Black shales

Black shales are sedimentary rocks with a high content of organic carbon, which leads to a dark grayish to black color. Because of their potential to contain oil or gas, black shales are of great ...

Black shale is a variety of shale containing lots of organic matter that gives it a black color. These rocks are rich in pyrite and several metals like vanadium ...Mo enrichments and isotopic signatures in black shales from the main negative CIE also indicate globally extensive seafloor euxinia during this phase of the T-OAE, in excess of 10x that in the modern (Pearce et al., 2008), and potentially between 2-10% of global seafloor area (Dickson, 2017), though an increase in seawater Mo isotopes …General overview of black shales Six Desmoinesian organic-rich marine black shales members — Anna Shale, Turner Mine Shale, Excello Shale, Mecca Quarry Shale, Carrier Mills Shale and Veale Shale — were the main targets of this study (Fig. 2). They each produce a high response on gamma-ray logs, have high organic matter content, and have largeThe host black shales display positive correlations for TOC and redox-sensitive elements, suggesting that they formed under suboxic conditions. We infer that the polymetallic Ni-Mo sulfide ores formed in a sediment-starved semi-restricted euxinic marine basin. In contrast, the V ores formed under both euxinic and intermittently suboxic to ...The Lungmachi black shales range in age from the Normalograptus persculptus Biozone of the uppermost Ordovician to the Spirograptus guerichi Biozone of the lower Telychian, and ten graptolite biozones can be recognized within this unit. The basal and upper contacts of the Lungmachi black shales are diachronous.Black shales of Devonian age in the Appalachian Basin are a unique rock sequence. The high content of organic matter, which imparts the characteristic lithology, has for years attracted considerable interest in the shales as a possible source of energy. The recent energy shortage prompted the U.S. Department of Energy through the Eastern Gas Shales Project of the Morgantown Energy Technology ...We present δ60Ni values for black shales, determined by double-spike MC-ICP-MS. The samples comprise Paleoproterozoic Talvivaara Ni–Zn–Co–Cu black shales from Finland, Neoproterozoic black shales from the Teplá-Barrandian Unit, Czech Republic, Early Cambrian Ni–Mo-rich black shales from the Yangtze Craton, and Devonian …Section snippets Composition, textures and modes of mineralization. Black shales are in broad terms composed of mineral and organic—kerogenous—matrix, whereas black primarily refers to any kind of organic matter (OM—humic, sapropelic, bituminous, graphitic) that provides the rock its color, and shale refers to fissile fine-grained sedimentary rock.

The black shales and sulfide layers, with the exception of replicate anal- yses of N21, lie on or between these reference lines, suggesting that, to a first approximation, the Re and Os were added close to the time of deposition. Regression of the data, how- ever, yields an errorchron with a negative '"Os/'^Os inter- cept. One replicate ...Shale gas is a type of natural gas generated from organic-rich black shale [10, 11]. When permeability and porosity were both low, shale may have been an effective natural gas reservoir [ 12 ]. Shale gas can be stored in several ways, including free gas in natural fissures and intergranular porosity, gas dissolved onto kerogen and clay surfaces ...Sep 1, 2015 · The black-shale intervals lack bioturbation and feature mm-thick sub-layers of varying dark-grey and sometimes grey-green colour (in web version). Occasionally, small 1–2 cm thick limestone layers are intercalated (e.g., in couplet 2). The prominent black-shale intervals in couplets 7 and 9 lack limy sub-layers. When black shales are weighted by preserved thickness, a time series (Isley and Abbott, 1999) shows three peaks in the Paleoproterozoic (i.e. ∼2.0, 1.85, and 1.7 Ga), with small peaks at 600 Ma and 1.45 Ga, ̄ and a maximum near the Archean/Proterozoic boundary between 2.7 and 2.5 Ga (Fig. 2).Plotted as a time series weighted by errors in …Less abundant elements Mo, Sb, Zn, and Se have median ranges of 10 to 100 ppm, and Ag, Bi, Te, Cd, and Au have median ranges of 0.01 to 10 ppm. Our dataset reveals three main groups of trace elements that are incorporated into pyrite in different ways. Group 1 elements (As, Ni, Co, Sb, Se, and Mo) are contained uniformly throughout the pyrite ...In black shales that have been heated to only 200-300°C, MoS 2 sheets have been found intercalated with graphite sheets in minute particles (the combination is designated MoSC; Kao et al., 2001 ...

