Article
Geosciences, Multidisciplinary
Tian Dong, Chuan Wang, Xing Liang, Gaocheng Wang, Shu Jiang
Summary: This study investigates the relative importance of productivity and anoxia in the accumulation of organic matter in the Wufeng-Longmaxi black shales. The research combines various analytical methods to understand the evolution of factors controlling organic matter accumulation across the Ordovician-Silurian boundary. The findings highlight the significance of elevated productivity driven by upwelling in the accumulation of organic matter.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Shaoze Zhao, Yong Li, Yingjiao Xu, Leli Cheng, Zhou Nie, Liang Zhao
Summary: This study examines the microstructural characteristics, TOC content, and well log characteristics of the black shales in the Wufeng-Longmaxi Formation in China's Upper Yangtze Region. It also explores the influence of Earth's orbital parameters on organic matter enrichment in these shales. The results show that the black shales have a higher level of organic matter enrichment during the long eccentricity minima, corresponding to Earth's cold period.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Energy & Fuels
Wang Yuman, Wang Hongyan, Qiu Zhen, Shen Junjun, Zhang Qin, Zhang Leifu, Wang Canhui, Li Xinjing
Summary: This study systematically examines the basic characteristics of key interfaces, mainly bentonite layers, in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in the Sichuan Basin and its surrounding areas. The study also investigates the relationship between these key interfaces and the deposition of organic-rich shale. There are four types of marker beds with interface attributes in the Wufeng Formation-Longmaxi Formation, which can be used for stratigraphic division and correlation of the graptolite shale. The shell layer in Guanyinqiao Member is the most standard key interface, and can also be used as an important indicator for judging the depositional scale of organic-rich shale in key areas.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2022)
Article
Energy & Fuels
Guan Quanzhong, Dong Dazhong, Zhang Hualing, Sun Shasha, Zhang Surong, Guo Wen
Summary: The coupling effect between organic matter and quartz plays a critical role in the analysis and characterization of biogenic silica in the shale layers of the Sichuan Basin. The presence of two types of biogenic quartz influences the development of organic matter pores and micro-cracks in the shale, affecting later hydraulic fracturing and well production. This coupling effect is a key factor for the high-quality development of shale reservoirs.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2021)
Article
Geosciences, Multidisciplinary
Liang Zhao, Yong Li, Chengjie Zou, Shaoze Zhao, Chaorong Wu
Summary: This study explores the mechanism behind organic matter enrichment (OME) in the black shales of the Yangtze foreland basin through a combined approach of organic and inorganic geochemical analyses. It identifies the favorable conditions for OME and provides valuable insights for exploring and developing shale gas resources in this region.
FRONTIERS IN EARTH SCIENCE
(2023)
Article
Energy & Fuels
Fei Zhao, Zaitian Dong, Chaoyong Wang, Wenli Zhang, Rui Yu
Summary: Investigations into the connectivity and complexity of pore systems in shales are essential for understanding the flow of shale gas and the capacities of the associated reservoirs. This study analyzed shale samples from the Wufeng-Longmaxi Formation in the southeast of the Sichuan Basin to examine their microstructural, pore network, and pore connectivity characteristics. The results revealed the presence of micropores, mesopores, and macropores in all shale samples, with micropores and mesopores dominating the total pore volume. The findings also showed that the porosity and specific surface area of pores were higher in samples from the WF Formation compared to the LMX Formation.
Article
Geosciences, Multidisciplinary
Lin Chen, Shu Jiang, Ping Chen, Xiaohong Chen, Baomin Zhang, Guotao Zhang, Weibing Lin, Yongchao Lu
Summary: Based on the analysis of the Wufeng-Longmaxi Formations, the influences of paleoredox conditions, paleoproductivity, terrestrial detrital influx, paleoclimate, and upwelling on organic matter enrichment are revealed. The results show that sea-level changes play a key role in controlling organic matter enrichment.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Xuebin Du, Jixin Jia, Ke Zhao, Jiacheng Shi, Yi Shu, Zhanhong Liu, Dan Duan
Summary: The volcanic activity in South China during the Ordovician-Silurian transition was not only part of global volcanic activity but also had unique characteristics, being potentially stronger and occurring slightly later than in other areas. The distribution of volcanic ash beds in South China corresponds to specific stages, indicating a potential influence on the formation of organic-rich shale.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Chao Wei, Tian Dong, Zhiliang He, Sheng He, Qing He, Rui Yang, Xiaowen Guo, Yuguang Hou
Summary: The study indicates that relative sea-level fluctuations influenced the organic matter enrichment in black shales during the Late Ordovician to Early Silurian stage, with higher organic matter content during sea-level rise and lower content during sea-level fall.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Energy & Fuels
Caiyuan Dong, Dejiang Li, Ye Zhang, Dahua Li, Mancang Liu, Zhongxi Han
Summary: This study investigates the Wufeng Formation shale in the Lower Paleozoic shales of Sichuan Basin, focusing on its provenance and paleoclimate conditions. The results suggest that the shales originated from an intermediate-felsic igneous source and experienced a gradual cooling trend in the Late Ordovician.
