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Platform Evolution in an Oligo-Miocene Back-arc Basin:An Example from the Central Iran Basin

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 185-206页

作者： Masoud SHARIFI-YAZDI Amirhossein ENAYATI Jamal SALEHI AGHDAM Mohammad BAHREHVAR Seyed Mustafa REZAEI Department of geology Faculty of Earth SciencesGeography and AstronomyUniversity of Vienna1090 Vienna.Austria geology and Geophysics Department Tehran Energy Consultants(TEC Co.)TehranIran school of geology College of ScienceUniversity of TehranTehranIran Department of geology Tarbiat Modares UniversityTehranIran

The Qom Formation is the most important hydrocarbon reservoir target in Central Iran.The Qom platform developed in a back-arc basin during the Oligo-Miocene due to the closing of the Tethyan Seaway.This formation consists of a variety of carbonate and non-carbonate facies deposited on a platform ranging from supratidal to basin.A combination of tectonic and eustatic events led to some lateral and vertical facies variations in the study area.Six third-order depositional sequences and related surfaces were identified regarding vertical facies changes in the studied sections of this Oligo-Miocene succession.According to all results and data,this succession was initially deposited during the Chattian upon a distally steepened ramp of siliciclastic-carbonate composition,including the Bouma sequence.Then,from the late Chattian to the Aquitanian,the platform changed into a homoclinal carbonate ramp with a gentle profile.With respect to tectonic activity,this phase was a calm period during the deposition of the Qom Formation.Finally,a drowned carbonate platform and a rimmed shelf emerged during the Burdigalian,terminated by the continental deposits of the Upper Red Formation.Regarding all geological characteristics,three main tectono-eustatic evolutionary phases have been recognized in the Qom back-arcbasin.

关键词： carbonate ramp depositional facies submarine fan eustasy basement faults back-arc basin

Multi-Elemental Chemostratigraphy,Sequence Development,Depositional History,and Environmental Importance of Early Eocene Red Beds(Kuldana Formation)in NW Himalayas,Pakistan

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Journal of Earth Science 2024年第2期35卷 349-375页

作者： Amir Shahzad George Kontakiotis Thierry Adatte Khawaja Shoaib Ahmed Muhammad Tayyib Riaz Hammad Tariq Janjuhah Evangelia Besiou Institute of geology University of Azad Jammu and KashmirMuzaffarabad13100Pakistan Department of Historical geology-Paleontology Faculty of Geology and GeoenvironmentSchool of Earth SciencesNational and Kapodistrian University of AthensPanepistimiopolisZografou15784Greece Institute of Earth Sciences(ISTE) University of LausanneLausanneCH-1015Switzerland Department of geology Shaheed Benazir Bhutto UniversitySheringalPeshawar18050Pakistan

The Eocene Kuldana Formation(KF)in the Yadgar area of Pakistan,comprises a diverse range of sedimentary facies,including variegated red beds of shales,mudstones,and sandstones,as well as interbedded limestone and marl.In this study,we conducted an integrated micropaleontological,sedimentological,mineralogical,and geochemical investigation to determine the depositional setting,biochronology,provenance,and paleoclimate of the KF.The study identified six lithofacies and six microfacies,which indicate a variety of environments ranging from floodplains and channels to the margins and shallow marine settings.The nannofossil biostratigraphy places the KF in the Early Eocene,more precisely the NP10 zone(Ypresian),and the fossil zone of benthic foraminifera classifies the study section as the Shallow Benthic Zone SBZ-8(Middle Ilerdian 2).In terms of petrography,the KF sandstone was classified as litharenite and feldspathic litharenite,while the QtFL diagram suggests a recycled orogen.Geochemical proxies indicate an oxidizing environment,a high-to-low regular sedimentation rate,moderate-to-intense chemical weathering in the source region,and a warm-humid to dry climate during the deposition of KF.Overall,the findings suggest that the deposition of KF marks the end of Neo-Tethys due to the Early Eocene Indian–Kohistan collision and that the uplifting of the Himalayas provided the source for the deposition of KF in the foreland basin.The study provides new insights into the depositional environment,biochronology,provenance,and paleoclimate of KF,and highlights the potential for red beds as reliable indicators of oxygenation levels in proximity to mineral deposits.