Jan 9, 2023 · The paleodepositional environments related to Ediacaran black shales from the Série Negra succession in Ossa-Morena tectonostratigraphic zone were investigated using their geochemical composition to identify the sedimentary sources and depositional conditions. Their potential for assisting the genesis of metal deposits was also discussed. The sedimentary sources of the black shales are ... Oil from Shale: The KGS-IMMR Mississippian-Devonian Black Shales Cores. This month we highlight an important collection of research cores gathered in response to global political crises resulting in oil price spikes, the 1973-74 Arab oil embargo, and the 1979 oil crisis. The recent increase in gasoline prices in response to the Russian invasion ...The Devonian black shales serve as both the source and trap for large quantities of natural gas; total gas in place for the shales in Kentucky is estimated to be between 63 and 112more » Most of this natural gas is adsorbed on clay and kerogen surfaces, analogous to methane storage in coal beds.China’s most successful horizon for shale-gas exploration and development is the Upper Ordovician Wufeng Formation through the Lower Silurian Longmaxi Formation in its Upper Yangtze Region. In this study, the Wufeng–Longmaxi Formation black shales in the Upper Yangtze Region are analysed to determine their microstructural …Aug 14, 2023 · Locations of samples of black shales with critical mineral geochemistry (Granitto and others, 2017) were used as an evidential layer to calculate prospectivity models for sediment-hosted Pb-Zn mineralization as described in Lawley and others (2022). Lowermost Silurian (Rhuddanian, lower Llandovery) black shales represent the main Palaeozoic petroleum source rock throughout North Africa and Arabia. The unit also occurs in parts of Morocco with recorded TOC values of up to 10.5%. However, in contrast to many other North African and Arabian countries, the Silurian‐Lower Devonian shale‐dominated succession in Morocco also contains a ...

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Lacustrine black shales are widely developed within the Late Cretaceous Nenjiang Formation (k 2 n) of the Songliao Basin. These black shales provide an ideal natural laboratory for reconstructing the paleoclimate and paleoenvironment during the Late Cretaceous in Northeast China and have great significance in the exploration for …Black shales are sedimentary rocks containing > 0.5% of organic carbon. They host polymetallic deposits which have been mined for Cu, Ni, Zn, Mn, P, Mo, V, U, Au and PGE (platinum group elements). ...These black shales are not only rich in organic matter, but also undergone an unexpectedly low thermal evolution process, both of which contribute to well-preserved indigenous hydrocarbons and promote the convincing discovery of the Precambrian biology. The combination of the absence or low concentrations of gammacerane, dibenzothiophene series ...Analysis shows that the semi-deep lake subfacies mainly deposit black-dark gray clayey shale. Because the location of well T1 in Puguang area is closer to the lake basin center than well Y1 in Yuanba area during the sedimentary period of J 1 da, the water body is deeper, the sedimentary facies is more stable, and the shale thickness is thicker ...The lower part is organic-rich black shale, composed by laminated carbonaceous and calcareous shale with a high concentration of graptolite and OM. The upper part, termed as Guanyingqiao limestone, is a kind of biogenic limestone with a thickness of less than 0.3m in this region, and can be a good mark for strata identification ( Chen et al ...Regional correlations of the black shales in New York show very similar field relations to those found by Conant and Swanson (1961). Close examination of these black shales reveals a number of features that indicate reworking and bedload sediment transport by waves and currents consistent with a shallow-marine inter - pretation.

