment toxicity post-Sandy was mostly unaffected relative to pre-Sandy conditions, but at the site with the greatest relative increase for trace elements, survival rate of the test amphipod decreased (indicating degradation). This study would not have been possible without comprehensive baseline data enabling the evaluation of storm-derived changes in sediment quality.

Macrofauna and meiofauna of two sandy beaches at Mombasa, Kenya

Digital Repository Service at National Institute of Oceanography (India)

Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

Macrofauna and meiofauna of 2 sandy beaches having medium and fine sand particles, respectively, were investigated, quantitatively Macrofauna density was highest around high water mark and progressively decreased towards low water mark Meiofauna...

Digital Rock Physics Aplications: Visualisation Complex Pore and Porosity-Permeability Estimations of the Porous Sandstone Reservoir

Science.gov (United States)

Handoyo; Fatkhan; Del, Fourier

2018-03-01

Reservoir rock containing oil and gas generally has high porosity and permeability. High porosity is expected to accommodate hydrocarbon fluid in large quantities and high permeability is associated with the rock’s ability to let hydrocarbon fluid flow optimally. Porosity and permeability measurement of a rock sample is usually performed in the laboratory. We estimate the porosity and permeability of sandstones digitally by using digital images from μCT-Scan. Advantages of the method are non-destructive and can be applied for small rock pieces also easily to construct the model. The porosity values are calculated by comparing the digital image of the pore volume to the total volume of the sandstones; while the permeability values are calculated using the Lattice Boltzmann calculations utilizing the nature of the law of conservation of mass and conservation of momentum of a particle. To determine variations of the porosity and permeability, the main sandstone samples with a dimension of 300 × 300 × 300 pixels are made into eight sub-cubes with a size of 150 × 150 × 150 pixels. Results of digital image modeling fluid flow velocity are visualized as normal velocity (streamline). Variations in value sandstone porosity vary between 0.30 to 0.38 and permeability variations in the range of 4000 mD to 6200 mD. The results of calculations show that the sandstone sample in this research is highly porous and permeable. The method combined with rock physics can be powerful tools for determining rock properties from small rock fragments.

Aggregations of the sandy-beach isopod, Tylos granulatus ...

African Journals Online (AJOL)

... lives as a scavenger in the intertidal zone of sandy beaches on the west coast of South Africa. Individuals emerge with the receding tide leaving exit holes, then forage for about two hours before returning to the vicinity of the high-water mark where they aggregate to bury themselves, leaving behind cone-shaped mounds.

Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

International Nuclear Information System (INIS)

Tan Chenglong

2006-01-01

The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

Long-Term Observations of Dust Storms in Sandy Desert Environments

Science.gov (United States)

Yun, Hye-Won; Kim, Jung-Rack; Choi, Yun-Soo

2015-04-01

Mineral dust occupies the largest portion of atmospheric aerosol. Considering the numerous risks that dust poses for socioeconomic and anthropogenic activities, it is crucial to understand sandy desert environments, which frequently generate dust storms and act as a primary source of atmospheric aerosol. To identify mineral aerosol mechanisms, it is essential to monitor desert environmental factors involving dust storm generation in the long term. In this study, we focused on two major environmental factors: local surface roughness and soil moisture. Since installments of ground observation networks in sandy deserts are unfeasible, remote sensing techniques for mining desert environmental factors were employed. The test area was established within the Badain Jaran and Kubuqi Deserts in Inner Mongolia, China, where significant seasonal aeolian processes emit mineral dust that influences all of East Asia. To trace local surface roughness, we employed a multi-angle imaging spectroradiometer (MISR) image sequence to extract multi-angle viewing (MAV) topographic parameters such as normalized difference angular index, which represents characteristics of the target desert topography. The backscattering coefficient from various space-borne SAR and stereotopography were compared with MAV observations to determine calibrated local surface roughness. Soil moisture extraction techniques from InSAR-phase coherence stacks were developed and compiled with advanced scatterometer (ASCAT) soil moisture data. Combined with metrological information such as the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA interim, correlations between intensity of sand dune activity as a proxy of aeolian processes in desert environments, surface wind conditions, and surface soil moisture were traced. Overall, we have confirmed that tracking sandy desert aeolian environments for long-term observations is feasible with space-borne, multi-sensor observations when combined with

Characterization of application of acu sandstone in ceramic mass; Caracterizacao da aplicacao do arenito acu na massa ceramica

Energy Technology Data Exchange (ETDEWEB)

Nobrega, L.F.P.M.; Souza, M.M.; Gomes, Y.S.; Fernandes, D.L., E-mail: junior.luiz09@hotmail.com [Universidade Federal do Rio Grande do Norte (DIAREN/UFRN), Natal, RN (Brazil). Laboratorio de Processamento Mineral e Residuo

2016-07-01

The sandstone is a sedimentary rock formed mainly by quartz grains. In Rio Grande do Norte, there is the Potiguar Basin with the Jandaira and Acu Formations. The latter consists of thick layers of whitish-colored sandstones. It stands out as a water storage facility in the state, but it is also used for building aggregates. This article aimed at the use of the sandstone of this formation in the ceramic mass for coating. Initially, the material was sampled. It went through the comminution process to achieve the required granulometry. After this, three formulations were made to incorporate this new material into the traditional ones. The methods were performed according to ISO 13816. After sintering at 1200 °C, the specimens were subjected to the physical tests. A positive result was obtained for the use of the Acu sandstone in low concentrations. It is clear, therefore, its use in ceramics for coating.

ACHIEVEMENTS AND PERSPECTIVES ON STONE FRUIT GROWING ON SANDY SOILS

Directory of Open Access Journals (Sweden)

Anica Durău

2012-01-01

Full Text Available Climatic conditions in the sandy soils of southern Oltenia encourage cultivation of tree species in terms of applying specific technologies. Possibility of poor sandy soils fertile capitalization, earliness in 7- 10 days of fruit ripening , high yields and quality are the main factors supporting the development of fruit growing in the sandy soils of southern Oltenia. The main objectives of the research were to CCDCPN Dăbuleni. Establish and improve stone fruit species assortment, adapted to the stress of the sandy soils, establishment and evaluation of the influence of stress on trees and their influence on the size and quality of production, development of technological links (planting distances, forms management, fertilization, getting high and consistent annual production of high quality, containing low as pesticide residues, to establish a integrated health control program of the trees with emphasis on biotechnical. Research has shown good stone species behavior, and their recommended proportion is 75% of all fruit trees (peach 36%, 14% apricot, plum15%, sweet and sour cherry fruit growing 10% of the total area. Results on peach varieties revealed: ’Redhaven’, ’Suncrest’, ’Loring’ with yields ranging from (24.8 t / ha to 29.0 t/ha with maturation period from July to August, and varieties ’NJ 244’, ’Fayette’, ’Flacara’ with productions ranging from (19.7 t / ha to 23.0 t/ha with maturation period from August to September. The sweet cherry varieties ’Van’, ’Rainier’, ’Stella’, with yields ranging from 17. 2 to 24.4 t / ha. In the range studied sour cherry were found ’Oblacinska’ varieties of 11.0 t / ha, ’Cernokaia’ with 10.5 t / ha, ’Schatten Morelle’ with 9.1 t / ha. Optimum planting density and shape of the peach crown found that the highest yields of fruit are produced in the form of vertical cordon crown, with values ranging from 15.9 t / ha at a distance of 2 m, 10.3 t / ha at a distance

Provenance, diagenesis, tectonic setting and reservoir quality of the sandstones of the Kareem Formation, Gulf of Suez, Egypt

Science.gov (United States)

Zaid, Samir M.

2013-09-01

The Middle Miocene Kareem sandstones are important oil reservoirs in the southwestern part of the Gulf of Suez basin, Egypt. However, their diagenesis and provenance and their impact on reservoir quality, are virtually unknown. Samples from the Zeit Bay Oil Field, and the East Zeit Oil Field represent the Lower Kareem (Rahmi Member) and the Upper Kareem (Shagar Member), were studied using a combination of petrographic, mineralogical and geochemical techniques. The Lower Rahmi sandstones have an average framework composition of Q95F3.4R1.6, and 90% of the quartz grains are monocrystalline. By contrast, the Upper Shagar sandstones are only slightly less quartzose with an average framework composition of Q76F21R3 and 82% of the quartz grains are monocrystalline. The Kareem sandstones are mostly quartzarenite with subordinate subarkose and arkose. Petrographical and geochemical data of sandstones indicate that they were derived from granitic and metamorphic terrains as the main source rock with a subordinate quartzose recycled sedimentary rocks and deposited in a passive continental margin of a syn rift basin. The sandstones of the Kareem Formation show upward decrease in maturity. Petrographic study revealed that dolomite is the dominant cement and generally occurs as fine to medium rhombs pore occluding phase and locally as a grain replacive phase. Authigenic quartz occurs as small euhedral crystals, locally as large pyramidal crystals in the primary pores. Authigenic anhydrites typically occur as poikilotopic rhombs or elongate laths infilling pores but also as vein filling cement. The kaolinite is a by-product of feldspar leaching in the presence of acidic fluid produced during the maturation of organic matter in the adjacent Miocene rocks. Diagenetic features include compaction; dolomite, silica and anhydrite cementation with minor iron-oxide, illite, kaolinite and pyrite cements; dissolution of feldspars, rock fragments. Silica dissolution, grain replacement and

Diagenesis, provenance and depositional environments of the Bunter Sandstone Formation

DEFF Research Database (Denmark)

Olivarius, Mette; Weibel, Rikke; Friis, Henrik

The Bunter Sandstone Formation in the northern North German Basin has large geothermal potential with high porosity and permeability (generally >15% and >100 mD, respectively) and with pore fluid temperatures that are adequate for geothermal energy production (c. 55–60˚C). A combined investigation...

Use of dolomite phosphate rock (DPR) fertilizers to reduce phosphorus leaching from sandy soil

International Nuclear Information System (INIS)

Chen, G.C.; He, Z.L.; Stoffella, P.J.; Yang, X.E.; Yu, S.; Calvert, D.

2006-01-01

There is increasing concern over P leaching from sandy soils applied with water-soluble P fertilizers. Laboratory column leaching experiments were conducted to evaluate P leaching from a typical acidic sandy soil in Florida amended with DPR fertilizers developed from dolomite phosphate rock (DPR) and N-Viro soil. Ten leaching events were carried out at an interval of 7 days, with a total leaching volume of 1183 mm equivalent to the mean annual rainfall of this region during the period of 2001-2003. Leachates were collected and analyzed for total P and inorganic P. Phosphorus in the leachate was dominantly reactive, accounting for 67.7-99.9% of total P leached. Phosphorus leaching loss mainly occurred in the first three leaching events, accounting for 62.0-98.8% of the total P leached over the whole period. The percentage of P leached (in the total P added) from the soil amended with water-soluble P fertilizer was higher than those receiving the DPR fertilizers. The former was up to 96.6%, whereas the latter ranged from 0.3% to 3.8%. These results indicate that the use of N-Viro-based DPR fertilizers can reduce P leaching from sandy soils. - Fertilizers developed from dolomite phosphate rock (DPR) reduce phosphorus leaching from sandy soil

Lack of inhibiting effect of oil emplacement on quartz cementation: Evidence from Cambrian reservoir sandstones, Paleozoic Baltic Basin

DEFF Research Database (Denmark)

Molenaar, Nicolaas; Cyziene, Jolanta; Sliaupa, Saulius

2008-01-01

Currently, the question of whether or not the presence of oil in sandstone inhibits quartz cementation and preserves porosity is still debated. Data from a number of Cambrian sandstone oil fields and dry fields have been studied to determine the effects of oil emplacement on quartz cementation. T...

High-resolution 3D X-ray microtomography as tool to investigate size distribution of grain phase and pore space in sandstones

Science.gov (United States)

Kahl, Wolf-Achim; Holzheid, Astrid

2013-04-01

The geometry and internal structures of sandstone reservoirs, like grain size, sorting, degree of bioturbation, and the history of the diagenetic alterations determine the quantity, flow rates, and recovery of hydrocarbons present in the pore space. In this respect, processes influencing the deep reservoir quality in sandstones are either of depositional, shallow diagenetic, or deep-burial origin. To assess the effect of compaction and cementation on the pore space during diagenesis, we investigated a set of sandstone samples using high-resolution microtomography (µ-CT). By high-resolution µ-CT, size distributions (in 2D and 3D), surface areas and volume fractions of the grain skeleton and pore space of sandstones and - in addition - of mineral powders have been determined. For this study, we analysed aliquots of sandstones that exhibit either complete, partial or no cemententation of the pore space, and sets of mineral powders (quartz, feldspar, calcite). As the resolution of the µ-CT scans is in the µm-range, the surface areas determined for sandstones and powders do detect the geometric surface of the material (Kahl & Holzheid, 2010). Since there are differing approaches to "size" parameters like e.g., long/short particle axes, area equivalent radius, Feret-diameter (2D), and structural thickness (3D), we decided to illustrate the effect of various size determinations for (a) single grains, (b) grain skeletons, and (c) pore space. Therefor, the computer-aided morphometric analysis of the segmented 3D models of the reconstructed scan images comprises versatile calculation algorithms. For example, size distribution of the pore space of partially cemented sandstones can be used to infer the timing of the formation of the cement in respect to tectonic/diagenetic activities. In the case of a late-stage partial cementation of a Bunter sandstone, both pore space and cement phase show identical size distributions. On the contrary, the anhydrite cement of a

Assessment of marine and urban-industrial environments influence on built heritage sandstone using X-ray fluorescence spectroscopy and complementary techniques

Science.gov (United States)

Morillas, Héctor; García-Galan, Javier; Maguregui, Maite; Marcaida, Iker; García-Florentino, Cristina; Carrero, Jose Antonio; Madariaga, Juan Manuel

2016-09-01

The sandstone used in the construction of the tower of La Galea Fortress (Getxo, north of Spain) shows a very bad conservation state and a high percentage of sandstone has been lost. The fortress is located just on a cliff and close to the sea, and it experiments the direct influence of marine aerosol and also the impact of acid gases (SOx and NOx) coming from the surrounding industry and maritime traffic. This environment seems to be very harmful for the preservation of the sandstone used in it, promoting different pathologies (disintegration, alveolization, cracking or erosion blistering, salts crystallization on the pores, efflorescences etc.). In this work, a multianalytical methodology based on a preliminary in-situ screening of the affected sandstone using a handheld energy dispersive X-ray fluorescence spectrometer (HH-ED-XRF) and a subsequent characterization of extracted sample in the laboratory using elemental (μ-ED-XRF, Scanning Electron Microscope coupled to an X-Max Energy-Dispersive (SEM-EDS) and Inductively coupled plasma mass spectrometry (ICP-MS)) and molecular techniques (micro-Raman spectroscopy (μ-RS) and X-ray Diffraction (XRD)) was applied in order to characterize the original composition of this kind of stone and related deterioration products. With the whole methodology, it was possible to assess that the sandstone contain a notable percentage of calcite. The sulfation and nitration of this carbonate detected in the stone led to the dissolution process of the sandstone, promoting the observed material loss. Additionally, the presence of salts related with the influence of marine aerosol confirms that this kind of environment have influence on the conservation state of the sandstone building.

Measurement and modelling of evapotranspiration in three fynbos vegetation types

CSIR Research Space (South Africa)

Dzikiti, Sebinasi

2014-04-01

Full Text Available sites. In this study we determined water use by 3 fynbos vegetation types growing at 4 different sites, namely: (i) lowland Atlantis Sand Plain fynbos growing on deep sandy soils, (ii) Kogelberg Sandstone fynbos growing in a riparian zone on deep...

REE characteristics and uranium metallogenesis of sandstone-type uranium deposits in northern Sichuan

International Nuclear Information System (INIS)

Zhu Xiyang; Wang Yunliang; Wang Zhichang; Zhang Chengjiang

2004-01-01

On the basis of the analysis of a large number of samples at sandstone-type uranium deposits in northern Sichuan, this paper analyses the REE composition of country rocks, ores, calcite-veins and uranium minerals, and systematically summarizes their REE geochemical characteristics, and discusses variation regularity of REE during depositional and diagenetic processes. By comparing these characteristics with those of typical hydrothermal volcanics-type and metamorphic rock type uranium deposits both at home and abroad, authors suggest that sandstone-type uranium deposits in northern Sichuan are characterized by REE geochemical features of hydrothermal reworking metallogenesis, the uranium mineralization has experienced two stages: the diagenetic preconcentration and the concentration of hydrothermal reworking

Wettability of Chalk and Argillaceous Sandstones Assessed from T1/T2 Ratio

DEFF Research Database (Denmark)

Katika, Konstantina; Saidian, M.; Fabricius, Ida Lykke

ratio can quantify the affinity between the rock and wetting pore fluid. The affinity is a measure directly linked to wettability. In order to investigate the T2-shortening, we performed T1-T2 NMR experiments on different samples of chalk, Berea sandstone, and chloritic greensand, saturated either...... with water, oil or oil/water at irreducible water saturation. The T1/T2 ratio obtained from T1-T2 maps reflects the T2-shortening. We compare the T1/T2 ratio for the same type of rock, saturated with different fluids. The chalk shows high affinity for water, Berea sandstone has no clear preference for oil...

Superstorm Sandy and the academic achievement of university students.

Science.gov (United States)

Doyle, Matthew D; Lockwood, Brian; Comiskey, John G

2017-10-01

Much of the literature on the consequences of natural disasters has focused on their physical and psychological ramifications. Few researchers have considered how the impacts of a natural disaster can influence academic achievement. This study analyses data collected from nearly 300 students at a mid-sized, private university in the northeast United States to determine if the effects of Cyclone Sandy in 2012 are associated with measures of academic achievement. The findings reveal that experiencing headaches after the event resulted in a higher likelihood of students suffering a loss of academic motivation. In addition, experiencing headaches and a loss of academic motivation were correlated with a lower grade point average (GPA) during the semester in which Sandy made landfall. However, the more direct effects of the superstorm, including displacement and a loss of power, did not have a significant bearing on academic achievement. Lastly, the paper examines the implications for higher education policy and future research. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

Permeability model of tight reservoir sandstones combining core-plug and miniperm analysis of drillcore; longyearbyen co2lab, Svalbard

NARCIS (Netherlands)

Magnabosco, Cara; Braathen, Alvar; Ogata, Kei

2014-01-01

Permeability measurements in Mesozoic, low-permeability sandstone units within the strata cored in seven drillholes near Longyearbyen, Svalbard, have been analysed to assess the presence of aquifers and their potentials as reservoirs for the storage of carbon dioxide. These targeted sandstones are

Effect of Crushed Sandstone Sand on the Properties of High ...

African Journals Online (AJOL)

This paper presents results of the laboratory investigation on high performance concrete (HPC) using crushed sandstone sand as 20%, 40%, and 60% replacement of river sand together with superplastisizer and silica fume (SF). The fresh concrete properties such as slump, air content and fresh concrete density have been ...

Aeromagnetic gradient survey used in sandstone type uranium deposits prospecting

International Nuclear Information System (INIS)

Li Xiaolu; Chang Shushuai

2014-01-01

The principle, advantage and data processing of aeromagnetic gradient survey approach is introduced in this paper which was used in sandstone type uranium deposits prospecting to study the shallow surface faults, uranium ore-forming environment and depth of magnetic body, which proved to be a good results. (authors)

Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms

Directory of Open Access Journals (Sweden)

Rebecca M. Schwartz

2017-08-01

Full Text Available Hurricane Sandy hit the eastern coast of the United States in October 2012, causing billions of dollars in damage and acute physical and mental health problems. The long-term mental health consequences of the storm and their predictors have not been studied. New York City and Long Island residents completed questionnaires regarding their initial Hurricane Sandy exposure and mental health symptoms at baseline and 1 year later (N = 130. There were statistically significant decreases in anxiety scores (mean difference = −0.33, p < 0.01 and post-traumatic stress disorder (PTSD scores (mean difference = −1.98, p = 0.001 between baseline and follow-up. Experiencing a combination of personal and property damage was positively associated with long-term PTSD symptoms (ORadj 1.2, 95% CI [1.1–1.4] but not with anxiety or depression. Having anxiety, depression, or PTSD at baseline was a significant predictor of persistent anxiety (ORadj 2.8 95% CI [1.1–6.8], depression (ORadj 7.4 95% CI [2.3–24.1 and PTSD (ORadj 4.1 95% CI [1.1–14.6] at follow-up. Exposure to Hurricane Sandy has an impact on PTSD symptoms that persists over time. Given the likelihood of more frequent and intense hurricanes due to climate change, future hurricane recovery efforts must consider the long-term effects of hurricane exposure on mental health, especially on PTSD, when providing appropriate assistance and treatment.

Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil.

Science.gov (United States)

Zhuang, Wenhua; Li, Longguo; Liu, Chao

2013-01-01

Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%.

Modal analysis and geochemistry of two sandstones of the Bhander ...

Indian Academy of Sciences (India)

and tectonic setting interpretations are based on modal analysis and whole rock geochemistry. The average ... that major part of the sediments were derived from the granitic source area. The sandstone ...... The geochemical gap shown by trace and rare ... of the Council of Scientific and Industrial Research,. New Delhi, in ...

Provenance of sandstone on the western flank of Anambra Basin ...

African Journals Online (AJOL)

Petrographic and heavy mineral studies were carried out on clastic deposits that crop out in Ikpeshi, Auchi and Fugar localities in order to determine the provenance of the ... The heavy mineral suites and the petrographic signatures of the sandstones suggest derivation mainly from acid igneous rocks, gneisses and older ...

Mineralogical and Micro-fabric investigation of the Sandy Facies of Opalinus Clay (Mont Terri)

International Nuclear Information System (INIS)

Kaufhold, Annette; Siegesmund, Siegfried; Dohrmann, Reiner; Graesle, Werner; Plischke, Ingo

2013-01-01

In the field of geological disposal of radioactive waste in many countries argillaceous formations are considered as potential host rock. For the understanding of the long-term behaviour of clay host rock, it is important to understand the interaction between mechanical behaviour, micro-fabric, and mineral composition. Previous publications showed that particularly the carbonate content and the arrangement of the carbonate grains (as cement in the matrix or as shells) determines the mechanical strength of Opalinus Clay and Callovo-Oxfordian Clay specimens, respectively. Klinkenberg et al. (2009) studied the shaly facies of Opalinus Clay, however, the actual deposit is planned to be built in the sandy facies of Opalinus Clay. The aim of the present study is to investigate the relation between micro-fabric, mineral composition, and mechanical properties of different samples derived from the sandy facies (BLT-A2). Image analysis showed that the carbonates in the sandy facies mainly occur as 1) matrix which in turn acts as cement. Carbonates also occur 2) in the fine sand fraction and 3) biogenic carbonates as traces. The carbonates of the sandy facies, therefore, appear to be similar to the carbonates of the Callovo-Oxfordian Clay with respect to their possible influence on failure strength. The mechanical testing showed that the shear strength increases with increasing carbonate content. This phenomenon was also observed for the samples of the Callovo-Oxfordian Clay, while the opposite relation was found for the shaly facies of the Opalinus Clay. Preliminary results presented here, indicate that the sandy facies (drilling BLT-A2) and Callovo-Oxfordian Clay show similar mechanical properties - in detail: 1) Micro-fabric: carbonates predominate in the matrix, 2) Mineralogy: high carbonate content and 3) Mechanical testing: shear strength increases with increasing carbonate content, where the type of carbonates which controls the increase of strength has to be

Replacement of Eocene white sandy limestone in historical buildings : over 100 years of practice in the Netherlands

NARCIS (Netherlands)

Quist, W.J.; Nijland, T.G.; Hees, R.P.J. van

2013-01-01

This paper discusses the replacement of white sandy limestone (Gobertange and Lede or Balegem) in the Netherlands in (successive) restorations from the mid-19th century onwards. White sandy limestone, transported from the southern part of the Low Countries (now Belgium), was extensively used in the

Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

DEFF Research Database (Denmark)

Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan

2001-01-01

Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The fin...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium.......Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...

Morphology of channels and channel-sand bodies in the Glauconitic sandstone member (Upper Mannville), Little Bow area, Alberta

Energy Technology Data Exchange (ETDEWEB)

Hopkins, J.C.; Hermanson, S.W.; Lawton, D.C.

1982-12-01

Large channels in the Glauconitic sandstone member of southern Alberta have proved to be difficult exploration targets because of an irregular distribution of reservoir sands within the channels. In the Little Bow area, two channels are present in the lower part of the Glauconitic member and have cut into the underlying Calcareous member. The channels can be recognized where they truncate regional markers of the Calcareous member -- the Bantry shale and Ostracod limestone, and where channel-fill deposits exhibit uniform geophysical log characters, indicating sandstone- or mudstone-filled reaches. Sediments of the Glauconitic member adjacent to the channels comprise a series of splay sandstones and mudstones that prograded into interdistributary bays of the lower delta plain. The two channels associated with these deposits are interpreted as distributary channels. Sand bodies within the channels formed as lateral bars and are isolated by mudstones which mark the abandoned stream course. Geological exploration for these discontinuous channel sandstones is difficult, and high-resolutio seismic data integrated with sound geologic modelling are critical for successful prospect delineation.

Experimental study and theoretical interpretation of saturation effect on ultrasonic velocity in tight sandstones under different pressure conditions

Science.gov (United States)

Li, Dongqing; Wei, Jianxin; Di, Bangrang; Ding, Pinbo; Huang, Shiqi; Shuai, Da

2018-03-01

Understanding the influence of lithology, porosity, permeability, pore structure, fluid content and fluid distribution on the elastic wave properties of porous rocks is of great significance for seismic exploration. However, unlike conventional sandstones, the petrophysical characteristics of tight sandstones are more complex and less understood. To address this problem, we measured ultrasonic velocity in partially saturated tight sandstones under different effective pressures. A new model is proposed, combining the Mavko-Jizba-Gurevich relations and the White model. The proposed model can satisfactorily simulate and explain the saturation dependence and pressure dependence of velocity in tight sandstones. Under low effective pressure, the relationship of P-wave velocity to saturation is pre-dominantly attributed to local (pore scale) fluid flow and inhomogeneous pore-fluid distribution (large scale). At higher effective pressure, local fluid flow gradually decreases, and P-wave velocity gradually shifts from uniform saturation towards patchy saturation. We also find that shear modulus is more sensitive to saturation at low effective pressures. The new model includes wetting ratio, an adjustable parameter that is closely related to the relationship between shear modulus and saturation.

Application of anatectic mineralization to prospecting in-situ leachable sandstone type uranium ore in South Songliao Basin

International Nuclear Information System (INIS)

Zhao Zhonghua

2001-01-01

The deep ore-forming origin is a new theory for prospecting in-situ leachable sandstone type uranium. Tectonics, lithologic and geochemistry are basic forecasting criteria. Previous unconsolidated sand, source area and geochemical barrier are three essential conditions for forming uranium deposit. Metallogenic environment and prospective region are found. Tertiary system is prospective layer for prospecting in-situ leachable sandstone type uranium ore in south Songliao Basin

2012 USACE Post Sandy Topographic LiDAR: Virginia and Maryland

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: VIRGINIA AND MARYLAND LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X2314841 Woolpert Project...

