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Copyright of Journal of China University of Petroleum is the property of China University of Petroleum and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The shale in Doushantuo Formation is the main source rock of the Ediacaran in Sichuan Basin and the major hydrocarbon source layer of the ancient marine strata for natural gas exploration in recent years. Forty-six samples were collected from two outcrops(Baibaoxi and Shiping)in Chengkou county in northeastern Sichuan Basin.We analyzed the change of the sedimentary environment of the Member Ⅱ and Ⅳ of Doushantuo Formation in terms of their organic geochemical characteristics(total organic carbon, rock pyrolysis, kerogen carbon isotopes)and element geochemical characteristics(major elements, trace elements and rare earth elements).Results show that the shale of Doushantuo Formation in northeastern Sichuan Basin exhibit a high abundance of organic matter, with TOC content ranging from 0.19 % to 20.38 % (mean value is 4.76 %). The dominant type of organic matter is type Ⅰ kerogen, and it has reached over-maturity stage. High δEu anomalies and abnormally richness in V, Mn, Mo, Ba and U elements of the black shale revealed strong hydrothermal action during this period. The distribution pattern of rare earth elements and various redox indexes indicated that the redox fluctuates repeatedly under the conditions of anaerobic-anoxic-sulfidic environment during the depositional period of the Member Ⅱ. The water environment of Member Ⅳ changed from anoxic to anaerobic-sulfidic environment. In general, the water connectivity of the basin is strong, the depositional rate is relative high. The nutrients carried by upwelling from hydrothermal sources proliferate productivity, which promotes the formation of organic shale.

[Objective] The Late Permian was a critical interval in geological history, with dramatic changes in tectonics, paleoclimate, paleo-oceanic environment, volcanic activities, and the biosphere. Reconstruction of the paleogeography, paleoclimate, and paleo-oceanic environment during this interval could provide a more complete picture of the interactions and relationships among different geological factors, as well as their influence on organic matter enrichment and the evolution of the biosphere. [Methods] Organic-rich rock series were widely deposited during this period in the Sichuan Basin of the Upper Yangtze Block, providing insights into the co-evolution of the geosphere and biosphere. To better address the coeval temporal and spatial changes in the paleogeographic settings, paleo-oceanic environment, primary productivity, and organic enrichment, we conducted a detailed sedimentological investigation integrated (major and trace) element contents, organic carbon isotopes and total organic carbon (TOC) contents in the Jianfeng section, located in an intrashelf basin in northeastern Sichuan Basin.[Results] The redox-sensitive trace element data (MoXS, UXS, VXS contents, MoXS/UXS ratios, and MoEF-UEF relationship) show that the redox environment of the Jianfeng section has experienced four intervals (I-IV) . Interval I (0-10.35 m, spanning from the upper part of the Wuchiaping Formation to the lower part of the Dalong Formation) was dominated by an oxic environment during deposition, Interval II (10.35-23.35 m, the middle Dalong Formation) experienced a ferruginous-dominant anoxic condition, Interval III (23.35-27.00 m, the upper Dalong Formation) was mainly a euxinic environment, and Interval IV (27.00-34.05 m, from the top of the Dalong Formation to the bottom of the Changhsing Formation) was dominated by an oxic or suboxic environment. Compared with the Xibeixiang section in the deeper water of the Kaijiang-Liangping trough, the redox environment in the intrashelf basin exhibits spatiotemporal heterogeneity. The nutrient-limiting elements (ZnXS, CuXS, NiXS ) contents demonstrate that primary productivity is high in both intervals II2 and III, coincident with the increasing terrestrial inputs (dedicated by Al, Zr, and Ti contents and K/Al values) . However, the CoxMn and Cd/Mo values indicated that the upwelling currents arose in intervals II2, II3, III, and IV, and the volcanic activities were only frequent in Interval IV, disagreeing with the eutrophication and organic matter enrichment in the middle Dalong Formation. Therefore, the high primary productivity of the Dalong Formation may be principally affected by a large number of terrestrial inputs. Furthermore, the upwelling currents also made contributions to the prosperity of plankton, but the volcanic activities have poor relationships with it. [Conclusions] Combined with the Xibeixiang section in the study area, the formation of euxinic water mass was found to be closely related to the high primary productivity, whereas its spatiotemporal fluctuations were controlled by the sea-level changes, which could drive its upslope incursion in intervals II and III, downslope retreat in the Interval IV, and even demise in the Interval V. In turn, the primary productivity could be further controlled by the upwelling currents particularly on the basinal slope, and terrigenous inputs on the more updipping basinal margin. In this case, the primary productivity played a leading role in the enrichment of organic matter. [ABSTRACT FROM AUTHOR]