Black shales occur widely in the Lower Cambrian and Neoproterozoic strata on the Yangtze Platform, South China. In this study, Lower Cambrian black shales from Xiuning section and Late Neoproterozoic black shales from Weng'an section were studied and Pb isotopic compositions were analyzed following a stepwise acid-leaching technique. The 206 Pb/ 204 Pb ratios in both sections show large ...The black shales in the Qusseir area (Duwi Formation, Campanian–Maastrichtian) were deposited in an anoxic marine environment, and are remarkably high in their enrichment of redox-sensitive and sulfide-forming trace metals. Measurements of Mn, U, V, and Mo reveal that the studied black shales deposited under shallow anoxic-sulfidic conditions.Dec 1, 2021 · An indicative classification of black shales can be compiled based on the literature that refers to the degree of commodity metal accumulation (Table 1).Vine and Tourtelot (1970) set the threshold of metalliferous black shales’ (MBS) definition above the 90th percentile of a metal concentration in given dataset, whereas the final classification depends on the frequency (percentage) of ... Black shale outcrops of the Belata Formation in Peninsular Malaysia were evaluated for their unconventional resource potential. The study revealed the presence of a high and good source of the organic carbon content in the Belata black shales, which ranges between 1.90 wt % to 4.05 wt% and averages 2.92 wt%. However, from the pyrolysis and ...Jan 25, 2002 · To test whether there is a positive relation between MSA and TOC in black shales, we sampled an organic-poor to organic-rich (0.5 to 13% TOC) interval through the Cretaceous (Campanian) upper Niobrara Formation and lower Pierre Shale and analyzed the stratigraphic trends in TOC, MSA, elemental composition, and clay mineralogy in Wyoming and South Dakota, USA (). 3.1 Mineral composition in shale. The following minerals were identified in the shales: quartz, feldspar, calcite, dolomite, illite, pyrite, chlorite, and apatite (Table 2, Fig. 1).Quartz and calcite were detected in all the samples (Fig. 1).Figures 2 and 3 show XRD distribution patterns and SEM-EDS images of the minerals in the shales. The amount of quartz in all the shale samples except ...Black shale is a dark-colored mudrock containing organic matter that may have generated hydrocarbons in the subsurface or that may yield hydrocarbons by pyrolysis. Many black shale units are enriched in metals severalfold above expected amounts in ordinary shale. Some black shale units have served as host rocks for syngenetic metal deposits ...A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for ...We investigated mineral weathering and elemental mobility on mid-Devonian Marcellus black shale on a forested northwest-facing planar hillslope located in Jackson Corner, Huntingdon County, Pennsylvania (Fig. 1).Our focus is an exposed section of the Oakta Creek unit that forms the basal portion of the Hamilton Group (Obermajer et al., 1997, Faill, 1998, Soeder, 2010).An indicative classification of black shales can be compiled based on the literature that refers to the degree of commodity metal accumulation (Table 1).Vine and Tourtelot (1970) set the threshold of metalliferous black shales’ (MBS) definition above the 90th percentile of a metal concentration in given dataset, whereas the final classification depends on the frequency (percentage) of ...The black shales formed in an anoxic environment caused by organisms, and the deposits were affected by hydrothermal fluids (Li, 2019). In summary, the ore-forming elements in mineral deposits from the lower Cambrian black shales of South China were mainly supplied by seawater and hydrothermal fluids, and biological activity was …The Jebel Oust region (north-eastern Tunisia) recorded two levels of marine black shale in the Lower Cretaceous marly series. Geodynamic evolution, biostratigraphic and Rock-Eval analysies allow classifying those black shales as unconventional shale oil resource systems that were deposited during two oceanic anoxic events: the Middel Barremian Event "MBE" and the Early Aptian Event "OAE1a ...