Effect of modified ethylsilicate consolidants on the mechanical properties of sandstone

Czech Academy of Sciences Publication Activity Database

Remzová, Monika; Šašek, Petr; Frankeová, Dita; Slížková, Zuzana; Rathouský, Jiří

2016-01-01

Roč. 112, JUN 2016 (2016), s. 674-681 ISSN 0950-0618 R&D Projects: GA MK(CZ) DF11P01OVV012 Keywords : sandstones * ethylsilicate consolidant * sol-gel process Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.169, year: 2016

Pore Fluid Effects on Shear Modulus for Sandstones with Soft Anisotropy

International Nuclear Information System (INIS)

Berryman, J G

2004-01-01

A general analysis of poroelasticity for vertical transverse isotropy (VTI) shows that four eigenvectors are pure shear modes with no coupling to the pore-fluidmechanics. The remaining two eigenvectors are linear combinations of pure compression and uniaxial shear, both of which are coupled to the fluid mechanics. After reducing the problem to a 2x2 system, the analysis shows in a relatively elementary fashion how a poroelastic system with isotropic solid elastic frame, but with anisotropy introduced through the poroelastic coefficients, interacts with the mechanics of the pore fluid and produces shear dependence on fluid properties in the overall mechanical system. The analysis shows, for example, that this effect is always present (though sometimes small in magnitude) in the systems studied, and can be quite large (up to a definite maximum increase of 20 per cent) in some rocks--including Spirit River sandstone and Schuler-Cotton Valley sandstone

Monitoring CO2 penetration and storage in the brine-saturated low permeable sandstone by the geophysical exploration technologies

Science.gov (United States)

Honda, H.; Mitani, Y.; Kitamura, K.; Ikemi, H.; Imasato, M.

2017-12-01

Carbon dioxide (CO2) capture and storage (CCS) plays a vital role in reducing greenhouse gas emissions. In the northern part of Kyushu region of Japan, complex geological structure (Coalfield) is existed near the CO2 emission source and has 1.06 Gt of CO2 storage capacity. The geological survey shows that these layers are formed by low permeable sandstone. It is necessary to monitor the CO2 behavior and clear the mechanisms of CO2 penetration and storage in the low permeable sandstone. In this study, measurements of complex electrical impedance (Z) and elastic wave velocity (P-wave velocity: Vp) were conducted during the supercritical CO2 injection experiment into the brine-saturated low permeable sandstone. The experiment conditions were as follows; Confining pressure: 20 MPa, Initial pore pressure: 10 MPa, 40 °, CO2 injection rate: 0.01 to 0.5 mL/min. Z was measured in the center of the specimen and Vp were measured at three different heights of the specimen at constant intervals. In addition, we measured the longitudinal and lateral strain at the center of the specimen, the pore pressure and CO2 injection volume (CO2 saturation). During the CO2 injection, the change of Z and Vp were confirmed. In the drainage terms, Vp decreased drastically once CO2 reached the measurement cross section.Vp showed the little change even if the flow rate increased (CO2 saturation increased). On the other hand, before the CO2 front reached, Z decreased with CO2-dissolved brine. After that, Z showed continuously increased as the CO2 saturation increased. From the multi-parameter (Hydraulic and Rock-physics parameters), we revealed the detail CO2 behavior in the specimen. In the brine-saturated low permeable sandstone, the slow penetration of CO2 was observed. However, once CO2 has passed, the penetration of CO2 became easy in even for brine-remainded low permeable sandstone. We conclude low permeable sandstone has not only structural storage capacity but also residual tapping

Sandstone uranium deposits: analogues for surf disposal in some sedimentary rocks

International Nuclear Information System (INIS)

Brookins, D.G.

1987-01-01

Sandstone uranium deposits are well suited as analogs for SURF. These deposits typically occur as tabular or lensoid masses of uraniferous sandstone, commonly where the argillaceous mineral and organic content is high. Primary minerals consist of pitchblende and/or coffinite, with possibly some urano-organic phases as well. The ore is usually associated with authigenic ferromagnesian clay minerals, such as chlorite and/or authigenic illite and/or mixed layer smectite-illite; and with pyrite ± jordisite ± seleniferrous species ± calcite. Organic matter is usually associated with the ore. The clay minerals in the ore zones are commonly vanadiferrous. The genesis of the sandstone uranium deposits is now fairly well understood and allows semi-quantitative estimates to be placed on behaviour of analog-elements for many constituents of SURF (or HLW). Prior to mineralization, oxidized species of U, V, Se, Mo, As are carried together as oxyanions; these species precipitate in a restricted range of Eh-pH when reducing conditions are met. Concomitant with removal of these species, due to formation of reduced, insoluble species, several other elements of interest are concentrated in the ore zones as well. Chalcophile elements, such as Cu, Co, Mn, Zn, Cd, Sb, and others are fixed in authigenic sulfide phases, and the alkalis Rb, K, and Cs are fixed in the authigenic illite and illitic mixed layer clays. The alkaline earth elements Sr and Ba are commonly fixed in sulfate-rich rock. The rare earth elements (REE) are incorporated into authigenic clay minerals or into oxy-hydroxide phases. (author)

Investigated Miscible CO2 Flooding for Enhancing Oil Recovery in Wettability Altered Chalk and Sandstone Rocks

Energy Technology Data Exchange (ETDEWEB)

Tabrizy, Vahid Alipour

2012-07-01

The thesis addresses oil recovery by miscible CO2 flooding from modified sandstone and chalk rocks. Calcite mineral surface is modified with stearic acid (SA) and asphaltene, and the silicate mineral surfaces are modified with N,N-dimethyldodecylamine (NN-DMDA) and asphaltene. The stability of adsorbed polar components in presence of SO4 2- and Mg2 + ions is also investigated. Recovery from sandstone cores is consistently lower than that from chalk cores saturated with the same oil and flooded with CO2 at all miscible flooding conditions. This may be due to the larger permeability contrasts in sandstone cores, which promote the fingering phenomenon. Miscible CO2 flooding for chalk and sandstone cores with distilled water, as initial water saturation, shows also lower oil recovery than cores saturated with different ions. At higher miscible flooding conditions, higher oil recovery is obtained. However, presence of light components (such as C1 or C3) in oil reduced the recovery. Oil recovery in presence of methane (C1) is lower than that in presence of methane and propane (C1/C3). A ternary diagram was constructed in order to understand the CO2 flooding mechanism(s) at the different flooding conditions and in presence of light components. The side effect of the flooding with CO2 is the probability for asphaltene deposition. An approach based on solubility parameter in the liquid, is used to assess the risk for asphaltene deposition during CO2 miscible flooding. The light components (C1/C3) and higher flooding conditions enhanced the risk for asphaltene instability. It is also shown higher amount of asphaltene deposition in chalk cores than that in sandstone cores at similar miscibility conditions.(au)

A Effect discussion of transient electromagnetic sounding technique in paleochannel-type sandstone-hosted uranium deposit

International Nuclear Information System (INIS)

Yang Jianchun; Fang Genxian; Yang Yaxin

2003-01-01

On the base of the application of transient electromagnetic technique of paleochannel-type sandstone-hosted uranium deposits in Tengchong region of Yunan Province, this paper analyses the detect example. It discusses the theory foundation of TEM, fieldwork means, data processing and interpret. By contrast with routine electricity farad, the transient electromagnetic technique have the special merit and favorable space resolve gender under conditions of intricacy terrain. This means can get good effect in detecting paleochannel-type sandstone-hosted uranium deposits space position. It is a good reference for other prospecting and exploration work

Uncertainties in sandy shorelines evolution under the Bruun rule assumption

Directory of Open Access Journals (Sweden)

Gonéri eLe Cozannet

2016-04-01

Full Text Available In the current practice of sandy shoreline change assessments, the local sedimentary budget is evaluated using the sediment balance equation, that is, by summing the contributions of longshore and cross-shore processes. The contribution of future sea-level-rise induced by climate change is usually obtained using the Bruun rule, which assumes that the shoreline retreat is equal to the change of sea-level divided by the slope of the upper shoreface. However, it remains unsure that this approach is appropriate to account for the impacts of future sea-level rise. This is due to the lack of relevant observations to validate the Bruun rule under the expected sea-level rise rates. To address this issue, this article estimates the coastal settings and period of time under which the use of the Bruun rule could be (invalidated, in the case of wave-exposed gently-sloping sandy beaches. Using the sedimentary budgets of Stive (2004 and probabilistic sea-level rise scenarios based on IPCC, we provide shoreline change projections that account for all uncertain hydrosedimentary processes affecting idealized coasts (impacts of sea-level rise, storms and other cross-shore and longshore processes. We evaluate the relative importance of each source of uncertainties in the sediment balance equation using a global sensitivity analysis. For scenario RCP 6.0 and 8.5 and in the absence of coastal defences, the model predicts a perceivable shift toward generalized beach erosion by the middle of the 21st century. In contrast, the model predictions are unlikely to differ from the current situation in case of scenario RCP 2.6. Finally, the contribution of sea-level rise and climate change scenarios to sandy shoreline change projections uncertainties increases with time during the 21st century. Our results have three primary implications for coastal settings similar to those provided described in Stive (2004 : first, the validation of the Bruun rule will not necessarily be

Hurricane Sandy: An Educational Bibliography of Key Research Studies

Science.gov (United States)

Piotrowski, Chris

2013-01-01

There, undoubtedly, will be a flurry of research activity in the "Superstorm" Sandy impact area on a myriad of disaster-related topics, across academic disciplines. The purpose of this study was to review the disaster research related specifically to hurricanes in the educational and social sciences that would best serve as a compendium…

Organisms associated with the sandy-beach bivalve Donax serra ...

African Journals Online (AJOL)

57: 134-136. BROWN, AC. & WEBB, S.c. 1994. Organisms associated \\.,.,ith burrowing whelks of the genus Bullia. S Afr. 1. Zool. 29: 144-151. BROWN, A.C., STENTON-DOZEY, J.~.E. & TRUEMAN, E.R.. 1989. Sandy-beach bivalves and gastropods; a comparison between Donax serra and Ruilia digitalis. Adv. mar. Bioi. 25:.

Hurricane Sandy Exposure Alters the Development of Neural Reactivity to Negative Stimuli in Children.

Science.gov (United States)

Kessel, Ellen M; Nelson, Brady D; Kujawa, Autumn; Hajcak, Greg; Kotov, Roman; Bromet, Evelyn J; Carlson, Gabrielle A; Klein, Daniel N

2018-03-01

This study examined whether exposure to Hurricane Sandy-related stressors altered children's brain response to emotional information. An average of 8 months (M age  = 9.19) before and 9 months after (M age  = 10.95) Hurricane Sandy, 77 children experiencing high (n = 37) and low (n = 40) levels of hurricane-related stress exposure completed a task in which the late positive potential, a neural index of emotional reactivity, was measured in response to pleasant and unpleasant, compared to neutral, images. From pre- to post-Hurricane Sandy, children with high stress exposure failed to show the same decrease in emotional reactivity to unpleasant versus neutral stimuli as those with low stress exposure. Results provide compelling evidence that exposure to natural disaster-related stressors alters neural emotional reactivity to negatively valenced information. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Superstorm Sandy: How the New York University Psychiatry Residency Training Program Weathered the Storm.

Science.gov (United States)

Capasso, Rebecca; Adler, Laura

2016-10-01

The teaching hospitals of the New York University psychiatry residency program were evacuated and then closed for a minimum of 3 months in the aftermath of Superstorm Sandy. Faculty and residents were deployed to alternate clinical sites. The authors examine the consequences of Superstorm Sandy and its implications for the New York University psychiatry residency training program. A survey was administered to faculty and residents. The authors tabulated 98 surveys, for which 24 % of faculty and 84 % of residents responded. Among respondents, 61 % believed that being involved in the evacuation of the hospitals was a positive experience. During deployment, most (85 %) found being placed with peers and supervisors to be beneficial, but there were significant disruptions. Despite facing multiple challenges including closed facilities, deployment to nonaffiliated hospitals, and exhausted personal resources, the training program continued to provide accredited clinical experiences, a core curriculum, and supervision for psychiatry residents during and after Superstorm Sandy.

CONTRIBUTIONS TO IMPROVING CULTURE TEHNOLOGIES OF PEACHES GROWN ON SANDY SOILS THE SOUTH OF OLTENIA

Directory of Open Access Journals (Sweden)

Anica Durau

2013-12-01

Full Text Available Technological factors with major implications in obtaining high yields and quality in peaches grown on sandy soils are planting row distance and shape of the crown, soil maintenance system, chemical, organic and foliar fertilzation. A smal size combined with the flatening of the crowns of the tres alows a dense planting, also ensure proper mechanization of work and easy penetration of light to the leaves and fruits. Crown form vertical belt proved to be suitable for al planting distances studied, easily made and maintained, having fruit production ranged betwen 15.9 t / ha at a distance of 2 m, 10.3 t / ha at a distance of 2.5 m and 7.9 t / ha at a distance of 3 m. The state of soil nutrient supply influence sucesful peach crop on sandy soils. The fertilzer dose of technology to N10 P80 K10 kg s.a / ha production was 34.9 t / ha. Organic fertilzation also contributes to obtaining high yields of peach. In sandy soil conditions most fruit production of 9.6 t / ha was obtained by fertilzation with organic manure 60t/ha. Besides fertilzation, soil maintenance system is one important link in the technology peach crop on sandy soils. The results found that the biggest peach fruit production was obtained from field maintenance system black-8,2t/ha. Using technology in foliar peaches culture on sandy soils, is an important means of providing nutrients that lead to improved proceses of growth and fructification. The best way is with foliar fertilzation Folibor in dose 5l/ha, the production obtained was 12.4 t /ha.

Quantifying the synergistic effect of the precipitation and land use on sandy desertification at county level: a case study in Naiman Banner, Northern China.

Science.gov (United States)

Xiaodong, Ge; Jinren, Ni; Zhenshan, Li; Ronggui, Hu; Xin, Ming; Qing, Ye

2013-07-15

Assessing the driving forces of sandy desertification is fundamental and important for its control. It has been widely accepted that both climatic conditions and land use have great impact on sandy desertification in northern China. However, the relative role and synergistic effect of each driving force of sandy desertification are still not clear. In this paper, an indicator named as SI was defined to represent the integrated probability of sandy desertification caused by land use. A quantitative method was developed for characterizing the relative roles of annual precipitation and land use to sandy desertification in both spatial and temporal dimensions at county level. Results showed that, at county level, land use was the main cause of sandy desertification for Naiman Banner since 1987-2009. In the case of spatial dimension, the different combination of land use types decided the distribution of sandy desertification probability and finally decided the spatial pattern of bared sand land. In the case of temporal dimension, the synergistic effect of land use and precipitation highly influenced the spatial distribution of sandy desertification. Copyright © 2013 Elsevier Ltd. All rights reserved.

Origin of brackish groundwater in a sandstone aquifer on Bornholm, Denmark

DEFF Research Database (Denmark)

Jørgensen, Niels Oluf; Heinemeier, Jan

2008-01-01

A multi-isotope approach in combination with hydrochemical data and borehole logging is applied to identify the source of brackish groundwater in a borehole in the well field of Neksø Municipal Waterworks in Bornholm, Denmark. The aquifer lithology consists of fractured Lower Cambrian sandstones...

Expanded uncertainty estimation methodology in determining the sandy soils filtration coefficient

Science.gov (United States)

Rusanova, A. D.; Malaja, L. D.; Ivanov, R. N.; Gruzin, A. V.; Shalaj, V. V.

2018-04-01

The combined standard uncertainty estimation methodology in determining the sandy soils filtration coefficient has been developed. The laboratory researches were carried out which resulted in filtration coefficient determination and combined uncertainty estimation obtaining.

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

Directory of Open Access Journals (Sweden)

Weijing Yao

2018-04-01

Full Text Available Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry injected into sand and sandy soil were explored. The investigated parameters were the dry density, wet density, moisture content, internal friction angle, and cohesion force. The results show that the consolidation effect of superfine cement is better than that of Portland cement due to the small size of superfine cement particles. The superfine cement can diffuse into the sand by infiltration, extrusion, and splitting. When the water–cement ratio of superfine cement slurry is less than 2:1 grouting into loose sand, the dry and wet density decrease with the increase in the water–cement ratio, while the moisture content and cohesive force gradually increase. When the water–cement ratio of superfine cement slurry is 1:1 grouting into loose sand and sandy soil, the dry density, wet density, and cohesive force of loose sand are larger than those of sandy soil. The results of the experiment may be relevant for engineering applications.

The Department of the Interior Strategic Sciences Group and its Response to Hurricane Sandy

Science.gov (United States)

Ludwig, K. A.; Machlis, G. E.; Applegate, D.

2013-12-01

This presentation will describe the history, mission, and current activities of the newly formed Department of the Interior (DOI) Strategic Sciences Group (SSG), with a focus on its response to Hurricane Sandy and lessons learned from using scenario building to support decision making. There have been several environmental crises of national significance in recent years, including Hurricane Katrina (2005), large-scale California wildfires (2007-2008), the Deepwater Horizon oil spill (2010), and Hurricane Sandy (2012). Such events are complex because of their impacts on the ecology, economy, and people of the affected locations. In these and other environmental disasters, the DOI has had significant responsibilities to protect people and resources and to engage in emergency response, recovery, and restoration efforts. In recognition of the increasingly critical role of strategic science in responding to such complex events, the DOI established the SSG by Secretarial Order in 2012. Its purpose is to provide the DOI with science-based assessments and interdisciplinary scenarios of environmental crises affecting Departmental resources; rapidly assemble interdisciplinary teams of scientists from government, academia, and non-governmental organizations to conduct such work; and provide results to DOI leadership as usable knowledge to support decision making. March 2013 was the SSG's first deployment since its formation. The SSG's charge was to support DOI's participation on the Hurricane Sandy Rebuilding Task Force by developing scenarios of Hurricane Sandy's environmental, economic, and social consequences in the New York/New Jersey area and potential interventions that could improve regional resilience to future major storms. Over the course of one week, the SSG Sandy team (Operational Group Sandy) identified 13 first-tier consequences and 17 interventions. The SSG briefed DOI leadership, Task Force representatives, and other policy makers in both Washington, DC and

Constraining Depositional Slope From Sedimentary Structures in Sandy Braided Streams

Science.gov (United States)

Lynds, R. M.; Mohrig, D.; Heller, P. L.

2003-12-01

Determination of paleoslopes in ancient fluvial systems has potentially broad application to quantitatively constraining the history of tectonics and paleoclimate in continental sequences. Our method for calculating paleoslopes for sandy braided streams is based upon a simple physical model that establishes depositional skin-frictional shear stresses from assemblages of sedimentary structures and their associated grain size distributions. The addition of a skin-frictional shear stress, with a geometrically determined form-drag shear stress results in a total boundary shear stress which is directly related to water-surface slope averaged over an appropriate spatial scale. In order to apply this model to ancient fluvial systems, it is necessary to measure the following: coarsest suspended sediment size, finest grain size carried in bed load, flow depth, dune height, and dune length. In the rock record, suspended load and bed load can be accurately assessed by well-preserved suspended load deposits ("low-energy" ripples) and bed load deposits (dune foresets). This model predicts an average slope for the North Loup River near Taylor, Nebraska (modern case study) of 2.7 x 10-3. The measured reach-averaged water surface slope for the same reach of the river is 1.37 x 10-3. We suggest that it is possible to calculate the depositional slope of a sandy fluvial system by a factor of approximately two. Additionally, preliminary application of this model to the Lower Jurassic Kayenta Formation throughout the Colorado Plateau provides a promising and consistent evaluation of paleoslope in an ancient and well-preserved, sandy braided stream deposit.

Determination of diffusion coefficients in cohesive and sandy sediment from the area of Gorleben

International Nuclear Information System (INIS)

Klotz, D.

1989-01-01

The cohesive and sandy sediments stem from shaft driving at the Gorleben salt done. For the cohesive materials, HTD was used as a tracer substance, while I-131 - was used for the sandy materials. Diffusion coefficients of HTD in cohesive materials in their natural texture are in the range of 2x10 -6 to 5x10 -6 cm 2 /s, those of I-131 - in the investigated uniform fine and middle sands are approximately 3x10 -6 cm 2 /s. (DG) [de

Disentangling diversity patterns in sandy beaches along environmental gradients.

Science.gov (United States)

Barboza, Francisco R; Gómez, Julio; Lercari, Diego; Defeo, Omar

2012-01-01

Species richness in sandy beaches is strongly affected by concurrent variations in morphodynamics and salinity. However, as in other ecosystems, different groups of species may exhibit contrasting patterns in response to these environmental variables, which would be obscured if only aggregate richness is considered. Deconstructing biodiversity, i.e. considering richness patterns separately for different groups of species according to their taxonomic affiliation, dispersal mode or mobility, could provide a more complete understanding about factors that drive species richness patterns. This study analyzed macroscale variations in species richness at 16 Uruguayan sandy beaches with different morphodynamics, distributed along the estuarine gradient generated by the Rio de la Plata over a 2 year period. Species richness estimates were deconstructed to discriminate among taxonomic groups, supralittoral and intertidal forms, and groups with different feeding habits and development modes. Species richness was lowest at intermediate salinities, increasing towards oceanic and inner estuarine conditions, mainly following the patterns shown for intertidal forms. Moreover, there was a differential tolerance to salinity changes according to the habitat occupied and development mode, which determines the degree of sensitivity of faunal groups to osmotic stress. Generalized (additive and linear) mixed models showed a clear increase of species richness towards dissipative beaches. All taxonomic categories exhibited the same trend, even though responses to grain size and beach slope were less marked for crustaceans and insects than for molluscs or polychaetes. However, supralittoral crustaceans exhibited the opposite trend. Feeding groups decreased from dissipative to reflective systems, deposit feeders being virtually absent in the latter. This deconstructive approach highlights the relevance of life history strategies in structuring communities, highlighting the relative

Copper and zinc distribution coefficients for sandy aquifer materials

DEFF Research Database (Denmark)

Christensen, Thomas Højlund; Astrup, Thomas; Boddum, J. K.

2000-01-01

Distribution coe�cients (Kd) were measured for copper (Cu) and zinc (Zn) in laboratory batch experiments for 17 sandy aquifer materials at environmentally relevant solute concentrations (Cu: 5±300 mg/l, Zn: 20±3100 mg/l). The Kd values ranged two to three orders of magnitude (Cu: 70±10,800 l/ kg...

Thermal study of sandstones from different Czech localities

Czech Academy of Sciences Publication Activity Database

Plevová, Eva; Vaculíková, Lenka; Kožušníková, Alena; Daněk, T.; Ritz, M.; Simha Martynková, G.

2011-01-01

Roč. 103, č. 3 (2011), s. 835-843 ISSN 1388-6150 R&D Projects: GA ČR GA105/08/1398; GA ČR GP105/07/P416 Grant - others:GA ČR(CZ) GP105/09/397 Institutional research plan: CEZ:AV0Z30860518 Keywords : thermomechanical and differential thermal analysis * optical microscopy * sandstones Subject RIV: CA - Inorganic Chemistry Impact factor: 1.604, year: 2011 http://www.springerlink.com/content/71n5427j2707g331/

The effectiveness of starting the developement of lenticular sandstone and siltstone

Energy Technology Data Exchange (ETDEWEB)

Oshitki, V M; Khmelevskiy, Y I; Kolesnkikova, S A; Musin, M M; Sukhanov, N A

1980-01-01

Studies the determination of the effectiveness of working reserves for several typical cases of implementing development of collector-sandstone and siltstonee lenses. Shows that Siltstones require the use of amore rapid development system: with a ratio of injection to working wells of at least 1:3.

Amelioration of sandy soils in drought stricken areas through use of ...

African Journals Online (AJOL)

ACSS

improving N, P, Ca and Mg content in sandy soils, and consequently support crop growth and yield. ... stress, soil moisture conservation, soil fertility management ... water many times its own weight. ... improves the productivity of degraded,.

Geological characteristics and prospecting potential of sandstone-type uranium deposits in the north margin of Qaidam basin

International Nuclear Information System (INIS)

Liu Lin; Song Xiansheng; Feng Wei

2012-01-01

The north margin of Qaidam Basin is composed with rift trough and Oulongbuluke landmass which is clamped by Qilian Mountain and Qaidam block Suture zone. The two activities provide a rich source of uranium for the basin area. The coal-bearing rocks as stratums of medium and lower Jurassic, is the main exploration target zones of sandstone-type uranium ore. Through geological survey and drilling, we think that the interlayer oxidation zone. being primary factors of sandstone-type uranium, can be divided into ancient type and modern type. The ancient interlayer oxidation zone type uranium deposit is the main prospecting types in the north margin of Qaidam Basin. Combined with analysis on geological conditions of sandstone-type uranium mineralization, we propose that eastern edge of Yuqia, southern edge of Lucao Mountain, Beidatan and northwest edge of Ulan depression are good prospects. (authors)

Hydrogeochemical and stream sediment sampling for uranium in the sandstone environment

International Nuclear Information System (INIS)

Wenrich, K.J.

1985-01-01

Sandstone terranes commonly host uranium occurrences in the western United States. In addition, because sedimentary terranes, particularly shales and immature, not well cemented sandstone, contribute more sediment and soluble material than do plutonic, volcanic, or metamorphic terranes they are an excellent regime for hydrogeochemical and stream-sediment prospecting. Because of higher conductivity, and hence higher uranium content, of waters draining such environments the sampling need not be as precise nor the analytical detection limit as low as in other terranes to yield a successful survey. Nevertheless, reasonable preparation and care of the samples is recommended: (1) The water samples should be filtered through 0.45 μm membranes and acidified to a pH of less than 1. (2) Because the adsorption of uranium by organic material is so significant it is recommended that the reasonable finest stream-sediment fraction, 4 , conductivity, etc.) are useful in the data reduction towards the elimination of false anomalies. (author)

Electro-desalination of sulfate contaminated carbonaceous sandstone – risk for salt induced decay during the process

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.

2016-01-01

Sodium-sulphate is known to cause severe stone damage. This paper is focused on removal of this salt from carbonaceous sandstone by electro-desalination (ED). The research questions are related to possible stone damage during ED and subsequently suction cycles are made in distilled water before......, during and after ED. During suction in water the salts are concentrated in the upper part of the sandstone. After 2 days of treatment the average water soluble SO42- concentration was half the initial and for this sample corners were damaged as was the case for the reference stone. After 4 days of ED...... in the poultice with carbonate. The acid would be highly damaging to the carbonaceous sandstone as the binder-CaCO3 is soluble in acid. From pH measurements of the poultice it seems as if the acid is buffered well, as pH is still slightly alkaline after ED, but this is a measurement of the average pH and thus...

Multi-scale nitrate transport in a sandstone aquifer system under intensive agriculture

Science.gov (United States)

Paradis, Daniel; Ballard, Jean-Marc; Lefebvre, René; Savard, Martine M.