关键词： sedimentary microfacies Paleocene–Eocene thermal maximum stratigraphic correlations paleoenvironmental reconstruction nannofossils paleontology

Development and applications of the quasi‐dynamic triaxial apparatus for deep rocks

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Deep Underground Science and Engineering 2024年第1期3卷 70-90页

作者： Jinzhi Luo Yanyan Cai Jin Yu Jianzhi Zhang Yaoliang Zhu Yao Wei school of Civil Engineering Huaqiao UniversityXiamenFujianChina Zijin school of geology and Mining Fuzhou UniversityFuzhouChina

The mechanical behaviors of deep rocks have always posed a challenge for the implementation and safe operation of major underground engineering projects.To this end,this study modified the existing mainstream rock mechanics instruments equipped with a dynamic disturbance loading system and developed a second‐generation TFD‐2000/D triaxial instrument.The first‐generation device is equipped with an independent disturbance system and an advanced EDC‐580 all‐digital servo controller,which can apply disturbing load independently,implement the function of cyclic disturbance,and combine dynamic and static disturbances.The instrument was found to be reliable for use in analyzing the damage process of rocks in the disturbance test of marbles.The second‐generation instrument tackles three limitations of the first‐generation instrument:(i)it upgrades the strain measurement system and uses extensometers with linear variable differential transformers to accurately measure deformation;(ii)it uses the self‐balanced chamber to replace the Hoek–Franklin triaxial cell and auto‐balancing triaxial pressure chamber;and(iii)the loading rod is independently equipped with an EDC‐580 all‐digital servo controller,which measures precise loads.The experimental findings confirmed that the second‐generation instrument can be used for rock mechanics testing under cyclic disturbance loading,the disturbance–stress relaxation cycle,and the creep–fatigue cycle.In this sense,the second‐generation instrument can be a useful addition to deep rock mechanical instruments and provide a valuable reference.

关键词： complex stress conditions deep rock disturbance loading modification of instrument rock mechanics

Respiratory protein-driven selectivity during the Permian-Triassic mass extinction

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The Innovation 2024年第3期5卷 122-128页

作者： Haijun Song Yuyang Wu Xu Dai Jacopo Dal Corso Fengyu Wang Yan Feng Daoliang Chu Li Tian Huyue Song William JFoster State Key Laboratory of Biogeology and Environmental geology School of Earth SciencesChina University of GeosciencesWuhan 430074China Biogéosciences UMR 6282CNRSUniversitéde Bourgogne21000 DijonFrance Universitat Hamburg Institute for Geology20148 HamburgGermany

Extinction selectivity determines the direction of macroevolution,especially during mass extinction;however,its driving mechanisms remain poorly understood.By investigating the physiological selectivity of marine animals during the Permian-Triassic mass extinction,we found that marine clades with lower O2-carrying capacity hemerythrin proteins and those relying on O2 diffusion experienced significantly greater extinction intensity and body-size reduction than those with higher O2-carrying capacity hemoglobin or hemocyanin proteins.Our findings suggest that animals with high O2-carrying capacity obtained the necessary O2 even under hypoxia and compensated for the increased energy requirements caused by ocean acidification,which enabled their survival during the Permian-Triassic mass extinction.Thus,high O2-carrying capacity may have been crucial for the transition from the Paleozoic to the Modern Evolutionary Fauna.