uraniferous black shales; in some black shales, phosphatic nodules and layers with 0.02 to 0.1 percent uranium contain much of the uranium in the shale, but in other uraniferous black shales the nodules contain only 0.001 to 0.003 percent uranium. The biogenic phosphate that settles into a rela­

The Ordovician–Silurian black shales in Well JY1 and Well YY2 are dominated by siliceous shale, mixed siliceous shale, mixed shale, and mixed argillaceous shale. From bottom to the top, the rock type changes from black siliceous shale to mixed argillaceous shale with a gradual increase of sandy deposits ( Fig. 4 ).The black shales and sulfide layers, with the exception of replicate anal- yses of N21, lie on or between these reference lines, suggesting that, to a first approximation, the Re and Os were added close to the time of deposition. Regression of the data, how- ever, yields an errorchron with a negative '"Os/'^Os inter- cept. One replicate ...The Lower Silurian black shale in the Southeast of Chongqing is of great potential in the accumulation of shale gas in South China. In order to understand the pore system of these black shales, mercury porosimetry, surface area study, mineralogy and image analyses by scanning electronic microscopy were performed. Four major pore types (interparticle pores, intraparticle pores, organic-matter ...Black shales are organic-rich, fine-grained strata deposited under oxygen-poor bottom waters which typically accumulate in deep-water, basinal locations (Demaison and Moore, 1980, Wignall and Maynard, 1993). However, thin examples often occur in more marginal locations, particularly within transgressive sedimentary records.BLACK SHALES OF THE PHOSPHORIA FORMATION By RICHARD P. SHELDON ABSTRACT Uranium in the Phosphoria formation of Permian age in the western phosphate field occurs mostly in phosphorite and partly in black shale. However, some of the phosphorites and most of the black shales of the formation are practically non- uraniferous.Black shales are currently of interest in geochemical and geological investigations because they may host gold and platinum deposits or petroleum and natural gas fields. To ensure the accuracy of analysis of such samples, standard reference materials SCHS-1 and SLg-1 are now being certified at the Institute of Geochemistry SB RAS, Russia [12] .Early Cambrian black shales are widely distributed on the southeastern margin of the Yangtze platform, South China (Guo et al., 2007; Wen et al., 2015; Fig. 1).They formed under a variety of physicochemical conditions due to variable contributions of continental and biotic components with increasing water and burial depth, and they have been shown to contain relatively high V concentrations (e ...Black shales contain ~ 3000 ppm heavy 20 metals (Pb, Co, Cr, Ni, Cu, V, Zn), whereas normal shales have concentra- tions of 500 ppm. The difference (2500 ppm = 14 kg m-2 Ma-1) originates from seawater. A seawater column of 2500 m3 contains about 10 g of heavy metals (at a seawater concentration of 4 ppb). ...The lacustrine black shales in the Chang7 Member from the Upper Triassic Yanchang Formation of the Ordos Basin in Central China are considered one of the most important hydrocarbon source rocks. However, the mechanism of organic accumulation in the black shales remains controversial. To resolve the controversy, with the former paleontological data of Yanchang Formation and sedimentation rate ...

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Black shale is a dark-colored mudrock containing organic matter that may have generated hydrocarbons in the subsurface or that may yield hydrocarbons by pyrolysis. Many black shale units are enriched in metals severalfold above expected amounts in ordinary shale. Some black shale units have served as host rocks for syngenetic metal deposits.Black …The black shale horizons are several meters to several tens of meters thick and are strongly deformed due to their low competence relative to the host graywackes. In some places, the black shales enclose graywacke clasts and, vice versa, are found as angular to subangular clasts within graywackes (Hajná et al., 2013). 3. The Liblín section3.1.AAPG Store. The Appalachian Basin has been an important shale-gas-producing province since the early 1800s, with an estimated 3.0 tcf already produced from Devonian black shale. [1] Until recently, the organic-rich Marcellus Shale, although recognized as a major source rock, was not a significant hydrocarbon producer in the Appalachian Basin.Chemical and isotopic signatures for black shales serve as potential proxies for reconstruction of paleoenvironmental conditions. Here we bring Rock‐Eval, major and trace element and Re‐Os isotopic data together to examine the environmental record at the Cambrian‐Ordovician Global Stratotype Section and Point (GSSP) at Green Point in …A shale is a sedimentary rock that is composed of small (mostly less than 0.1 mm) particles dominated by phyllosilicate (clay) minerals and containing subordinate amounts of quartz, carbonate, and phosphate minerals and, in some cases, organic matter and pyrite [for a discussion, see Spears (1980)].Black shales often are metalliferous and may host or are associated with economically important ore deposits, such as the famous Triassic "Kupferschiefer" or "marl slate" in Germany and Poland (Wedepohl, 1964). In order to explain TM enrichments in the non-metalliferous Kupferschiefer settings the author proposed that seawater seems to ...Black shale is a dark-colored mudrock containing organic matter that may have generated hydrocarbons in the subsurface or that may yield hydrocarbons by pyrolysis. Many black shale units are enriched in metals severalfold above expected amounts in ordinary shale. Some black shale units have served as host rocks for syngenetic metal deposits.Black …Black shales are sedimentary rocks containing > 0.5% of organic carbon. They host polymetallic deposits which have been mined for Cu, Ni, Zn, Mn, P, Mo, V, U, Au and PGE (platinum group elements).The Lower Cambrian black shales of the Sansui vanadium deposits, located in South China, host a thin accumulation of Ni, Mo, V, and platinum group of elements (PGE). However, among them, the origin of V-bearing deposits remains controversial. To characterize the enrichment process of V-bearing deposits, samples of the mineralized layer and surrounding rocks from the Sansui area, South China ... The Jurassic Da'anzhai Member in Sichuan Basin is an important target for shale oil exploration. Whole rock X-ray diffraction analysis, thin section, SEM and TOC testing, as well as major and trace element analysis are used to analyze the relationship of lithofacies and pore types with the sedimentary environment of the Da'anzhai Member in the Central Sichuan Basin. The results show the Da ... ….