2018-03-01

Nitrate transport in heterogeneous bedrock aquifers is influenced by mechanisms that operate at different spatial and temporal scales. To understand these mechanisms in a fractured sandstone aquifer with high porosity, a groundwater-flow and nitrate transport model—reproducing multiple hydraulic and chemical targets—was developed to explain the actual nitrate contamination observed in groundwater and surface water in a study area on Prince Edward Island, Canada. Simulations show that nitrate is leached to the aquifer year-round, with 61% coming from untransformed and transformed organic sources originating from fertilizers and manure. This nitrate reaches the more permeable shallow aquifer through fractures in weathered sandstone that represent only 1% of the total porosity (17%). Some of the nitrate reaches the underlying aquifer, which is less active in terms of groundwater flow, but most of it is drained to the main river. The river-water quality is controlled by the nitrate input from the shallow aquifer. Groundwater in the underlying aquifer, which has long residence times, is also largely influenced by the diffusion of nitrate in the porous sandstone matrix. Consequently, following a change of fertilizer application practices, water quality in domestic wells and the river would change rapidly due to the level of nitrate found in fractures, but a lag time of up to 20 years would be necessary to reach a steady level due to diffusion. This demonstrates the importance of understanding nitrate transport mechanisms when designing effective agricultural and water management plans to improve water quality.

Petrological features of selected components of the Cergowa sandstones (Outer Carpathians) recorded by scanning electron microscopy - preliminary study

Science.gov (United States)

Pszonka, Joanna

2017-11-01

The scanning electron microscope analysis of the Cergowa sandstones brings new data on their petrological features and chemical composition. Previous work in standard petrographic examination, e.g. polarising (PL) or cathodoluminescence (CL) microscopy, displayed limited information on grain surface topography and only assumptions to their geochemistry. Both identification and characterisation of minerals are fundamental in the progress of mining and minerals processing systems. Detrital grains of the Cergowa sandstones are bound by calcite and dolomitic cement and commonly corroded by diagenetic fluids, however, in varying degrees, which is illustrated here by feldspar, quartz and dolomite minerals. Dissolution processes of marginal parts of these mineral grains resulted in corrosion, which increased the contact surface between the grains and the cement. The difference in resistance to these processes was observed not only among distinct groups of minerals, but also within the group of feldspars: between K-feldspars and minerals of plagioclase. That combination resulted in exceptionally strong cementation of the Cergowa sandstones, which is expressed by their high hardness and resistance to abrasion, freezing, and thawing. Inherent parameters of sandstones are characterised by their petrographical properties.

Hydrocarbon Potential in Sandstone Reservoir Isolated inside Low Permeability Shale Rock (Case Study: Beruk Field, Central Sumatra Basin)

Science.gov (United States)

Diria, Shidqi A.; Musu, Junita T.; Hasan, Meutia F.; Permono, Widyo; Anwari, Jakson; Purba, Humbang; Rahmi, Shafa; Sadjati, Ory; Sopandi, Iyep; Ruzi, Fadli

2018-03-01

Upper Red Bed, Menggala Formation, Bangko Formation, Bekasap Formation and Duri Formationare considered as the major reservoirs in Central Sumatra Basin (CSB). However, Telisa Formation which is well-known as seal within CSB also has potential as reservoir rock. Field study discovered that lenses and layers which has low to high permeability sandstone enclosed inside low permeability shale of Telisa Formation. This matter is very distinctive and giving a new perspective and information related to the invention of hydrocarbon potential in reservoir sandstone that isolated inside low permeability shale. This study has been conducted by integrating seismic data, well logs, and petrophysical data throughly. Facies and static model are constructed to estimate hydrocarbon potential resource. Facies model shows that Telisa Formation was deposited in deltaic system while the potential reservoir was deposited in distributary mouth bar sandstone but would be discontinued bedding among shale mud-flat. Besides, well log data shows crossover between RHOB and NPHI, indicated that distributary mouth bar sandstone is potentially saturated by hydrocarbon. Target area has permeability ranging from 0.01-1000 mD, whereas porosity varies from 1-30% and water saturation varies from 30-70%. The hydrocarbon resource calculation approximates 36.723 MSTB.

Experimental measurements of the SP response to concentration and temperature gradients in sandstones with application to subsurface geophysical monitoring

Science.gov (United States)

Leinov, E.; Jackson, M. D.

2014-09-01

Exclusion-diffusion potentials arising from temperature gradients are widely neglected in self-potential (SP) surveys, despite the ubiquitous presence of temperature gradients in subsurface settings such as volcanoes and hot springs, geothermal fields, and oil reservoirs during production via water or steam injection. Likewise, with the exception of borehole SP logging, exclusion-diffusion potentials arising from concentration gradients are also neglected or, at best, it is assumed that the diffusion potential dominates. To better interpret these SP sources requires well-constrained measurements of the various coupling terms. We report measurements of thermoelectric and electrochemical exclusion-diffusion potentials across sandstones saturated with NaCl brine and find that electrode effects can dominate the measured voltage. After correcting for these, we find that Hittorf transport numbers are the same within experimental error regardless of whether ion transport occurs in response to temperature or concentration gradients over the range of NaCl concentration investigated that is typical of natural systems. Diffusion potentials dominate only if the pore throat radius is more than approximately 4000 times larger than the diffuse layer thickness. In fine-grained sandstones with small pore throat diameter, this condition is likely to be met only if the saturating brine is of relatively high salinity; thus, in many cases of interest to earth scientists, exclusion-diffusion potentials will comprise significant contributions from both ionic diffusion through, and ionic exclusion from, the pore space of the rock. However, in coarse-grained sandstones, or sandstones saturated with high-salinity brine, exclusion-diffusion potentials can be described using end-member models in which ionic exclusion is neglected. Exclusion-diffusion potentials in sandstones depend upon pore size and salinity in a complex way: they may be positive, negative, or zero depending upon sandstone

Hydrophobization by Means of Nanotechnology on Greek Sandstones Used as Building Facades

Directory of Open Access Journals (Sweden)

Georgios Karagiannis

2013-01-01

Full Text Available Modern sustainable architecture indicates the use of local natural stones for building. Greek sandstones from Epirus (Demati, Greece, EN 12440 used as building facades meet aesthetic and have high mechanical properties, but the inevitable interaction between stone materials and natural or anthropogenic weathering factors controls the type, and extent of stone damages. In the present paper, samples of sandstone were treated with a conventional hydrophobic product and four solutions of the same product, enriched with nanosilica of different concentrations. The properties of the treated samples, such as porosity and pore size distribution, microstructure, static contact angle of a water droplet, and durability to deterioration cycles (freeze-thaw were recorded and conclusions were drawn. The research indicates the increased hydrophobic properties in nanosilica solutions but also the optimum content in nanoparticles that provides hydrophobicity without altering the properties of the stone.

2014 NOAA Ortho-rectified Mosaic of Hurricane Sandy Coastal Impact Area

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles at 0.35m GSD created for NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative in Hurricane Sandy coastal...

Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

Energy Technology Data Exchange (ETDEWEB)

Adams, S.S.; Smith, R.B.

1981-01-01

Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced, pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H/sub 2/S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H/sub 2/S.

Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

International Nuclear Information System (INIS)

Adams, S.S.; Smith, R.B.

1981-01-01

Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced, pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H 2 S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H 2 S

Muddy and dolomitic rip-up clasts in Triassic fluvial sandstones: Origin and impact on potential reservoir properties (Argana Basin, Morocco)

Science.gov (United States)

Henares, Saturnina; Arribas, Jose; Cultrone, Giuseppe; Viseras, Cesar

2016-06-01

The significance of rip-up clasts as sandstone framework grains is frequently neglected in the literature being considered as accessory components in bulk sandstone composition. However, this study highlights the great value of muddy and dolomitic rip-up clast occurrence as: (a) information source about low preservation potential from floodplain deposits and (b) key element controlling host sandstone diagenetic evolution and thus ultimate reservoir quality. High-resolution petrographic analysis on Triassic fluvial sandstones from Argana Basin (T6 and T7/T8 units) highlights the significance of different types of rip-up clasts as intrabasinal framework components of continental sediments from arid climates. On the basis of their composition and ductility, three main types are distinguished: (a) muddy rip-up clasts, (b) dolomitic muddy rip-up clasts and (c) dolomite crystalline rip-up clasts. Spatial distribution of different types is strongly facies-related according to grain size. Origin of rip-up clasts is related to erosion of coeval phreatic dolocretes, in different development stages, and associated muddy floodplain sediments. Cloudy cores with abundant inclusions and clear outer rims of dolomite crystals suggest a first replacive and a subsequent displacive growth, respectively. Dolomite crystals are almost stoichiometric. This composition is very similar to that of early sandstone dolomite cement, supporting phreatic dolocretes as dolomite origin in both situations. Sandstone diagenesis is dominated by mechanical compaction and dolomite cementation. A direct correlation exists between: (1) muddy rip-up clast abundance and early reduction of primary porosity by compaction with irreversible loss of intergranular volume (IGV); and (2) occurrence of dolomitic rip-up clasts and dolomite cement nucleation in host sandstone, occluding adjacent pores but preserving IGV. Both processes affect reservoir quality by generation of vertical and 3D fluid flow baffles and

Characterization and 3D reservoir modelling of fluvial sandstones of the Williams Fork Formation, Rulison Field, Piceance Basin, Colorado, USA

International Nuclear Information System (INIS)

Pranter, Matthew J; Vargas, Marielis F; Davis, Thomas L

2008-01-01

This study describes the stratigraphic characteristics and distribution of fluvial deposits of the Upper Cretaceous Williams Fork Formation in a portion of Rulison Field and addresses 3D geologic modelling of reservoir sand bodies and their associated connectivity. Fluvial deposits include isolated and stacked point-bar deposits, crevasse splays and overbank (floodplain) mudrock. Within the Williams Fork Formation, the distribution and connectivity of fluvial sandstones significantly impact reservoir productivity and ultimate recovery. The reservoir sandstones are primarily fluvial point-bar deposits interbedded with shales and coals. Because of the lenticular geometry and limited lateral extent of the reservoir sandstones (common apparent widths of ∼500–1000 ft; ∼150–300 m), relatively high well densities (e.g. 10 acre (660 ft; 200 m) spacing) are often required to deplete the reservoir. Heterogeneity of these fluvial deposits includes larger scale stratigraphic variability associated with vertical stacking patterns and structural heterogeneities associated with faults that exhibit lateral and reverse offsets. The discontinuous character of the fluvial sandstones and lack of distinct marker beds in the middle and upper parts of the Williams Fork Formation make correlation between wells tenuous, even at a 10 acre well spacing. Some intervals of thicker and amalgamated sandstones within the middle and upper Williams Fork Formation can be correlated across greater distances. To aid correlation and for 3D reservoir modelling, vertical lithology proportion curves were used to estimate stratigraphic trends and define the stratigraphic zonation within the reservoir interval. Object-based and indicator-based modelling methods have been applied to the same data and results from the models were compared. Results from the 3D modelling indicate that sandstone connectivity increases with net-to-gross ratio and, at lower net-to-gross ratios (<30%), differences exist in

effect of tractor forward speed on sandy loam soil physical ...

African Journals Online (AJOL)

Dr Obe

Ilorin on a sandy loam soil to evaluate the effect of the imposition of different .... of the blade is 10.5cm. ... arranged in an inverted cone shape with ... replicates were taken for each speed run. The ..... Thakur, T. C; A. Yadav; B. P. Varshney and.

Sorption and Migration Mechanisms of 237 Np through Sandy Soil

International Nuclear Information System (INIS)

Chantaraprachoom, Nanthavan; Tanaka, Tadao

2003-06-01

In order to evaluate migration behavior of radioactive nuclides in the disposal of low-level radioactive waste into a shallow land burial, the sorption characteristic and migration behavior of 237 Np through sandy soil was studied. Two experimental methods were performed by using batch and column systems. The distribution coefficients (K d ) obtained from the adsorption and desorption process are rather small about 16 and 21 cm 3 /g respectively. Size distribution of 237 Np species in the influent solution was measured by ultra-filtration technique. Migration mechanism of 237 Np was studied by column experiments. The experimental condition was the influence of volume of eluting solution; 100, 300, 500, 1000 and 2000 ml respectively. The result from five column experiments confirm that the sorption characteristics of 237 Np are mainly controlled by a reversible ion-exchange reaction and the migration of 237 Np in the sandy soil can be estimated by using the K d concept

2012 USGS EAARL-B Coastal Topography: Post-Sandy, First Surface (NJ)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

The Saint Martin de Belleville syncline and its uraniferous permian sandstone

International Nuclear Information System (INIS)

Schade, Johannes

1983-01-01

This dissertation (these de specialite) is a study of the geology of the St.Martin d.B. syncline and the uranium prospect 'le Cochet' in the Carboniferous Brianconnais Zone of Savoy. Stratigraphy and sedimentology: This syncline presents continental detrital sediments ranging from U.Carboniferous to L.Triassic. In the U.Carboniferous, magmatic activity begins with the Moriaz Layers acid volcanics that are considered as a lateral equivalent of the Stephanian Courchevel Conglomerates. In Permian times, parts of an alluvial fan seem to occupy the north of the study area (gray and green conglomeratic sandstone). Southwards these inter-finger with flood plain sediments (red slate) including a locally oolitic limestone. Volcanic detritus is important in the Permian. Tourmalinite pebbles are frequent and seem to be related to the regional Permian magmatism. Albitization of feldspars is general in the Carboniferous and the Permian. The Permo-triassic typically shows microcline bearing dolomitic sandstones. In the Scythian quartzites orthoclase is the dominant feldspar. The quartzites are overlain by L.Triassic evaporites identified by the sulfur isotope ratio of their gypsum. The morphology of the zircons in the sandstones has been investigated using the typological method of J.P. Pupin. Regional Permian magmatism apparently produces volcanics of the calc-alkalic and tholeiitic series as well as a high level granitic intrusion of anatectic origin. The uranium occurrences are strata-bound on a kilometric and hecto-metric scale. They are developed almost exclusively in the gray variety of the Permian sandstones whose gray and red varieties are always barren. Within this unit, the mineralization impregnates irregularly distributed lenses and pods of coal material. Uranium is accompanied by vanadium occurring as roscoelite. The association U-V, of bio-philic character, reflects the concentration in the sedimentary environment and argues for a quite indirect relation with the

Fine organic particles in a sandy beach system (Puck Bay, Baltic Sea

Directory of Open Access Journals (Sweden)

Lech Kotwicki

2005-06-01

Full Text Available A total of over 550 samples of particulate organic matter (POM were obtained from swash and groundwater samples taken on a monthly basis from seven localities on the sandy shores of Puck Bay in 2002 and 2003. Sandy sediment cores from the swash zone were collected to assess the amount of POM in the pore waters. The mean annual concentrations of POM varied between localities from 20 to 500 mg in groundwater and from 6 to 200 mg dm-3 in swash water. The carbon/nitrogen (C/N ratio in suspended matter was always higher in groundwater (annual mean 12 than in swash water (annual mean 7. The C/N ratio indicates a local, algal origin of POM in the shallow coastal zone.

Physical and chemical properties for sandstone and bentonites

International Nuclear Information System (INIS)

Sato, Haruo

2004-01-01

Physical and chemical properties such as porosity, pore-size distribution, dry density, solid density, mineralogy and chemical composition, which are important parameters for the understanding and analysis of the diffusion phenomena of radionuclides and ions in bentonite and in the geosphere, were measured. The measurements were performed for sandstone, of which fundamental data and information are limited. For bentonite, 3 kinds of bentonites with different smectite contents (Kunigel-V1, Kunipia-F, MX80) were used. In the measurements of the physical and chemical properties of rock, the measurements of solid density by pychnometer, the measurements of porosity, dry density and solid density by water saturation method, the measurements of porosity, dry density, solid density, pore-size distribution and specific surface area of pores by Hg porosimetry, the identifications of constituent minerals by X-ray Diffractometry (XRD), the measurement of chemical composition by whole rock analysis, the observations of micropore structure by Laser Confocal Microscope (LCM), the measurements of water vaporization curves and the measurements of the homogeneity of the rock by penetration of KMnO 4 were performed. While, in the measurements of the physical and chemical properties for bentonite, water basis water content, water content, porosity, dry density, solid density and their distributions in samples were measured, and the degree of inhomogeneity was quantitatively evaluated by comparing with data and information reported up to date. The porosities of sandstone are 15.6±0.21% for water saturation method and 15.5±0.2% for Hg porosimetry, and similar values were obtained in both methods. The solid densities ranged 2.65-2.69 Mg/m 3 for 3 methods, and the average value was 2.668±0.012 Mg/m 3 . The average pore size was 88.8±0.5nm, and pore sizes ≤10μm shared 80% of total pore volume and pore sizes ≤1μm shared 40%. The specific surface area of the pores is 4.09±0.017 m

Validation of regression models for nitrate concentrations in the upper groundwater in sandy soils

International Nuclear Information System (INIS)

Sonneveld, M.P.W.; Brus, D.J.; Roelsma, J.

2010-01-01

For Dutch sandy regions, linear regression models have been developed that predict nitrate concentrations in the upper groundwater on the basis of residual nitrate contents in the soil in autumn. The objective of our study was to validate these regression models for one particular sandy region dominated by dairy farming. No data from this area were used for calibrating the regression models. The model was validated by additional probability sampling. This sample was used to estimate errors in 1) the predicted areal fractions where the EU standard of 50 mg l -1 is exceeded for farms with low N surpluses (ALT) and farms with higher N surpluses (REF); 2) predicted cumulative frequency distributions of nitrate concentration for both groups of farms. Both the errors in the predicted areal fractions as well as the errors in the predicted cumulative frequency distributions indicate that the regression models are invalid for the sandy soils of this study area. - This study indicates that linear regression models that predict nitrate concentrations in the upper groundwater using residual soil N contents should be applied with care.

STRUCTURAL HETEROGENEITIES AND PALEO FLUID FLOW IN AN ANALOG SANDSTONE RESERVOIR 2001-2004

International Nuclear Information System (INIS)

Pollard, David; Aydin, Atilla

2005-01-01

Fractures and faults are brittle structural heterogeneities that can act both as conduits and barriers with respect to fluid flow in rock. This range in the hydraulic effects of fractures and faults greatly complicates the challenges faced by geoscientists working on important problems: from groundwater aquifer and hydrocarbon reservoir management, to subsurface contaminant fate and transport, to underground nuclear waste isolation, to the subsurface sequestration of CO2 produced during fossil-fuel combustion. The research performed under DOE grant DE-FG03-94ER14462 aimed to address these challenges by laying a solid foundation, based on detailed geological mapping, laboratory experiments, and physical process modeling, on which to build our interpretive and predictive capabilities regarding the structure, patterns, and fluid flow properties of fractures and faults in sandstone reservoirs. The material in this final technical report focuses on the period of the investigation from July 1, 2001 to October 31, 2004. The Aztec Sandstone at the Valley of Fire, Nevada, provides an unusually rich natural laboratory in which exposures of joints, shear deformation bands, compaction bands and faults at scales ranging from centimeters to kilometers can be studied in an analog for sandstone aquifers and reservoirs. The suite of structures there has been documented and studied in detail using a combination of low-altitude aerial photography, outcrop-scale mapping and advanced computational analysis. In addition, chemical alteration patterns indicative of multiple paleo fluid flow events have been mapped at outcrop, local and regional scales. The Valley of Fire region has experienced multiple episodes of fluid flow and this is readily evident in the vibrant patterns of chemical alteration from which the Valley of Fire derives its name. We have successfully integrated detailed field and petrographic observation and analysis, process-based mechanical modeling, and numerical

Ferroan dolomite cement in Cambrian sandstones: burial history and hydrocarbon generation of the Baltic sedimentary basin

DEFF Research Database (Denmark)

Sliaupa, S.; Cyziene, J.; Molenaar, Nicolaas

2008-01-01

The conditions and timing of carbonate cementation in Cambrian sandstones of the Baltic sedimentary basin were determined by oxygen and carbon stable isotope and chemical data in combination with optical and cathodoluminescence petrographic studies. Studied samples represent a range in present...... burial depth from 340 to 2150 m. The carbonate cement is dominantly ferroan dolomite that occurs as dispersed patches of poikilotopic crystals. Temperatures of dolomite precipitation, based on delta O-18 values, range from 27 degrees C in the shallow buried to 95 degrees C in the deep buried sandstones...

Aeromagnetic gradient survey and elementary application in sandstone type uranium deposits prospecting

International Nuclear Information System (INIS)

Li Xiaolu; Chang Shushuai

2009-01-01

The principle,advantage and data processing of aeromagnetic gradient survey approach is introduced in this paper, and used to identify the shallow surface faults, uranium ore-forming environment and depth of magnetic body for the prospecting of sandstone type uranium deposits. (authors)

The Sandy Hook Elementary School shooting as tipping point

Science.gov (United States)

Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M

2013-01-01

Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States. PMID:28228989

A study on the aseismic safety of the experimental VHTR on the dense sandy layer

International Nuclear Information System (INIS)

Fujita, Shigeki; Ito, Yoshio; Baba, Osamu; Suzuki, Hideyuki; Takewaki, Naonobu; Kondo, Tsukasa; Yoshimura, Takashi; Yamada, Hitoshi.

1986-12-01

A series of studies has been carried out in 1983 and 1985 for the purpose of confirming the aseismic safety of the Experimental VHTR on the dense sandy layer. In 1983, effect of some of soil properties on seismic responses of the reactor building was estimated by means of parametric survey, and soil properties were estimated by analyzing the obserbed earthquake record. In 1985, literature review, linear, nonlinear parametric analyses and nonlinear simulation analyses were carried to study and compare the analysis method. In addition, seismic response of proposed construction site was estimated with nonlinear analysis method. As a result of these studies, the seismic response of reactor building on the dense sandy layers and wave propagation characteristics of sandy layers are understood. Especially, by means of many parametric studies, the effect of input wave characteristics, soil stiffness, nonlinear characteristics of soil properties and nonlinear analysis method on the reactor building responses were evaluated. (author)

What would happen to Superstorm Sandy under the influence of a substantially warmer Atlantic Ocean?

Science.gov (United States)

Lau, William K. M.; Shi, J. J.; Tao, W. K.; Kim, K. M.

2016-01-01

Based on ensemble numerical simulations, we find that possible responses of Sandy-like superstorms under the influence of a substantially warmer Atlantic Ocean bifurcate into two groups. In the first group, storms are similar to present-day Sandy from genesis to extratropical transition, except they are much stronger, with peak Power Destructive Index (PDI) increased by 50-80%, heavy rain by 30-50%, and maximum storm size (MSS) approximately doubled. In the second group, storms amplify substantially over the interior of the Atlantic warm pool, with peak PDI increased by 100-160%, heavy rain by 70-180%, and MSS more than tripled compared to present-day Superstorm Sandy. These storms when exiting the warm pool, recurve northeastward out to sea, subsequently interact with the developing midlatitude storm by mutual counterclockwise rotation around each other and eventually amplify into a severe Northeastern coastal storm, making landfall over the extreme northeastern regions from Maine to Nova Scotia.

Cyclicity recorded in the provenance sandstones in the sedimentary in fill of the Cameros basin (N. Spain)

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Acebron, L.; Arribas, J.; Omodeo-Sale, S.; Arribas, E.; Le Pera, E.; Mas, R.; Lopez-Elorza, M.; Fernandez-Diaz, P. R.

2013-06-01

The intra plate Cameros rift basin in the north of Spain was formed came into being between the Tithonian and the Early Albian and contains 9 000 m of mostly continental sediments. This basin is a good example of cyclicity of different depositional sequences (DSs) in sedimentary environments, which show clear repetition in their sandstone composition (petrofacies) and diagenetic patterns. The DSs are arranged in two mega sequences (MSs) separated by a tectonic unconformity. A similar vertical sandstone compositional evolution, subdivided into two stages that repeat cyclically, has been recognised in both MSs: the first comprises quartzo-sedimentolithic petrofacies and the second is made up of several quartzo-feldspathic petrofacies. This was caused by a progression from the recycling of the pre-rift sedimentary cover to the erosion of the mainly plutonic and metamorphic crystalline basement. These changes in the erosion of the different source areas were conditioned by the tectonics of the basin. Furthermore, the original sandstone framework composition conditioned the diagenetic pattern of the two stages: quartzo-sedimentolithic sandstones containing large amounts of very pervasive carbonate cement that reduce their original porosity considerably, and quartzo-feldspathic petrofacies with a rigid framework that maintained the original pores during burial diagenesis. This compositional and diagenetic pattern is probably applicable to other non-volcanic rifted basins, depending upon the original amount of carbonate rock fragments present. (Author)

Methodology for the design of the method of siliceous sandstones operation using special software

Directory of Open Access Journals (Sweden)

Luis Ángel Lara-González

2014-12-01

Full Text Available The methodologies used for the design of the method of sandstones explotation by descending staggered banks using specialized software tools are reported. The data analyzed were collected in the field for the operating license 14816 in Melgar, Tolima. The characterization of the rock mass was held from physical and mechanical tests, performed on cylindrical test tubes in order to obtain the value of the maximum strenght and elastic modulus of the rock. The direction and dip of the sandstone package was rock. The direction and dip of the sandstone package was determined by using the stereographic projection whit DIPS®  software, and the safety factor of the slope was obtained with established banks whit SLIDE® . The slops are 8 meters high and 8 meters wide whit a tilt angle 60°, which generated a safety factor  of 2.1. The design  of the mining method was carried out with GEOVIA SURPAC® , at an early stage of development ascending to the level 11 of the exploitation, to then start mining in descending order to control the stabiLity of slopes. The results obtained allow a general methodology for the development of projects to optimize the process of evaluation and selection of mining method by using specialized design tools.

Formation factor in Bentheimer and Fontainebleau sandstones: Theory compared with pore-scale numerical simulations

Science.gov (United States)

Ghanbarian, Behzad; Berg, Carl F.

2017-09-01

Accurate quantification of formation resistivity factor F (also called formation factor) provides useful insight into connectivity and pore space topology in fully saturated porous media. In particular the formation factor has been extensively used to estimate permeability in reservoir rocks. One of the widely applied models to estimate F is Archie's law (F = ϕ- m in which ϕ is total porosity and m is cementation exponent) that is known to be valid in rocks with negligible clay content, such as clean sandstones. In this study we compare formation factors determined by percolation and effective-medium theories as well as Archie's law with numerical simulations of electrical resistivity on digital rock models. These digital models represent Bentheimer and Fontainebleau sandstones and are derived either by reconstruction or directly from micro-tomographic images. Results show that the universal quadratic power law from percolation theory accurately estimates the calculated formation factor values in network models over the entire range of porosity. However, it crosses over to the linear scaling from the effective-medium approximation at the porosity of 0.75 in grid models. We also show that the effect of critical porosity, disregarded in Archie's law, is nontrivial, and the Archie model inaccurately estimates the formation factor in low-porosity homogeneous sandstones.

A economic evaluation system software on in-situ leaching mining sandstone uranium deposits

International Nuclear Information System (INIS)

Yao Yixuan; Su Xuebin; Xie Weixing; Que Weimin

2001-01-01

The author presents the study results of applying computer technology to evaluate quantitatively the technical-economic feasibility of in-situ leaching mining sandstone uranium deposits. A computer system software have been developed. Under specifying deposit conditions and given production size per year, the application of the software will generate total capital and mine life operating costs as well as solve for the movable and static financial assessment targets through discounted cash flow analysis. According to the characters of two kinds of sandstone uranium deposits, a data bases of economic and technique parameters of in-situ leaching have been designed. Also the system software can be used to study the economic value of deposits and to optimize the key project parameters. Its features, data input method and demand, main functions, structure and operating environments are described

EFFECT OF IRRIGATION INTERVAL AND SOIL AMENDMENTS ON SOIL ORGANIC C, NITROGEN AND POTASSIUM OF SANDY SOIL AND GROWTH OF Jatropha curcas L.

