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Late Ordovician Mass Extinction: earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.T.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

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

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： David J.Bottjer department of earth sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Effect of stress-dependent microannulus aperture on well leakage

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 1967-1976页

作者： Meng Meng Luke P.Frash J.William Carey Mohamed Mehana Wenfeng Li Bailian Chen earth and environmental sciences Los Alamos National LaboratoryLos AlamosNMUSA

Debonding at the cement-casing interface is recognized as a principal failure mechanism leading to CO_(2) leakage in *** detachment gives rise to a microannulus,which notably possesses greater permeability than undamaged cement,undermining its sealing ***,the permeability of the microannulus is regarded as a uniform value throughout the ***,fundamentally,a microannulus is one type of fracture,and its gap or aperture size is affected by the effective *** this work,we developed a unique experimental *** equipment facilitates the curing of cement inside a steel casing,the formation of a microannulus between the casing and the cement,and the investigation of the fluid flow dynamics along the microannulus under laboratory-replicated in situ *** microannulus was formed by injecting fluid from one end of the setup,and receiving similar amount of fluid on the other end signified the development of the leakage ***,strain gauges affixed to the casing’s external surface yielded key information on the microannulus’s opening and *** observed a noticeable decline in microannulus hydraulic aperture(or permeability)in relation to effective stress and an exponential equation fits their *** findings also indicate a distinct behavior when comparing liquid CO_(2) with ***,it is easier for liquid CO_(2) to create the ***,the hydraulic aperture range for this microannulus(0.7-6 mm)is considerably smaller than that created by water flow(2-17 mm).Finally,we integrated the stressdependent microannulus aperture size into the combined analysis of well mechanical integrity and well *** outcomes consistently demonstrated that when factoring in the stress-dependent aperture sizes,the leakage rates are 3e5 times compared to a fixed aperture *** traditional assumption of a constant aperture significantly underestimates fluid leakage risks.

关键词： Microannulus Leakage assessment Aperture size Triaxial experiment Carbon sequestration

Identifying flow regime in the aquifer of fractured rock system in Germi Chai Basin,Iran

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Journal of Mountain Science 2024年第2期21卷 574-589页

作者： VAEZIHIR Abdorreza SEPEHRIPOUR Ali TABARMAYEH Mehri department of earth sciences University of TabrizTabriz ***Iran

Considering the importance of fractured rock aquifers in the hydrogeologic process,this research aimed to analyze the flow regime,internal degree of karstification,and estimate storage volume in fractured rock aquifers of the Germi Chai Basin in northwest Iran,which is attributed to its active tectonics,erosion,and the lithological *** the geological setting,the hypothesis is that this basin is characterized by a high degree of karstification and diffuse or intermediate flow regime leading to variation in discharge flow *** hydrodynamic and hadrochemical analysis was conducted on 9 well distributed springs across the basin from 2019 to *** maximum flow rate in most of the springs appeared in the early wet season despite their different levels of fluctuations on the monthly discharge time *** the spring recession curve form revealed an aquifer containing multiple micro-regimes withαrecession coefficients and a degree of karstification ranging between 0.001 to 0.06 and 0.55 to 2.61,*** findings indicated a dominant diffuse and intermediate flow system resulting from the development of a high density of fractures in this *** electrical conductivity of the spring changes inversely proportional to the change in flow discharge,indicating the reasonable hydrological response of the aquifer to rainfall *** analysis revealed that the delay time of spring discharge after rainfall events mostly varies between 10 to 30 *** total dynamic storage volume of the spring for a given period(2019-2020)was estimated to be approximately 1324 million cubic meters reflecting the long-term drainage potential and high perdurability of dynamic *** the maximum and minimum ratio revealed that the springs recharging system in Germi Chai Basin comes under the slow aquifers *** finding provides valuable insight into the hydrogeological properties of fractured rock aquifers contributing to effective w

关键词： Fractured rock aquifer Hydrodynamic and hadrochemical analysis Germi Chai Basin Recession coefficient

Phanerozoic co-evolution of O2-CO2 and ocean habitability

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National Science Review 2024年第06期 18-21页

作者： Zunli Lu Rosalind E.M.Rickaby Jonathan L.Payne Ashley N.Prow department of earth & environmental sciences Syracuse University department of earth sciences University of Oxford department of earth and Planetary sciences Stanford University

Atmospheric carbon dioxide and oxygen concentrations are partially linked via the geological cycle of organic carbon （Fig. 1A–C; e.g. CO2+H2O■CH2O+O2）. The history of these two biologically active components, controls on their concentrations, and implications for the complexity of the biosphere and habitability of earth have been hotly debated, but are generally considered independently.

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Pumping-induced Well Hydraulics and Groundwater Budget in a Leaky Aquifer System with Vertical Heterogeneity in Aquitard Hydraulic Properties

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 477-490页

作者： ZHUANG Chao LÜChenyang YAN Long LI Yabing ZHOU Zhifang WANG Jinguo DOU Zhi Walter A.ILLMAN School of earth sciences and Engineering Hohai UniversityNanjing 211100China School of Geography Earth and Environmental SciencesUniversity of BirminghamBirmingham B152TTU.K. department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China department of earth and environmental sciences University of WaterlooOntario N2L 3G1Canada

In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity(K)and specific storage(S_(s)).The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or S_(s).Two scenarios of analytical investigations are explored:one is the presence of aquitard interlayers with distinct K or S_(s) values,a common field-scale occurrence;another is an exponentially depth-decaying aquitard S_(s),a regional-scale phenomenon supported by statistical *** investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion;a high-S_(s) interlayer can noticeably reduce aquifer drawdown and increase aquitard *** of low-K or high-S_(s) interlayers also significantly impact well hydraulics and groundwater *** the context of an exponentially depth-decaying aquitard S_(s),a larger decay exponent can enhance aquifer *** using current models with a vertically homogeneous aquitard,half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard S_(s) should be used to calculate aquitard depletion and unconfined aquifer leakage.

