Was the Late Ordovician mass extinction truly exceptional?

Trends in Ecology & Evolution, Год журнала: 2023, Номер 38(9), С. 812 - 821

Опубликована: Май 12, 2023

Язык: Английский

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Late Ordovician Mass Extinction: Earth, fire and ice

National Science Review, Год журнала: 2023, Номер 11(1)

Опубликована: Дек. 18, 2023

The Late Ordovician Mass Extinction was the earliest of 'big' five extinction events and to affect trajectory metazoan life. Two phases have been identified near start Hirnantian period in middle. It a massive taxonomic extinction, weak phylogenetic relatively benign ecological extinction. A rapid cooling, triggering major ice age that reduced temperature surface waters, prompted drop sea level some 100 m introduced toxic bottom waters onto shelves. These symptoms more fundamental planetary processes associated with range factors an underlying driver as volcanicity. Volcanic eruptions, other products, may extended back time at least Sandbian early Katian, suggesting extinctions were protracted influential than hitherto documented.

Язык: Английский

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Upwelling-driven biogenic silica accumulation in the Yangtze Sea, South China during Late Ordovician to Early Silurian time: A possible link with the global climatic transitions

Sedimentary Geology, Год журнала: 2024, Номер 461, С. 106571 - 106571

Опубликована: Янв. 8, 2024

Язык: Английский

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Changes in palaeoclimate and palaeoenvironment in the Upper Yangtze area (South China) during the Ordovician–Silurian transition

Scientific Reports, Год журнала: 2022, Номер 12(1)

Опубликована: Авг. 1, 2022

Abstract The Ordovician–Silurian transition was a critical period in geological history, during which profound changes climatic, biotic, and oceanic conditions occurred. To explore the provenance, palaeoclimate, palaeoredox Sichuan Basin Late Ordovician–early Silurian interval, we conducted mineralogical, geochemical, isotopic analyses of three formations (Wufeng, Guanyinqiao Longmaxi formations) Xindi No. 2 well. ternary bivariate diagrams indicate that provenance is mainly felsic igneous rocks originated from collisional setting, presumably due to an active continental margin. chemical index alteration (CIA) values lower Wufeng are relatively high (67.48–73.57), indicating warm humid climate. In contrast, CIA declined rapidly (58.30–64.66) late Katian early Hirnantian, had fluctuating cold dry climate interrupted by transient indices (Mo concentrations Mo auth /U , U/Th, V/Cr, Ni/Co, V/V + Ni values) two cycles water column euxinia. first cycle occurred Formation deposition, with bottom waters evolving oxic-suboxic suboxic-anoxic. Most samples show low redox-sensitive trace element Formation, pointing conditions. second cycle, transitioned oxic euxinic Our δ 13 C org data comparable previously reported records exhibit strong correlation between Hirnantian carbon excursion (HICE), change, redox We suggest variations related elements: (1) increased photosynthetic activity under conditions, (2) carbonate weathering exposed glacio-eustatic sea- level. addition, might more shelf-proximal setting well deposition. effectively constrain timing Ordovician mass extinction (LOME) evolution temporal climatic ocean suggesting apparent stratigraphic coincidence fluctuations two-phase extinctions, implies causal relationship. LOME systematically driven combination cooler glacial temperatures, sea-level fluctuations, anoxic caused pulses Yangtze shelf sea.

Язык: Английский

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Speculations on the Paleozoic legacy of Gondwana amalgamation

Gondwana Research, Год журнала: 2023, Номер 129, С. 107 - 131

Опубликована: Дек. 14, 2023

Язык: Английский

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Petrogenesis and Geochemistry of Upper Paleozoic Komatiites (Mashhad, NE Iran)

