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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 Ecosystem and Climate Change Shanghai Jiao Tong UniversityMinistry of 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 *** 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 *** 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 *** productivity records exhibit a long-term decreasing trend and several distinct phased evolutionary ***,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 *** 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 *** ice expansion might have decreased productivity during 3.3-3.0 Ma by light *** in eolian dust input have little effect on *** 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 *** 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

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A Novel Three-stage Tectonic Model for Mississippi Valleytype Zn-Pb Deposits in Orogenic Fold-and-Thrust Belts

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 843-849页

作者： SONG Yucai SinoProbe Laboratory Institute of GeologyChinese Academy of Geological SciencesBeijing 100037China

Mississippi Valley-type(MVT) Zn-Pb deposits predominantly form within both orogenic forelands and fold-andthrust belts, yet the mineralization process within the latter tectonic setting remains inadequately understood. This study, through a comprehensive review of MVT deposits across global fold-and-thrust belts, introduces a novel model elucidating the mineralization process in the context of tectonic belt evolution. It is demonstrated that during the stage Ⅰ, regional compression is introduced by early stages of plate convergence, causing the folding and thrusting and creating structural or lithological traps such as evaporite diapirs and unconformity-related carbonate dissolution-collapse structures. Thereafter, in stage Ⅱ, hydrocarbons begin to migrate and accumulate within these traps, where reduced sulfur is generated through thermochemical or bacterial sulfate reduction concurrent with or preceding Zn-Pb mineralization. In the subsequent stage Ⅲ, as plate convergence persists, the regional stress transitions from compression to transpression or extension. Under these conditions, steeply-dipping extensional faults are generated, facilitating the ascent of metalliferous brines into early-formed structural or lithological traps. Precipitation of Zn and Pb sulfides occurs through the mixing of Zn-Pb-transporting fluids with pre-existing reduced sulfur or by interaction with hydrocarbons.

关键词： Mississippi Valley-type Zn-Pb deposits fold-and-thrust belts tectonic model structural or lithological traps extensional faults

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Mottled dolomite in the lower Cambrian Longwangmiao formation in the Northern Sichuan Basin, South China

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Petroleum 2024年第1期10卷 19-29页

作者： Xuefei Yang Hao Tang Junyi Zhang Yao Du Ruifeng Tang Shuang Pan Xiang Zhou Yan Xu State Key Laboratory of Oil and Gas Reservoir geology and Exploitation Southwest Petroleum University Sichuan Provincial Key Laboratory of Gas geology Southwest Petroleum University CCDC Chuandong Drilling Company Exploration Department Petrochina Southwest Oil& Gasfield Company

At the end of Early Cambrian time, the Sichuan basin（South China） was located in a wide carbonate platform, with hundreds of meters of carbonate deposited. The Longwangmiao Formation carbonate in Sichuan basin is partially to completely dolomitized, displaying a mottled texture in the northern area of the exposure. The mottled dolomitic limestone developed parallel to bedding, with shape irregular boundaries with limestone that has not been dolomitized. The mottled dolomite is composed of powder crystalline and finely crystalline dolomite, while the matrix limestone is composed of micritic calcite. the isotopic composition of mottled dolomite(δ13C = +0.29‰PDB, δ18O =-1.15‰PDB) is similar to that of micrite calcite(δ13C =-0.49‰PDB, δ18O =-1.45‰PDB). Both isotopic values and trace element data indicate that the dolomitized fluid is originated from sea water. Some beds contain gypsum pseudomorphs and mud cracks, indicating a shallow and evaporative environment with local high salinity during deposition. Dolomitization likely took place early, in part as a result of sea water salinity concentration. Trace fossils thalassinoides horizontalis, thalassinoides callianassa and planolites developed in the Longwangmiao Formation, and the sharp edges of mottled dolomite are similar to these trace fossils. The beds are intensely bioturbated. In the burrow network, the sediments and burrow fill were coarse and loose with little clay, and it is interpreted here as being easier to be dolomitized than the surrounding *** dolomitization is thus interpreted to have occurred in the burrow system, and the degree of dolomitization was related to the degree of bioturbation, which is controlled by the trace-making creatures.

关键词： Mottled dolomite Dolomitization Longwangmiao Formation Early Cambrian Northern Sichuan basin

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Cyclodextrin nanofilms with hydrophobic and hydrophilic channels for solvent permeation and molecular sieving

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Nano Research 2024年第7期17卷 6638-6644页

作者： Kai Zhang Yu Dai Yongli Shi Zhaoxin Zhang Linji Li Xiaojin Zhang Fan Xia Faculty of Materials Science and Chemistry China University of GeosciencesWuhan 430074China Henan Academy of geology Zhengzhou 450052China

Nanofilms that can fast permeate solvents and accurately sieve molecules are of significant importance for separation.A promising strategy is to align the inner cavities of macrocycles into the channels within nanofilms,and control the channel size by selecting the ***,the channels outside the macrocycles are ***,we prepare nanofilms with hydrophobic channels(cyclodextrin inner cavity)and hydrophilic channels(cyclodextrin outer space)through interfacial polymerization of azobenzene-4,4’-dicarbonyl dichloride and amino-functionalizedβ-*** utilizing the significant geometric changes caused by the photoisomerization of azobenzene,nanofilms with adjustable hydrophilic channel sizes were *** nanofilms have high permeability to polar and non-polar solvents,and can distinguish molecules with almost the same molecular weight but different *** work expands the development of next-generation nanofilms generated through interfacial polymerization by incorporating rational molecular design.