[Objective] The organic-enriched black bedded cherts in the Kuhfeng Formation were deposited in the Lower Yangtze during the Middle Permian. The hydrothermal cherts may be the key part for the relationship analysis between chert deposits and the extra-ordinarily high organic matter enrichment. This would be the basic theories for the shale gas exploration in this area. [Methods] This work uses major, minor, and rare-earth elements, combined with the petrology, to analyze the origin of chert and their tectonic setting for the Kuhfeng Formation in the Yeshan of Tongling and Pingdingshan of Chaohu, Anhui province. [Results] The black bedded cherts in the Chaohu area contain abundant siliceous sponge spicules and radiolarians. The cinerous cherts in the Kuhfeng Formation in the Tongling area contain extremely rare siliceous fossils and consist of micro-quartz. Hydrothermal proxies, such as Al/(Al+Fe+Mn), Eu/Eu*, Al-Fe-Mn diagram, and LuN/LaN, indicate a hydrothermal and biotic origin for the chert in the Kuhfeng Formation in the Tongling and Chaohu areas, respectively. The La-Th-Sc diagram and crossplot between La/Sc and Ti/Zr indicate oceanic island arc and active continental margin origins for the Tongling and Chaohu areas. [Conclusions] The chert in the Kuhfeng Formation in the Tongling area was primary deposited by hydrothermal activity. The silicic acid was brought by a hydrothermal vent near the slope environments. The black bedded cherts in the Lower Yangtze area are biotic in origin, but the source of silicon was related to the hydrothermal activity. The organic matter enrichment in the Kuhfeng Formation in the Lower Yangtze area may be related to the phytoplankton flourishment induced by the nutrient element input from hydrothermal activity. [ABSTRACT FROM AUTHOR]

[Objective] The Lower Cambrian Shuijingtuo Formation black shale is an important source rock and shale gas exploration target in the Sichuan Basin. However, the enrichment mechanism of organic matter in this series of black shale is still unclear. [Methods] Here, we reported total organic carbon (TOC) contents, sedimentary microfacies, major and trace elements, and pyritic framboid size distributions in the lower part of Shuijingtuo Formation in the Chengkou area, northeastern Sichuan Basin on the Upper Yangtze Platform, providing new evidence for reconstructing the paleogeography, paleoenvironment, and main controlling factors of organic matter enrichment. The results show that the black shale succession in the Shuijingtuo Formation developed five sedimentary microfacies which related to the deep-water shelf slope environment. Productivity index (BaXS, P/Ti) and continental input index Ti, Al indicate that the sedimentary environment of black shale in the Shuijingtuo Formation is at a low level of paleoproductivity, and the continental input is relatively stable and has no obvious correlation with TOC. Therefore, paleoproductivity and continental input are not the main controlling factors of organic matter enrichment in the black shale of the Shuijingtuo Formation. The redox-sensitive element index (U/Th, UEF, MoEF ) and pyrite framboid size distributions show that the organic matter content is positively correlated with the redox index, indicating that the organic matter enrichment in Shuijingtuo Formation is mainly controlled by the change of redox conditions of the water column. [Conclusions] Based on the above understanding, it can be inferred that the organic matter enrichment of the black shale of the Shuijingtuo Formation was controlled by the fluctuation of redox conditions of the bottom water caused by the large-scale transgression event during the stage 2 to stage 3 Cambrian (529-514 Ma), and the organic matter enrichment model was proposed here. [ABSTRACT FROM AUTHOR]

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The Lucaogou Formation in the Jimsar Sag is the main target layer of shale oil exploration and development in continental basins. However, its paleo-environmental information and organic matter enrichment mechanism still need to be determined. In order to investigate the paleo-environment of the Permian Lucaogou Formation, based on core and thin section observation, we carried out major and trace element analyses on 26 source rocks from Well J10025 by using X-ray fluorescence spectroscopy(XRF) and inductively coupled plasma mass spectrometry(ICP-MS). This analysis, combined with GC-MS biomarker data and typical sedimentary structures, reflects the paleo-environmental characteristics of the Luchaogou Formation. Geochemical indicators such as C-value, Sr/Ba, V/Cr, Pr/Ph, P, and Co show that the Lucaogou Formation was generally developed in a saline lake environment under an arid to semi-arid climate, with relatively deep water during deposition and hypoxic to anoxic conditions. The upper member was deposited in a semi-arid, brackish lake with weak reducibility, deep water body, and high productivity. In contrast, the lower member was deposited in an extremely dry, highly saline, and strongly reductive shallow lake with low productivity. The paleo-environment of the upper member fluctuated wildly, while that of the lower member was relatively stable. The correlation analyses between paleo-environmental indicators and TOC show that the preservation conditions and dilution rate of organic matter have limited influence on organic matter enrichment of the Lucaogou Formation. At the same time, the primary productivity is the main controlling factor.