ENERGY EXPLORATION & EXPLOITATION
(2023)
Article
Geochemistry & Geophysics
Donglin Lin, Shuheng Tang, Zhaodong Xi, Bing Zhang, Yapei Ye
Summary: This study investigated the redox environment changes in Late Ordovician seawater, revealing higher paleoproductivity in the P. pacificus zone compared to the M. extraordinarius zone. The results suggest that continental weathering and uplift of the Xiang'e Submarine High played a role in the redox environment change in the inner Yangtze Sea during this time period.
Article
Multidisciplinary Sciences
Xin Men, Chuanlong Mou, Xiangying Ge
Summary: The Ordovician-Silurian transition was a critical period in geological history, characterized by significant changes in climate, biota, and oceanic conditions. Through a detailed analysis of formations in the Sichuan Basin, this study provides insights into the provenance, paleoclimate, and paleoredox conditions during the Late Ordovician-early Silurian. The results highlight the influence of collisional settings on the provenance, fluctuations in climate, and shifts in oceanic redox conditions, offering valuable information about the timing of the Late Ordovician mass extinction and its relationship with climatic and oceanic changes.
SCIENTIFIC REPORTS
(2022)
Article
Geosciences, Multidisciplinary
Xiaoshi Li, Hongjian Zhu, Kaixun Zhang, Zhuo Li, Yuxi Yu, Xingqiang Feng, Zongxiu Wang
Summary: Marine shales in southern China have experienced multiple complex tectonic movements, which highly impact shale pore characteristics and evolution. Through integrated experimental procedures, it was found that increasing deformation leads to higher shale permeability and changes in pore structure. This study provides insights for better understanding the pore structure evolution process in shale exploration and development under tectonic deformation.
MARINE AND PETROLEUM GEOLOGY
(2021)
Article
Geochemistry & Geophysics
Bin Wu
Summary: The study on shale gas reservoir characteristics and gas-bearing properties in the basin margin area of the Sichuan Basin shows that the black shale reservoir in the Qianjiang area has a thickness of up to 33 m, with dominant kerogen sapropelic type (I) and a Ro range between 2.2 wt% to 3.39 wt%. The mineral composition is complex, mainly composed of quartz and clay minerals. Organic pores are the main pore types, with nanopores having a volume range of 0.009897-0.017177 cm(3)/g and a specific surface area ranging from 12.1 m(2)/g to 35.1 m(2)/g. The development of different mineral components restricts the enrichment of shale gas.
Article
Geosciences, Multidisciplinary
Zhen Qiu, Bei Liu, Bin Lu, Zhensheng Shi, Zhiyang Li
Summary: This study focused on the depositional and diagenetic processes controlling the fabric and petrophysical properties of black shales through the analysis of the Wufeng-Longmaxi Shale. It was found that the studied shale is mainly composed of over-mature black shales with organic matter dominated by pyrobitumen and graptolite, while minerals consist of quartz, carbonates, and clay minerals. Vertical variations in lithofacies and mineral content exhibited three cycles, likely corresponding to three transgressive-regressive cycles.
MARINE AND PETROLEUM GEOLOGY
(2022)
Review
Geosciences, Multidisciplinary
Na Li, Chao Li, Thomas J. Algeo, Meng Cheng, Chengsheng Jin, Guangyou Zhu, Junxuan Fan, Zongyuan Sun
Summary: During the Late Ordovician mass extinction, two pulses of faunal mortality occurred as a result of expanded marine euxinia, affecting both inner and outer Yangtze Sea. The less-studied outer Yangtze Sea sections show changes in marine redox conditions, chemical weathering rates, and primary productivity. The contraction and expansion of oceanic euxinia in response to continental weathering intensity and sulfate availability played a significant role in shaping marine redox variations and influencing the biotic crisis during this time period.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Zhongyang Chen, Peep Mannik, Junxuan Fan, Chengyuan Wang, Qing Chen, Zongyuan Sun, Dongyang Chen, Chao Li
Summary: The age of the Silurian Lower Red Beds in the Upper Yangtze region is still a matter of debate. Most exposures in the region correspond to the Telychian Stage, but there are several localities where the Lower Red Beds can be roughly dated to an interval between the upper Aeronian and lower Telychian.