关键词： nanofilm β-cyclodextrin azobenzene interfacial polymerization solvent permeation molecular sieving

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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 *** microfacies are interpreted,namely planktonic foraminifera wackestone,planktonic foraminifera mudstone and sandy mudstone indicating low energy depositional environment i.e.,outer *** biostratigraphic studies show plentiful planktonic foraminifera species of Globotruncana,Heterohelix and ***,no association of benthic or siliceous organisms was *** the basis of available species assemblage,a single local planktonic foraminifera biozone i.e.,Globotruncana-Heterohelix-Globotruncanita Assemblage Biozone is *** biozone information is combined with published literature and Lower Santonian to Middle Maastrichtian age has been assigned to the Kawagarh *** trend of species occurrences evinces that species number decreases over time with pulsated rise in the Kawagarh *** 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

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Revisiting the theoretical prediction of the explosive performance found by the Trauzl test

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Defence Technology（防务技术） 2024年第6期36卷 163-174页

作者： Ivana Dobrilovic Mario Dobrilovic Muhamed Suceska Faculty of Mining Geology and Petroleum EngineeringDepartment of Mining Engineering and GeotechnicsUniversity of ZagrebPierottijeva 6Zagreb10000Croatia

The Trauzl lead block test allows the determination of the approximate performance of explosives in blasting applications by measuring the volume increase(expansion)that is produced by the detonation of an explosive charge in the cavity of a lead *** this paper,we reconsider the possibility of interpreting the Trauzl test results in terms of detonation parameters or *** detonation parameters used in the analysis are calculated using the thermochemical code EXPLO5,while the hydrocode AUTODYN is used to simulate the effect of explosive charge density and reaction rate on the results of the Trauzl *** increase in the volume of the lead block cavity was found to correlate best with the product of the detonation heat and the root of the volume of detonation *** simulation showed that the density of explosive charge and the rate of explosive decomposition affect the dynamics of the interaction of the detonation product and the lead block,and consequently the lead block cavity volume increase.

关键词： Trauzl lead block test Performance of explosives EXPLO5 AUTODYN Detonation heat

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Geochronological and geochemical constraints on the petrogenesis and geodynamic process of Hemler,Vlinder,and Il'ichev seamount lavas in NW Pacific

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Science China Earth Sciences 2024年第6期67卷 1856-1871页

作者： Xun WEI Yan ZHANG Xuefa SHI Hui ZHANG Key Laboratory of Marine geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine geology Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Deep Sea Mineral Resources Development(Preparatory) Qingdao 266061China

Oceanic intraplate volcanoes with linear age progressions are usually accepted to be derived from melting of an upwelling mantle *** seamount groups in NW Pacific,however,show complex age-distance relationships that are difficult to explain using the classic“mantle plume hypothesis”,and thus their origins are *** this study,we present ^(40)Ar-^(39)Ar age,geochemical,and Sr-Nd-Pb-Hf isotopic data of lavas from Hemler,Vlinder,and Il’ichev seamounts in NW Pacific,to elucidate their petrogenesis and geodynamic *** lavas from Hemler,Vlinder,and Il’ichev seamounts are classified as alkali basalt,basanite/nephelinite,and *** with Mg O>8 wt.%exhibit high contents of CaO,FeO^(T),and TiO_(2),similar to the composition of melts formed from reaction between carbonated eclogite-derived melts and fertile *** lavas have elevated Zr/Hf ratios(40.6-45.2)and negative Zr and Hf anomalies,indicating the presence of a carbonate component in the mantle *** are enriched in incompatible trace elements and have enriched mantle 1(EM1)-like SrNd-Pb-Hf isotopic *** isotopic compositions of Vlinder,Il’ichev basanite,and Hemler lavas in this study are similar to the Rarotonga *** occurring at the same seamount,the Il’ichev alkali basalts display more depleted SrNd-Hf isotopic compositions compared to Il’ichev *** to plate tectonic reconstruction results,the ages of Hemler(100.1 Ma),Vlinder pre-(100.2 Ma)and post-shield(87.5 Ma),and Il’ichev(56.4 Ma)lavas clearly deviate from the Macdonald,Arago,Rarotonga,and Samoa hotspot tracks,indicating that they cannot directly originate from mantle *** propose that in the mid-Cretaceous,when the Pacific plate passed over Rarotonga hotspot,melting of Rarotonga plume formed the Vlinder(main-shield stage),Pako,and Ioah *** Rarotonga(and possibly Samoa)plume materials would have been dispersed into the surrounding asthenosphere by mantle conve

