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The great catastrophe: causes of the Permo-Triassic marine mass extinction

National Science Review 2024年第1期11卷 37-50页

作者： Paul B.Wignall David P.G.Bond school of earth & Environment University of Leeds school of Environmental sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

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Provenance of the Lower Jurassic pyroclastic sediments in the Zigui Basin:Implication for crustal thickening in the eastern Qinling orogenic belt

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Science China earth sciences 2024年第1期67卷 196-207页

作者： Rong CHAI Jianghai YANG Yuansheng DU Chengshan WANG school of earth sciences and Resources China University of Geosciences(Beijing)Beijing 100023China school of earth sciences China University of Geosciences(Wuhan)Wuhan 430074China Chinese Academy of Geological sciences Beijing 100037China

The Late Triassic witnessed significant collisional orogenic events in the Qinling orogenic belt,accompanied by magma underplating and tectonic *** processes potentially resulted in substantial crustal thickening and uplift of the Qinling ***,due to the absence of igneous rock records from this period in the eastern section of the Qinling orogen,the changes in crustal thickness during this orogenic process have not been thoroughly investigated.A series of foreland basins emerged during the Early Mesozoic to the south of the East Qinling orogenic *** basins have preserved clastic sedimentary rocks derived from the uplift and erosion of the orogenic *** sedimentary records serve as crucial records to reconstruct the evolutionary history of the Qinling *** further clarify the collisional orogenic process of the Qinling orogenic belt,this study conducted in situ volcanic lithic fragment geochemistry,detrital zircon U-Pb chronology and trace element composition analysis on the sandstones of the Lower Jurassic Tongzhuyuan Formation in the Zigui *** results suggest that the sandstones,which exhibit a significant abundance of volcanic lithic fragments,has a characteristic detrital zircon age group of 250–200 Ma,indicating a major provenance from the Triassic volcanic *** with regional correlation and paleocurrent analysis,the detrital zircon U-Pb age data show that the source area of volcanic rocks should be in the Qinling orogenic belt to the north of the *** interpretation is further supported by the Triassic granitic rocks exposed in the western part of the orogenic belt,representing the magmatism during the Triassic collisional orogenesis in the Qinling *** on the co-varying relationships between present-day crust thickness with the chemical compositions of granite rocks and zircons,the La/Yb ratio of volcanic lithic fragments in the Tongzhuyuan Formation and the Eu/Eu*ratio of detrital zircon

关键词： Qinling orogenic belt Zigui Basin Late Triassic Detrital zircons Crustal thickening

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Red algal evidence for a marine regression during closure of the Paleo-Asian Ocean in the Junggar Basin and its linkage to hydrocarbon generation

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Science China earth sciences 2024年第9期67卷 2845-2863页

作者： Ruijie ZHANG Jian CAO Lizeng BIAN Wenxuan HU Liuwen XIA Bin ZHANG Yong TANG Wenjun HE school of earth sciences and engineering Nanjing University PetroChina Xinjiang Oilfield Company

The closure of the Paleo-Asian Ocean was a significant geological event in northern Pangea during the Carboniferous-Permian. It had a significant effect on climate, biota, and environmental conditions of the Late Paleozoic Ice Age, and resulted in the development of vast energy resources. This paper reports on the first discovery of marine red algal fossils in the Junggar Basin and its linkage to hydrocarbon generation. Red algae occur mainly in the Fengcheng Formation（ca. 300 Ma） and provide direct fossil evidence for closure of the Paleo-Asian Ocean. The red algal fossils contain well-preserved reproductive organs, such as cystocarps and carpospores. High concentrations of C27steranes(C27regular steranes/sum of C27–C29regular steranes×100=14.30%–21.30%) and the marine biomarker 24-n-propylcholesterane(C30diasterane [βα20S]/sum of C27–C30diasteranes [βα20S]×100=1.15%–1.85%) were detected in the red-algae-bearing hydrocarbon source rocks. Thermal experiments that simulate hydrocarbon generation show that the oil generation potential of the red-algae-bearing source rocks is363.71 mg g–1total organic C. This result, combined with oil-source rock correlations, indicates these rocks contributed to the formation of oil and gas resources, particularly in the marginal areas of the depression. The lake basin inherited the water and biological conditions of the Paleo-Asian Ocean during a marine regression, which was an important factor in the development of these high-quality hydrocarbon source rocks in an alkaline saline lake. The results advance our understanding of the evolution of the Paleo-Asian Ocean, interactions between the ocean and a lake during the deposition of terrestrial hydrocarbon source rocks,and whether red algae can effectively generate hydrocarbons.