JOURNAL OF EARTH SCIENCE
(2021)
Review
Multidisciplinary Sciences
Chengshan Wang, Robert M. Hazen, Qiuming Cheng, Michael H. Stephenson, Chenghu Zhou, Peter Fox, Shu-zhong Shen, Roland Oberhansli, Zengqian Hou, Xiaogang Ma, Zhiqiang Feng, Junxuan Fan, Chao Ma, Xiumian Hu, Bin Luo, Juanle Wang, Craig M. Schiffries
Summary: Barriers hindering data-driven discoveries in deep-time Earth include data not being digitized, databases not adhering to FAIR principles, and lack of a systematic knowledge graph. The Deep-Time Digital Earth program aims to develop a systematic knowledge graph, a FAIR data infrastructure, and tailored tools to facilitate data-driven discovery and global data sharing.
NATIONAL SCIENCE REVIEW
(2021)
Article
Geography, Physical
Shu-han Zhang, Jun-xuan Fan, Chad A. Morgan, Charles M. Henderson, Shu-zhong Shen
Summary: This study examines the trilobite diversity pattern in the middle-late Cambrian of South China, constructing a high time-resolution species-level richness curve and identifying distinct changes in species diversity at different stages, as well as exploring trilobite evolutionary mechanisms associated with environmental changes and biotic competition.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Yukun Shi, Xiangdong Wang, Junxuan Fan, Hao Huang, Huiqing Xu, Yingying Zhao, Shuzhong Shen
Summary: Recent study revealed a rapid increase of marine fauna species and genus richness during the Late Paleozoic Ice Age, lasting 41.2 million years and named as Carboniferous-earliest Permian Biodiversification Event (CPBE). The event included a slow increase episode and a main radiation episode, with most distinct patterns in fusulinid foraminifera and decreasing trends in nektonic conodonts and cephalopods, possibly related to marine environmental shifts caused by the Rheic Ocean closure.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Lei Jiang, Chunfang Cai, Lei Xiang, Junxuan Fan, Kaikai Li, Liulu Cai, Thomas J. Algeo, Feifei Zhang
Summary: This study investigates the sulfur isotopic variation of kerogen and pyrite in marine sections from the late Permian period in South China. The results show that oxidation of H2S in anoxic water leads to negative shifts in sulfur isotopes, and the pyritization process is slow below the sediment-water interface. In deep-water sections, microbial sulfate reduction is observed. The increase in sedimentation rates and organic matter inputs during the Permian-Triassic transition are likely contributing factors to the observed sulfur isotopic changes.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geosciences, Multidisciplinary
Shengchao Yang, Wenxuan Hu, Junxuan Fan, Yiying Deng
Summary: By analyzing and correlating the geochemical features of bentonites, this study established a set of new geochemical fingerprints for identifying invisible volcanic ash layers in shales. The study reconstructed volcanic activities and discussed the impact of volcanism on mass extinction and climate events.