关键词： extinction selectivity finding

Water-soluble brown carbon in atmospheric aerosols from the resource-dependent cities:Optical properties,chemical compositions and sources

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Journal of Environmental Sciences 2024年第4期138卷 74-87页

作者： Haoji Wang Yue Su Yangzheng Liu Fei Xie Xingjun Zhou Ruihong Yu Changwei Lü Jiang He school of Ecology and Environment Inner Mongolia UniversityHohhot 010021China Institute of Environmental geology Inner Mongolia UniversityHohhot 010021China Environmental Monitoring Center of Inner Mongolia Hohhot 010011China

As a vital type of light-absorbing aerosol,brown carbon(BrC)presents inherent associations with atmospheric photochemistry and climate change.However,the understanding of the chemical and optical properties of BrC is limited,especially in some resource-dependent cities with long heating periods in northwest China.This study showed that the annual average abundances of Water-soluble BrC(WS-BrC)were 9.33±7.42 and 8.69±6.29μg/m^(3)in Baotou and Wuhai and the concentrations,absorption coefficient(Abs_(365)),and mass absorption efficiency(MAE365)of WS-BrC presented significant seasonal patterns,with high values in the heating season and low values in the non-heating season;while showing opposite seasonal trends for the Absorption Angstr?m exponent(AAE_(300-400)).Comparatively,the levels of WS-BrC in developing regions(such as cities in Asia)were higher than those in developed regions(such as cities in Europe and Australia),indicating the significant differences in energy consumption in these regions.By combining fluorescence excitation-emission matrix(EEM)spectra with the parallel factor(PARAFAC)model,humic-like(C1 and C2)and proteinlike(C3)substances were identified,and accounted for 61.40%±4.66%and 38.6%±3.78%at Baotou,and 60.33%±6.29%and 39.67%±4.17%at Wuhai,respectively.The results of source apportionment suggested that the potential source regions of WS-BrC varied in heating vs.non-heating seasons and that the properties of WS-BrC significantly depended on primary emissions(e.g.,combustion emissions)and secondary formation.

关键词： Water-soluble brown carbon Atmospheric aerosols Optical properties PARAFAC Source apportionment

End-Triassic storm deposits in the lacustrine Sichuan Basin and their driving mechanisms

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Science China Earth Sciences 2024年第7期67卷 2383-2400页

作者： Jianli ZENG Tingshan ZHANG Mihai Emilian POPA Yongdong WANG Xi ZHANG Liqin LI Yuanyuan XU Ning LU Xiaoqing ZHANG school of Geoscience and Technology Southwest Petroleum Universiy Chengdu 610500China Sichuan Key Laboratory of Natural Gas geology Southwest Petroleum University Chengdu 610500China Faculy of geology and Geophysics Doctoral Schoolof Geology Laboratory of Palaontology University of Bucharest.Bucharest 010041Romania Nanjing Institute of geology and Palaeontology Chinese Academy of Sciences Nanjing 210008China University of Chinese Academy of Sciences NanjingNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China

Storm deposits or tempestites are event sequences formed by storms,requiring at least a water temperature of 26.5℃.While inland lakes are unlikely to form storm deposits because of their limited width and water temperature.The Upper Triassic Xujiahe Formation in the Sichuan Basin is a set of coal-bearing,clastic sequences with dominant sedimentary facies varying from braided river delta to lacustrine settings,with storm deposits widely reported.In the Zilanba of Guanyuan area,in situ tree trunks on a palaeosol surface in Member Vof the Xujiahe Formation provide new evidence of a storm event.Six fallen-down directions of nine in situ tree trunks were predominant in the NW direction,contrary to the palaeocurrent direction of the underlying strata,suggesting that the southeasterlies prevailed during the end-Triassic in the northern Sichuan Basin.Massive mud clasts were frequently recorded in sandstones of the Xujiahe Formation,as well as in the Xindianzi section.These mud clasts showed a rip-up or a plastic deformation with upside-down V-shapes,were capped on an erosional surface,showed no transport traces and were therefore interpreted as a storm lag deposit.The megamonsoonal climate prevailed during the Late Triassic,although the megamonsoons themselves could not generate a storm deposition in the Xujiahe Formation due to its low maximum surface wind speed.The driving mechanism for generating storm deposits in the Xujiahe Formation is suggested to be tropical cyclones over the Tethys Ocean moving eastward,further landfalling on the western margin of the Sichuan Basin.Statistics of storm events in the circum-Tethys region show a widespread storm surge in low latitudes during the end-Triassic.The storm deposits at the top of the Xujiahe Formation represent a sedimentary response to the end-Triassic hyperthermal event.