关键词： Biotic precursor 24-n-propylcholesterane Regressive lake basin Fengcheng Formation Junggar Basin

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Petrogenesis and Tectonic Significance of Shenxianshui Alkaline Granite in Gejiu,Yunnan Province,China

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 368-385页

作者： YANG Rong CHEN Yongqing school of earth sciences and Resources China University of GeosciencesBeijing 100083China

The Shenxianshui granites in the western Gejiu area were formed in the Late *** ablation inductively coupled plasma mass spectrometry indicates zircon U-Pb ages ranging from 90.67±0.7 to 85.97±0.6 *** intrusive rocks are peraluminous(A/CNK=1.03 to 1.33)and calc-alkaline,showing an affinity towards I-type *** ion lithophilic elements are enriched in K and Rb,while high field strength elements are ***,light rare earth elements are significantly enriched,showing a slight negative Eu anomaly(Eu/Eu^(*)=0.39 to 0.58).Shenxianshui granite has a relatively high initial Sr isotope ratio(^(87)Sr/^(86)Sr)_(i)(0.7098-0.7105),negative ε_(Nd)(t)values(−7.99 to−7.44)and negative ε_(Hf)(t)values(−8.37 to−2.58).Combined with previous studies,these characteristics suggest that the Shenxianshui alkaline granites were formed in a post-collision extensional *** alkaline granitic magma possibly originated from the partial melting of the lower crust during the Mesoproterozoic era and may have contained mantle source *** alkaline granite was formed from mixed magma with a high degree of crystal *** abundance of ore-forming elements indicates that Shenxianshui granite has the potential to mineralize key metals and rare earth elements.

关键词： I-type granite zircon U-Pb geochronology Sr-Nd-Pb isotopes Hf isotope Gejiu

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Water Vapor Information from Satellite and Its Applications

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Advances in Atmospheric sciences 2024年第1期41卷 188-189页

作者： B.J.SOHN school of earth and Environmental sciences Seoul National UniversitySeoul 08826Korea

Water vapor is a critical component of the hydrological cycle because it plays a vital role in transporting water from one part of the cycle to *** vapor evaporated from surfaces such as oceans,lakes,and rivers conden... 详细信息

关键词： motion oceans lakes

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Chronological Study of Coal-seam Water and its Implication on Gas Production in the South Qinshui Basin

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 207-219页

作者： CHEN Biying FANG Lujia LANG Yunchao XU Sheng LIU Congqiang ZHANG Luyuan HOU Xiaolin Institute of Surface-earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China Institute of earth Environments Chinese Academy of SciencesXi’an 710061China

The knowledge of the residence time of formation water is fundamental to understanding the subsurface flow and hydrological *** better identify the origin and evolution of coal seam water and its impact on gas storage and production,this study collected coalbed methane co-produced water in the southeast Qinshui Basin and detected chemical and isotopic compositions,especially 36Cl and 129I *** calculated tracer ages of 129I(5.2–50.6 Ma)and 36Cl(0.13–0.76 Ma)are significantly younger than the age of coal-bearing formation(Pennsylvanian-Cisuralian),indicating freshwater recharge after coal *** model that utilises 129I/I and 36Cl/Cl ratios to constrain the timing of recharge and the proportion of recharge water reveals that over 60%of pre-anthropogenic meteoric water entered coal seams since 10 Ma and mixed with residue initial deposition water,corresponding to the basin inversion in *** spatial distribution of major ion concentrations reveals the primary recharge pathway for meteoric water from coal outcrops at the eastern margin to the basin *** study demonstrates the occurrence of higher gas production rates from wells that accept water recharge in recent times and suggests the possible potential of the non-stagnant zones for high gas production.

关键词： CBM co-produced water iodine-129 chlorine-36 water chemistry Qinshui Basin

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15N tracers and microbial analyses reveal in situ N2O sources in contrasting water regimes of a drained peatland forest

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Pedosphere 2024年第4期34卷 749-758页

作者： Mohit MASTA Mikk ESPENBERG Laura KUUSEMETS Jaan P?RN Sandeep THAYAMKOTTU Holar SEPP Kalle KIRSIM?E Fotis SGOURIDIS Kuno KASAK Kaido SOOSAAR ülo MANDER Institute of Ecology and earth sciences University of Tartu school of Geographical sciences University of Bristol University Road