关键词： hydrogeology aquitard vertical heterogeneity semi-analytical solution well hydraulics groundwater budget

Circum-Indian Holocene sea-level database:A repository of distinct relative sea-level plots across the Indian Peninsula

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Journal of Palaeogeography 2024年第1期13卷 1-17页

作者： Shradha Menon Pankaj Khanna Santanu Banerjee REEFS Lab Department of Earth SciencesIIT GandhinagarPalajGandhinagarGujarat382355India department of earth sciences IIT BombayPowaiMumbai400076India

The Indian Peninsula is one of the most well-studied regions for Holocene sea-level fluctuations in the world, however, standardized relative sea-level datasets are missing. This study provides an archive of sealevel indicators(n = 162, 20 locations) along the western and the eastern sides of the peninsula, that have been used to develop Relative Sea Level(RSL) plots. Each dated sea-level indicator is recalibrated for its elevation based on tidal and tectonic correction, as well as age with reservoir correction, and have been separated into six zones based on coastal geomorphology and number of datasets. The database spans throughout the Holocene and covers sea-level depth/elevations from-45 m to +5 m from mean sea-level(MSL). Approximately 90 % of the dataset range from 8 ka to the present day. The first transgression is highly variable and identified between 8.5-8 ka BP in Gujarat(Zone 1), ~ 5.5 ka BP in Maharashtra(Zone 2), between 8 and 7 ka BP in Tamil Nadu(Zone 4) and between 8 and 7.5 ka BP in the Bengal coasts(Zone 6). No transgression above present sea-level is observed along Andhra Pradesh(Zone 5)(no data for Kerala-Zone 3).Further, Zones 1, 2, 4 and 6 show a strong uplift component(tectonic), whereas Zone 5 exhibits subsidence during the Holocene(Zone 3-insufficient data). Based on these findings, and given the region's coastal topography and tidal components, Zones 6 and 1 will likely undergo the largest coastal inundation, followed by Zones 5, 4, 2, and 3. These insights are critical in planning future coastal inundation measures across the Indian Peninsula.

关键词： Indian ocean Terraces Relative sea level curve Holocene Arabian sea Bay of Bengal

Petrologic evolution of the Gysian ophiolitic serpentinites,NW Iran

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Acta Geochimica 2024年第5期43卷 996-1011页

作者： Monir Modjarrad Donna L.Whitney Hadi Omrani department of Geology Faculty of SciencesUrmia UniversityUrmiaIran department of earth and environmental sciences University of MinnesotaMinneapolisMNUSA department of Geology Faculty of SciencesGolestan UniversityGorgānIran

The Gysian ophiolite of NW Iran is located at the intersection of the ophiolite belts of SE Turkey,NE Iraq,and Iran,and provides the opportunity to investigate the preserved subduction and obduction history of an important tectonic site that has not previously been *** serpentinized peridotites of the Gysian ophiolite contain the assemblagelizardite+chrysotile+spinel/Mg-spinelwith relict clinopyroxene(diopside)and very rare relict orthopyroxene and *** compositions of clinopyroxenes and spinels are more consistent with the formation of the inferred protolithharzburgitesinafore-arcorsupra-subduction zone instead of an abyssal *** Gysian ophiolite is a remnant of the Neo-Tethyan arc-ophiolitic system and records shallow subduction(<50 km,indicated by the absence of antigorite)in the Late Cretaceous to Paleocene beforeobductionalongthrustfaultsoverthecontinental *** review the spatial trends of the metamorphic grade of the Neo-Tethyan ophiolites in this region and provide detailed information about the petrology and mineral chemistry of the Gysian ophiolite.

关键词： Ophiolite Neo-Tethyan Gysian Serpentinite Iran

Microfacies and diagenetic alteration in a semi-deep to deep lacustrine shale: The Yanchang Formation in the Ordos Basin, China

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Petroleum Science 2024年第3期21卷 1524-1538页

作者： Bin Bai Jing-Yue Hao Ling Fu Yu-Xi Liu Jian-Peng Wang Lan Wang Kevin GTaylor Lin Ma PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China department of earth and environmental sciences University of ManchesterM139PLUK College of earth sciences Jilin UniversityChangchun130061jilinChina department of Chemical Engineering University of ManchesterM139PLUK

The mineralogical development and diagenetic sequence of lacustrine shales in the Chang 7 Member of the Yanchang Formation in the Ordos Basin are detailed studied.A model of their depositional system and a diagenetic diagram are proposed in this *** detailed petrographic,mineralogical,and elemental analyses,four distinct shale types are identified:argillaceous shale,siliceous shale,calcareous shale,and carbonate,clay,and silt-bearing *** main diagenetic process in argillaceous shale is the transformation of illite to smectite,negatively impacting shale *** shale undergoes carbonate cementation and quartz dissolution,contributing to increased porosity,particularly in *** shale experiences diagenesis characterised by carbonate formation and dissolution,with a prevalence of *** carbonate,clay,and silt-bearing shale,the dissolution of K-feldspar contributes to illitization of *** shale,characterised by more clay minerals and lower mesopore volume,is identified as a potential hydrocarbon *** shale,with the highest pore volume and abundant inter-mineral pores,emerges as a promising shale oil *** findings contribute to a comprehensive understanding of shale properties,aiding in the prediction of shale oil exploration potential in the studied area.

关键词： Ordos Basin Yanchang Formation Chang 7 Member Diagenesis Microfacies