关键词： Sichuan Basin End-Triassic Xujiahe Formation Storm deposits

Depositional and Bio-Sequence Stratigraphic Framework of Late Cretaceous Kawagarh Formation,Kala-Chitta Range,Pakistan:Equivalent of Gurpi Formation(Iran)

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Journal of Earth Science 2024年第2期35卷 332-348页

作者： Muhammad Awais Bilal Wadood Muhammad Ishaq Muhammad Bilal Zeeshan Zafar Nasar Khan Aminullah Khan Department of geology University of SwabiAnbar-SwabiKhyber PakhtunkhwaSwabi23561Pakistan Department of Earth Environmental and Resources SciencesUniversity of Naples FedericoⅡNaples80126Italy State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an710069China National Centre of Excellence in geology University of PeshawarPeshawarKhyber Pakhtunkhwa25130Pakistan Department of Geological Engineering School of Earth Sciences and EngineeringXi’an Shiyou UniversityXi’an610500China Department of Petroleum geology and Engineering School of Earth ResourcesChina University of GeosciencesWuhan430074China Department of geology University of MalakandDir Lower18800ChakdaraPakistan Department of Earth and Environmental Sciences KU LeuvenLeuven3001Belgium

The present study is focused on evaluation of deep marine pelagic sediments of Late Cretaceous Kawagarh Formation of Kala-Chitta Range in the context of microfacies analysis,paleoenvironmental interpretation,planktonic foraminiferal biostratigraphy,sequence stratigraphy and diversification of species.A total of thirty three rock samples were collected from the measured section.Three microfacies are interpreted,namely planktonic foraminifera wackestone,planktonic foraminifera mudstone and sandy mudstone indicating low energy depositional environment i.e.,outer ramp.The biostratigraphic studies show plentiful planktonic foraminifera species of Globotruncana,Heterohelix and Globotruncanita.However,no association of benthic or siliceous organisms was observed.On the basis of available species assemblage,a single local planktonic foraminifera biozone i.e.,Globotruncana-Heterohelix-Globotruncanita Assemblage Biozone is established.The biozone information is combined with published literature and Lower Santonian to Middle Maastrichtian age has been assigned to the Kawagarh Formation.The trend of species occurrences evinces that species number decreases over time with pulsated rise in the Kawagarh Formation.The Kawagarh Formation carbonates show an overall Transgressive Systems Tract(TST).The Kawagarh Formation of Pakistan evinces analogous characteristics to that of the Late Cretaceous Gurpi Formation of Iran based on the geologic age,outcrop lithology,microfacies,planktonic foraminiferal assemblages,depositional setting and sequence stratigraphy.

关键词： depositional fabric biostratigraphy sequence stratigraphy Late Cretaceous Kawagarh Formation Pakistan Gurpi Formation Iran

Challenges and opportunities in Quaternary palynology

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Science China Earth Sciences 2024年第7期67卷 2148-2161页

作者： Qinghai XU Houyuan LU Zhuo ZHENG College of Geographical Sciences Hebei Key Laboratory of Environmental Change and Ecological ConstructionHebei Normal UniversityShijiazhuang 050024China Key Laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China school of Earth Sciences and Engineering Sun Yat-sen UniversityZhuhai 519082China