Black shales intercalated with phosphorites of the Duwi Formation outcrop in the Qusseir-Safaga area, Red Sea coast (Fig. 1).Based on its lithology, Baioumy and Tada (2005) subdivided the Duwi Formation in the studied area into four members (Fig. 2).The lower member that ranges in thickness from 35 to 50 m is composed by yellowish-grey, laminated, silty claystone, greyish-yellow, laminated ...First, that black shale deposition was the result of basin-wide anoxic conditions (Murphy et al., 2000; Chen and Sharma, 2016; Bingham-Koslowski et al., 2016). According to this explanation, black shale deposition should be isochronous and the relationship between black shales and gray shales should be abrupt vertical contacts.Among these are black shales: fine-grained laminated sedimentary rocks rich in organic carbon (∼3% by weight or more) that also usually contain chemically distinct distributions of redox sensitive metals and sulfide minerals. When ancient sedimentary rocks rich in organic carbon are exposed on Earth's continents through uplift and erosion ...Black shales and massive sulfides represent reduced lithofacies that require isolation from oxic environments to be preserved. This, together with the sedimentary affinity of both lithofacies, can explain their common concurrence in the geologic record. The present study is based on the comparison of Rammelsberg in Germany, Tharsis in Spain, and Draa Sfar in Morocco, three massive sulfide ...Sequences of black shales, present in the subducting sediment piles, are highly enriched in Mo and have unusually high 98 Mo/ 95 Mo. Despite their low mass fraction in the sediment package (<10% in Deep Sea Drilling Project Site 144), they dominate the Mo content and isotopic composition of the bulk sediment subducting at the Lesser Antilles ...Definition Most modern and ancient aquatic (marine, brackish, and lacustrine) environments were sufficiently oxygenated to permit colonization by numerous benthic, planktic, and …The Global Geochemical Database for Critical Metals in Black Shales (CMIBS) contains new geochemical data compilations for fine-grained sedimentary rocks in which each geologic material sample has one best value determination for each analyzed species, greatly improving speed and efficiency of use (Granitto and others, 2013).Several outcrops of black shales from the Triassic turbidite sequences of the Semanggol and Semantan formations have been described and logged (Table 1 & Fig. 3). Black shales in the Semanggol Formation occur as thin-to medium-bedded, finely-laminated dark grey to grey shales up to 15 m thick (Fig. 4 A-D). On the other hand, black shales of ...black shale deposition occurred in transgressions, whereas regressions are characterized by depo- sition of bioturbated facies, allowing changes in lithofacies and deep-water redox conditions to beThe black shale mineral composition is mainly composed of calcite, apatite, quartz, pyrite and clay minerals. The average values of Cu, Ni, Zn, Cr, V, As and Se and the ratios Rb/Sr and Cr/Ni in ... Black shales, The Ankang black shales in P. R. of China provides an important example of natural geological materials containing toxic elements. This paper presents the results of environmental geochemical research on black shales, soils, waters and edible plants in the Ankang area, Shaanxi Province, P. R. of China. The study area lies in the northern …, Comparing the TOC content of Paleozoic Kroh black shales with other worldwide shale gas rocks. Table. Many studies have shown that TOC is one of the critical ..., Mo contents and isotopic compositions of the black shales were determined by the double-spike method. Mo was separated and purified by ion-exchange chromatography using BPHA resin, and analyzed by MC-ICP-MS (Thermo-Fisher Scientific Neptune Plus)., Black organic shales are the source rock for many of the world's most important oil and natural gas deposits. These shales obtain their black color from tiny particles of organic …, Jul 28, 2003 · A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for ... , The results show that in addition to the ca. 1,380 Ma LIP activity that is coeval with black shales, other major LIPs during this period can preliminarily be divided into several stages and are ..., The black organic-rich shales mainly developed in Quse and Sewa Formations. The Biluo Co (or Bilong Co or Bilong Cuo) area, about 