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Upper Ordovician-Lower Silurian Wufeng-Longmaxi shales in the Middle Yangtze area have strong vertical heterogeneity, affecting the gas-bearing capacity of shale reservoirs and the fracturing ability.This study integrates wire-line logs, drilling cores, thin section observations, total organic carbon content, X-ray diffraction mineralogy measurement, and major, trace elements measurement.Under the stratigraphic sequence framework in the study area, the vertical variation of TOC content, mineralogical composition and shale lithofacies were studied.Combined with geochemical proxies for paleoclimate and paleoenvironmental conditions, the main factors controlling vertical heterogeneity were discussed.The results show that the Wufeng-Longmaxi shales have two 3rd-order sequences.The Wufeng Formation is divided into the transgressive systems tract(TST1) and high stand systems tract(HST), and the Longmaxi Formation is divided into the transgressive systems tract(TST2) and the early high stand systems tract(EHST).During the transgression period, the shale has high silica content, low clay content, and high organic carbon content, and mainly developed siliceous shale facies and clay-bearing siliceous shale facies.In the early high-stand systems tract period, shale developed silty bands and lenticular bedding, with high clay content, and low organic carbon content, and mainly developed siliceous-clay mixed shale lithofacies.The vertical changes of paleoclimate indicators(CIA, Rb/Sr), paleo-productivity indicators(Cu/Al, P/Al), redox environmental indicators(MoEF, UEF), and terrestrial input(Ti, Zr) indicators indicate a high productivity, anoxic sedimentary environment, low terrestrial input and relatively dry and cold climate conditions for the transgression period, while during the high-stand systems tract deposition, the study area has low productivity, oxic-dysoxic environment, high terrestrial input and relatively warm and humid climateconditions.The paleo climate, paleo productivity, redox conditions, volcanic activity, terrestrial input and bottom currents are the main factors controlling the stratigraphic heterogeneity of the Wufeng-Longmaxi shales in the study area.Finally, by comparing with some parameters of the shale in the Upper Yangtze region, it is found that the study area shows the differences in deeper burial depth, thinner organic shale, lower gas content and more brittle mineral content.

Copyright of Journal of Northeast Petroleum University is the property of Journal of Northeast Petroleum University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lithofacies paleogeography shows that a set of black shale in the foreland basin front zone is mainly developed in the Lower Yangtze region at the turn of Ordovician-Silurian, and the Lower Yangtze region is obviously different with the Middle and Upper Yangtze regions. The study on the sedimentary environment evolution of the black shale is relatively weak, especially the related study on organic matter enrichment. Therefore, it is necessary to clarify the sedimentary environment and organic matter enrichment mechanism of Wufeng Formation-Gaojiabian Formation shale in the Lower Yangtze region, which is of great significance for deepening the understanding of shale gas enrichment law. Based on the continuous underground core data obtained by the latest shale gas geological survey well(WDD1)in the southwest of the Lower Yangtze region, 38 core samples were tested for organic carbon, major and trace elements. The vertical variation characteristics of major and trace elements in the profile and their relationship with the sedimentary environment of the basin were analyzed. The main controlling factors of organic matter enrichment of Ordovician-Silurian shale in the southwest of the Lower Yangtze region were discussed. The results show that Wufeng Formation and the second member of Gaojiabian Formation are enriched in organic matter, and the CIAcorr value indicates that the climate of Jiangnan transitional zone is relatively warm and humid at the turn of Ordovician-Silurian. Contents of Babio, Cu, Zn and other indicators confirm Wufeng-Gaojiabian deposition period has a high level of paleoproductivity; V/Cr, V/(V+Ni)and V/Sc values reveal that the bottom water of Wufeng Formation during the deposition period is an anaerobic sulfide state, and the bottom water of the first member of Gaojiabian Formation during the deposition period is converted into an oxygen-poor oxidation state. Diagram of Mo-TOC and covariation diagram of EFMo-EFU show that Wufeng deposition period is medium-retention sedimentary environment, and Gaojiabian deposition period is medium-weak retention sedimentary environment. TOC shows a weak positive correlation with contents of Al and Ti in Wufeng deposition period, while it turns into a negative correlation in Gaojiabian deposition period. The enrichment mechanism of organic matter in black shale of Wufeng Formation and Gaojiabian Formation is different. The main controlling factor of organic matter enrichment in black shale of Wufeng Formation is the semi-retention environment of reduction-sulfidation, and the nutrients brought by terrigenous clastic input promote to some extent. The differences in the enrichment mechanism between Wufeng Formation and Gaojiabian Formation show that the paleo-ocean environment in the Lower Yangtze region has undergone significant changes at the turn of Ordovician-Silurian. [ABSTRACT FROM AUTHOR]