Directory of Open Access Journals (Sweden)

Djajadi

2013-06-01

Full Text Available Inherently, sandy soil is the unfertile soil with low in all aspects of soil fertility and has a low capacity to retain water applied nutrients. To improve the fertility of sandy soil as media growth of Jatropha curcas, clay and organic matter may have important role when they are incorporated to the sandy soil. This study investigated the effect of irrigation interval and incorporation of clay together with organic matter to sandy soil on soil organic C, N, and K and growth of J. curcas. The rates of clay and organic matter incorporated to top sandy soil were 5% clay + 0.8% organic matter and 10% clay + 1.6% organic matter. Two irrigation intervals tested were 10 day and 20 day. The results found that incorporation of 10% clay + 1.6% organic matter to sandy soil increased soil C organic, N total and exchangeable K which in turn increased number of leaves and number of lateral branches of J curcas. Irrigation intervals had no effect on all parameters observed.

Patterns of species richness in sandy beaches of South America ...

African Journals Online (AJOL)

The middle shore is primarily occupied by cirolanids and bivalves, and hippid crabs, bivalves and amphipods dominate the lower beach. Generally, species richness increases from upper to lower beach levels. Studies carried out on exposed sandy beaches of south-central Chile (ca. 40°S) show that different beach states ...

Local diversity versus geographical distribution of arthropods occuring in a sandstone rock labyrinth

Czech Academy of Sciences Publication Activity Database

Růžička, Vlastimil; Mlejnek, R.; Šmilauer, P.

2010-01-01

Roč. 58, č. 3 (2010), s. 533-544 ISSN 1505-2249 Institutional research plan: CEZ:AV0Z50070508 Keywords : sandstone * microclimate * paleorefugium Subject RIV: EH - Ecology, Behaviour Impact factor: 0.542, year: 2010

Comparison of Buffer Effect of Different Acids During Sandstone Acidizing

International Nuclear Information System (INIS)

Shafiq, Mian Umer; Mahmud, Hisham Khaled Ben; Hamid, Mohamed Ali

2015-01-01

The most important concern of sandstone matrix acidizing is to increase the formation permeability by removing the silica particles. To accomplish this, the mud acid (HF: HCl) has been utilized successfully for many years to stimulate the sandstone formations, but still it has many complexities. This paper presents the results of laboratory investigations of different acid combinations (HF: HCl, HF: H 3 PO 4 and HF: HCOOH). Hydrofluoric acid and fluoboric acid are used to dissolve clays and feldspar. Phosphoric and formic acids are added as a buffer to maintain the pH of the solution; also it allows the maximum penetration of acid into the core sample. Different tests have been performed on the core samples before and after the acidizing to do the comparative study on the buffer effect of these acids. The analysis consists of permeability, porosity, color change and pH value tests. There is more increase in permeability and porosity while less change in pH when phosphoric and formic acids were used compared to mud acid. From these results it has been found that the buffer effect of phosphoric acid and formic acid is better than hydrochloric acid. (paper)

Structural diagenesis in Upper Carboniferous tight gas sandstones. Lessons learned from the Piesberg analog study

Energy Technology Data Exchange (ETDEWEB)

Steindorf, P.; Hoehne, M.; Becker, S.; Hilgers, C. [RWTH Aachen Univ. (Germany). Energy and Mineral Resources Group (EMR); Koehrer, B. [Wintershall Holding GmbH, Barnstorf (Germany)

2013-08-01

Upper Carboniferous tight gas sandstone reservoirs in NW-Germany consist of thick successions of cyclothems. Our focus is the Westphalian D of the Piesberg quarry near Osnabrueck, which exposes cemented, faulted and jointed third-order coarse- to fine-grained sandstone cycles separated by anthracite coal seams. We characterize the rocks and the lateral variation of rock properties such as porosity to better constrain input data for reservoir modelling. Three cycles are exposed, each approximately 50 m thick. Rock types can be clearly distinguished by spectral gamma ray in the quarry. Sandstones are intensely compacted and cemented with quartz and generally characterized by low porosities < 8 % (Hepycnometry on plugs and cuttings). Porosities are secondary and mainly related to detrital carbonate dissolution. Around faults dissolution is higher and the porosities can increase to up to 25%. The normal faults show different throws in the quarry and bands of shale and coal have smeared into the fault at juxtaposed beds, which may result in compartments. They dominantly strike W-E and NNW-SSE, but subordinate NE-SW striking fault patterns are also present. Joints were analyzed in a 50 x 50 m section of the quarry wall using Lidar (Light detection and ranging) laser scanning, which allows the characterization of the lithology and quantitative measurement of bedding and fracture orientation data in inaccessible areas. NNE-SSW and W-E joint sets are accompanied by northeasterly and northwesterly striking sets. Around faults, fault planes and fractures are cemented with quartz veins, showing localized mass transport. Due to the intense cementation, the sandstones can reach uniaxial strengths of more than 100 MPa normal to bedding, and approximately 50 MPa parallel to bedding. Sandstone beds within and close to faults are leached by fluids, and their uniaxial strength is reduced by a factor of more than two. Our high resolution field data enables a better understanding of

Perspective and resource evaluation and metallogenic studies on sandstone-type uranium deposit in Qianjiadian depression of Songliao Basin

Energy Technology Data Exchange (ETDEWEB)

Yuliang, Xia; Jinrong, Lin; Ziying, Li; Shengxiang, Li; Hanbin, Liu; Zhiming, Wang; Guang, Fan [Beijing Research Inst. of Uranium Geology, Beijing (China); Jiwei, Zheng; Zhenji, Li; Mingyu, Zhang [Liaohe Oil Field, Panjin (China)

2003-07-01

The geotectonic evolution history of the southeastern part of Songliao Basin has been clearly described and it is pointed out that both of the provenance rocks and evolution features of the studied area are favorable to the formation of U-rich sandstone bodies, development of interlayered oxidation and providing uranium source for mineralization. Yaojia Formation in Qianjiadian depression has been found out to be the favorable target ore bed for looking for sandstone-type uranium deposit. On the basis of analysis of metallogenetic conditions, the perspective target area has been circled and a sandstone-type uranium deposit with a certain amounts of uranium tonnages has been discovered. The achievements and data have been gotten in the following aspects: constitution and features of ore-forming beds and sandstone bodies, uranium existence forms and mineralogical and chemical compositions of the ores, associated elements and their economic values for comprehensive mining. The study of metallogenetic features and mechanism of the uranium deposit suggested that pre-enrichment of uranium during the depositional-diagenetic stage provide a good basis for uranium mineralization, and hereafter interlayered oxidation as well as oil-gas reduction processes played a decisive role to uranium mineralization. U-Pb isotopic studies indicate that the ores have two isochron ages of 53{+-}3 Ma and 7.0{+-}0 Ma, corresponding to the periods of arid and semiarid paleo-climates which are favorable to interlayered oxidation development and uranium mineralization. It is concluded that the Qianjiadian sandstone-type uranium deposit is genetically related to interlayered oxidation and secondary reduction of oil-gas. The metallogenic model of Qianjiadian uranium deposit was set up. (authors)

Perspective and resource evaluation and metallogenic studies on sandstone-type uranium deposit in Qianjiadian depression of Songliao Basin

International Nuclear Information System (INIS)

Xia Yuliang; Lin Jinrong; Li Ziying; Li Shengxiang; Liu Hanbin; Wang Zhiming; Fan Guang; Zheng Jiwei; Li Zhenji; Zhang Mingyu

2003-01-01

The geotectonic evolution history of the southeastern part of Songliao Basin has been clearly described and it is pointed out that both of the provenance rocks and evolution features of the studied area are favorable to the formation of U-rich sandstone bodies, development of interlayered oxidation and providing uranium source for mineralization. Yaojia Formation in Qianjiadian depression has been found out to be the favorable target ore bed for looking for sandstone-type uranium deposit. On the basis of analysis of metallogenetic conditions, the perspective target area has been circled and a sandstone-type uranium deposit with a certain amounts of uranium tonnages has been discovered. The achievements and data have been gotten in the following aspects: constitution and features of ore-forming beds and sandstone bodies, uranium existence forms and mineralogical and chemical compositions of the ores, associated elements and their economic values for comprehensive mining. The study of metallogenetic features and mechanism of the uranium deposit suggested that pre-enrichment of uranium during the depositional-diagenetic stage provide a good basis for uranium mineralization, and hereafter interlayered oxidation as well as oil-gas reduction processes played a decisive role to uranium mineralization. U-Pb isotopic studies indicate that the ores have two isochron ages of 53±3 Ma and 7.0±0 Ma, corresponding to the periods of arid and semiarid paleo-climates which are favorable to interlayered oxidation development and uranium mineralization. It is concluded that the Qianjiadian sandstone-type uranium deposit is genetically related to interlayered oxidation and secondary reduction of oil-gas. The metallogenic model of Qianjiadian uranium deposit was set up. (authors)

Facies analysis, sedimentology and paleocurrent of the quaternary nenering formation, Pengkalan Hulu, Malaysia

International Nuclear Information System (INIS)

Yuniarti Ulfa; Evonne Hooi Rong Yu; Ooi Cheng Kit

2014-01-01

Nenering Formation is essentially made up of semi-consolidated sediments, which are divided into basal conglomerate beds, conglomeratic sandstone, cross-bedded sandstone, and siltstone to muddy layers facies. It is overlie unconformable to the Berapit Formation, but conformable to the Kroh and Grik Formations. The stratigraphy of Nenering Formation is a fining upwards sequence where the thickness of conglomerate beds become thinner upwards and become thicker for conglomeratic sandstone. The thickness varies from 0.5 m to tenths of meters. The more sandy in the upper portion (cross-bedded sandstone) overlie with thin siltstone and mud stone facies. The clast and grain composition suggested that the material making up the sedimentary sequence were derived predominantly from the erosion of granitoid rocks and sedimentary and metamorphic rocks constitute a minor provenance. Imbrications and the trend sizes of clasts indicate that the paleo-current flow toward northeast. Cross bedding that was found in conglomerate and sandstone indicates the main channel depositional environment. The sequence stratigraphy of this area match with the Saskatchewan fluvial braided channel model. (author)

Characterization of Carbon Monoxide Exposure During Hurricane Sandy and Subsequent Nor'easter.

Science.gov (United States)

Schnall, Amy; Law, Royal; Heinzerling, Amy; Sircar, Kanta; Damon, Scott; Yip, Fuyuen; Schier, Josh; Bayleyegn, Tesfaye; Wolkin, Amy

2017-10-01

Carbon monoxide (CO) is an odorless, colorless gas produced by fossil fuel combustion. On October 29, 2012, Hurricane Sandy moved ashore near Atlantic City, New Jersey, causing widespread morbidity and mortality, $30 to $50 billion in economic damage, and 8.5 million households to be without power. The combination of power outages and unusually low temperatures led people to use alternate power sources, placing many at risk for CO exposure. We examined Hurricane Sandy-related CO exposures from multiple perspectives to help identify risk factors and develop strategies to prevent future exposures. This report combined data from 3 separate sources (health departments, poison centers via the National Poison Data System, and state and local public information officers). Results indicated that the number of CO exposures in the wake of Hurricane Sandy was significantly greater than in previous years. The persons affected were mostly females and those in younger age categories and, despite messaging, most CO exposures occurred from improper generator use. Our findings emphasize the continued importance of CO-related communication and ongoing surveillance of CO exposures to support public health response and prevention during and after disasters. Additionally, regional poison centers can be a critical resource for potential on-site management, public health promotion, and disaster-related CO exposure surveillance. (Disaster Med Public Health Preparedness. 2017;11:562-567).

Sandstone uranium deposits in the United States: a review of the history, distribution, genesis, mining areas, and outlook

International Nuclear Information System (INIS)

Crawley, R.A.

1983-03-01

Sandstone uranium deposits account for about 94 percent of uranium reserves in the United States. Most sandstone uranium districts had been found by the mid-1950s in response to incentives promulgated by the US Atomic Energy Commission. Principal uranium resource regions in the United States are the Colorado Plateau, Wyoming Basins, and Texas Coastal Plain. Statistical data published annually by the US Department of Energy show trends of uranium exploration and production, estimates of resources, and distributions and characteristics of reserves. At present, US exploration and production are curtailed because of uranium oversupply, a trend that will continue for the next few years. Although the outlook is more optimistic over the longer term, it is clouded by possible competition from foreign low-cost, nonsandstone uranium. Roll-type and peneconcordant are the two principal types of sandstone uranium deposits. Roll deposits are formed at geochemical fronts where oxidizing uranium-bearing groundwater penetrates reduced sandstone. Uranium is precipitated by reduction at the front. Under mildly reducing conditions, uranium may remain in solution until it is locally precipitated by reduction, chelation, or complexing to form peneconcordant deposits. Proposed precipitating agents include carbonaceous matter, humate, pyrite, and hydrogen sulfide. The uranium is thought to have been derived from leaching of tuffaceous or arkosic sediments, or of granitic rocks

An Experimental Study of the Fracture Coalescence Behaviour of Brittle Sandstone Specimens Containing Three Fissures

Science.gov (United States)

Yang, S. Q.; Yang, D. S.; Jing, H. W.; Li, Y. H.; Wang, S. Y.

2012-07-01

To analyse the fracture coalescence behaviour of rock, rectangular prismatic sandstone specimens (80 × 160 × 30 mm in size) containing three fissures were tested under uniaxial compression. The strength and deformation behaviours of the specimens are first analysed by investigating the effects of the ligament angle β2 on the peak strength, peak strain and crack initiation stress of the specimens. To confirm the sequence of crack coalescence, a photographic monitoring technique is used throughout the entire period of deformation. Based on the results, the relationship between the real-time crack coalescence process and the axial stress-strain curve of brittle sandstone specimens is also developed, and this relationship can be used to evaluate the macroscopic deformation characteristics of pre-cracked rock. The equivalent strain evolution fields of the specimen, with α = β1 = 45° and β2 = 90°, are obtained using the digital image correlation technique and show good agreement with the experimental results of pre-cracked brittle sandstone. These experimental results are expected to improve the understanding of fracture mechanisms and be used in rock engineering with intermittent structures, such as deep underground excavated tunnels.

The sandstone's chromatic alteration of the florentine cultural heritage

Science.gov (United States)

Vettori, S.; Pecchioni, E.; Cantisani, E.; Ricci, M.; Fratini, F.; Garzonio, C. A.

2012-04-01

Pietra Serena is one of the materials more used in Florentine architecture. It is a sandstone that outcrops in the hills north of the city in the municipality of Fiesole and it has been employed mainly for ornamental purposes. This litotype belongs to the the Macigno Formation (Oligocene Upper- Miocene Lower) which consists of beds of turbiditic sandstones separated by pelitic levels which are the finest components of each single turbidity layer. Petrographically, Pietra Serena can be defined as a medium-coarse-grained greywacke made of quartz, feldspars, micas, fragments of metamorphic and magmatic rocks. The clayey matrix is quite abundant, mainly composed by illite, kaolinite and chlorite-vermiculite (present only in some quarries). It is well known that the processes of decay of the sandstones are related to the type of matrix, the amount of cement, the kind of clay minerals and to the pore size distribution, which lead to water infiltrations, swelling of the clay minerals, separation of the clayey matrix, with resulting exfoliation and peeling of the stone artefacts. Pietra Serena has a bluish-grey colour in fresh cut, but many times it is easily oxidized acquiring an ochraceous-reddish brown colour on buildings. Such changes in colour, appear to be due in part to the oxidation of iron, proceeding very quickly from the surface to the inside, though the cohesion is not affected. It is possible to hypothesize that the chromatic changes not necessarily involve a progressive state of alteration of the artefact, but they may often to represents a natural patina acquired with the time. Nevertheless it is necessary to remember that the oxidized layer and its hardness could also be the result of treatments performed in the past. In Florence, several monuments and buildings are affected by such phenomenon, in particular it is possible to note an intense and diffuse reddish colouring on the Pietra Serena utilized for columns and for façade's decorations. In this work

Petrological features of selected components of the Cergowa sandstones (Outer Carpathians recorded by scanning electron microscopy – preliminary study

Directory of Open Access Journals (Sweden)

Pszonka Joanna

2017-01-01

Full Text Available The scanning electron microscope analysis of the Cergowa sandstones brings new data on their petrological features and chemical composition. Previous work in standard petrographic examination, e.g. polarising (PL or cathodoluminescence (CL microscopy, displayed limited information on grain surface topography and only assumptions to their geochemistry. Both identification and characterisation of minerals are fundamental in the progress of mining and minerals processing systems. Detrital grains of the Cergowa sandstones are bound by calcite and dolomitic cement and commonly corroded by diagenetic fluids, however, in varying degrees, which is illustrated here by feldspar, quartz and dolomite minerals. Dissolution processes of marginal parts of these mineral grains resulted in corrosion, which increased the contact surface between the grains and the cement. The difference in resistance to these processes was observed not only among distinct groups of minerals, but also within the group of feldspars: between K–feldspars and minerals of plagioclase. That combination resulted in exceptionally strong cementation of the Cergowa sandstones, which is expressed by their high hardness and resistance to abrasion, freezing, and thawing. Inherent parameters of sandstones are characterised by their petrographical properties.

Impact of Superstorm Sandy on Medicare Patients' Utilization of Hospitals and Emergency Departments.

Science.gov (United States)

Stryckman, Benoit; Walsh, Lauren; Carr, Brendan G; Hupert, Nathaniel; Lurie, Nicole

2017-10-01

National health security requires that healthcare facilities be prepared to provide rapid, effective emergency and trauma care to all patients affected by a catastrophic event. We sought to quantify changes in healthcare utilization patterns for an at-risk Medicare population before, during, and after Superstorm Sandy's 2012 landfall in New Jersey (NJ). This study is a retrospective cohort study of Medicare beneficiaries impacted by Superstorm Sandy. We compared hospital emergency department (ED) and healthcare facility inpatient utilization in the weeks before and after Superstorm Sandy landfall using a 20% random sample of Medicare fee-for-service beneficiaries continuously enrolled in 2011 and 2012 (N=224,116). Outcome measures were pre-storm discharges (or transfers), average length of stay, service intensity weight, and post-storm ED visits resulting in either discharge or hospital admission. In the pre-storm week, hospital transfers from skilled nursing facilities (SNF) increased by 39% and inpatient discharges had a 0.3 day decreased mean length of stay compared to the prior year. In the post-storm week, ED visits increased by 14% statewide; of these additional "surge" patients, 20% were admitted to the hospital. The increase in ED demand was more than double the statewide average in the most highly impacted coastal regions (35% versus 14%). Superstorm Sandy impacted both pre- and post-storm patient movement in New Jersey; post-landfall ED surge was associated with overall storm impact, which was greatest in coastal counties. A significant increase in the number and severity of pre-storm transfer patients, in particular from SNF, as well as in post-storm ED visits and inpatient admissions, draws attention to the importance of collaborative regional approaches to healthcare in large-scale events.

Measurement of earthquake-induced shear strain in sandy gravel

International Nuclear Information System (INIS)

Ohkawa, I.; Futaki, M.; Yamanouchi, H.

1989-01-01

The nuclear power reactor buildings have been constructed on the hard rock ground formed in or before the Tertiary in Japan. This is mainly because the nuclear reactor building is much heavier than the common buildings and requires a large bearing capacity of the underlying soil deposit, and additionally the excessive deformation in soil deposit might cause damage in reactor building and subsequently cause the malfunction of the internal important facilities. Another reason is that the Quaternary soil deposit is not fully known with respect to its dynamic property. The gravel, and the sandy gravel, the representative soils of the Quaternary, have been believed to be suitable soil deposits to support the foundation of a common building, although the soils have rarely been investigated so closely on their physical properties quantitatively. In this paper, the dynamic deformability, i.e., the shear stress-strain relationship of the Quaternary diluvial soil deposit is examined through the earthquake ground motion measurement using accelerometers, pore-pressure meters, the specific devices developed in this research work. The objective soil deposit in this research is the sandy gravel of the diluvial and the alluvial

Thermophysical behavior of St. Peter sandstone: application to compressed air energy storage in an aquifer

Energy Technology Data Exchange (ETDEWEB)

Erikson, R.L.

1983-12-01

The long-term stability of a sandstone reservoir is of primary importance to the success of compressed air energy storage (CAES) in aquifers. The purpose of this study was to: develop experimental techniques for the operation of the CAES Porous Media Flow Loop (PMFL), an apparatus designed to study the stability of porous media in subsurface geologic environments, conduct experiments in the PMFL designed to determine the effects of temperature, stress, and humidity on the stability of candidate CAES reservoir materials, provide support for the CAES field demonstration project in Pittsfield, Illinois, by characterizing the thermophysical stability of Pittsfield reservoir sandstone under simulated field conditions.

Genesis of sandstone-type uranium deposits in the Sierra Pintada district, Mendoza, Argentina: a Moessbauer study

International Nuclear Information System (INIS)

Labenski, F.; Saragovi-Badler, C.

1982-01-01

The genesis of sandstone-type uranium deposits in the Cochico Group (Permo-Triassic) of the Sierra Pintada district, San Rafael, Mendoza, has been studied. This is the most important uranium district in Argentina. Uranium sources, uranium transport and precipitation are discussed. Uraninite and brannerite, the main uranium minerals, occur within the matrix of sandstone. Several phenomena can be deduced regarding the depositional environment. Where oxygen was available, precipitation of hydrated ferric oxides occurred; γFe 2 O 3 .nH 2 O varieties (identified by Moessbauer spectroscopy) precipitated in the upper levels of the aquifer, where CO 2 partial pressure was lower, giving reddish or reddish-brown beds. The CO 2 partial pressure also determines the distribution of biogenic agents such as bacteria. Bacteria thus find a more favourable environment for their development and action in upper levels of an aquifer. In the corresponding horizons local reduction occurred where UO 2 precipitated; therefore the highest uranium concentrations correspond to sandstone levels with reddish or reddish-brown pigment. These pigments have been identified by Moessbauer spectroscopy. (Auth.)

influence of tillage practices on physical properties of a sandy loam

African Journals Online (AJOL)

DR. AMINU

many regions of the world if the mechanics of tillage effects on soil physical properties is to be well understood. Thus, the ... tillage systems on water storage of a sandy loam soil after 22 years of ..... Soil infiltration ... and processes. Academy ...

Interpreting Fracture Patterns in Sandstones Interbedded with Ductile Strata at the Salt Valley Anticline, Arches National Park, Utah

OpenAIRE

Lorenz, John C.; Cooper, Scott P.

2001-01-01

Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with examples from Paleozoic strata at the southern edge of the Holbrook basin in northeastern Arizona, a...

Microbial mat structures in profile: The Neoproterozoic Sonia Sandstone, Rajasthan, India

Science.gov (United States)

Samanta, Pradip; Mukhopadhyay, Soumik; Mondal, Anudeb; Sarkar, Subir

2011-01-01

Ubiquitous microorganisms, especially cyanobacteria preferably grow on the sediment surface thereby producing microbial mats. In the absence of grazers and bioturbators, microbial mat is a unique feature of the Proterozoic. Most of the papers so far published described a wide variety of bed surface microbial mat structures with rare illustrations from sections perpendicular to bedding. Nonetheless, bed surface exposures are relatively rare in rock records. This limitation of bed surface exposures in rock records suggest that a study of microbial mats in bed-across sections is needed. The 60 m thick coastal marine interval of the Sonia Sandstone Formation is bounded between two terrestrial intervals, a transgressive lag at the base and an unconformity at the top, and has been chosen for exploration of microbial mat structures in bed-across sections. A wide variety of microbial mat-induced structures in bed-across sections are preserved within the coastal interval of the Sonia Sandstone. Though many of these structures are similar in some aspects with bed surface structures, some of those presented here are new. The palaeogeographic range of these microbial structures extends from supralittoral to neritic. Diagenetic alterations of microbial mats produce pyrite and those zones are suitable for the preservation of microbial remains. SEM and EDAX analyses show fossil preservation of filamentous microbial remains that confirm the presence of microbial mats within the coastal interval of the Sonia Sandstone. Effects of proliferation of microbial mats in the siliciclastic depositional setting are numerous. The mat-cover on sediment surfaces hinders reworking and/or erosion of the sediments thereby increases the net sedimentation rate. Successive deposition and preservation of thick microbial mat layer under reducing environments should have a great potential for hydrocarbon production and preservation and therefore these Proterozoic formations could be a target for

Research and application of information system for sandstone-type uranium exploration

International Nuclear Information System (INIS)

Han Shaoyang; Huang Shutao; Hou Huiqun

2003-01-01

The GIS (Geographical Information System) technique is applied to the exploration and evaluation of in-situ leachable sandstone-type uranium deposits and the GIS application system of desktop is created for non-GIS professionals. ArcView3.2 is taken as compositive platform of the information system. The secondary design is developed through the AVENUE language provided by ArcView3.2 on the software functions. According to the needs of multi-source information management and integrated evaluation, a series of new functions are appended to the basic platform through AVENUE language on a basis of sufficiently inheriting ArcView3.2 software functions and a friendly graphic user interface is also created, so that the system implements the following functions better, including information query, data base management, editing graphics, geologic mapping, image processing, spatial analysis, model analysis and result output. In order to manage the plenty of borehole data better and quickly realize the borehole mapping, a system software of borehole data management and mapping on the base of GIS software platform is developed. The system software has been applied to uranium survey project in the west of Hailaer basin. Based on multi-source geoscience information database including geologic, geophysical, geochemical and remote sensing data, the system software has been used to perform the integrated analysis of spatial data for realizing the deep analysis and studies of the metallogenic geologic environments of sandstone-type uranium deposits. In the Kelulun basin, the weights of evidence analysis have been used to quantitatively predict the prospective areas of sandstone uranium deposits. Information system has also been applied to the integrated evaluation of uranium resource in the south of Yili basin, Songliao basin and other areas. (authors)

Utilisation of Sand from Kaolin Washing for the Manufacture of Alkali-activated Artificial Sandstone

Science.gov (United States)

Vavro, Martin; Vavro, Leona; Mec, Pavel; Soucek, Kamil; Pticen, Frantisek; Reiterman, Pavel

2017-04-01

Sandstones represent a traditional natural stones which are widely used in Czech architecture and sculpture over a long time. Thanks to their relatively easy workability, sandstones provide a wide range of stone products and also represent a popular material for architectural and sculptural purposes. In the field of restoration of artworks, they are therefore often used for manufacturing stone statue copies originally made from the same or similar type of stone. Despite a relatively common and varied occurrence of natural sandstones, the method of the artificial stone facsimiles creation in the form of various cast elements is also often applied in restoration practice. The history of application of artificial stones in civil engineering and architecture goes back to the ancient times, i.e. to Roman antiquity and possibly up to the time of ancient Egypt. The lack of appropriate natural rock, suitable in the view of colour, grain size or texture is the main reason of manufacturing copies based on synthetic mixtures. The other reason is high financial costs to create a sculpture copy from natural materials. Mixtures made from white and/or grey cements, sands, carefully selected crushed stone or well graded natural gravels, and mineral coloring pigments or mixtures with acrylate, polyester, and epoxy resins binder are the most frequently used artificial materials for cast stone manufacturing. This paper aims to bring information about composition and properties of artificial sandstones made from alkali-activated binder mixtures based on metakaolin and granulated blast furnace slag. The filler of this artificial stone is represented by fine-grained sand generated during kaolin wet processing. Used sand is mainly formed by quartz, feldspars, micas (muscovite > biotite), residual kaolin, and to a lesser extent also by Fe oxyhydroxides ("limonite"), titanium dioxide mineral (probably anatase), and carbonate mineral unidentified in detail. Annual Czech production of this

Interpreting Fracture Patterns in Sandstones Interbedded with Ductile Strata at the Salt Valley Anticline, Arches National Park, Utah; TOPICAL

International Nuclear Information System (INIS)

LORENZ, JOHN C.; COOPER, SCOTT P.