EARTH-SCIENCE REVIEWS
(2022)
Article
Geography, Physical
Qiang Fang, Huaichun Wu, Shu-zhong Shen, Junxuan Fan, Linda A. Hinnov, Dongxun Yuan, Shihong Zhang, Tianshui Yang, Jun Chen, Qiong Wu
Summary: This study investigates the response of tropical climate to the late Paleozoic deglaciation, the Earth's first transition from icehouse to greenhouse. By analyzing deep marine carbonate records in South China, the study reveals the complex linkage between low and high latitudes during this transition. The results show that in the final stage of the Early Permian icehouse, the delivery of moisture from low to high latitudes was reduced, facilitating the development of tropical coal forests. In the greenhouse condition, a rise in atmospheric pCO(2) resulted in continental drying and ocean stagnation. Furthermore, obliquity cycles triggered ice-sheet expansion and increased tropical precipitation during the icehouse condition.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Multidisciplinary Sciences
Jitao Chen, Isabel P. Montanez, Shuang Zhang, Terry T. Isson, Sophia Macarewich, Noah J. Planavsky, Feifei Zhang, Sofia Rauzi, Kierstin Daviau, Le Yao, Yu-Ping Qi, Yue Wang, Jun-Xuan Fan, Christopher J. Poulsen, Ariel D. Anbar, Shu-Zhong Shen, Xiang-Dong Wang
Summary: Understanding the carbon perturbation events and their effects on the Earth system is crucial for studying how the Earth responds to abrupt warming. This study investigates an abrupt carbon perturbation and global warming event that occurred during a paleo-glacial state using an integrated proxy and modeling approach. The results show significant isotopic excursions coinciding with a doubling of atmospheric CO2 partial pressure and a biodiversity nadir. Earth system modeling suggests that widespread anoxic conditions during this global warming event can be attributed to enhanced thermocline stratification and increased nutrient fluxes.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Paleontology
Zongyuan Sun, Petr Storch, Junxuan Fan, Michael J. Melchin, Anna Suyarkova
Summary: The lower Aeronian graptolite species Rastrites longispinus longispinus Perner, R. approximatus Perner, R. peregrinus Barrande, R.? norilskensis Obut & Sobolevskaya, and Stavrites rossicus Obut & Sobolevskaya have been revised using material from China, the Czech Republic, Siberia, Canada and Spain, together with published data. A new biogeographical subspecies, Rastrites longispinus chenxui subsp. nov., is identified and is only found in China and Canada. Several junior synonyms are also recognized. The study supports the hypothesis of two graptolite palaeobiographical provinces in the early Aeronian and has significant implications for palaeogeographical interpretations.
PAPERS IN PALAEONTOLOGY
(2022)
Article
Geography, Physical
Yu Liu, Yuanchun Li, Mingcai Hou, Jun Shen, Thomas J. Algeo, Junxuan Fan, Xiaolin Zhou, Qing Chen, Zongyuan Sun, Chao Li
Summary: The study suggests that sulfur-normalized Hg concentrations are the best proxy to assess Hg anomalies in Upper Ordovician sediments of the Yangtze Platform. The findings show that the dominant source of Hg in the study sections is terrigenous, rather than volcanic.
GLOBAL AND PLANETARY CHANGE
(2023)
Editorial Material
Geosciences, Multidisciplinary
Shuzhong Shen, Junxuan Fan, Xiangdong Wang, Feifei Zhang, Yukun Shi, Shuhan Zhang
JOURNAL OF EARTH SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Qiang Fang, Huaichun Wu, Shu-zhong Shen, Junxuan Fan, Linda A. Hinnov, Dongxun Yuan, Chuanzhen Ren, Maoyang Zhou, Shihong Zhang, Tianshui Yang, Yifei Zhang, Jun Chen, Qiong Wu, Mengkai Liu
Summary: In this study, a cyclostratigraphic analysis of the Tieqiao section in South China was conducted to investigate the climatic and biological responses during the late Paleozoic icehouse-to-greenhouse transition. The results show that variations in gamma rays reflecting continental weathering strength are paced by Milankovitch cycles. It was found that increased marine speciation was associated with elevated climatic humidity when Gondwana land was minimally glaciated, but as the glaciation weakened and tropical aridification continued, arid conditions and marine transgression at obliquity nodes led to a decrease in marine biodiversity.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Linna Zhang, Junxuan Fan, Bo Wang, Yuandong Zhang, Jianbo Liu, Hao Huang, Qing Chen
Summary: High-resolution, quantitative paleogeographical reconstruction based on geological big data and GIS is crucial for visualizing regional and global paleogeographical features and their evolution, as well as understanding the interaction of lithosphere, hydrosphere, and biosphere. This study collected and standardized a comprehensive dataset of 807 Ordovician sections in South China, and reconstructed lithofacies paleogeographical maps and stratigraphical thickness isopach maps for ten consecutive time intervals. Precise timing and processes of land-sea distribution and basin basement transformation were revealed, showing distinct paleogeographical processes among different terranes. The study recognized a new evolutionary process of the paleogeographical pattern in South China and provided insights into depositional centers, provenance regions, and the effects of tectonic movement and sea-level changes.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Linna Zhang, Zhangshuai Hou, Boheng Shen, Qing Chen, Shaochun Dong, Junxuan Fan
Summary: Paleobiogeography investigates the distribution of fossil organisms in geological history and its relationship with environmental factors. However, the scattered data and semantic heterogeneity make data queries, reuse, and sharing difficult. Knowledge graph provides a solution for organizing and mining paleobiogeographic information, enabling unrestricted data sharing.
JOURNAL OF EARTH SCIENCE
(2023)