关键词： Mantle plume Magellan seamount trail Carbonated mantle component Hotspot Lithosphere extension

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Using neural network modeling to improve the detection accuracy of land subsidence due to groundwater withdrawal

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Journal of Mountain Science 2024年第7期21卷 2320-2333页

作者： Ali M.RAJABI Ali EDALAT Yasaman ABOLGHASEMI Mahdi KHODAPARAST Department of Engineering geology University of TehranTehran ***Iran Department of Civil Engineering University of QomQom ***Iran

Despite the high efficiency of remote sensing methods for rapid and large-scale detection of subsidence phenomena,this technique has limitations such as atmospheric impact and temporal and spatial decorrelation that affect the accuracy of the *** paper proposes a method based on an artificial neural network to improve the results of monitoring land subsidence due to groundwater overexploitation by radar interferometry in the Aliabad plain(Central Iran).In this regard,vertical ground deformations were monitored over 18 months using the Sentinel-1A SAR *** model the land subsidence by a multilayer perceptron(MLP)artificial neural network,four parameters,including groundwater level,alluvial thickness,elastic modulus,and transmissivity have been *** model's generalizability was assessed using data derived for 144 *** to the results,the neural network estimates the land subsidence at each ground point with an accuracy of 6.8 mm.A comparison between the predicted and actual values indicated a significant *** MLP model can be used to improve the results of subsidence detection in the study area or other areas with similar characteristics.

关键词： DInSAR Land subsidence Groundwater withdrawal Aliabad plain Artificial neural network

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Structural,^(40)Ar/^(39)Ar Geochronological and Rheological Feature Analysis of the Guoxuepu Shear Zone:Indications for the Jitang Metamorphic Complex in the Northern Lancangjiang Zone

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Acta Geologica Sinica(English Edition) 2024年第1期98卷 32-49页

作者： FENG Yipeng WANG Genhou WANG Shulai LI Dian WANG Huan LU Yang LIU Han ZHANG Peilie Beijing Institute of geology for Mineral Resources Co. Ltd.Beijing 100012China School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China College of Earth Sciences Chengdu University of TechnologyChengdu 610059China Rock Analysis Laboratory Regional Geology Survey Institute of Hebei ProvinceLangfangHebei 065099China Chengdu Center China Geology SurveyChengdu 610081China

The Jitang metamorphic complex is key to studying the tectonic evolution of the Northern Lancangjiang *** structural-lithological mapping,structural analysis and laboratory testing,the composition of the Jitang metamorphic complex was *** macro-and microstructural analyses of the ductile detachment shear zone(Guoxuepu ductile shear zone,2–4 km wide)between the metamorphic complex and the overlying sedimentary cap show that the shear sense of the ductile shear zones is *** presence of various deformation features and quartz C-axis electron backscatter diffraction(EBSD)fabric analysis suggests multiple deformation events occurring at different *** average stress is 25.68 MPa,with the strain rates(έ)ranging from 9.77×10^(−14)s^(−1)to 6.52×10^(−16)s^(−1).The finite strain of the Guoxuepu ductile shear zone indicates an elongated strain *** average kinematic vorticity of the Guoxuepu ductile shear zone is 0.88,implying that the shear zone is dominated by simple *** muscovite selected from the protomylonite samples in the Guoxuepu ductile shear zone yields a 40Ar-39Ar age of 60.09±0.38 *** is suggested that,coeval with the initial Indo–Eurasian collision,the development of strike-slip faults led to a weak and unstable crust,upwelling of lower crust magma,then induced the detachment of the Jitang metamorphic complex in the Eocene.

关键词： ^(40)Ar/^(39)Ar dating strain pattern vorticity EBSD Guoxuepu shear zone Jitang metamorphic complex

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Molybdenum isotope composition of the upper mantle and its origin:insight from mid-ocean ridge basalt

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Journal of Oceanology and Limnology 2024年第3期42卷 705-708页

作者： Shuo CHEN Key Laboratory of Marine geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China

The molybdenum(Mo)isotope system is pivotal in reconstructing marine redox changes throughout Earth’s history and has emerged as a promising tracer for igneous and metamorphic *** its composition and variation across major geochemical reservoirs is essential for its application in investigating high-temperature ***,there is debate regarding theδ^(98/95)Mo value of the Earth’s mantle,with estimates ranging from sub-chondritic to super-chondritic *** analyses of global mid-ocean ridge basalt(MORB)glasses revealed significantδ^(98/95)Mo variations attributed to mantle heterogeneity,proposing a two-component mixing model to explain the observed *** studies confirmed the sub-chondriticδ^(98/95)Mo of the depleted upper mantle,suggesting remixing of subduction-modified oceanic crust as a plausible *** findings underscore the role of Mo isotopes as effective tracers for understanding dynamic processes associated with mantle-crustal recycling.

关键词： molybdenum(Mo)isotope mantle crustal recycling mid-ocean ridge basalt(MORB)

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