2001-01-01

Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with examples from Paleozoic strata at the southern edge of the Holbrook basin in northeastern Arizona, and sandstones of the Frontier Formation along the western edge of the Green River basin in southwestern Wyoming), show that although each fracture domain may contain consistently oriented fractures, the orientations and patterns of the fractures vary considerably from domain to domain. Most of the fracture patterns in the brittle sandstones are related to local stresses created by subtle, irregular flexures resulting from mobility of the associated, interbedded ductile strata (halite or shale). Sequential episodes of evaporite dissolution and/or mobility in different directions can result in multiple, superimposed fracture sets in the associated sandstones. Multiple sets of superimposed fractures create reservoir-quality fracture interconnectivity within restricted localities of a formation. However, it is difficult to predict the orientations and characteristics of this type of fracturing in the subsurface. This is primarily because the orientations and characteristics of these fractures typically have little relationship to the regional tectonic stresses that might be used to predict fracture characteristics prior to drilling. Nevertheless, the high probability of numerous, intersecting fractures in such settings attests to the importance of determining fracture orientations in these types of fractured reservoirs

An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

Science.gov (United States)

Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

2016-04-01

To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

Enhancing the biodegradation of oil in sandy sediments with choline: A naturally methylated nitrogen compound

International Nuclear Information System (INIS)

Mortazavi, Behzad; Horel, Agota; Anders, Jennifer S.; Mirjafari, Arsalan; Beazley, Melanie J.; Sobecky, Patricia A.

2013-01-01

We investigated how additions of choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments contaminated with moderately weathered crude oil (4000 mg kg −1 sediment). Addition of lauroylcholine chloride (LCC) and tricholine citrate (TCC) to oil contaminated sediments resulted in 1.6 times higher hydrocarbon degradation rates compared to treatments without added choline derivatives. However, the degradation rate constant for the oil contaminated sediments amended with LCC was similar to that in contaminated sediments amended with inorganic nitrogen, phosphorus, and glucose. Additions of LLC and TCC to sediments containing extensively weathered oil also resulted in enhanced mineralization rates. Cultivation-free 16S rRNA analysis revealed the presence of an extant microbial community with clones closely related to known hydrocarbon degraders from the Gammaproteobacteria, Alphaproteobacteria, and Firmicutes phyla. The results demonstrate that the addition of minimal amounts of organic compounds to oil contaminated sediments enhances the degradation of hydrocarbons. -- Highlights: •Aerobic degradation of weathered crude oil in sandy sediments was determined. •The effect of input of choline on degradation rates was determined. •16S rRNA clone library analyses were used to examine the microbial phylogeny. •The bacterial community was consisted of clones related to hydrocarbon degraders. •Hydrocarbon degradation in sandy sediments was accelerated by addition of choline. -- Choline, a naturally occurring methylated nitrogen-containing compound, accelerated hydrocarbon degradation in sandy sediments by an extant microbial community

Food habits of fishes on an exposed sandy beach at Fukiagehama, South-West Kyushu Island, Japan

Science.gov (United States)

Nakane, Yukinori; Suda, Yusuke; Sano, Mitsuhiko

2011-06-01

To clarify the feeding habits and major food sources of sandy beach fishes, the gut contents of 55 fish species collected on a sandy beach at Fukiagehama, South-West Kyushu Island, Japan, were examined. Ontogenetic changes in food preference were recognized in nine species ( Hypoatherina valenciennei, Lateolabrax japonicus, Trachurus japonicus, Sillago japonica, Sphyraena japonica, Paralichthys olivaceus, Heteromycteris japonica, Paraplagusia japonica, and Takifugu niphobles). A cluster analysis based on dietary overlaps showed that the sandy beach fish assemblage comprised six trophic groups (mysid, amphipod, zooplankton, juvenile fish, terrestrial insect, and mollusk feeders). Of these, the first three groups were the most abundantly represented, whereas the last two were represented by only a single species. These results indicated that epibenthic macrofauna, such as mysids and gammaridean amphipods, and zooplankton, were important food resources for the fish assemblage at the study site, but infaunal macrobenthos, such as polychaetes and bivalves, being relatively unimportant.

Study of phosphatic nodules as a possible source of uranium mineralization in warcha sandstone of nilawahan group salt range using SSNTD technique

International Nuclear Information System (INIS)

Qureshi, A.A.; Ullah, K.; Ullah, N.; Mohammad, A.

2004-07-01

The strong in the sedimentary depositional characteristics between the Warcha Sandstone of Nilawahan Group in the Salt Range and the uranium bearing sandstones of Siwalik Group in the foot hills of Himalaya and Sulaiman Ranges tempted the geologists to investigate the former group for the occurrence of any uranium deposits in it. Like volcanic ash beds in Siwaliks, phosphatic nodules may be a possible source of uranium mineralization in Warcha Sandstone of Nilawahan Group. Samples of phosphatic nodules occurring in the Sandstone of Nilawahan Group Salt Range were analyzed using Solid State Nuclear Track Detention Technique (SSNTD) for the determination of their uranium concentration. The results obtained are quite encouraging and favour the idea of exploring the area in detail for any possible occurrence of uranium deposit. Uranium concentration in these samples ranges from (434 + - 39) ppm to (964+ -81)ppm with and average concentration of (699 + - 62) ppm. (author)

Measuring the zeta potential. The relationships with sandstone fineness

Directory of Open Access Journals (Sweden)

de Luxán, M. P.

1989-09-01

Full Text Available The application of the zeta potential technique in the area of construction materials and Portland cement is quite recent. The initial research work involved the study of cement suspensions or suspensions of one of the components of cement, such as alite, tricalcium alumínate, in the presence of additives and, more specifically, superplasticizers. The studies of this sort were extended with the mixing of active additions into cement (fly ashes, etc.. The present study discusses the application of siliceous materials (sandstone as a basis of the research into the behaviour of sandstone mortars containing repair products.

La aplicación de la técnica del potencial zeta en el campo de los materiales de construcción y del cemento portland es muy reciente. Las primeras investigaciones se refieren al estudio de suspensiones de cemento o de alguno de sus compuestos que lo forman como alita, aluminato tricálcico, en presencia de aditivos y, más concretamente, de superfluidificantes. Con la incorporación de adiciones activas al cemento (cenizas volantes,... se amplían los estudios de este tipo de cementos. En este trabajo se considera la aplicación a los materiales silíceos (arenisca como base para la investigación del comportamiento de los morteros de arenisca conteniendo productos de reparación.

Cyclicity and reservoir properties of Lower-Middle Miocene sediments of South Kirinsk oil and gas field

Science.gov (United States)

Kurdina, Nadezhda

2017-04-01

Exploration and additional exploration of oil and gas fields, connected with lithological traps, include the spreading forecast of sedimentary bodies with reservoir and seal properties. Genetic identification and forecast of geological bodies are possible in case of large-scale studies, based on the study of cyclicity, structural and textural features of rocks, their composition, lithofacies and depositional environments. Porosity and permeability evaluation of different reservoir groups is also an important part. Such studies have been successfully completed for productive terrigenous Dagi sediments (Lower-Middle Miocene) of the north-eastern shelf of Sakhalin. In order to identify distribution of Dagi reservoirs with different properties in section, core material of the one well of South Kirinsk field has been studied (depth interval from 2902,4 to 2810,5 m). Productive Dagi deposits are represented by gray-colored sandstones with subordinate siltstones and claystones (total thickness 90,5 m). Analysis of cyclicity is based on the concepts of Vassoevich (1977), who considered cycles as geological body, which is the physical result of processes that took place during the sedimentation cycle. Well section was divided into I-X units with different composition and set of genetic features due to layered core description and elementary cyclites identification. According to description of thin sections and results of cylindrical samples porosity and permeability studies five groups of reservoirs were determined. There are coarse-grained and fine-coarse-grained sandstones, fine-grained sandstones, fine-grained silty sandstones, sandy siltstones and siltstones. It was found, in Dagi section there is interval of fine-coarse-grained and coarse-grained sandstones with high petrophysical properties: permeability 3000 mD, porosity more than 25%, but rocks with such properties spread locally and their total thickness is 6 meters only. This interval was described in the IV unit

Uranium isotopes in groundwater: their use in prospecting for sandstone-type uranium deposits

International Nuclear Information System (INIS)

Cowart, J.B.; Osmond, J.K.

1977-01-01

The relative abundances of dissolved 238 U and its daughter 234 U appear to be greatly affected as the uranium is transported downdip in sandstone aquifers. In an actively forming uranium accumulation at a reducing barrier, an input of 234 U occurs in proximity to the isotopically non-selective precipitation of uranium from the water. The result is a downdip water much lower in uranium concentration but relatively enriched in 234 U. The measurement of isotopic as well as concentration changes may increase the effectiveness of hydrogeochemical exploration of uranium. The investigation includes the uranium isotopic patterns in aquifers associated with known uranium orebodies in the Powder River and Shirley Basins, Wyoming, and Karnes County, Texas, USA. In addition, the Carrizo sandstone aquifer of Texas was studied in detail and the presence of an uranium accumulation inferred

Changes in the composition and properties of Ashalchinskoye bitumen-saturated sandstones when exposed to water vapor

Science.gov (United States)

Korolev, E.; Eskin, A.; Kolchugin, A.; Morozov, V.; Khramchenkov, M.; Gabdelvalieva, R.

2018-05-01

Ashalchinskoye bitumen deposit is an experimental platform for testing technology of high-viscosity oil extraction from reservoir rocks. Last time for enhanced of oil recovery in reservoir used pressurization a water vapor with a temperature of ∼ 180 ° C (SAGD technology). However, what happens in sandstone reservoir is little known. We did a study of the effects of water vapor on the structural components of bitumen saturated sandstone. In paper were studied the rock samples at base condition and after one week exposure by water vapour. The thermal analysis showed that steaming helps to removes light and middle oil fractions with a boiling point up to 360 ° C from oil saturated sandstones. Content of heavy oil fractions virtually unchanged. Studying the composition of water extractions of samples showed that the process of aquathermolysis of oil is accompanied by a lowering of the pH of the pore solution from 7.4 to 6.5 and rise content in several times of mobile cations Ca2+, Mg2+ and HCO3 -, SO4 2- anions. Follows from this that the thermal steam effect by bitumen saturated sandstones leads to partial oxidation of hydrocarbons with to form a carbon dioxide. The source of sulfate ions were oxidized pyrite aggregates. Due to the increasing acidity of condensed water, which fills the pore space of samples, pore fluid becomes aggressive to calcite and dolomite cement of bitumen saturated sandstones. As a result of the dissolution of carbonate cement the pore fluid enriched by calcium and magnesium cations. Clearly, that the process is accompanied by reduction of contact strength between fragments of minerals and rocks. Resulting part of compounds is separated from the outer side of samples and falls to bottom of water vapor container. Decreasing the amount of calcite and dolomite anions in samples in a steam-treated influence is confirmed by X-Ray analysis. X-Ray analysis data of study adscititious component of rocks showed that when influenced of water vapor to

Patterns of Arbuscular Mycorrhizal Fungal Distribution on Mainland and Island Sandy Coastal Plain Ecosystems in Brazil.

Science.gov (United States)

da Silva, Iolanda Ramalho; de Souza, Francisco Adriano; da Silva, Danielle Karla Alves; Oehl, Fritz; Maia, Leonor Costa

2017-10-01

Although sandy coastal plains are important buffer zones to protect the coast line and maintain biological diversity and ecosystem services, these ecosystems have been endangered by anthropogenic activities. Thus, information on coastal biodiversity and forces shaping coastal biological diversity are extremely important for effective conservation strategies. In this study, we aimed to compare arbuscular mycorrhizal (AM) fungal communities from soil samples collected on the mainland and nearby islands located in Brazilian sandy coastal plain ecosystems (Restingas) to get information about AM fungal biogeography and identify factors shaping these communities. Soil samples were collected in 2013 and 2014 on the beachfront of the tropical sandy coastal plain at six sites (three island and three mainland locations) across the northeast, southeast, and south regions of Brazil. Overall, we recorded 53 AM fungal species from field and trap culture samples. The richness and diversity of AM fungal species did not differ between mainland and island locations, but AM fungal community assemblages were different between mainland and island environments and among most sites sampled. Glomeromycota communities registered from island samples showed higher heterogeneity than communities from mainland samples. Sandy coastal plains harbor diverse AM fungal communities structured by climatic, edaphic, and spatial factors, while the distance from the colonizing source (mainland environments) does not strongly affect the AM fungal communities in Brazilian coastal environments.

Challenges in estimating the health impact of Hurricane Sandy using macro-level flood data.

Science.gov (United States)

Lieberman-Cribbin, W.; Liu, B.; Schneider, S.; Schwartz, R.; Taioli, E.

2016-12-01

Background: Hurricane Sandy caused extensive physical and economic damage but the long-term health impacts are unknown. Flooding is a central component of hurricane exposure, influencing health through multiple pathways that unfold over months after flooding recedes. This study assesses concordance in Federal Emergency Management (FEMA) and self-reported flood exposure after Hurricane Sandy to elucidate discrepancies in flood exposure assessments. Methods: Three meter resolution New York State flood data was obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. FEMA data was compared to self-reported flood data obtained through validated questionnaires from New York City and Long Island residents following Sandy. Flooding was defined as both dichotomous and continuous variables and analyses were performed in SAS v9.4 and ArcGIS 10.3.1. Results: There was a moderate agreement between FEMA and self-reported flooding (Kappa statistic 0.46) and continuous (Spearman's correlation coefficient 0.50) measures of flood exposure. Flooding was self-reported and recorded by FEMA in 23.6% of cases, while agreement between the two measures on no flooding was 51.1%. Flooding was self-reported but not recorded by FEMA in 8.5% of cases, while flooding was not self-reported but indicated by FEMA in 16.8% of cases. In this last instance, 84% of people (173/207; 83.6%) resided in an apartment (no flooding reported). Spatially, the most concordance resided in the interior of New York City / Long Island, while the greatest areas of discordance were concentrated in the Rockaway Peninsula and Long Beach, especially among those living in apartments. Conclusions: There were significant discrepancies between FEMA and self-reported flood data. While macro-level FEMA flood data is a relatively less expensive and faster way to provide exposure estimates spanning larger geographic areas affected by Hurricane Sandy than micro-level estimates from cohort studies, macro

Physical Properties of Sandy Soil Affected by Soil Conditioner Under Wetting and Drying cycles

Directory of Open Access Journals (Sweden)

M.I. Choudhary

1998-06-01

Full Text Available Information on the effectiveness of soil conditioners over a prolonged period is scarce. A laboratory experiment was undertaken to evaluate the effectiveness of a polyacrylamide (Broadleaf P4 soil conditioner on the physical properties of sandy soil subjected to wetting and drying cycles. Four concentrations of Broadleaf P4 0, 0.2, 0.4, and 0.6% on dry weight basis were uniformly mixed with a calcareous sandy soil. Addition of Broadleaf P4 to sandy soil increased the water holding capacity, decreased the bulk density, and increased the porosity and void ratio at 0 and 16 wetting and drying cycles. The coefficient of linear extensibility increased considerably with increasing concentrations of the polymer. The addition of polymer at 0 and 16 cycles increased considerably the retention and availability of water in sandy soil. Saturated hydraulic conductivity decreased with increasing concentrations of Broadleaf P4 whereas unsaturated hydraulic conductivity at 0 and 16 cycles showed an increase with increasing soil moisture contents. After I6 wetting and drying cycles, the capacity of the soil to hold water was lost on average by 15.8% when compared to the 0 wetting and drying cycle. The effectiveness of the soil conditioner on bulk density, coefficient of linear extensibility, available water and saturated hydraulic conductivity was reduced on average by 14.1, 24.5, 21.l and 53.7% respectively. The significant changes in soil properties between 0 and 16 cycles suggested that the effectiveness of the conditioner decreased with the application of wetting and drying cycles. However, its effect was still considerable when compared to untreated soil under laboratory conditions.

Behavioural adaptations of two sympatric sandhoppers living on a mesotidal European Atlantic sandy beach

Science.gov (United States)

Bessa, Filipa; Marques, João Carlos; Scapini, Felicita

2014-06-01

Behavioural adaptations of supralittoral species on sandy beaches are expressed as responses to environmental changes and constitute a key factor in their survival and evolution. Two sympatric talitrid amphipods (Talitrus saltator and Britorchestia brito) from a mesotidal exposed sandy beach on the European Atlantic coast (Portugal) were compared as regards orientation and littoral zonation patterns under natural conditions. Orientation experiments were carried out during spring and summer 2011 and 2012 at Quiaios beach, a highly dynamic exposed sandy beach. Multiple regression models were fitted to the angular data and the environmental effects on orientation were investigated for each species. Both talitrids were shown to be well orientated towards the shoreline and finely adapted to the mesotidal environment but a different use of local cues and climatic features between the two species was apparent. T. saltator showed a lower precision in the orientation performance (with a bimodal distribution sea- and land-wards), with less dependence on the sun cues and higher dependence on climatic features. In addition, the zonation of T. saltator was across the land-sea axis during both seasons. For B. brito the landscape vision, sun visibility and the tidal range enhanced the orientation to the shoreline. On this mesotidal Atlantic beach, T. saltator appeared to have a more flexible orientation with respect to B. brito, which appeared to be more dependent on the conditions offered by the intertidal zone, a behaviour confirmed by its restricted zonation below the high tide mark. Consequently, T. saltator showed a more flexible behaviour that may be considered an important evolutionary adaptation to dynamic and mesotidal sandy beaches.

[Introduction of upland rice cultivars to eastern Keerqin sandy land and their biological characteristics].

Science.gov (United States)

Zeng, Dehui; Zhang, Chunxing; Wang, Guirong; Fan, Zhiping

2004-10-01

Developing water-saving rice cultivation is one important strategy for food security in China. This paper reported the experimental results of introducing six upland rice cultivars to eastern Keerqin sandy land. The field experiment results showed that under the condition of 60% water-saving, the yield of cultivars XH 95-13 and XH 95-13-6 was 10.2% and 5.5% higher than the control, respectively, while other four cultivars decreased by 6.7%-18.6%. Economically, all the cultivars except JP 121 had a higher income than the control, and the profitability of cultivars XH 95-13 and XH 95-13-6 reached 24.0% and 19.3%, respectively. The water productivity of all the six cultivars was over 0.566 kg x m(-3), increased by 59.89%-116.38%. Pot experiment showed that 12.1%-16.3% of soil moisture in 0-15 cm layer was beneficial to the growth of upland rice. In eastern Keerqin sandy land, effective tillers occurred before July 18. In brief, upland rice production could be extensively applicable in eastern Keerqin sandy land to gradually alternate the traditional lowland rice cultivation with continuous flooding, and save much underground water.

Caracterização e classificação de solos desenvolvidos de arenitos da formação Aquidauana-MS Characterization and classification of soils developed from sandstone of the Aquidauana formation

Directory of Open Access Journals (Sweden)

Jolimar Antonio Schiavo

2010-06-01

Full Text Available A formação Aquidauana é constituída por um conjunto de sedimentos com até 500 m de espessura, predominando arenito de granulometria fina a média, intercalado com conglomerado arenoso. Nesse ambiente, o relevo é um dos principais fatores condicionantes na formação de solos. Objetivou-se, neste trabalho, caracterizar e classificar os solos desenvolvidos desses arenitos. Para isso, foram estudados quatro perfis ao longo de uma topossequência, de uma pendente representativa das colinas suaves onduladas verificadas na área de estudo. Os perfis localizavam-se no terço superior (P1, terço médio (P2, terço inferior (P3 e sopé de encosta (P4. Eles foram morfologicamente descritos, e os horizontes, caracterizados quanto às propriedades físicas e químicas. Os solos estudados apresentaram predomínio da fração areia (> 680 g kg-1, com textura variando de franco-arenosa (P4 a franco-argiloarenosa. Os valores de pH em água variaram de 4,2 a 6,5. Os valores de capacidade de troca catiônica variaram de 1,6 cmol c kg-1 no P4 a 10,3 cmol c kg-1 no P2, com predomínio dos íons H+ no P1 e P4 e Ca2+ no P2 e P3. Os horizontes subsuperficiais do P1 e P4 são distróficos, enquanto em P2 e P3 verificou-se elevada saturação por bases, evidenciando caráter eutrófico. À exceção do P2, os demais apresentaram argila de baixa atividade. Em todos os perfis verificaram-se atributos morfológicos, físicos, químicos e mineralógicos condicionados pelo material de origem e relevo, demonstrando a influência desses fatores na pedogênese.The Aquidauana geological formation consists of a set of up to 500 m thick sediments predominantly composed of sandstone with fine to medium grain size, interspersed with sandy conglomerates. In this environment, the topography is one of the main conditioning factors of the formation of different soil types in the landscape. The objective of this study was to characterize and classify soils developed from these

Coronation Hill U-Au mine, South Alligator Valley, Northern Territory: an epigenetic sandstone-type deposit hosted by debris-flow conglomerate

International Nuclear Information System (INIS)

Needham, R.S.; Stuart-Smith, P.G.

1987-01-01

The host rock at the Coronation Hill U-Au mine is a debris flow conglomerate, developed in a high-energy fluvial environment during deposition of the Coronation Sandstone of the El Sherana Group. Mineralisation took place by movement of low-temperature fluids from the U-enriched volcanics into the conduit sandstone and eventually into the reduced debris flow conglomerate and carbonaceous shale

Hospital emergency preparedness and response during Superstorm Sandy.

Science.gov (United States)

2015-01-01

This article presents the findings of a report by the HHS Office of Inspector General (OIG) on the performance of 172 Medicare-certified hospitals in the New York Metropolitan Area before, during, and after Sandy. It makes recommendations on how to close gaps that were found in emergency planning and execution for a disaster of this magnitude. To download the complete 40-page report and a Podcast based on it, go to http://oig.hhs.gov/oei/ reports/oei-06-13-00260. asp.

Different Behavior of Enteric Bacteria and Viruses in Clay and Sandy Soils after Biofertilization with Swine Digestate

Science.gov (United States)

Fongaro, Gislaine; García-González, María C.; Hernández, Marta; Kunz, Airton; Barardi, Célia R. M.; Rodríguez-Lázaro, David

2017-01-01

Enteric pathogens from biofertilizer can accumulate in the soil, subsequently contaminating water and crops. We evaluated the survival, percolation and leaching of model enteric pathogens in clay and sandy soils after biofertilization with swine digestate: PhiX-174, mengovirus (vMC0), Salmonella enterica Typhimurium and Escherichia coli O157:H7 were used as biomarkers. The survival of vMC0 and PhiX-174 in clay soil was significantly lower than in sandy soil (iT90 values of 10.520 ± 0.600 vs. 21.270 ± 1.100 and 12.040 ± 0.010 vs. 43.470 ± 1.300, respectively) and PhiX-174 showed faster percolation and leaching in sandy soil than clay soil (iT90 values of 0.46 and 2.43, respectively). S. enterica Typhimurium was percolated and inactivated more slowly than E. coli O157:H7 (iT90 values of 9.340 ± 0.200 vs. 6.620 ± 0.500 and 11.900 ± 0.900 vs. 10.750 ± 0.900 in clay and sandy soils, respectively), such that E. coli O157:H7 was transferred more quickly to the deeper layers of both soils evaluated (percolation). Our findings suggest that E. coli O157:H7 may serve as a useful microbial biomarker of depth contamination and leaching in clay and sandy soil and that bacteriophage could be used as an indicator of enteric pathogen persistence. Our study contributes to development of predictive models for enteric pathogen behavior in soils, and for potential water and food contamination associated with biofertilization, useful for risk management and mitigation in swine digestate recycling. PMID:28197137

Detrital zircon provenance of the Hartselle Sandstone Unit, Southeastern USA: Insights into sediment source, paleogeography, and setting

Science.gov (United States)

Harthy, M. A.; Gifford, J.

2017-12-01

The Hartselle sandstone is an excellent example of an Oil sand, a resource rich in bitumen. The unit is a light-colored thick-bedded to massive quartzose sandstone, that is widespread across an area from Georgia in the east to Mississippi in the west, and south from Alabama to Kentucky as a northern border. Formation thickness ranges from 0 to more than 150 feet. The unit has been stratigraphically dated to the Middle-Upper Mississippian age. One hypothesis suggests that the sandstone unit formed from the geological remains of barrier islands located in the ocean between Gondwana and Laurentia. The Hartselle is thought to have formed by the movement waves and currents along the shoreline, which carried sand and concentrated it into a set of northwest to southeast trending barrier islands. Transgression-regression events shifted the islands back and forth in relation to the position of the shoreline, leading to the large areal extent of the unit. However, the current data are not enough to explain the geographical position of the Hartselle sandstone unit as it is not running parallel to the ancient shoreline. Another mystery is the source of the sand, some believing the source was from the south (Gondwana) and others that erosion was from the north (Laurentia). Detrital zircon provenance analysis will address the uncertainty in sediment source. We will compare zircon U-Pb age spectra to possible Laurentian and Gondwanan source areas to discriminate between these possibilities. In addition, the age of the youngest detrital zircon population will provide additional constraints on the maximum age of deposition for the unit. These detrital ages will also help us to understand the tectonic setting at the time of Hartselle deposition. Lastly, we aim to explain the widespread nature of the unit and the processes involved in the formation of the Hartselle sandstone. When taken together, these interpretations will illuminate the age, depositional and tectonic setting of a

Reservoir characterization of Pennsylvanian sandstone reservoirs. Final report

Energy Technology Data Exchange (ETDEWEB)

Kelkar, M.

1995-02-01

This final report summarizes the progress during the three years of a project on Reservoir Characterization of Pennsylvanian Sandstone Reservoirs. The report is divided into three sections: (i) reservoir description; (ii) scale-up procedures; (iii) outcrop investigation. The first section describes the methods by which a reservoir can be described in three dimensions. The next step in reservoir description is to scale up reservoir properties for flow simulation. The second section addresses the issue of scale-up of reservoir properties once the spatial descriptions of properties are created. The last section describes the investigation of an outcrop.

Early cretaceous Obernirchen and Bentheim sandstones from Germany used as dimension stone in the Netherlands: geology physical properties, architectural use and comparative weathering

NARCIS (Netherlands)

Dubelaar, C.W.; Nijland, T.G.