Managed peatlands are a significant source of nitrous oxide（N2O）, a powerful greenhouse gas and stratospheric ozone depleter. Due to the complexity and diversity of microbial N2O processes, different methods such as tracer, isotopomer, and microbiological technologies are required to understand these processes. The combined application of different methods helps to precisely estimate these processes, which is crucial for the future management of drained peatlands, and to mitigate soil degradation and negative atmospheric impact. In this study, we investigated N2O sources by combining tracer, isotopomer,and microbial analysis in a drained peatland forest under flooded and drained treatments. On average, the nitrification genes showed higher abundances in the drained treatment, and the denitrification genes showed higher abundances in the flooded treatment. This is consistent with the underlying chemistry,as nitrification requires oxygen while denitrification is anaerobic. We observed significant differences in labelled N2O fluxes between the drained and flooded treatments. The emissions of N2O from the flooded treatment were nearly negligible, whereas the N2O evolved from the nitrogen -15(15N)-labelled ammonium(15NH4+) in the drained treatment peaked at 147 μg15N m-2h-1. This initially suggested nitrification as the driving mechanism behind N2O fluxes in drained peatlands, but based on the genetic data, isotopic analysis, and N2O mass enrichment, we conclude that hybrid N2O formation involving ammonia oxidation was the main source of N2O emissions in the drained treatment. Based on the15N-labelled nitrate(15NO3-) tracer addition and gene copy numbers, the low N2O emissions in the flooded treatment came possibly from complete denitrification producing inert dinitrogen. At atomic level, we observed selective enrichment of mass 45 of N2O molecule under15NH4+amendment in the drained treatment and enrichment of both masses 45 and 46under15NO3-amendment in the flooded trea

关键词： denitrification field experiment isotopes nitrification nitrous oxide qPCR

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Global weirding at mass extinction horizons

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National Science Review 2024年第1期11卷 10-12页

作者： Gregory J.Retallack Department of earth sciences University of Oregon

A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].

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Sustainable management of campus fallen leaves through low-temperature pyrolysis and application in Pb immobilization

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Journal of Environmental sciences 2024年第5期139卷 281-292页

作者： Rongli Tan Ke Li Yue Sun Xiaoliang Fan Zhengtao Shen Lingyi Tang school of Environment Nanjing UniversityNanjing 210023China school of Chemistry and Chemical engineering Nanjing UniversityNanjing 210023China school of earth and engineering sciences Nanjing UniversityNanjing 210023China Department of earth and Atmospheric sciences University of AlbertaEdmonton T6G 2E3Canada

Realizing campus sustainability requires the environmental-friendly and economical treatment of tremendous fallen *** fallen leaf biochar at a low temperature is a candidate *** this study,six common types of fallen leaves on the campus were pyrolyzed at 300℃.The obtained biochars were characterized and the adsorption mechanisms of lead(Pb)by the fallen leaf biochars were *** adsorption capacity of leaf biochar for Pb was relatively high,up to 209 mg/g(Yulania denudata leaf biochar).Adsorption of Pb onto active sites was the rate-limiting step for most leaf *** for Platanus leaf biochar,intraparticle diffusion of Pb^(2+)dominated owing to the lowest adsorption ***,the highest exchangeable Pb fraction(27%)indicated its potential for removing aqueous Pb^(2+).Ginkgo and Prunus cerasifera leaf biochar immobilized Pb by surface complexation and precipitation as lead ***,they were suitable for soil heavy metal *** study shed the light on the sustainable utilization of campus fallen leaves and the application of fallen leaf biochars in heavy metal remediation.

关键词： Fallen leaves Waste management Biochar Lead removal Sorption Circular campus

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AHFO-based soil water content sensing technology considering soile sensor thermal contact resistance

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Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2715-2731页

作者： Mengya Sun Peng Wu Bin Shi Jin Liu Jie Liu Juncheng Yao Yipin Lu Yunqiang Wang Xiaoyan Li school of earth sciences and engineering Hohai UniversityNanjing210098China school of earth sciences and engineering Nanjing UniversityNanjing210023China Department of Architecture and Civil engineering City University of Hong Kong999077Hong KongChina State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an710061China

The actively heated fiber-optic(AHFO)technology has become emerged as a research focus due to its advantages of distributed,real-time measurement and good *** attributes have led to the gradual application of AHFO technology to the water content measurement of in situ ***,all existing in situ applications of AHFO technology fail to consider the effect of soilesensor contact quality on water content measurements,limiting potential for the wider application of AHFO *** address this issue,the authors propose a method for determining the soilesensor thermal contact resistance based on the principle of an infinite cylindrical heat *** is then used to establish an AHFO water content measurement technology that considers the thermal contact *** reliability and validity of the new measurement technology are explored through a laboratory test and a field case study,and the spatial-temporal evolution of the soil water content in the case is *** results demonstrate that method for determining the soilesensor thermal contact resistance is highly effective and applicable to all types of *** method requires only the moisture content,dry density,and thermal response of the in situ soil to be *** the field case,the measurement error of soil water content between the AHFO method,which takes into account the thermal contact resistance,and the neutron scattering method is only *** water content of in situ soil exhibits a seasonal variation,with an increase in spring and autumn and a decrease in summer and ***,the response of shallow soils to precipitation and evaporation is *** findings contribute to the enhancement of the accuracy of the AHFO technology in the measurement of the water content of in situ soils,thereby facilitating the dissemination and utilization of this technology.

关键词： Soil water content Actively heated fiber-optic(AHFO) technology Soilesensor thermal contact resistance Reliability In situ application

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