Linking environmental changes and organic matter enrichment in the middle part of the Yanchang Formation (Ordos Basin, China) to the rollback of an oceanic slab in the eastern Paleo-Tethys

Sedimentary Geology, Journal Year: 2023, Volume and Issue: 455, P. 106480 - 106480

Published: Aug. 6, 2023

Language: Английский

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Mercury evidences link intensive volcanism to the Late Ordovician mass extinction and changes in the atmosphere-land-ocean system

The Innovation Geoscience, Journal Year: 2025, Volume and Issue: unknown, P. 100124 - 100124

Published: Jan. 1, 2025

<p>The Late Ordovician mass extinction (LOME, ca. 445 Ma), which occurred over two intervals (LOMEI-1 and LOMEI-2), was the first “Big Five” biotic crises of Phanerozoic. The ultimate trigger this remains debated, with glacially induced global cooling volcanism-driven warming events separately suggested as underlying cause. Here, we report anomalously high mercury (Hg) levels in Ordovician-Silurian successions from a shelf-to-slope transect South China, indicating abnormally Hg loading to ocean. Analyses isotopes through reveal near-zero Δ¹⁹⁹Hg late Katian earliest Hirnantian (LOMEI-1), suggesting that mainly derived large-scale volcanism. Positive shifts are observed during stage, coincident glaciation, enhanced sequestration sediments driven by subsidence cold dense surface seawater. Negative values across LOMEI-2 within likely suggest terrestrial sulfate fluxes ocean due volcanism-induced warming, promoted oceanic anoxic/euxinic conditions. This study provides novel evidences linking intensive volcanism significant changes atmosphere-land-ocean system transition, particularly euxinic conditions triggered LOME.</p>

Language: Английский

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磷循环及磷组分在古海洋环境重建中的应用

Earth Science-Journal of China University of Geosciences, Journal Year: 2025, Volume and Issue: 50(1), P. 246 - 246

Published: Jan. 1, 2025

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The redox transformation in the Yangtze Sea across the Ordovician-Silurian transition: Evidence from zinc isotopes in organic-rich shales

Journal of Asian Earth Sciences, Journal Year: 2025, Volume and Issue: unknown, P. 106579 - 106579

Published: March 1, 2025

Language: Английский

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Depositional environment and organic matter enrichment mechanism of the lower cambrian shale in the southern Sichuan Basin

Frontiers in Earth Science, Journal Year: 2025, Volume and Issue: 13

Published: April 4, 2025

The Ediacaran-Cambrian transition was one of the most important periods in Earth’s history. Based on analysis lithofacies, mineral composition, total organic carbon major and trace elements, we have studied depositional environment matter enrichment mechanism Qiongzhusi Formation shale southern Sichuan Basin. results show that V/Cr, Ni/Co, U/Th, Mo-EF U-EF values suggest stronger reducing conditions black compared to grey shale, with anoxic decreasing from interior faulted-sag its exterior. Mo-TOC crossplots U-Mo covariation analyses indicate a moderately restricted during deposition Formation. Ba/Al biogenic barium (Ba xs ) had higher paleoproductivity than slope outside faulted-sag. Ti/Al ratio indicates stable terrigenous input deposition. chemical index alteration (CIA) formation range mostly 50 70, indicating low weathering under cold arid climate. Cd/Mo Co (μg/g) × Mn (%) plot upwelling minor influence general. Overall, primarily controlled by redox conditions, which were influenced Mianyang-Changning We proposed two models for Basin: (1) OM-enriched deposited anoxic-suboxic experiencing weathering, climate high paleoproductivity; (2) OM-lean suboxic-oxic paleoproductivity.

Language: Английский

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Multigenetic origins of pyrite in sedimentary systems: A NanoSIMS sulfur isotope study of the Silurian Longmaxi Formation

Marine and Petroleum Geology, Journal Year: 2025, Volume and Issue: unknown, P. 107423 - 107423

Published: April 1, 2025

Language: Английский

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Mechanisms of global climate change during the five major mass extinctions

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: May 12, 2025

Since the emergence of diverse animal phyla around 500 million years ago, five major mass extinction events have occurred, each coinciding with abnormal climate changes. We analyzed sedimentary organic molecules from first and least understood event at end Ordovician period. divided all extinctions into two phases each, totaling ten events, examined relationship between shifts "coronene index"-an indicator heating temperatures in rocks caused by volcanic activity or meteorite impacts. As a result, we found that four began global cooling ended warming, while one started an unknown anomaly also warming. During initial phases, showed low-temperature heating, high-temperature, moderate-temperature. All subsequent warming moderate-temperature heating. These findings suggest large-scale eruptions impacts heated sulfides, sulfates, hydrocarbons varying temperatures, releasing SO2 soot stratosphere, blocking sunlight, triggering extinction. This was followed moderate carbonates, increasing CO2 emissions driving long-term leading to secondary events.

Language: Английский

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Evaluation of gas content in organic-rich shale: A review of the history, current status, and future directions

Geoscience Frontiers, Journal Year: 2024, Volume and Issue: 15(6), P. 101921 - 101921

Published: Aug. 31, 2024

Language: Английский

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Drivers of the global phosphorus cycle over geological time

Nature Reviews Earth & Environment, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 19, 2024

Language: Английский

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Mineralogy and Geochemistry of the Upper Ordovician and Lower Silurian Wufeng-Longmaxi Shale on the Yangtze Platform, South China: Implications for Provenance Analysis and Shale Gas Sweet-Spot Interval

Minerals, Journal Year: 2022, Volume and Issue: 12(10), P. 1190 - 1190

Published: Sept. 22, 2022

The sediment provenance influences the formation of shale gas sweet-spot interval Upper Ordovician–Lower Silurian Wufeng–Longmaxi from Yangtze Platform, South China. To identify provenance, mineralogy and geochemistry were investigated. methods included optical microscopy analysis, X-ray diffraction testing, field-emission scanning electron imaging, major trace element analysis. is mainly composed quartz (avg. 39.94%), calcite 12.29%), dolomite 11.75%), clay minerals 28.31%). LM1 has highest contents total 62.1%, among which microcrystalline accounts for 52.8% on average) organic carbon 4.6%). relatively narrow range TiO2–Zr variation close correlation between Th/Sc Zr/Sc signify no obvious sorting recycling source rocks. Sedimentary a limited impact geochemical features shale. high value ICV (index compositional variability) (1.03–3.86) low CIA (chemical index alteration values) (50.62–74.48) indicate immature rocks, probably undergoing weak to moderate chemical weathering. All samples have patterns moderately enriched light rare-earth elements flat heavy with negative Eu anomalies (Eu/Eu* = 0.35–0.92) in chondrite-normalized diagrams. According Th/Sc, Zr/Sc, La/Th, Zr/Al2O3, TiO2/Zr, Co/Th, SiO2/Al2O3, K2O/Na2O, La/Sc, it can be inferred that rocks acidic igneous derived active continental margin island arc. A terrigenous supply caused by inactive tectonic setting an alternative interpretation interval.

Language: Английский

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