2015-01-01

The Netherlands, with only scarce occurrences of outcropping or shallow buried natural stone, has over centuries imported huge quantities of Early Cretaceous Bentheim Sandstone and Obernkirchen Sandstone from Germany. The present paper provides an overview of their distribution and properties

Anatomy of an ancient aeolian sandstone on Mars: the Stimson formation, Gale crater, Mars

Science.gov (United States)

Gupta, Sanjeev; Banham, Steven; Rubin, David; Watkins, Jessica; Sumner, Dawn; Grotzinger, John P.; Lewis, Kevin; Edgett, Kenneth S.; Edgar, Lauren; Stack, Kathryn; Day, McKenzie; Ewing, Ryan; Lapotre, Mathieu

2016-10-01

Since landing in 2012, the Mars Science Laboratory's (MSL) rover Curiosity has traversed the plains and foothills of Aeolis Mons (informally known as Mt. Sharp) investigating the environments preserved in the stratigraphic record of Gale crater. Recently, the Curiosity team has been investigating the Stimson formation, a sandstone exhibiting abundant crossbedding that drapes the underlying Murray formation mudstones. The contact between the Stimson and underlying Murray formation exhibits several meters relief over several 100 m hundred metres where encountered thus far. The Stimson is observed to onlap onto this contact, indicating that accumulating Stimson sandstones unconformably onlapped or buried local palaeotopography.Facies and architectural elements observed within the Stimson are interpreted to represent deposition within an ancient dune field. The Stimson formation is typically composed of decimeter-scale and meter-scale crossbedded sandstones, (exhibiting wind-ripple lamination and well rounded particles up to granule size). Architectural elements are visible in outcrops oriented perpendicular to the regional northwest dip. These consist of undulating surfaces parallel to the regional dip with observed lateral extents up to 30 m that truncate underlying cross-sets and commonly act as basal surfaces to overlying cross-sets. Undulating surfaces are interpreted possibly to be deflationary supersurfaces, which formed in response to deflation or dune-field stabilisation across a regional extent. Surfaces inclined relative to the regional dip ascend between supersurfaces towards the north east at an observed angle of 3-4°. These surfaces are interpreted to be dune bounding surfaces, which are preserved when dunes climb as a result of dune-field aggradation. Aggradation of the system during the duration of the dune field's existence possibly occurred as a response to episodic increases of sediment supply into the basin, allowing dunes to climb and preserving

Hurricane Sandy Economic Impacts Assessment: A Computable General Equilibrium Approach and Validation

Energy Technology Data Exchange (ETDEWEB)

Boero, Riccardo [Los Alamos National Laboratory; Edwards, Brian Keith [Los Alamos National Laboratory

2017-08-07

Economists use computable general equilibrium (CGE) models to assess how economies react and self-organize after changes in policies, technology, and other exogenous shocks. CGE models are equation-based, empirically calibrated, and inspired by Neoclassical economic theory. The focus of this work was to validate the National Infrastructure Simulation and Analysis Center (NISAC) CGE model and apply it to the problem of assessing the economic impacts of severe events. We used the 2012 Hurricane Sandy event as our validation case. In particular, this work first introduces the model and then describes the validation approach and the empirical data available for studying the event of focus. Shocks to the model are then formalized and applied. Finally, model results and limitations are presented and discussed, pointing out both the model degree of accuracy and the assessed total damage caused by Hurricane Sandy.

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

OpenAIRE

Weijing Yao; Jianyong Pang; Yushan Liu

2018-01-01

Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry inject...

The analyzing stratum formation and sediment environment using TEM for finding sandstone type uranium deposits in Mahuangquan area

International Nuclear Information System (INIS)

Zhao Xigang; He Jianguo; Zhao Cuiping; Lou Hansheng

2010-01-01

Transient electromagnetic method (TEM) is used to detect deep geological information for insidious sandstone type uranium deposits in Mahuangquan area. TEM surveying data is processed to build the relation between resistance rate and different petrology, to ensure three large electronic strata, and to explain the space position of sediment center and alluvial fan. Combining with ore control factors of sandstone type uranium deposit, it can conclude that the slope area and the alluvial fan are the key areas for further exploration work. (authors)

Dzhezkazgan and associated sandstone copper deposits of the Chu-Sarysu basin, Central Kazakhstan

Science.gov (United States)

Box, Stephen E.; Seltmann, Reimar; Zientek, Michael L.; Syusyura, Boris; Creaser, Robert A.; Dolgopolova, Alla

2012-01-01

Sandstone-hosted copper (sandstone Cu) deposits occur within a 200-km reach of the northern Chu-Sarysu basin of central Kazakhstan (Dzhezkazgan and Zhaman-Aibat deposits, and the Zhilandy group of deposits). The deposits consist of Cu sulfide minerals as intergranular cement and grain replacement in 10 ore-bearing members of sandstone and conglomerate within a 600- to 1,000-m thick Pennsylvanian fluvial red-bed sequence. Copper metal content of the deposits ranges from 22 million metric tons (Mt, Dzehzkazgan) to 0.13Mt (Karashoshak in the Zhilandy group), with average grades of 0.85 to 1.7% Cu and significant values for silver (Ag) and rhenium (Re). Broader zones of iron reduction (bleaching) of sandstones and conglomerates of the red-bed sequence extend over 10 km beyond each of the deposits along E-NE-trending anticlines, which began to form in the Pennsylvanian. The bleached zones and organic residues within them are remnants of ormer petroleum fluid accumulations trapped by these anticlines. Deposit sites along these F1anticlines are localized at and adjacent to the intersections of nearly orthogonal N-NW-trending F2synclines. These structural lows served to guide the flow of dense ore brines across the petroleum-bearing anticlines, resulting in ore sulfide precipitation where the two fluids mixed. The ore brine was sourced either from the overlying Early Permian lacustrine evaporitic basin, whose depocenter occurs between the major deposits, or from underlying Upper Devonian marine evaporites. Sulfur isotopes indicate biologic reduction of sulfate but do not resolve whether the sulfate was contributed from the brine or from the petroleum fluids. New Re-Os age dates of Cu sulfides from the Dzhezkazgan deposit indicate that mineralization took place between 299 to 309 Ma near the Pennsylvanian-Permian age boundary. At the Dzhezkazgan and some Zhilandy deposits, F2fold deformation continued after ore deposition. Copper orebodies in Lower Permian

Origin of sandstone-hosted uranium deposits, Frome Embayment, South Australia

International Nuclear Information System (INIS)

Sanford, R.F.

1985-01-01

The formation of sandstone-hosted uranium deposits in the Frome Embayment of South Australia is largely a result of tectonic events possibly as old as the Archean. Uranium deposits of several types and ages in the region demonstrate the importance of uranium enrichment in the source area. Mobile zones around the Archean terrane of the Gawler block have been the locus of intermittent tectonic activity from Early Proterozoic to recent time. Vein-type uranium deposits in basement source rocks are concentrated in these zones, because they favor deep crustal partial melting and ascent of Na-rich granitic magmas and hydrothermal solutions. Relatively stable areas bordered by mobile zones, are important for the formation of sandstone-hosted uranium deposits because they act as platforms for terrigenous sedimentation from the surrounding, uplifted, uranium-rich basement rocks. Wet, subtropical conditions prevailing at the time of uplift aided rapid erosion and subaerial deposition of channel sands with intermixed organic detritus. Later uplift accompanied by erosion of the recently deposited sands in the headwater area caused increased recharge of oxygenated uraniferous ground water, which led to the formation of geochemical-cell roll-front type deposits like those in the Wyoming basins. Subsequent arid conditions helped preserve the deposits. (author)

Pore network properties of sandstones in a fault damage zone

Science.gov (United States)

Bossennec, Claire; Géraud, Yves; Moretti, Isabelle; Mattioni, Luca; Stemmelen, Didier

2018-05-01

The understanding of fluid flow in faulted sandstones is based on a wide range of techniques. These depend on the multi-method determination of petrological and structural features, porous network properties and both spatial and temporal variations and interactions of these features. The question of the multi-parameter analysis on fluid flow controlling properties is addressed for an outcrop damage zone in the hanging wall of a normal fault zone on the western border of the Upper Rhine Graben, affecting the Buntsandstein Group (Early Triassic). Diagenetic processes may alter the original pore type and geometry in fractured and faulted sandstones. Therefore, these may control the ultimate porosity and permeability of the damage zone. The classical model of evolution of hydraulic properties with distance from the major fault core is nuanced here. The hydraulic behavior of the rock media is better described by a pluri-scale model including: 1) The grain scale, where the hydraulic properties are controlled by sedimentary features, the distance from the fracture, and the impact of diagenetic processes. These result in the ultimate porous network characteristics observed. 2) A larger scale, where the structural position and characteristics (density, connectivity) of the fracture corridors are strongly correlated with both geo-mechanical and hydraulic properties within the damage zone.

2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New Jersey)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New Jersey CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

Tectono-sedimentary evolution of Erlian basin since late mesozoic and sandstone-hosted uranium metallogenesis

International Nuclear Information System (INIS)

Wei Sanyuan; Qin Mingkuan; Li Yuexiang; He Zhongbo; Chen Anping; Shen Kefeng; Cao Jianying

2006-01-01

Various mineral resources in a basin are associated with its tectono-sedimentary evolution. Based on the analysis of the tectono-sedimentary evolution of Erlian basin, three evolutional stages of Erlian basin are classified, they are: the continental extensional down-faulting stage, the transitional stage from down-faulting to down-warping in Early Cretaceous, and slightly compressional differentiated uplifting-subsidence since Late Cretaceous. According to the mechanism of sandstone-hosted uranium metallogenesis it is suggested that the grey clastic rock series deposited at the stage of down-faulting down-warping transition must be the important target for uranium prospecting, and the differentiated uplifting-subsidence offers necessary conditions for sandstone-hosted uranium ore-formation. Then, types of uranium mineralization that could occur in Erlian basin are discussed, and uranium metallogenic model has been preliminarily summarized. (authors)

Biological soil crust formation under artificial vegetation effect and its properties in the Mugetan sandy land, northeastern Qinghai-Tibet Plateau

Science.gov (United States)

Li, Y. F.; Li, Z. W.; Jia, Y. H.; Zhang, K.

2016-08-01

Mugetan sandy land is an inland desertification area of about 2,065 km2 in the northeastern Qinghai-Tibet Plateau. In the ecological restoration region of the Mugetan sandy land, different crusts have formed under the action of vegetation in three types of sandy soil (i.e. semi-fixed sand dune, fixed sand dune and ancient fixed aeolian sandy soil). The surface sand particle distribution, mineral component and vegetation composition of moving sand dunes and three types of sandy soil were studied in 2010-2014 to analyze the biological crust formation properties in the Mugetan sandy land and the effects of artificial vegetation. Results from this study revealed that artificial vegetation increases the clay content and encourages the development of biological curst. The fine particles (i.e. clay and humus) of the surface layer of the sand dunes increased more than 15% ten years after the artificial vegetation planting, and further increased up to 20% after one hundred years. The interaction of clay, humus, and other fine particles formed the soil aggregate structure. Meanwhile, under the vegetation effect from the microbes, algae, and moss, the sand particles stuck together and a biological crust formed. The interconnection of the partial crusts caused the sand dunes to gradually be fixed as a whole. Maintaining the integrity of the biological crust plays a vital role in fixing the sand under the crust. The precipitation and temperature conditions in the Mugetan sandy land could satisfy the demand of biological crust formation and development. If rational vegetation measures are adopted in the region with moving sand dunes, the lichen-moss-algae biological curst will form after ten years, but it still takes more time for the sand dunes to reach the nutrient enrichment state. If the biological curst is partly broken due to human activities, reasonable closure and restoration measures can shorten the restoration time of the biological crust.

Effects of deposition of heavy-metal-polluted harbor mud on microbial diversity and metal resistance in sandy marine sediments

DEFF Research Database (Denmark)

Toes, Ann-Charlotte M; Finke, Niko; Kuenen, J Gijs

2008-01-01

Deposition of dredged harbor sediments in relatively undisturbed ecosystems is often considered a viable option for confinement of pollutants and possible natural attenuation. This study investigated the effects of deposition of heavy-metal-polluted sludge on the microbial diversity of sandy...... the finding that some groups of clones were shared between the metal-impacted sandy sediment and the harbor control, comparative analyses showed that the two sediments were significantly different in community composition. Consequences of redeposition of metal-polluted sediment were primarily underlined...... with cultivation-dependent techniques. Toxicity tests showed that the percentage of Cd- and Cu-tolerant aerobic heterotrophs was highest among isolates from the sandy sediment with metal-polluted mud on top....

Sensibility test for uranium ores from Qianjiadian sandstone type uranium deposit

International Nuclear Information System (INIS)

Zhang Mingyu

2005-01-01

Sensibility tests for uranium ores from Qianjiadian sandstone type uranium deposit in Songliao Basin which is suitable to in-situ leach are carried out, including water sensibility, velocity sensibility, salt sensibility, acid sensibility and alkaline sensibility. The sensibility critical value of this ore is determined. Some references on mining process and technical parameter are provided for in-situ leaching of uranium. (authors)

Sandstone columns of the 3rd Nile Cataract (Nubia, Northern Sudan)

Czech Academy of Sciences Publication Activity Database

Cílek, Václav; Adamovič, Jiří; Suková, L.

2015-01-01

Roč. 59, Supplement 1 (2015), s. 151-165 ISSN 0372-8854 Grant - others:Program interní podpory projektů mezinárodní spolupráce AV ČR(CZ) M100130902 Institutional support: RVO:67985831 Keywords : Nubian sandstone * columnar jointing * Voronoi fragmentation * 3rd Nile Cataract * Sudan Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.103, year: 2015

The mineralogical composition of sandstone and its effect on sulphur dioxide deposition

Directory of Open Access Journals (Sweden)

Müller, Urs

2008-06-01

Full Text Available Air pollutants often accelerate stone deterioration in historical buildings and monuments in urban areas. The pollutants are themselves the products of fossil fuel combustion and intensive farming. While this trend seems to have been curbed by strict emission laws in the European Union, in most developing and emerging countries air pollution is an ongoing process due to increasing energy needs and vehicle traffic. Many factors condition natural stone behaviour with respect to gaseous pollutants. Two of the more prominent of such factors are the composition of the atmosphere and the type of stone. Due to their porosity, sandstones are particularly vulnerable to air pollutant attack. Many of the reactions between non-carbonaceous sandstones and these gases are not well understood, however. The present study aimed to acquire an understanding of the processes and factors governing sandstone behaviour when exposed to sulphur dioxide. Seven different sandstones from southern and eastern Germany were analyzed for the study. The binder composition of the stones varied significantly. They also exhibited completely different behaviour in connection with SO2 sorption. Interestingly, while the amount of SO2 deposited was unrelated to the specific surface area of the sandstones, this parameter was closely correlated to the iron oxide content. Iron oxide phases are believed to act as a catalyst in the oxidation of SO2 to SO3. The type and amount of clay mineral, in turn, was found to have no significant impact on initial SO2 deposition in sandstones.Los contaminantes atmosféricos son con frecuencia responsables de la aceleración de la degradación de la piedra en los edificios y monumentos históricos de las zonas urbanas. Los contaminantes en sí son productos de reacción procedentes de la combustión de los hidrocarburos y de la agricultura intensiva. Dentro de la Comunidad Europea, el avance parece haberse ralentizado mediante restrictivas leyes sobre

Geochemical interpretation of the Precambrian basement and overlying Cambrian sandstone on Bornholm, Denmark: Implications for the weathering history

DEFF Research Database (Denmark)

Zhou, Lingli; Friis, Henrik; Yang, Tian

2017-01-01

show a depletion of major elements in the following order: Na N Ca N Mg N Si; Al and Ti are immobile and stay constant; K shows sample dependent enrichment or depletion; Fe is slightly enriched. The Cambrian sandstone overlying the basement in the Borggård borehole, assigned to the Gadeby Member...... but lost most of the plagioclase. The LSF has a comparable weathering history (CIA = 63–73), but the plagioclase is better preserved (PIA = 65–78). The significant variation of weathering rates of plagioclase and K-feldspar in the basement granite and the provenance of sandstone from the Borggård borehole...... are likely due to the different permeability developed within the internal crystal structures, a Ca- rich plagioclase original composition of the plagioclase, and the occurrence of weathering in a very humid climate. K metasomatism occurred in the basement granite and sandstone in both the Borggård and the G...

Effect of drilling fluids on permeability of uranium sandstone. Report of Investigations/1984

International Nuclear Information System (INIS)

Ahlness, J.K.; Johnson, D.I.; Tweeton, D.R.

1984-01-01

The Bureau of Mines conducted laboratory and field experiments to determine the amount of permeability reduction in uranium sandstone after its exposure to different drilling fluids. Seven polymer and two bentonite fluids were laboratory-tested in their clean condition, and six polymer fluids were tested with simulated drill cuttings added. Sandstone cores cut from samples collected at an open pit uranium mine were the test medium. The clean fluid that resulted in the least permeability reduction was an hydroxyethyl cellulose polymer fluid. The greatest permeability reduction of the clean polymers came from a shale-inhibiting synthetic polymer. Six polymer fluids were tested with simulated drill cuttings added to represent field use. The least permeability reduction was obtained from a multi-polymer blend fluid. A field experiment was performed to compare how two polymer fluids affect formation permeability when used for drilling in situ uranium leaching wells

2012-2013 Post-Hurricane Sandy EAARL-B Submerged Topography - Barnegat Bay, New Jersey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data for part of Barnegat Bay, New Jersey, post-Hurricane Sandy (October 2012 hurricane), were produced from remotely sensed, geographically...

2012 USACE Post Sandy Topographic LiDAR: Eastern Long Island, New York

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: EASTERN LONG ISLAND, NEW YORK LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X23208588 Woolpert...

Strength curves for shales and sandstones under hydrostatic confining pressures

International Nuclear Information System (INIS)

Gupta, S.C.; Sikka, S.K.

1978-01-01

The experimental data for the effect of confining pressures on the fracture stress have been analysed for shales and sandstones. The normalized compressive strengths are found to lie in a narrow region so that Ohnaka's equation for crystalline rocks, can be fitted to the data. The fitted parameters are physically reasonable and indicate that the functional dependence of strength on porosity, strain rate and temperature is independent of the confining pressures. (author)

Geological and petrophysical characterization of the Ferron Sandstone for 3-D simulation of a fluvial-deltaic reservoir. Deliverable 2.5.4, Ferron Sandstone lithologic strip logs, Emergy & Sevier Counties, Utah: Volume I

Energy Technology Data Exchange (ETDEWEB)

Allison, M.L.

1995-12-08

Strip logs for 491 wells were produced from a digital subsurface database of lithologic descriptions of the Ferron Sandstone Member of the Mancos Shale. This subsurface database covers wells from the parts of Emery and Sevier Counties in central Utah that occur between Ferron Creek on the north and Last Chance Creek on the south. The lithologic descriptions were imported into a logging software application designed for the display of stratigraphic data. Strip logs were produced at a scale of one inch equals 20 feet. The strip logs were created as part of a study by the Utah Geological Survey to develop a comprehensive, interdisciplinary, and qualitative characterization of a fluvial-deltaic reservoir using the Ferron Sandstone as a surface analogue. The study was funded by the U.S. Department of Energy (DOE) under the Geoscience/Engineering Reservoir Characterization Program.

[Advance in the study of the powdered weathering profile of sandstone on China Yungang Grottoes based on VIS/NIR hyperspectral imaging].

Science.gov (United States)

Zhou, Xiao; Gao, Feng; Zhang, Ai-wu; Zhou, Ke-chao

2012-03-01

Yungang Grottoes were built in the mid-5th century A. D., and named as a UNESCO World Heritage site in 2001. Most of the grottoes were built on the feldspathic quartz sandstones. They were seriously damaged due to the environmental impact. The main form of the weathering is the powdered weathering. The weathering conditions are generally characterized by electrical sounding, penetration resistance, molecular spectroscopy, etc. However, although these methods can give good results about the weathering conditions for a specified sample or site, they are not suitable for providing a global profile of the weathering conditions. The present paper provides a method for effectively and roundly assessing the overall powdered weathering conditions of the Yungang Grottoes based on hyperspectral imaging. Powdered weathering could change the structure and granularity of the sandstone, and thus change the spectral reflectance of the sandstone surface. Based on the hyperspectral data collected from 400 nm to 1 000 nm and normalized by log residuals method, the powdered weathering conditions of the sandstones were classified into strong weathering and weak weathering. The weathering profile was also mapped in the Envi platform. The mapping images were verified using the measured hyperspectal data of the columns in front of the 9th and 10th grottoes as the examples. The mapping images were substantially fitted to the real observations, showing that hyperspectral imaging can be used to estimate the overall powdered weathering of the sandstones.

New discovery in study of remote sensing image characteristics at sandstone-type uranium deposits in China and its important significance

International Nuclear Information System (INIS)

Liu Dechang; Huang Xianfang; Ye Fawang

2004-01-01

Sandstone-type uranium deposit now is one of main targets in uranium prospecting in China. During the prospecting, the study is often emphasized on those ore-controlling factors such as the lithology and lithofacies of ore-hosting strata. While the ore-controlling factor of fault structure is usually neglected. By means of systematic research on remote sensing image features of sandstone-type uranium deposits, it is found that fault structure is always present at most main sandstone-type uranium ore districts. Based on above research achievements characteristics of ore-controlling fault and its ore-controlling role are analysed and a new metallogenetic model--'structural-geochemical barrier model' is put forward. Finally, the difference between the sturctural-geochemical barrier model and traditional interlayer oxidation zone front model is elaborated and its important significance is discussed. (authors)

Patterns of species richness in sandy beaches of South America

African Journals Online (AJOL)

beaches with rdkctive and dissip:1tive characteristics (sensu. R eprodu ced by Sabin et G atew ay u n der licen ce gran ted by th e P u blish er (dated 2009). ... beach intertidal communities WaS reviewed, (b) location of len sam.!y beaches studied in south-central Chile, imd (c) location of two sandy beaches studied on the ...

Amelioration of sandy soils in drought stricken areas through use of ...

African Journals Online (AJOL)

Soil moisture shortage is a major limiting factor to agricultural production in eastern Africa, in view of increased drought incidences and seasonal rainfall variability. This study evaluated the potential for Ca-bentonite (a 2:1 clay mineral) as a possible amendment for increased moisture retention by sandy soils in drought ...

Assessment of structural stability of a degraded sandy clay loam soil ...

African Journals Online (AJOL)

The effects of bare, two legumes and four grasses cover treatments on the structural stability of a sandy clay loam Ultisol were studied within a two year period. The experiment was of a randomised complete block design with seven treatments. The legume treatments were Centrosema pubescens (Ce) and Pueraria ...

New geochronologic and stratigraphic evidence confirms the paleocene age of the dinosaur-bearing ojo alamo sandstone and animas formation in the San Juan Basin, New Mexico and Colorado

Science.gov (United States)

Fassett, J.E.

2009-01-01

Dinosaur fossils are present in the Paleocene Ojo Alamo Sandstone and Animas Formation in the San Juan Basin, New Mexico, and Colorado. Evidence for the Paleo-cene age of the Ojo Alamo Sandstone includes palynologic and paleomagnetic data. Palynologic data indicate that the entire Ojo Alamo Sandstone, including the lower dinosaur-bearing part, is Paleocene in age. All of the palynomorph-productive rock samples collected from the Ojo Alamo Sandstone at multiple localities lacked Creta-ceous index palynomorphs (except for rare, reworked specimens) and produced Paleocene index palynomorphs. Paleocene palynomorphs have been identified strati-graphically below dinosaur fossils at two separate localities in the Ojo Alamo Sand-stone in the central and southern parts of the basin. The Animas Formation in the Colorado part of the basin also contains dinosaur fossils, and its Paleocene age has been established based on fossil leaves and palynology. Magnetostratigraphy provides independent evidence for the Paleocene age of the Ojo Alamo Sandstone and its dinosaur-bearing beds. Normal-polarity magnetochron C29n (early Paleocene) has been identified in the Ojo Alamo Sandstone at six localities in the southern part of the San Juan Basin. An assemblage of 34 skeletal elements from a single hadrosaur, found in the Ojo Alamo Sandstone in the southern San Juan Basin, provided conclusive evidence that this assemblage could not have been reworked from underlying Cretaceous strata. In addition, geochemical studies of 15 vertebrate bones from the Paleocene Ojo Alamo Sandstone and 15 bone samples from the underlying Kirtland Formation of Late Creta-ceous (Campanian) age show that each sample suite contained distinctly different abundances of uranium and rare-earth elements, indicating that the bones were miner-alized in place soon after burial, and that none of the Paleocene dinosaur bones ana-lyzed had been reworked. ?? U.S. Geological Survey, Public Domain April 2009.

Absence of arabinan in the side chains of the pectic polysaccharides strongly associated with cell walls of Nicotiana plumbaginifolia non-organogenic callus with loosely attached constituent cells.

Science.gov (United States)

Iwai, H; Ishii, T; Satoh, S

2001-10-01

When leaf disks from haploid plants of Nicotiana plumbaginifolia Viv. were transformed with T-DNA and cultured on shoot-inducing medium, nonorganogenic callus. designated nolac (for non-organogenic callus with loosely attached cells), appeared on approximately 7% of leaf disks. In contrast, normal callus was generated on T-DNA-transformed leaf disks from diploid plants and on non-transformed leaf disks from haploid and diploid plants. Transmission electron microscopy revealed that the middle lamellae and the cell walls of one line of mutant callus (nolac-H14) were barely stained by ruthenium red. even after demethylesterification with NaOH, whereas the entire cell wall and the middle lamella were strongly stained in normal callus. In cultures of nolac-H14 callus, the level of sugar components of pectic polysaccharides in the hemicellulose fraction was reduced and that in the culture medium was elevated, as compared with cultures of normal callus. These results indicate that pectic polysaccharides are not retained in the cell walls and middle lamellae of nolac-H14 callus. In nolac-H14, the ratio of arabinose to galactose was low in the pectic polysaccharides purified from all cell wall fractions and from the medium, in particular, in the hemicellulose fractions. The low levels of arabinofuranosyl (T-Araf, 5-Araf, 2,5-Araf, and 3,5-Araf) residues in the pectic polysaccharides of the hemicellulosic fraction of nolac-H,14 indicated that no neutral-sugar side chains, composed mainly of linear arabinan. were present in nolac-H14. Arabinose-rich pectins. which are strongly associated with cellulose-hemicellulose complexes, might play an important role in intercellular attachment in the architecture of the cell wall.

The Influence of Shoreline Curvature on Rates of Shoreline Change on Sandy Coasts

Science.gov (United States)

Murray, A. B.; Lauzon, R.; Cheng, S.; Liu, J.; Lazarus, E.