Copyright of Acta Sedimentologica Sinica is the property of Acta Sedimentologica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Sedimentologica Sinica is the property of Acta Sedimentologica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Late Ordovician Early Silurian transition period is an important geological history period. Global plate tectonics 1 paileoclimaie conditions. paleo-ocean environment and biota types occur during this relatively short period (440 153 Ma). With these great changes, there are two sets of organic rich shales in Wuf eng Formation and Longmaxi Formation in Yangtze area. It is a key exploration layer for shale g ;as exploration and hi is received extensive attention. A lot of influencing factors on organic matter enrichment are paleo ocean primary productivity. palaeoredox facies and sedimentation rale- diagenetic degradation, etc. However, the two sets of organic rich shales in Wufeng F< )rmation and Longm; ixi Formation show strong heterogeneity vertically. Therefore, systematic measuring, continuous sampling and detailed petromineralogy and sedimentary geochemistry ( major, trace, and rare earth elements) of Tianlin profile in Xuyong area were conducted in order to make better sense of the evolution of the vertical sedimentary environment and the causes of differences in organic matter enrichment of Wufeng Longmaxi Formations. The resul ts show that the ratio of Al/( Al+Fe+Mn). Ce anomaly and Eu anomaly indicate that non terrestrial Si is in biogenic origin; the contents of SiO2 and Sixs are significantly negative correlated with the contents of Ci :i and TiO2, indicating that silica contents are mainly affected by terrigenous flux and paleo water depth; the ratios of Mo/TOC and Mo/U indicate thai the early period of Wufeng Formation has a strong restricted environment, while the organic richintervals form in moderately restricted environment; the intervals with dense bentoniie layers have higher paleoproductivity; stronger positive correlation between paleoredox proxy coefficient and rOC indicates ihat paleoredox is the main controlling factor of organic matter enrichment; due to the different biohabital types and the different influences of terrigenous flux on paleoproductivity and paleoredox. the correlation between paleoproductivity proxy coefficient and TOC is poor in the mass. A comprehensive analysis suggests that organic matter enrichment patterns in different sedimentary stages of Wufeng Longmaxi Formations are different. Organic matter enrichment of Wufeng Longmaxi Formations is mainly affected by anoxic environment, which is caused by deep waier environment with low terrigenous flux during non extinction period. Ii is mainly affected by high sedimentation rate of bio-precursors, which is caused by explosion of bio-precursors and "marine snow" during the first episode extinction period (corresponding to the terminal period of Wufeng Formation), and is affected by high sedimentation rate of bio-precursors and extremely anoxic environment caused by rapid transgression and organic decomposition during the second extinction period (corresponding to the early period of Longmaxi Formation). [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

some tests were carried out on organic carbon，sulfur content，major and trace elements of 64 shale samples from well core in Zhangjiatan shale of Yanchang Formation，south-center of Ordos basin. Based on the analysis of the characteristics of major and trace element contents，the paleoclimates，redox conditions and paleoproductivity of Zhangjiatan Shale were studied. Moreover，the major controlling factors for organic matter enrichment in Zhangjiatan Shale were explored. Research results show that the organic carbon content was high (2.14%~11.44%). Compared with organic-poor shale，the Na2O，CaO，U，V，Ba，Cu contents of organic rich shale are apparently higher，but the Al2O3，TiO2，K2O and MgO are lower. Palaeosedimentary environment proxies show that the Zhangjitan shales were mostly deposited in humid-warm to semi-arid climatic conditions. The bottom water was suboxic to anoxic in the sedimentary stage of Zhangjiatan shale. The paleoproductivity proxies reflect a middle to high paleoproductivity. TOC content has a positive correlation with redox proxies，suggesting that the changes in organic matter content is predominantly controlled by redox environment. Further research shows that the organic matter enrichment in Zhangjiatan shale is mainly controlled by the degree of water anoxic resulting from the change of paleoclimate. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The removal characteristics of various pollution factors in municipal wastewater by membrane-based physical and chemical treatment, especially the enrichment characteristics of dissolved organic matter, were investigated by high performance liquid chromatography and three-dimensional fluorescence spectroscopy. The results showed that the municipal wastewater had a low COD/TN ratio after the treatment. The micro-flocculation filtration mainly enriched the non-dissolvable organic matter in the raw water and aromatic protein substances with relative molecular mass greater than 30 000. The enrichment degree was up to 60.93%, especially for tyrosine-like and tryptophan-like substances. The dissolved organic matter (DOM) with a molecular weight greater than 30 000 was enriched fully by 0.45 μm and 0.22 μm acetate membranes, but the microfiltration membrane was not selective for the enrichment of organic matter. Thus, NF mainly enriched the fulvic acid and humic acid in urban sewage. The enrichment degree was 52.01% and 53.57%, respectively, and the total enrichment degree of dissolved organic matter was about 42%.