Quaternary palynology plays a pivotal role in investigating global climate change and various other research fields,serving as an essential tool for the quantitative analysis of paleoenvironment changes.However,due to the vast diversity of terrestrial ecosystems and intricate interactions between vegetation,climate,and human activities,further advancements are required in the following aspects within this discipline.(1)The accuracy of classification in pollen morphology and fossil pollen identification needs improvement,particularly at the species level.This represents a significant challenge in present Quaternary palynology.Computer-aided intelligent recognition holds promise as a solution for species identification based on more detail pollen morphology.(2)Most pollen-based vegetation and climate reconstructions overlook the significance of bare ground.Neglecting bare ground can lead to substantial inaccuracies when quantitatively reconstructing past vegetation and climate.(3)While pollen records provide reliable information on paleoclimate changes,current quantitative climate reconstruction models heavily rely on modern pollen datasets derived from present-day vegetation disturbed more or less by human activities.This introduces bias and uncertainties into paleoclimate reconstruction.(4)Although pollen can serve as an indicator of human activities,accurately quantifying the intensity of human influence remains challenging.Improving accurate identification of crop pollen,reconstructing reliable land cover/use data,and integrating multidisciplinary data may enhance the identification and quantification of signals related to human activity in pollen records.

关键词： Quaternary palynology Paleoclimate Paleovegetation Human activity

Productivity in the Southern Ocean Antarctic Zone during the Northern Hemisphere Glaciation(NHG)and its link to atmospheric pCO_(2)

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Science China Earth Sciences 2024年第7期67卷 2242-2252页

作者： Yiming WU Jingteng GUO Xiangyu ZHAO Wenshen XIAO Heng LIU Zhifang XIONG Tiegang LI Key Laboratory of Marine geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine geology Laoshan LaboratoryQingdao 266237China school of Oceanography Shanghai Jiao Tong UniversityShanghai 200030China Key Laboratoryof Polar Eosystem and Climate Change Shanghai Jiao Tong UniversiyMinistryof EducationShanghai 200030China State Key Laboratory of Marine geology Tongji UniversityShanghai 200092China

A decrease in atmospheric CO_(2)partial pressure(pCO_(2))is considered an important prerequisite for the onset and intensification of Northern Hemisphere Glaciation(NHG).However,how the ocean sequestered missing CO_(2)during the NHG is still uncertain.Changes in surface productivity and deep ventilation in the Southern Ocean(SO)have been proposed to explain the variations in atmospheric pCO_(2)over the last eight glacial cycles,but it is unclear whether these mechanisms contributed to the decrease in atmospheric pCO_(2)during the NHG.Using titanium-normalized contents and mass accumulation rates of biogenic opal and total organic carbon from the International Ocean Discovery Program(IODP)Expedition 374 Site U1524A,we reconstruct the productivity in the Ross Sea,Antarctica,from 3.3 Ma to 2.4 Ma.The productivity records exhibit a long-term decreasing trend and several distinct phased evolutionary features.Specifically,the local productivity fluctuated dramatically during 3.3-3.0 Ma,decreased gradually during 3.0-2.6 Ma,and remained relatively constant during 2.6-2.4 Ma.By comparing productivity with its potential influences,we infer that the phased and long-term evolutions of productivity were mainly controlled by changes in deep ocean ventilation.Sea ice expansion might have decreased productivity during 3.3-3.0 Ma by light attenuation.Changes in eolian dust input have little effect on productivity.Further analysis revealed no coupling linkage between productivity and atmospheric pCO_(2),indicating that the productivity in the SO Antarctic Zone(AZ)was not the main factor controlling the atmospheric CO_(2)decrease during the NHG.To improve our understanding of the role of SO processes in the NHG,further studies should focus on the potential influences of deep ocean ventilation on atmospheric pCO_(2)in the AZ,and similar studies should also be extended to the sea area in the Subantarctic Zone.

关键词： Ross Sea Biogenic opal Total organic carbon Deep ocean ventilation Sea ice Ocean carbon cycle