2017-12-01

The sandy, low-lying barrier islands which characterize much of the US East and Gulf coasts are popular spots to live and vacation, and are often heavily developed. However, sandy shorelines and barriers are also naturally mobile landforms, which are vulnerable to sea level rise and storms and can experience high rates of shoreline change. Many previous studies have attempted to understand and quantify the factors that contribute to those rates of shoreline change, such as grain size, underlying geology, sea level rise, and anthropogenic modification. Shoreline curvature has not been considered in such analyses, but previous research has demonstrated that subtle coastline curvature (and therefore alongshore variation in relative offshore wave angle) can result in gradients in net alongshore transport that cause significant shoreline erosion or accretion. Here we present the results of a spatially extensive analysis of the correlation between shoreline curvature and shoreline change rates for the sandy shorelines of the US East and Gulf coasts. We find that, for wave-dominated sandy coasts where nourishment and shoreline stabilization do not dominate the shoreline change signal (such as parts of Texas, North Carolina, and Florida), there is a significant negative correlation between shoreline curvature and shoreline change rates over 1 - 5 km and decadal to centurial space and time scales. This correlation indicates that a portion of the coastal erosion (and accretion) observed in these areas can be explained by the smoothing of subtle coastline curvature by gradients in alongshore transport, and suggests that shoreline curvature should be included in future attempts to understand historical and future rates of shoreline change. Shoreline stabilization, especially through beach nourishment, complicates the relationship between curvature and shoreline change. Beach construction during nourishment creates a seaward convex curvature in the part of the shoreline moves

Transport of water and solutes in wettable and water repellent sandy soils

NARCIS (Netherlands)

Ritsema, C.J.; Dekker, L.W.

1996-01-01

The research yielded the following conclusions and results: preferential flow can be expected in recently deposited, loosely packed, wettable dune sands; preferential flow is common in most water-repellent sandy soils; distribution flow in topsoils isa process of major importance, resulting in a

Biodegradation of phenols in a sandstone aquifer under aerobic conditions and mixed nitrate and iron reducing conditions

DEFF Research Database (Denmark)

Broholm, Mette; Arvin, Erik

2000-01-01

in the groundwater. The potential for biodegradation of the phenols in the sandstone aquifer at the site has been investigated in laboratory microcosms under aerobic (oxygen amended) and mixed nitrate and iron reducing (nitrate enriched and unamended) anaerobic conditions, at a range of concentrations (low: similar...... to 5 mg 1(-1): high: similar to 60 mg 1(-1), and very high: similar to 600 mg 1(-1)) and in the presence of other organic coal-tar compounds (mono- and polyaromatic hydrocarbons (BTEXs and PAHs) and heterocyclic compounds (NSOs)) and ammonia liquor. Sandstone cores and groundwater for the microcosms...

Pore-size distribution and compressibility of coarse sandy subsoil with added biochar

DEFF Research Database (Denmark)

Petersen, C. T.; Hansen, E.; Larsen, H. H.

2016-01-01

Sustainable agricultural production on coarse sandy soil is constrained by the restricted growth of roots, and poor water and nutrient retention. Amending the soil with biochar can reduce these problems, but the processes involved are not known in detail. We investigated in the laboratory...... the effects of two fine-grained gasification biochars made of straw (LTST) and other materials (LTSN) and of one fast pyrolysis straw biochar (FPST) on pore-size distribution and soil compressibility when added to coarse sandy subsoil. Water retention and therefore pore-size distribution were affected...... systematically. All biochars converted drainable pore space with pore diameters in the range 60–300 µm into water-retaining pores of size 0.2–60 µm, which was taken as an estimate of available water capacity (AWC). Effects were linear over the whole range of biochar (0–4% by mass). The effect of LTST and LTSN...

Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

DEFF Research Database (Denmark)

Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh

2012-01-01

Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand...... compost had greater effect in improving tomato productivity. A decade-long application of composts on loamy sand improved basic chemical and physical properties which were reflected in increased fruit yield in tomato. Since no negative effect of compost was observed, we suggest that sandy soils may serve...... and greenhouse tomato productivity. Disturbed and intact soil samples were taken from a decade-long compost field experiment on loamy sand with three compost types at application rate of 30 m3 ha-1 yr-1 (7.5 ton ha-1 yr-1). The soils were characterized for chemical and physical properties. Tomato was planted...

Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

Directory of Open Access Journals (Sweden)

Baille Wiebke

2016-01-01

Full Text Available In the former open-pit mines of the Lusatian region in Germany, several liquefaction events have occurred during the recent years in the anthropogenic deposits made of very loose sandy soils. These events are related to the rising ground water table after the stop of controlled ground water lowering. The very loose state is due to the formation of sand aggregates (pseudo-grains during the deposition process. The pseudo-grains enclose larger voids of dimension greater than the single sand grain. Wetting induced collapse of the pseudo-grains is presumed to be one of the possible mechanisms triggering liquefaction. In the present study, the effect of larger voids on the wetting induced deformation behaviour of sandy soils is experimentally investigated by laboratory box tests. The deformation field in the sample during wetting was measured using Digital Image Correlation (DIC technique. The results show that the observed deformations are affected by the pore size distribution, thus the amount of voids between the pseudo-grains (macro-void ratio and the voids inside the pseudo-grains (matrix void ratio. The global void ratio of a sandy soil is not sufficient as single state parameter, but the pore size distribution has to be taken into account, experimentally as well as in modelling.

Early Cretaceous marine sediments of the Lower Saxony Basin. The Gildehaus Sandstone

Energy Technology Data Exchange (ETDEWEB)

Dellepiane, S.; Weiel, D. [Wintershall Holding GmbH, Barnstorf (Germany); Gerwert, D.; Mutterlose, J. [Bochum Univ. (Germany). Inst. fuer Geologie, Mineralogie und Geophysik

2013-08-01

During the Early Cretaceous (Berriasian - Aptian) the Lower Saxony Basin (LSB) formed the southernmost extension of the North Sea Basin. Sedimentation patterns of the LSB were controlled by divergent dextral shear movement causing differential subsidence related to early rifting in the North Sea. Up to 2000m of fine grained mudstones accumulated in the basin centre, while marginal marine, coarser grained siliciclastics were deposited along the western and southern margins of the LSB. The western marginal facies, outcropping along the Dutch-German border, is characterised by shallow marine sandstones of Valanginian - Hauterivian age. These units, which are separated by clay rich intervals, include the Bentheim Sdst., the Dichotomites Sdst., the Grenz Sdst., the Noricum Sdst. and the Gildehaus Sdst. These sandstones form a series of overall backstepping units, controlled by a main transgressive trend. Economically important are the Bentheim Sdst. and the Gildehaus Sdst., with a long oil producing history. The Bentheim Sdst. (early Valanginian) has been interpreted as an overall retrograding unit related to an incised valley infill with material mainly coming from the South. Tidal processes dominated the deposition of the Bentheim Sdst. The origin and genesis of the Gildehaus Sdst. (mid Hauterivian) is, however, less well understood. Here we present data from two wells drilled to the Gildehaus Sdst. (Emlichheim oil field) which provide evidence for a two fold subdivision of the unit. A well sorted massive quartz sandstone is followed by an interval composed of reworked coarse clastics of massflow origin. Micropalaeontological evidence suggests a fully marine, hemi-pelagic origin of the mud dominated matrix throughout the Gildehaus Sdst. These findings indicate a depositional environment quite different from that of the Bentheim Sdst. Short termed pulses of substantial input of clastic material from two different sources in the West to Southwest punctuated the overall

Enhancing crude oil degradation in a sandy soil: Effects of addition ...

African Journals Online (AJOL)

This study investigated the effects of the addition of poultry manure alone and in combination with surfactant (Goldcrew or Corexit) and/or alternate carbon substrate (glucose or starch) on crude oil degradation in a sandy soil. With poultry manure alone, optimal crude oil degradation was obtained at a concentration of 4.0% ...

Reservoir heterogeneity in carboniferous sandstone of the Black Warrior basin. Final report

Energy Technology Data Exchange (ETDEWEB)

Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

1994-06-01

Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

Reservoir heterogeneity in Carboniferous sandstone of the Black Warrior basin. Final report

Energy Technology Data Exchange (ETDEWEB)

Kugler, R.L.; Pashin, J.C.; Carroll, R.E.; Irvin, G.D.; Moore, H.E.

1994-04-01

Although oil production in the Black Warrior basin of Alabama is declining, additional oil may be produced through improved recovery strategies, such as waterflooding, chemical injection, strategic well placement, and infill drilling. High-quality characterization of reservoirs in the Black Warrior basin is necessary to utilize advanced technology to recover additional oil and to avoid premature abandonment of fields. This report documents controls on the distribution and producibility of oil from heterogeneous Carboniferous reservoirs in the Black Warrior basin of Alabama. The first part of the report summarizes the structural and depositional evolution of the Black Warrior basin and establishes the geochemical characteristics of hydrocarbon source rocks and oil in the basin. This second part characterizes facies heterogeneity and petrologic and petrophysical properties of Carter and Millerella sandstone reservoirs. This is followed by a summary of oil production in the Black Warrior basin and an evaluation of seven improved-recovery projects in Alabama. In the final part, controls on the producibility of oil from sandstone reservoirs are discussed in terms of a scale-dependent heterogeneity classification.

Study of Maowusu Sandy Land Vegetation Coverage Change Based on Modis Ndvi

Science.gov (United States)

Ye, Q.; Liu, H.; Lin, Y.; Han, R.

2018-04-01

This paper selected 2006-2016 MODIS NDVI data with a spatial resolution of 500m and time resolution of 16d, got the 11 years' time series NDVI data of Maowusu sandy land through mosaicking, projection transformation, cutting process in batch. Analysed the spatial and temporal distribution and variation characteristics of vegetation cover in year, season and month time scales by maximum value composite, and unary linear regression analysis. Then, we combined the meteorological data of 33 sites around the sandy area, analysed the response characteristics of vegetation cover change to temperature and precipitation through Pearson correlation coefficient. Studies have shown that: (1) The NDVI value has a stable increase trend, which rate is 0.0075 / a. (2) The vegetation growth have significantly difference in four seasons, the NDVI value of summer > autumn > spring > winter. (3) The NDVI value change trend is conformed to the gauss normal distribution in a year, and it comes to be largest in August, its green season is in April, and yellow season is in the middle of November, the growth period is about 220 d. (4) The vegetation has a decreasing trend from the southeast to the northwest, most part is slightly improved, and Etuokeqianqi improved significantly. (5) The correlation indexes of annual NDVI with temperature and precipitation are -0.2178 and 0.6309, the vegetation growth is mainly affected by precipitation. In this study, a complete vegetation cover analysis and evaluation model for sandy land is established. It has important guiding significance for the sand ecological environment protection.

EFFECT OF SANDSTONE ANISOTROPY ON ITS HEAT AND MOISTURE TRANSPORT PROPERTIES

Directory of Open Access Journals (Sweden)

Jan Fořt

2015-09-01

Full Text Available Each type of natural stone has its own geological history, formation conditions, different chemical and mineralogical composition, which influence its possible anisotropy. Knowledge in the natural stones anisotropy represents crucial information for the process of stone quarrying, its correct usage and arrangement in building applications. Because of anisotropy, many natural stones exhibit different heat and moisture transport properties in various directions. The main goal of this study is to analyse several anisotropy indices and their effect on heat transport and capillary absorption. For the experimental determination of the anisotropy effect, five types of sandstone coming from different operating quarries in the Czech Republic are chosen. These materials are often used for restoration of culture heritage monuments as well as for other building applications where they are used as facing slabs, facade panels, decoration stones, paving, etc. For basic characterization of studied materials, determination of their bulk density, matrix density and total open porosity is done. Chemical composition of particular sandstones is analysed by X-Ray Fluorescence. Anisotropy is examined by the non-destructive measurement of velocity of ultrasonic wave propagation. On the basis of ultrasound testing data, the relative anisotropy, total anisotropy and anisotropy coefficient are calculated. Then, the measurement of thermal conductivity and thermal diffusivity in various directions of samples orientation is carried out. The obtained results reveal significant differences between the parameters characterizing the heat transport in various directions, whereas these values are in accordance with the indices of anisotropy. Capillary water transport is described by water absorption coefficient measured using a sorption experiment, which is performed for distilled water and 1M NaCl water solution.  The measured data confirm the effect of anisotropy which is

The role of sediment compaction and groundwater withdrawal in local sea-level rise, Sandy Hook, New Jersey, USA

Science.gov (United States)

Johnson, Christopher S.; Miller, Kenneth G.; Browning, James V.; Kopp, Robert E.; Khan, Nicole S.; Fan, Ying; Stanford, Scott D.; Horton, Benjamin P.

2018-02-01

The rate of relative sea-level (RSL) rise at Sandy Hook, NJ (4.0 ± 0.5 mm/yr) was higher than The Battery, NY (3.0 ± 0.3 mm/yr) from 1900 to 2012 despite being separated by just 26 km. The difference cannot be explained by differential glacial isostatic adjustment (GIA; 1.4 ± 0.4 and 1.3 ± 0.4 mm/yr RSL rise, respectively) alone. We estimate the contribution of sediment compaction to subsidence at Sandy Hook using high-resolution grain size, percent organic matter, and porosity data from three upper Quaternary (≤13,350 cal yr) cores. The organic matter content (indicates that compaction of deglacial silts likely reduced the column thickness by 10-20% over the past 13,350 cal yrs. While compaction rates were high immediately after the main silt deposition (13,350-13,150 cal yrs BP), rates decreased exponentially after deposition to an average 20th century rate of 0.16 mm/yr (90% Confidence Interval (C.I.), 0.06-0.32 mm/yr). The remaining ∼0.7 mm/yr (90% C.I. 0.3-1.2 mm/yr) difference in subsidence between Sandy Hook and The Battery is likely due to anthropogenic groundwater withdrawal. Historical data from Fort Hancock wells (2 km to the southeast of the Sandy Hook tide gauge) and previous regional work show that local and regional water extraction lowered the water levels in the aquifers underlying Sandy Hook. We suggest that the modern order of contribution to subsidence (highest to lowest) appears to be GIA, local/regional groundwater extraction, and compaction of thick Quaternary silts.

Chemical and physical hydrogeology of coal, mixed coal-sandstone and sandstone aquifers from coal-bearing formations in the Alberta Plains region, Alberta

International Nuclear Information System (INIS)

Lemay, T.G.

2003-09-01

With the decline of conventional oil and gas reserves, natural gas from coal (NGC) is an unconventional gas resource that is receiving much attention from petroleum exploration and development companies in Alberta. Although the volume of the NGC resource is large, there are many challenges facing NGC development in Alberta, including technical and economic issues, land access, water disposal, water diversion and access to information. Exploration and development of NGC in Alberta is relatively new, therefore there is little baseline data on which to base regulatory strategies. Some important information gaps have been filled through water well sampling in coal, mixed coal-sandstone and sandstone aquifers throughout Alberta. Analyses focused on the chemical and physical characteristics aquifers in use for domestic or agricultural purposes. Aquifer depths were generally less than 100 metres. Samples collected from Paskapoo-Scollard Formation, Horseshoe Canyon Formation and Belly River Group aquifers exceed Canadian water quality guideline values with respect to pH, sodium, manganese, chloride, chromium, sulphate, phenols and total dissolved solids. Pump tests conducted within the aquifers indicate that the groundwater flow is complicated. Water quality will have to be carefully managed to ensure responsible disposal practices are followed. Future studies will focus on understanding the chemical and biological process that occur within the aquifers and the possible link between these processes and gas generation. Mitigation and disposal strategies for produced water will also be developed along with exploration strategies using information obtained from hydrogeologic studies. 254 refs., 182 tabs., 100 figs., 3 appendices

Wettability Alteration of Sandstone and Carbonate Rocks by Using ZnO Nanoparticles in Heavy Oil Reservoirs

Directory of Open Access Journals (Sweden)

Masoumeh Tajmiri

2015-10-01

Full Text Available Efforts to enhance oil recovery through wettability alteration by nanoparticles have been attracted in recent years. However, many basic questions have been ambiguous up until now. Nanoparticles penetrate into pore volume of porous media, stick on the core surface, and by creating homogeneous water-wet area, cause to alter wettability. This work introduces the new concept of adding ZnO nanoparticles by an experimental work on wettability alteration and oil recovery through spontaneous imbibition mechanism. Laboratory tests were conducted in two experimental steps on four cylindrical core samples (three sandstones and one carbonate taken from a real Iranian heavy oil reservoir in Amott cell. In the first step, the core samples were saturated by crude oil. Next, the core samples were flooded with nanoparticles and saturated by crude oil for about two weeks. Then, the core samples were immersed in distilled water and the amount of recovery was monitored during 30 days for both steps. The experimental results showed that oil recovery for three sandstone cores changed from 20.74, 4.3, and 3.5% of original oil in place (OOIP in the absence of nanoparticles to 36.2, 17.57, and 20.68% of OOIP when nanoparticles were added respectively. Moreover, for the carbonate core, the recovery changed from zero to 8.89% of OOIP by adding nanoparticles. By the investigation of relative permeability curves, it was found that by adding ZnO nanoparticles, the crossover-point of curves shifted to the right for both sandstone and carbonate cores, which meant wettability was altered to water- wet. This study, for the first time, illustrated the remarkable role of ZnO nanoparticles in wettability alteration toward more water-wet for both sandstone and carbonate cores and enhancing oil recovery.

Limits to intensity of milk production in sandy areas in The Netherlands

NARCIS (Netherlands)

Aarts, H.F.M.; Habekotté, B.; Keulen, van H.

1999-01-01

Agricultural land in sandy areas is mainly in use by dairy farms. As a result of intensive fertilisation and irrigation, environmental quality is threatened by lost nutrients and lowered groundwater levels. Therefore, Dutch government put decreasing limits to losses of nutrients, with lowest values

Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas

Science.gov (United States)

Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

Sediment and discharge yields within a minimally disturbed, headwater watershed in North Central Pennsylvania, USA, with an emphasis on Superstorm Sandy

Science.gov (United States)

Maloney, Kelly O.; Shull, Dustin R.

2015-01-01

We estimated discharge and suspended sediment (SS) yield in a minimally disturbed watershed in North Central Pennsylvania, USA, and compared a typical storm (September storm, 4.80 cm) to a large storm (Superstorm Sandy, 7.47 cm rainfall). Depending on branch, Sandy contributed 9.7–19.9 times more discharge and 11.5–37.4 times more SS than the September storm. During the September storm, the upper two branches accounted for 60.6% of discharge and 88.8% of SS at Lower Branch; during Sandy these percentages dropped to 36.1% for discharge and 30.1% for SS. The branch with close proximity roads had over two-three times per area SS yield than the branch without such roads. Hysteresis loops showed typical clockwise patterns for the September storm and more complicated patterns for Sandy, reflecting the multipeak event. Estimates of SS and hysteresis in minimally disturbed watersheds provide useful information that can be compared spatially and temporally to facilitate management.

The impact of onsite wastewater disposal systems on groundwater in areas inundated by Hurricane Sandy in New York and New Jersey

Science.gov (United States)

Fisher, Irene; Phillips, Patrick J.; Colella, Kaitlyn; Fisher, Shawn C.; Tagliaferri, Tristen N.; Foreman, William T.; Furlong, Edward T.

2016-01-01

Coastal onsite wastewater disposal systems (OWDS) were inundated by Hurricane Sandy's storm tide. This study compares the shallow groundwater quality (nutrients, pharmaceuticals, and hormones) downgradient of OWDS before and after Hurricane Sandy, where available, and establishes a baseline for wastewater influence on groundwater in coastal communities inundated by Hurricane Sandy. Nutrients and contaminants of emerging concern (CECs) were detected in shallow groundwater downgradient of OWDS in two settings along the New Jersey and New York coastlines: 1) a single, centralized OWDS in a park; and 2) multiple OWDS (cesspools) in low-density residential and mixed-use/medium density residential areas. The most frequently detected pharmaceuticals were lidocaine (40%), carbamazepine (36%), and fexofenadine, bupropion, desvenlafaxine, meprobamate, and tramadol (24–32%). Increases in the number and total concentration of pharmaceuticals after Hurricane Sandy may reflect other factors (seasonality, usage) besides inundation, and demonstrate the importance of analyzing for a wide variety of CECs in regional studies.

Pore Structure Model for Predicting Elastic Wavespeeds in Fluid-Saturated Sandstones

Science.gov (United States)

Zimmerman, R. W.; David, E. C.

2011-12-01

During hydrostatic compression, in the elastic regime, ultrasonic P and S wave velocities measured on rock cores generally increase with pressure, and reach asymptotic values at high pressures. The pressure dependence of seismic velocities is generally thought to be due to the closure of compliant cracks, in which case the high-pressure velocities must reflect only the influence of the non-closable, equant "pores". Assuming that pores can be represented by spheroids, we can relate the elastic properties to the pore structure using an effective medium theory. Moreover, the closure pressure of a thin crack-like pore is directly proportional to its aspect ratio. Hence, our first aim is to use the pressure dependence of seismic velocities to invert the aspect ratio distribution. We use a simple analytical algorithm developed by Zimmerman (Compressibility of Sandstones, 1991), which can be used for any effective medium theory. Previous works have used overly restrictive assumptions, such as assuming that the stiff pores are spherical, or that the interactions between pores can be neglected. Here, we assume that the rock contains an exponential distribution of crack aspect ratios, and one family of stiff pores having an aspect ratio lying somewhere between 0.01 and 1. We develop our model in two versions, using the Differential Scheme, and the Mori-Tanaka scheme. The inversion is done using data obtained in dry experiments, since pore fluids have a strong effect on velocities and tend to mask the effect of the pore geometry. This avoids complicated joint inversion of dry and wet data, such as done by Cheng and Toksoz (JGR, 1979). Our results show that for many sets of data on sandstones, we can fit very well the dry velocities. Our second aim is to predict the saturated velocities from our pore structure model, noting that at a given differential stress, the pore structure should be the same as for a dry test. Our results show that the Biot-Gassmann predictions always

Experimental Investigation of Crack Extension Patterns in Hydraulic Fracturing with Shale, Sandstone and Granite Cores

Directory of Open Access Journals (Sweden)

Jianming He

2016-12-01

Full Text Available Hydraulic fracturing is an important method of reservoir stimulation in the exploitation of geothermal resources, and conventional and unconventional oil and gas resources. In this article, hydraulic fracturing experiments with shale, sandstone cores (from southern Sichuan Basin, and granite cores (from Inner Mongolia were conducted to investigate the different hydraulic fracture extension patterns in these three reservoir rocks. The different reactions between reservoir lithology and pump pressure can be reflected by the pump pressure monitoring curves of hydraulic fracture experiments. An X-ray computer tomography (CT scanner was employed to obtain the spatial distribution of hydraulic fractures in fractured shale, sandstone, and granite cores. From the microscopic and macroscopic observation of hydraulic fractures, different extension patterns of the hydraulic fracture can be analyzed. In fractured sandstone, symmetrical hydraulic fracture morphology could be formed, while some micro cracks were also induced near the injection hole. Although the macroscopic cracks in fractured granite cores are barely observed by naked eye, the results of X-ray CT scanning obviously show the morphology of hydraulic fractures. It is indicated that the typical bedding planes well developed in shale formation play an important role in the propagation of hydraulic fractures in shale cores. The results also demonstrated that heterogeneity influenced the pathway of the hydraulic fracture in granite cores.

Geology of groundwater occurrences of the Lower Cretaceus sandstone aquifer in East Central Sinai, Egypt

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Saad Younes Ghoubachi

2017-01-01

Full Text Available The present study focused on investigating the impact of geological setting on the groundwater occurrences of the Lower Cretaceous sandstone aquifer (Malha. The Lower Cretaceous sandstone aquifer is subdivided into 3 units according to their lithological characters for the first time in this present work. The study area is dissected by normal faults with their downthrown sides due north direction. The groundwater flows from southeast recharge area (outcrop to the northwest direction with an average hydraulic gradient of 0.0035. The hydraulic parameters of the Lower Cretaceous sandstone aquifer were determined and evaluated through 7 pumping tests carried out on productive wells. The Lower Cretaceous aquifer in the study area is characterized by moderate to high potential. The calculated groundwater volume of the Lower Cretaceous aquifer (6300 km2 in the study area attains about 300 bcm, while the estimated recharge to the same aquifer reaches about 44,500 m3/day with an annual recharge of 16 mcm/year. Expended Durov diagram plot revealed that the groundwater has been evolved from Mg-SO4 and Mg-Cl dissolution area types that eventually reached a final stage of evolution represented by a Na-Cl water type. This diagram helps also in identifying groundwater flow direction. The groundwater salinity ranges from 1082 ppm (Shaira to 1719 ppm (Nakhl, in the direction of groundwater movement towards north.

Effect of Irrigation Water Type on Infiltration Rates of Sandy Soil

International Nuclear Information System (INIS)

Al-Omran, A.M.; Al-Matrood, S.M.; Choudhary, M.I.

2004-01-01

A laboratory experiment was conducted to test the effect of three water types (tap water, well water and sewage water) on the infiltration rate of three soils varying in texture (sand. loamy sand and sandy loam). A stationary rainfall simulator dispensing water at a rate of 45 mm h-1, connected to the different sources of water, was used to measure the infiltration rates. A total of 5 runs were carried out using each water quality. The volume of runoff against the time was recorded at each 5 minute interval. The infiltration rate was calculated as the difference between the water applied and the excesses water measured as surface runoff. Infiltration rate at first run were rapid in all the three soils and then progressively declined as the number of runs increased. The same trend was observed for each water quality tested. The reduction in infiltration rate with increasing number of runs for prewetted surface than for the initial dry surface was attributed to break down and settling of fine particles that took place earlier during prewetting. The infiltration curves for all the three soils when irrigared with different qualities of water was not distinguishable. The relationship between infiltration rate as function of time for the treatments applied were tested using Kostiakov equation I=bt-n. The infiltration data gave a coefficient of determination R2 >0.90 for all the treatments. The infiltration parameters B, and n varied strongly with respect to soil texture. Values of B decreased with changing soil textures, being highest for the sandy soil, and lowest for the sandy loamy soil, whereas n values showed the opposite trend. It was concluded that effect of soil texture on the infiltration rate was very pronounced while water qualities showed a little effect. (author)

Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Science.gov (United States)

Chrząstek, Alina; Wypych, Monika

2018-03-01

The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils: Gyrochorte isp., Ophiomorpha nodosa (Lundgren, 1891), Ophiomorpha isp., Phycodes cf. curvipalmatum (Pollard, 1981), ?Phycodes isp., Planolites cf. beverleyensis (Billings, 1862), Thalassinoides paradoxicus (Woodward, 1830) and ?Thalassinoides isp. Moreover, interesting compound burrow systems, here referred to as Thalassinoides-Phycodes cf. palmatus and ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorte isp., Phycodes cf. flabellum (Miller and Dyer, 1878) and ?Treptichnus isp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropod Nerinea bicincta (Bronn, 1836) and the bivalve Lima haidingeri (Zittel, 1866) were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by (Scupin (1912-1913)). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha, Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte, Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha, Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes, Gyrochorte and ?Treptichnus). The assemblage of trace fossils is characteristic of the Skolithos ichnofacies and Cruziana ichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member

Assessment of undiscovered sandstone copper deposits of the Kodar-Udokan area, Russia: Chapter M in Global mineral resource assessment

Science.gov (United States)

Zientek, Michael L.; Chechetkin, Vladimir S.; Parks, Heather L.; Box, Stephen E.; Briggs, Deborah A.; Cossette, Pamela M.; Dolgopolova, Alla; Hayes, Timothy S.; Seltmann, Reimar; Syusyura, Boris; Taylor, Cliff D.; Wintzer, Niki E.