Journal of Petrology, Год журнала: 2025, Номер unknown

Опубликована: Янв. 4, 2025

Abstract Upper Paleozoic, probably Permian, komatiites have been found in the Paleo Tethys suture zone NE Iran. These rocks are divided into three groups: (i) differentiated and undifferentiated komatiite lava flows, (ii) komatiitic basalts, (iii) ultramafic-mafic pillow lavas. The a wide range of textures including random olivine spinifex, layered string-beef pyroxene micrographic intergrowths plagioclase clinopyroxene, cumulate textures. MgO contents from 7.1 wt% basalts gabbros flows to 38.0 cumulates, flow margins samples with spinifex content parental melt is estimated using Fo (89-91) be between 20 25 wt%, higher (30 36 wt%) attributed accumulation olivine. low Al2O3/TiO2 relatively depleted heavy rare earth elements. They therefore classified as Al-depleted komatiite, first report this magma type Phanerozoic locality. characteristics presence garnet source during mantle melting extraction. also more incompatible trace elements indicating derivation source. Our study indicates that formed by 10- (about) 20% partial plume at pressures about 4-5 GPa (depths 120-150 km). Ascent Late Paleozoic subduction margin Paleo-Tethys ocean possible petrogenetic model for generation these komatiites.

Язык: Английский

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Two stages of magmatism at the northern edge of Gondwana (SE Iran): New insights into tectono-magmatic evolution from U Pb zircon geochronology

Lithos, Год журнала: 2025, Номер unknown, С. 108066 - 108066

Опубликована: Март 1, 2025

Язык: Английский

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Mechanisms of global climate change during the five major mass extinctions

Scientific Reports, Год журнала: 2025, Номер 15(1)

Опубликована: Май 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.

Язык: Английский

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Tempo of the Late Ordovician mass extinction controlled by the rate of climate change

Science Advances, Год журнала: 2025, Номер 11(22)

Опубликована: Май 30, 2025

The Late Ordovician mass extinction (LOME) included two phases (I and II) of high species turnover that have been hypothetically linked to the Hirnantian glaciation subsequent rapid warming, respectively. However, timing tempo LOME remain uncertain, which hinders our understanding feedback between paleoclimatic change. Here, we present high-precision radioisotopic dates for Ordovician-Silurian transition in South China reveal began at 442.76 + 0.35/−0.22 million years ago, with lasting 0.34 0.46/−0.34 0.06 0.31/−0.06 years, switch from icehouse greenhouse conditions, along higher mean rate temperature change during II, resulted a much II than I (71.6% versus 8.4% loss per 100 thousand respectively), implying climate was primary control on LOME.

Язык: Английский

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Roller-coaster atmospheric-terrestrial-oceanic-climatic system during Ordovician-Silurian transition: Consequences of large igneous provinces

Geoscience Frontiers, Год журнала: 2023, Номер 14(3), С. 101537 - 101537

Опубликована: Янв. 18, 2023

The Ordovician-Silurian transition (OST) hosted profound and frequent changes in the atmospheric-terrestrial-oceanic-climatic system (ATOCS). Previous studies have found contrasting stages for such changes, primarily based on hiatus-interrupted sections. However, dominant driving factors mechanisms reconciling remain controversial. Mercury isotopes, which undergo both mass-dependent mass-independent fractionation, can provide critical insights into deep-time ATOCSs, especially those impacted by large igneous provinces (LIPs) events. Here, we build a high-resolution multi-proxy record of Hg (concentrations isotopic compositions) combined with organic carbon isotopes (δ13Corg) whole-rock geochemical data (including trace elements phosphorus) from continuous cores Yangtze Platform, South China. Our data, reported ones, indicate occurrence LIP eruptions against localized volcanism, four successive, yet ATOCSs during OST. Moreover, identified coupling between two-pulse magmatism extreme each special pCO2, weathering rate, primary productivity, redox condition, climatic mode, biotic evolution. For stage I, first pulse triggered global warming, enhanced terrestrial weathering, oceanic acidification, eutrophication, anoxia, P recycling, thereby widespread deposition black shales. During II, Hirnantian glaciation oxygenation arose intense chemical shale I; slashed facilitated CO2 accumulation. In III, another de-glaciation, ATOCS was largely similar to that I. This led round positive δ13Corg excursion IV. Compared environmental pressure peculiar stage, their transitions might been more devastating triggering prolonged Late Ordovician Mass Extinction (LOME). limited recovery possible later portion I III. study strata OST provides an excellent framework better illuminating LIPs' essential role "roller-coaster" behavior thus crisis pivotal period

Язык: Английский

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