45 km from the Shuanghu special district ( Fig. 1 b), is located in the southern Qiangtang depression (northern Tibet, China) and cropped out brown to dark, well-laminated shale horizons with a few intercalated ..., 13.19.5.12 Black Shale and Seawater. Black shales and seawater also represent significant reserves of uranium, although economic extraction of uranium from each is a challenge. Uranium in shales resides with organic matter. The uranium contents of black shales are variable but can reach 400 ppm, such as in the Ranstad deposit in Sweden., May 1, 2019 · Black shales are sedimentary rocks containing > 0.5% of organic carbon. They host polymetallic deposits which have been mined for Cu, Ni, Zn, Mn, P, Mo, V, U, Au and PGE (platinum group elements ... , The Lower Silurian black shale in the Southeast of Chongqing is of great potential in the accumulation of shale gas in South China. In order to understand the pore system of these black shales, mercury porosimetry, surface area study, mineralogy and image analyses by scanning electronic microscopy were performed. Four major pore types (interparticle pores, intraparticle pores, organic-matter ..., The specific surface area and pore volume of OM in black shales follow a parabolic pattern with increasing thermal maturity (quantified via vitrinite reflectance, Ro). The initial increase reflects development of OM-hosted pores, and the subsequent decrease is due to denser stacking of aromatic units in the macromolecular structure of OM, with ..., DST black shales display slight enrichment of Mo (2.0–6.8 ppm; average = 4.2 ppm; n = 7), suggesting deposition under anoxic bottom conditions. Moreover, the patterns of Mo-TOC co-variation can provide valuable information about paleohydrographic conditions, especially the degree of watermass restriction, but only under anoxic …, The black shales below and above show relatively lower Fe T /Al ratios, reflecting the same range as sediments from the Black Sea, which is the largest modern anoxic ocean basin (Severmann et al., 2008). Table 1., Within the densest black shale are microscopic layers, commonly less than 0.1 mm thick, composed of quartz grains ranging from 0.02 to 0.06 mm and averaging about 0.03 mm in greatest diameter. Still finer quartz ranging in diameter from about 0.004 to 0.012 mm and averaging 0.008 mm is disseminated fairly uniformly throughout the massive shale. . ., It was shown that the contents of Ni, Mo, and Co in the siliceous clay black shale rocks of the normal sections of the Bazhenov Formation are several times higher than the global mean contents of these elements in black shales. These rocks have the highest contents of pyrite and organic carbon and show evidence for strongly reducing formation conditions at the slowest background rate of ..., Black shales and massive sulfides represent reduced lithofacies that require isolation from oxic environments to be preserved. This, together with the sedimentary affinity of both lithofacies, can explain their common concurrence in the geologic record. The present study is based on the comparison of Rammelsberg in Germany, Tharsis in Spain, and Draa Sfar in Morocco, three massive sulfide ..., Semantic Scholar extracted view of "Late Barremian / Early Aptian Re-Os age of the Ipubi Formation black shales: Stratigraphic and paleoenvironmental implications for Araripe Basin, northeastern Brazil" by Thales Lúcio et al., The ore-forming role of black shales is discussed. Correlation of their distribution with high phosphorus and manganese concentrations is shown. Associations of black shales, phosphorites, and manganese ores are described. A mechanism is proposed for explaining their co-occurrence in natural environments. It is emphasized that back shales serve as not only ore-forming sequences, but also ore ..., limestones are enclosed within the black shales and nodular to bioturbated limestones occur between the marls [1,11,33]. Black Shale . The black shales, also known as dark, laminated shales [33], form thin (a few cm) to thick (up to 2 m) beds. They are blue-grey and fissile in weathered surfaces, but dark-grey to black and laminated, The black shales of the Lower Cambrian in southern China are located on the southern margin of the Yangtze Platform in the transition zone between the Yangtze Platform and the Jiangnan Basin (Gao and Li, 1998). In Early Cambrian, the Yangtze