2014-01-01

Mineral resource assessments integrate and synthesize available information as a basis for estimating the location, quality, and quantity of undiscovered mineral resources. This probabilistic mineral resource assessment of undiscovered sandstone copper deposits within Paleoproterozoic metasedimentary rocks of the Kodar-Udokan area in Russia is a contribution to a global assessment led by the U.S. Geological Survey (USGS). The purposes of this study are to (1) delineate permissive areas (tracts) to indicate where undiscovered sandstone-hosted copper deposits may occur within 2 km of the surface, (2) provide a database of known sandstone copper deposits and significant prospects, (3) estimate numbers of undiscovered deposits within these permissive tracts at several levels of confidence, and (4) provide probabilistic estimates of amounts of copper (Cu) and mineralized rock that could be contained in undiscovered deposits within each tract. The workshop for the assessment, held in October 2009, used a three-part form of mineral resource assessment as described by Singer (1993) and Singer and Menzie (2010).

Topological representation of the porous structure and its evolution of reservoir sandstone under excavation-induced loads

Directory of Open Access Journals (Sweden)

Ju Yang

2017-01-01

Full Text Available The porous structure of a reservoir rock greatly influences its evolutive deformation and fracture behavior during excavation of natural resources reservoirs. Most numerical models for porous structures have been used to predict the quasi-static mechanical properties, but few are available to accurately characterize the evolution process of the porous structure and its influence on the macroscopic properties of reservoir rocks. This study reports a novel method to characterize the porous structure of sandstone using its topological parameters and to determine the laws that govern the evolutive deformation and failure of the topological structure under various uniaxial compressive loads. A numerical model of the porous sandstone was established based on the pore characteristics that were acquired using computed tomography imaging techniques. The analytical method that integrates the grassfire algorithm and the maximum inscribed sphere algorithm was proposed to create the 3-D topological model of the deformed porous structure, through which the topological parameters of the structure were measured and identified. The evolution processes of the porous structure under various loads were characterized using its equivalent topological model and parameters. This study opens a new way to characterize the dynamic evolution of the pore structure of reservoir sandstone under excavation disturbance.

Sandstone uranium deposits of Eurasia – from genetic concepts to forecasting and new discoveries

International Nuclear Information System (INIS)

Pechenkin, I.

2014-01-01

Along the Eurasian continent’s southern borders lie uranium ore provinces and regions controlling medium-sized and, on rare occasions, large sandstone deposits. Central French, Eastern Rhodope and other regions are known in the west. Large uranium ore provinces were discovered in the south of the Turan Plate and in the depressions of South Kazakhstan, viz. Central Kyzyl Kum, Syr Darya, Chu Sarysu. A common criterion has been established for all objects of the sandstone type, located in oil and gas, coal etc. sedimentary basins – the zone of interlayer or ground-interlayer oxidation, controlling uranium mineralization. In 2003 we were able to justify the concept that the formation of giant deposits in Chu Sarysu province was caused by the collision between the Indian Plate and the southern part of the Eurasian continent. Within the limits of Pacific ore belt there is a zonal distribution of ore deposits. Ordinary mineralization is drawn towards its eastern fringe: gold, tin, copper, tungsten etc. Volcanic and tectonic structures of central type of Mesozoic age are located further west, from the north to the south, that is large calderas – Streltsovskaya (Russia), Dornot (Mongolia), Sian Shan (China), which control large and unique endogene uranium deposits. In the far west, in the region of subsiding tectonic tensions, there are sandstone deposits of uranium in Transbaikalia, Mongolia and Yunnan, which are specially connected to young basalts. Infiltration deposits of Vitim region are adjacent to endogene deposits of Streltsovsky region in the southern-easterly direction, and to the east of the deposits of Yunnan at the same latitude lay the Sian Shan caldera with geothermal deposits of uranium and other metals. We combined them into the unified submeridional Baikal-Southern China uranium ore belt. After examining the southern extremities of the Eurasian continent, the region of the collision of the Indian Plate, a distinct similarity can be perceived between

Characterization of the Oriskany and Berea Sandstones: Evaluating Biogeochemical Reactions of Potential Sandstone–Hydraulic Fracturing Fluid Interaction

Energy Technology Data Exchange (ETDEWEB)

Verba, Circe [National Energy Technology Lab. (NETL), Albany, OR (United States); Harris, Aubrey [National Energy Technology Lab. (NETL), Albany, OR (United States)

2016-07-07

The Marcellus shale, located in the mid-Atlantic Appalachian Basin, has been identified as a source for natural gas and targeted for hydraulic fracturing recovery methods. Hydraulic fracturing is a technique used by the oil and gas industry to access petroleum reserves in geologic formations that cannot be accessed with conventional drilling techniques (Capo et al., 2014). This unconventional technique fractures rock formations that have low permeability by pumping pressurized hydraulic fracturing fluids into the subsurface. Although the major components of hydraulic fracturing fluid are water and sand, chemicals, such as recalcitrant biocides and polyacrylamide, are also used (Frac Focus, 2015). There is domestic concern that the chemicals could reach groundwater or surface water during transport, storage, or the fracturing process (Chapman et al., 2012). In the event of a surface spill, understanding the natural attenuation of the chemicals in hydraulic fracturing fluid, as well as the physical and chemical properties of the aquifers surrounding the spill site, will help mitigate potential dangers to drinking water. However, reports on the degradation pathways of these chemicals are limited in existing literature. The Appalachian Basin Marcellus shale and its surrounding sandstones host diverse mineralogical suites. During the hydraulic fracturing process, the hydraulic fracturing fluids come into contact with variable mineral compositions. The reactions between the fracturing fluid chemicals and the minerals are very diverse. This report: 1) describes common minerals (e.g. quartz, clay, pyrite, and carbonates) present in the Marcellus shale, as well as the Oriskany and Berea sandstones, which are located stratigraphically below and above the Marcellus shale; 2) summarizes the existing literature of the degradation pathways for common hydraulic fracturing fluid chemicals [polyacrylamide, ethylene glycol, poly(diallyldimethylammonium chloride), glutaraldehyde

Study of the Effect of Clay Particles on Low Salinity Water Injection in Sandstone Reservoirs

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Sina Rezaei Gomari

2017-03-01

Full Text Available The need for optimal recovery of crude oil from sandstone and carbonate reservoirs around the world has never been greater for the petroleum industry. Water-flooding has been applied to the supplement primary depletion process or as a separate secondary recovery method. Low salinity water injection is a relatively new method that involves injecting low salinity brines at high pressure similar to conventional water-flooding techniques, in order to recover crude oil. The effectiveness of low salinity water injection in sandstone reservoirs depends on a number of parameters such as reservoir temperature, pressure, type of clay particle and salinity of injected brine. Clay particles present on reservoir rock surfaces adsorb polar components of oil and modify wettability of sandstone rocks to the oil-wet state, which is accountable for the reduced recovery rates by conventional water-flooding. The extent of wettability alteration caused by three low salinity brines on oil-wet sandstone samples containing varying clay content (15% or 30% and type of clay (kaolinite/montmorillonite were analyzed in the laboratory experiment. Contact angles of mica powder and clay mixture (kaolinite/montmorillonite modified with crude oil were measured before and after injection with three low salinity sodium chloride brines. The effect of temperature was also analyzed for each sample. The results of the experiment indicate that samples with kaolinite clay tend to produce higher contact angles than samples with montmorillonite clay when modified with crude oil. The highest degree or extent of wettability alteration from oil-wet to intermediate-wet state upon injection with low salinity brines was observed for samples injected with brine having salinity concentration of 2000 ppm. The increase in temperature tends to produce contact angles values lying in the higher end of the intermediate-wet range (75°–115° for samples treated at 50 °C, while their corresponding

Hurricane Sandy science plan: impacts of environmental quality and persisting contaminant exposure

Science.gov (United States)

Caskie, Sarah A.

2013-01-01

Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: • Coastal topography and bathymetry

A new biostratigraphical tool for reservoir characterisation and well correlation in permo-carboniferous sandstones

NARCIS (Netherlands)

Garming, J.F.L.; Cremer, H.; Verreussel, R.M.C.H.; Guasti, E.; Abbink, O.A.

2010-01-01

Permo-Carboniferous sandstones are important reservoir rocks for natural gas in the Southern North Sea basin. This is a mature area which makes tools for reservoir characterization and well to well correlation important for field optimalisation and ongoing exploration activities. Within the

Subsidence estimation of breakwater built on loosely deposited sandy seabed foundation: Elastic model or elasto-plastic model

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Jianhua Shen

2017-07-01

Full Text Available In offshore area, newly deposited Quaternary loose seabed soils are widely distributed. There are a great number of offshore structures has been built on them in the past, or will be built on them in the future due to the fact that there would be no very dense seabed soil foundation could be chosen at planed sites sometimes. However, loosely deposited seabed foundation would bring great risk to the service ability of offshore structures after construction. Currently, the understanding on wave-induced liquefaction mechanism in loose seabed foundation has been greatly improved; however, the recognition on the consolidation characteristics and settlement estimation of loose seabed foundation under offshore structures is still limited. In this study, taking a semi-coupled numerical model FSSI-CAS 2D as the tool, the consolidation and settlement of loosely deposited sandy seabed foundation under an offshore breakwater is investigated. The advanced soil constitutive model Pastor-Zienkiewics Mark III (PZIII is used to describe the quasi-static behavior of loose sandy seabed soil. The computational results show that PZIII model is capable of being used for settlement estimation problem of loosely deposited sandy seabed foundation. For loose sandy seabed foundation, elastic deformation is the dominant component in consolidation process. It is suggested that general elastic model is acceptable for subsidence estimation of offshore structures on loose seabed foundation; however, Young's modulus E must be dependent on the confining effective stress, rather than a constant in computation.

Toward a Unified Military Response: Hurricane Sandy and the Dual Status Commander

Science.gov (United States)

2015-04-01

18th tropical depression of the season formed over the southwestern Caribbean Sea and quickly strength- ened into Tropical Storm Sandy late that... Centennial , a combined Title 10 and 32 operation, during the Sep- tember 2013 response to the Colorado Floods. 117 APPENDIX I ACRONYMS AAR After Action

Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes.

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Wil Lieberman-Cribbin

Full Text Available Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD. Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231 following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1-1.9], depression (ORadj: 1.7 [1.3-2.2], and PTSD (ORadj: 2.5 [1.8-3.4], while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01-1.12] and PTSD (ORadj: 1.2 [1.1-1.2]. Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5-2.8] or FEMA continuous flooding (ORadj: 1.1 [1.1-1.2] were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms.

Barrier-island and estuarine-wetland physical-change assessment after Hurricane Sandy

Science.gov (United States)

Plant, Nathaniel G.; Smith, Kathryn E.L.; Passeri, Davina L.; Smith, Christopher G.; Bernier, Julie C.

2018-04-03

IntroductionThe Nation’s eastern coast is fringed by beaches, dunes, barrier islands, wetlands, and bluffs. These natural coastal barriers provide critical benefits and services, and can mitigate the impact of storms, erosion, and sea-level rise on our coastal communities. Waves and storm surge resulting from Hurricane Sandy, which made landfall along the New Jersey coast on October 29, 2012, impacted the U.S. coastline from North Carolina to Massachusetts, including Assateague Island, Maryland and Virginia, and the Delmarva coastal system. The storm impacts included changes in topography, coastal morphology, geology, hydrology, environmental quality, and ecosystems.In the immediate aftermath of the storm, light detection and ranging (lidar) surveys from North Carolina to New York documented storm impacts to coastal barriers, providing a baseline to assess vulnerability of the reconfigured coast. The focus of much of the existing coastal change assessment is along the ocean-facing coastline; however, much of the coastline affected by Hurricane Sandy includes the estuarine-facing coastlines of barrier-island systems. Specifically, the wetland and back-barrier shorelines experienced substantial change as a result of wave action and storm surge that occurred during Hurricane Sandy (see also USGS photograph, http://coastal.er.usgs.gov/hurricanes/sandy/photo-comparisons/virginia.php). Assessing physical shoreline and wetland change (land loss as well as land gains) can help to determine the resiliency of wetland systems that protect adjacent habitat, shorelines, and communities.To address storm impacts to wetlands, a vulnerability assessment should describe both long-term (for example, several decades) and short-term (for example, Sandy’s landfall) extent and character of the interior wetlands and the back-barrier-shoreline changes. The objective of this report is to describe several new wetland vulnerability assessments based on the detailed physical changes

What Happened to Our Environment and Mental Health as a Result of Hurricane Sandy?

Science.gov (United States)

Lin, Shao; Lu, Yi; Justino, John; Dong, Guanghui; Lauper, Ursula

2016-06-01

This study describes findings of the impacts of Hurricane Sandy on environmental factors including power outages, air quality, water quality, and weather factors and how these affected mental health during the hurricane. An ecological study was conducted at the county level to describe changes in environmental factors-especially power outages-and their relationships to emergency department (ED) visits for mental health problems by use of a Poisson regression model. We found that many environmental hazards occurred as co-exposures during Hurricane Sandy in addition to flooding. Mental health ED visits corresponded with the peak of maximum daily power blackouts, with a 3-day lag, and were positively associated with power blackouts in Bronx (prevalence ratio [PR]: 8.82, 95% confidence interval [CI]: 1.27-61.42) and Queens (PR: 2.47, 95% CI: 1.05-5.82) counties. A possible dose-response relationship was found between the quantile of maximum blackout percentage and the risk of mental health in the Bronx. We found that multiple co-environmental hazards occurred during Hurricane Sandy, especially power blackouts that mediated this disaster's impacts. The effects of power outage on mental health had large geographic variations and were substantial, especially in communities with low sociodemographic status. These findings may provide new insights for future disaster response and preparedness efforts. (Disaster Med Public Health Preparedness. 2016;10:314-319).

Vertical small scale variations of sorption and mineralization of three herbicides in subsurface limestone and sandy aquifer

DEFF Research Database (Denmark)

Janniche, Gry Sander; Mouvet, C.; Albrechtsen, Hans-Jørgen

2011-01-01

, France. From two intact core drills, four heterogenic limestone sections were collected from 4.50-26.40 m below surface (mbs) and divided into 12 sub-samples of 8-25 cm length, and one sandy aquifer section from 19.20-19.53 m depth divided into 7 sub-samples of 4-5 cm length. In the sandy aquifer section...... showed that a 30 cm active layer with the measured sorption and mineralization values hardly impacted the fate of the investigated herbicides, whereas a total thickness of layers of 1 m would substantially increase natural attenuation....

A GIS-based model of potential groundwater yield zonation for a sandstone aquifer in the Juye Coalfield, Shangdong, China

Science.gov (United States)

Yin, Huiyong; Shi, Yongli; Niu, Huigong; Xie, Daolei; Wei, Jiuchuan; Lefticariu, Liliana; Xu, Shuanxiang

2018-02-01

Resolving the potential groundwater yield zonation of sandstone aquifers occurring at depths of several hundred meters has been an important and challenging objective of the hydrogeological research focused on preventing flood hazards in coal mines. Using accessible geological exploration data we put forward a method of predicting the spatial distribution of groundwater storage potential in sandstone aquifers from Permian-age coal deposits in Juye Coalfield, Shangdong, China. A Geological, Tectonic and Lithological Composition Index (GTLCI) model was created using the following parameters: sandstone depth and thickness, faults length density (FaLD), faults density (FaD), fault frequency density (FaFD), fault scale density (FaSD), variation coefficient of the slope (VCS) of the coal seam, intensity index of folds in horizontal direction (IIFoH), and lithological composition index (LCI). Each of these factors was subsequently divided into 5 classes. The analytic hierarchy process (AHP) and trapezoidal fuzzy number (TFN) method was applied to calculate the weight of the conditioning factor and their respective sub-classes. Groundwater yield potential contour map, which was initially constructed using the GTLCI values revealed four groundwater abundance zones. The map was further refined by taking into account hydrogeologic data collected during mining activities. The GTLCI model predictive success rate of 80% was explained by the limited number of boreholes available for validation. It is considered that the GTLCI model is effective at predicting zonation of groundwater yield in the sandstone aquifers from Permian- age coal deposits in Juye Coalfield, China.

Palaeoclimatic trends deduced from the hydrochemistry of a Triassic sandstone aquifer, U.K

International Nuclear Information System (INIS)

Bath, A.H.; Edmunds, W.M.; Andrews, J.N.

1978-01-01

A detailed geochemical study (elemental, isotopic and dissolved inert gases) of unconfined and confined sections of the Triassic non-marine sandstone aquifer in Eastern England has been undertaken. Aspects of the recharge history of this aquifer over the past 40 000 years are revealed by examination of the data. (orig./HK) [de

Combined rock-physical modelling and seismic inversion techniques for characterisation of stacked sandstone reservoir

NARCIS (Netherlands)

Justiniano, A.; Jaya, Y.; Diephuis, G.; Veenhof, R.; Pringle, T.

2015-01-01

The objective of the study is to characterise the Triassic massive stacked sandstone deposits of the Main Buntsandstein Subgroup at Block Q16 located in the West Netherlands Basin. The characterisation was carried out through combining rock-physics modelling and seismic inversion techniques. The

Development of a Geologic Exploration Model foe the Permo-Pennsylvanian Petroleum System in South-Central Montana

Energy Technology Data Exchange (ETDEWEB)

David A. Lopez

2007-06-30

Eolian sands are the main Pennsylvanian Tensleep Sandstone reservoir rocks, and were deposited in a near-shore environment interbedded with near-shore marine and sabkha calcareous and dolomitic rocks. Within the Tensleep, numerous cycles are characterized by basal marine or sabkha calcareous sandstone or dolomitic sandstone overlain by porous and permeable eolian sandstone, which in turn is capped by marine sandstone. The cycles represent the interplay of near-shore marine, sabkha, and eolian environments. On the west side of the project area, both the lower and upper Tensleep are present and the total thickness reaches a maximum of about 240 ft. The lower Tensleep is 100 to 120 ft thick and consists of a sequence of repeating cycles of limey shallow marine sandstone, sandy limestone, and sandy dolomite. The upper Tensleep is generally characterized by cycles of sandy limestone or dolomite, overlain by light-colored, eolian dune sandstone capped by marine limey sandstone. In the central and eastern parts of the project area, only the lower Tensleep is present, but here eolian sandstones are in cycles much like those in the west in the upper Tensleep. The lower Tensleep is quite variable in thickness, ranging from about 25 ft to over 200 ft. Oil accumulations in the Tensleep are best described as structurally modified paleostratigraphic accumulations. At Frannie Field, the irregular oil column can be explained by a post-Tensleep channel scour on the west flank of the anticline. On the Powder River Basin side of the project area, the Soap Creek and Lodge Grass Fields produce from the Permo-Pennsylvanian system. In these two fields, erosional remnants of eolian sandstone control the production, similar to the situation at Frannie Field. At Soap Creek the trap is enhanced by structural closure. In the Lodge Grass area, Tensleep oil is trapped in preserved dunes in the footwall of a Laramide reverse fault. Oil generation and migration was early. Two hypotheses have been

Importance of phytodetritus and microphytobenthos for heterotrophs in a shallow subtidal sandy sediment

NARCIS (Netherlands)

Evrard, V.; Huettel, M.; Cook, P.L.M.; Soetaert, K.; Heip, C.H.R.; Middelburg, J.J.

2012-01-01

The relative importance of allochthonous phytodetritus deposition and autochthonous microphytobenthos (MPB) production for benthic consumers in an organic carbon (C-org)-poor sandy sediment was assessed using a C-13-stable isotope natural abundance study combined with a dual C-13-tracer addition

Textural patterns, mineralogy, and chemistry of sandstone-related Calçadinha chalcedony (Piauí, Brazil

Directory of Open Access Journals (Sweden)

Marcondes Lima da Costa

Full Text Available ABSTRACT: Paleozoic sandstones of the Parnaíba Basin, in addition to hosting opal deposits, also have occurrences of chalcedonies with potential for mineral and ornamental handicrafts, in addition to assisting the understanding of the geological evolution of the basin. However, the chalcedonies were not investigated yet, and this study intended to fulfill this gap by the investigation of the chalcedonies of Calçadinha in Piauí. Fieldwork, microtexturals analysis, X-ray diffraction and scanning electron microscopy with energy dispersive spectrometry, chemical analysis, and gemological assessments were developed. Four distinct types of chalcedonies have been distinguished. They stand out for their well distribution of Fe and Mn dendrites, which involves opal nodules, and contains microcavities with well-formed microcrystalline quartz, nontronite, and palygorskite. The mesoscopic features of these chalcedonies and cabochon and free forms cutting show potential for use in mineral crafts and semi-jewels. As expected, the chalcedonies are dominated by high contents of SiO2, besides the low and variable contents of Al2O3, Fe2O3, MgO, and TiO2. Among trace elements that show high Ba contents, bound in barite, seem also to be a geochemical signature of the country sandstones in Parnaíba basin. These chalcedonies were formed during the partial solubilization of SiO2 of sandstones, which was promoted during their tectonic formation in faults and fractures zones.

Estimates of vertical hydraulic conductivity in the middle Dakota Sandstone, Monticello, Utah

International Nuclear Information System (INIS)

Kautsky, M.; Kearl, P.M.; Dexter, J.J.; Zinkl, R.J.

1986-01-01

There are about 2 million tons of uranium mill tailings which lie directly on top of an alluvial aquifer at the Monticello millsite, Utah. The aquifer is contaminated as a consequence of leachate percolating through the tailings. The Burro Canyon Formation which is the local culinary aquifer, underlies the site at depth, but is isolated from the alluvial aquifer by an aquitard composed primarily of middle Dakota Sandstone, and some Mancos Shale. Water quality monitoring of the Burro Canyon aquifer has indicated that it contains very low to no contamination by radionuclides. Tritium data have shown that the recharge to the aquifer predates 1953. Pump tests conducted on the system using the ratio method, have shown the vertical hydraulic conductivity of the aquitard is some 5.2 x 10/sup -7/ to 8.0 x 10/sup -9/ m/d (1.7 x 10/sup -6/ to 2.6 x 10/sup -8/ ft/d). Based upon the aquifer monitoring and test data, the middle Dakota Sandstone appears to be an effective aquitard impeding the downward migration of contaminants from the alluvial aquifer to the Burro Canyon aquifer

Correlation development between indentation parameters and uniaxial compressive strength for Colombian sandstones

International Nuclear Information System (INIS)

Mateus, Jefferson; Saavedra, Nestor Fernando; Calderon Carrillo, Zuly; Mateus, Darwin

2007-01-01

A new way to characterize the perforated formation strength has been implemented using the indentation test. This test can be performed on irregular cuttings mounted in acrylic resins forming a disc. The test consists of applying load on each sample by means of a flat and indenter. A graph of the load applied VS penetration of the indenter is developed, and the modules of the test, denominated indentation modulus (IM) and Critical Transition Force (CTF) are obtained (Ringstad et al., 1998). Based on the success of previous studies we developed correlations between indentation and mechanical properties for some Colombian sandstone. These correlations were obtained using o set of 248 indentation tests and separate compression fasts on parallel sandstone samples from the same depth. This analysis includes Barco Formation, Mirador Formation, and Tambor Formation. For the correlations, IM-UCS and CTF-UCS, the correlation coefficient is 0.81 and 0.70 respectively. The use of the correlations and the indentation test is helpful for in-situ calibration of the geomechanical models since the indentation test can be performed in real time thus reducing costs and time associated with delayed conventional characterization

High-resolution mapping of yield curve shape and evolution for high porosity sandstones

Science.gov (United States)

Bedford, J. D.; Faulkner, D.; Wheeler, J.; Leclere, H.

2017-12-01

The onset of permanent inelastic deformation for porous rock is typically defined by a yield curve plotted in P-Q space, where P is the effective mean stress and Q is the differential stress. Sandstones usually have broadly elliptical shaped yield curves, with the low pressure side of the ellipse associated with localized brittle faulting (dilation) and the high pressure side with distributed ductile deformation (compaction). However recent works have shown that these curves might not be perfectly elliptical and that significant evolution in shape occurs with continued deformation. We therefore use a novel stress-probing methodology to map in high-resolution the yield curve shape for Boise and Idaho Gray sandstones (36-38% porosity) and also investigate curve evolution with increasing deformation. The data reveal yield curves with a much flatter geometry than previously recorded for porous sandstone and that the compactive side of the curve is partly comprised of a near vertical limb. The yield curve evolution is found to be strongly dependent on the nature of inelastic strain. Samples that were compacted under a deviatoric load, with a component of inelastic shear strain, were found to have yield curves with peaks that are approximately 50% higher than similar porosity samples that were hydrostatically compacted (i.e. purely volumetric strain). The difference in yield curve evolution along the different loading paths is attributed to mechanical anisotropy that develops during deviatoric loading by the closure of preferentially orientated fractures. Increased shear strain also leads to the formation of a plateau at the peak of the yield curve as samples deform along the deviatoric loading path. These results have important implications for understanding how the strength of porous rock evolves along different stress paths, including during fluid extraction from hydrocarbon reservoirs where the stress state is rarely isotropic.

Research and performance evaluation on an HA integrated acid system for sandstone acidizing

Directory of Open Access Journals (Sweden)

Liqiang Zhao

2018-03-01

Full Text Available When the conventional sandstone acidizing technologies are adopted, many slugs are needed in the injection of prepad fluid, treatment fluid and postpad fluid, and consequently the production and operation suffers inconveniences and difficulties. In view of this, a kind of HA integrated acid system which is mainly composed of organic polybasic acids (HA+HCl + HF and an efficient organic solvent was developed in this paper based on the idea of integrated acid replacing ''multiple steps'' and high efficiency and intensification. Via this HA integrated acid system, the complicated blockage in sandstone reservoirs can be removed effectively. Then, experiments were carried out on this system to evaluate its performance in terms of its retardance, organic blockage dissolution, chelating and precipitation inhibition. It is indicated that this new system can not only realize the acidizing of conventional integrated acid, but also present a good retarding performance by controlling H+ multi-stage ionization step by step and by forming silica acid-aluminum phosphonate film on the surface of clay minerals; that via this new HA integrated acid system, the organic blockage can be removed efficiently; and that it is wider in pH solution range than conventional APCs (aminopolycarboxyliates chelants, stronger in chelating capacity of Ca2+, Mg2+ and Fe3+ than conventional chelants (e.g. EDTA, NTA and DTPA, and better in precipitation inhibition on metal fluoride, fluosilicic acid alkali metal, fluoaluminic acid alkali metal and hydroxide than multi-hydrogen acid, fluoboric acid and mud acid systems. These research results provide a technical support for the plugging removal in high-temperature deep oil and gas reservoirs. Keywords: Organic polybasic acid, Integrated acid, Retardance, Chelating, Precipitation, Acidizing, Sandstone, Reservoir

Gravity-induced stress as a factor reducing decay of sandstone monuments in Petra, Jordan

Czech Academy of Sciences Publication Activity Database

Řihošek, J.; Bruthans, J.; Mašín, D.; Filippi, Michal; Carling, G. T.; Schweigstillová, Jana

2016-01-01

Roč. 19, 1 May (2016), s. 415-425 ISSN 1296-2074 R&D Projects: GA ČR GA13-28040S Institutional support: RVO:67985831 ; RVO:67985891 Keywords : Decay * Petra * sandstone monument * stability * stress Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.838, year: 2016