Platform was essentially dominated by fine-grained sandstone, siltstone and shale provided by the ..., Classic black shales such as those from Chongqing, China (Conclusion. The black shales parent rocks have elevated Cd concentration and Cd would be released to the environment once black shales were exposed. The surrounding soil of black shales outcrop was highly acidized and enriched in Cd., Black shales are in broad terms composed of mineral and organic—kerogenous—matrix, whereas black primarily refers to any kind of organic matter (OM—humic, sapropelic, bituminous, graphitic) that provides the rock its color, and shale refers to fissile fine-grained sedimentary rock. Grain size is very fine and sedimentologically they could ..., Mudstone, sandstone, and carbonates are found in the Silurian–lower Devonian Dadas II and Dadas III members. Black to dark-gray, laminated pyrite-rich shales indicates the hot shale. Anoxic conditions existed in the depositional habitat, which was an open marine but temporally restricted [29]. 2.2. Tectonic features2.2.1., Jan 1, 2023 · Black shales are sedimentary rocks containing > 0.5% of organic carbon. They host polymetallic deposits which have been mined for Cu, Ni, Zn, Mn, P, Mo, V, U, Au and PGE (platinum group elements). , May 17, 2017 · Highly metalliferous black shales (HMBS) are enriched in organic carbon and a suite of metals, including Ni, Se, Mo, Ag, Au, Zn, Cu, Pb, V, As, Sb, Se, P, Cr, and U ± PGE, compared to common black shales, and are distributed at particular times through Earth history. They constitute an important future source of metals. HMBS are relatively thin units within thicker packages of regionally ... , Cd in paddy soil was primarily from geogenic source and effected little by anthropogenic source. The concentration as well as mobility and bioavailability of Cd were high in paddy soil in black shales area, which lead to elevated Cd concentration in roots, shoots and grains of rice. As a result, residents in black shales area suffer increased ... , Of the two black-shale sequences in the basin, the upper is the Devonian and Mississippian shales, which have attracted interest as a source of uranium, oil and gas, and pyrolytic oil. These studies have provided the necessary framework for resource evaluations and for geochemical characterizations, including analysis of the chemical structure ..., The calibration of the Tl isotope redox tracer in modern euxinic (anoxic and containing dissolved sulfide in the water column, such as the Black Sea and Cariaco Basin) and anoxic but non-euxinic (sulfidic conditions limited to sediment pore fluids, such as the Santa Barbara Basin) environments suggests that black shales deposited under these conditions have the potential to faithfully record ..., A possible, but untested, sequestration strategy is to inject CO{sub 2} into organic-rich shales. Devonian black shales underlie approximately two-thirds of Kentucky and are thicker and deeper in the Illinois and Appalachian Basin portions of Kentucky than in central Kentucky. The Devonian black shales serve as both the source and trap for ..., Selected Malaysian black shale sequences of the Permo-Triassic and Devonian ages that crop out in the Central Belt were investigated to discuss their chemical composition, provenance, tectonic setting, and weathering history. X-ray fluorescence (XRF) analysis shows that the BRSZ Unit 1 black shale has elevated SiO2, TiO2, and K2O contents compared to the Semantan and Gua Musang black shale., Black shales, which are deposited in marine environment with many features such as fine grain sedimentary rock, organic matter enrichment, and some special geochemical characteristics, have been research hotspot for a long time [1–3].The black shales in lower Cambrian are mainly distributed in Yangtze and Tarim Block of China …, Of the two black-shale sequences in the basin, the upper is the Devonian and Mississippian shales, which have attracted interest as a source of uranium, oil and gas, and pyrolytic oil. These studies have provided the necessary framework for resource evaluations and for geochemical characterizations, including analysis of the chemical structure ..., Black shales are mixtures of terrigenous, biogenous, and hydrogenous sediment in which organic matter constitutes at least 0.5% of the material. Shales are the end product of the processes that ...