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Characteristics of Paleontological Communities in Surface Sediments of the Southern South China Sea and Their Paleoclimatic and Paleoenvironmental Significance

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Journal of Earth Science 2024年第1期35卷 144-154页

作者： Jing Zhao Li Zhang Xiaoyan Wang Jinglian Ge Min Xu Wei Chen Mao Luo Qianyong Liang Qiuhua Yu Shuaibing Luo Wenkun Qie key laboratory of marine Mineral Resoures Ministry of Natural ResourcesGuangzhou Marine Geological SurveyChina Geological SurveyGuangzhou 511458China National Engineering Research Center for Gas Hydrate Exploration and Development Guangzhou 511458China State key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China

Understanding the spatial and temporal distribution of different paleontological communities in the southern South China Sea(SCS)is fundamental to explore its paleoclimatic and paleoenvironmental *** this study,foraminifera,pollen and diatoms from 100 surface sediment samples covering 40000 km^(2) of sea floor in the southern SCS were comprehensively investigated in terms of their assemblage and *** results showed the existence of abundant foraminifera and pollen in most of the samples,although diatom communities were relatively *** were dominated by ***,***,***,while diatoms were characterized by ***,*** and ***,indicating a typical tropical marine *** pollen assemblages showed a better reflection of montane rainforest,tropical rainforest and *** spatial differences among foraminifera assemblages may indicate the effect of water depth and a warmer environment in the southeast part of the study area,while the spatial patterns of diatom and pollen assemblages imply the influence of coastal *** study also noted that the compositions of paleontological communities in the SCS can vary significantly in a short distance,and synthesized studies on multiple biological groups are needed to reconstruct the Quaternary climate and the oceanographic environment.

关键词： southern South China Sea sediments foraminifera diatom pollen

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Low Resource Chinese Geological Text Named Entity Recognition Based on Prompt Learning

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Journal of Earth Science 2024年第3期35卷 1035-1043页

作者： Hang He Chao Ma Shan Ye Wenqiang Tang Yuxuan Zhou Zhen Yu Jiaxin Yi Li Hou Mingcai Hou State key laboratory of Oil and Gas Reservoir geology and Exploitation Institute of Sedimentary GeologyCollege of Computer Science and Cyber SecurityChengdu University of TechnologyChengdu 610059China key laboratory of Deep-Time Geography and environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of TechnologyChengdu 610059China School of Information Engineering China University of Geosciences(Beijing)Beijing 100083China

Geological reports are a significant accomplishment for geologists involved in geological investigations and scientific research as they contain rich data and textual *** the rapid development of science and technology,a large number of textual reports have accumulated in the field of ***,many non-hot topics and non-English speaking regions are neglected in mainstream geoscience databases for geological information mining,making it more challenging for some researchers to extract necessary information from these *** Language Processing(NLP)has obvious advantages in processing large amounts of textual *** objective of this paper is to identify geological named entities from Chinese geological texts using NLP *** propose the RoBERTa-Prompt-Tuning-NER method,which leverages the concept of Prompt Learning and requires only a small amount of annotated data to train superior models for recognizing geological named entities in low-resource dataset *** RoBERTa layer captures context-based information and longer-distance dependencies through dynamic word ***,we conducted experiments on the constructed Geological Named Entity Recognition(GNER)*** experimental results show that the proposed model achieves the highest F1 score of 80.64%among the four baseline algorithms,demonstrating the reliability and robustness of using the model for Named Entity Recognition of geological texts.

关键词： Prompt Learning Named Entity Recognition(NER) low resource geological text text information mining big data geology.

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Uncovering the largest negative carbon isotope excursion in Earth history

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Science China Earth Sciences 2024年第3期67卷 885-889页

作者： Chao LI Haiyang WANG State key laboratory of Oil and Gas Reservoir geology and Exploitation Chengdu University of TechnologyChengdu 610059China Institute of Sedimentary geology Chengdu University of TechnologyChengdu 610059China key laboratory of Deep-time Geography and environment Reconstruction and Applications of Ministry of Natural Resources Chengdu University of TechnologyChengdu 610059China International Center for Sedimentary Geochemistry and Biogeochemistry Research Chengdu University of TechnologyChengdu 610059China State key laboratory of Biogeology and environmental geology China University of GeosciencesWuhan 430074China

The carbon cycle plays a pivotal role in regulating Earth’s surface environment through atmospheric-oceanic acid-base and redox processes, functioning as the engine driving the evolution of our planet’s surface. A deep understanding of the carbon cycle’s evolution is thus essential for our understanding of the evolution of our planet’s habitability.

关键词： carbon planet evolution

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Glacial-interglacial cycles recorded in clay minerals from the eastern Tibetan Plateau over the last 800 ka and their indications

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Science China Earth Sciences 2024年第7期67卷 2162-2177页

作者： Xiaoyan ZHANG Chunxia ZHANG Yan ZHAO Bin HU Zhengtang GUO key laboratory of Cenozoic geology and environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China key laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Clay mineral proxies have been widely used to reconstruct changes in provenance and the ***,high-altitude clay mineral indications and long-term and orbital variations have not been fully ***,we present an800-ka clay-mineral record from a lacustrine sediment core(ZB13-C2)from the Zoige Basin on the eastern Tibetan Plateau(TP).X-ray diffraction and scanning electron microscopy were used to identify the clay mineral assemblages and their micromorphological characteristics of core *** results revealed that the clay minerals in core ZB13-C2 are mainly illite,with small amounts of chlorite,kaolinite,and smectite(including irregular mixed-layers of illite-smectite(I/S)and chloritesmectite(C/S)).The clay mineral assemblages and proxies exhibit three stages of change,which are mainly controlled by the Zoige watershed range under different climate *** watershed was limited to the southeastern region with altitudes ranging from~3500 to~4200 meters above sea level(m a.s.l.),and glacial-interglacial hydraulic erosion controlled the input of bedrock debris during 800-621 ka *** expanded to higher altitudes(~4200 to~4700 m a.s.l.)due to stronger seasonal freezethaw weathering without significant glacial-interglacial variations under a cooling and drying climate during 621-100 ka ***,it expanded to its highest altitudes of~4700 to~5200 m *** of the watershed after 100 ka BP,and hydraulic erosion increased obviously under a warm climate of the interstadial MIS 3 on the *** watershed underwent two major expansions under different climatic conditions at~621 ka and 100 ka BP,with the wet/dry alternation became strong at~621 ka *** results reveal that long-term temperature changes and the wet/dry alternation at high altitudes controlled the watershed range and degree of the physical erosion,and that the indications of clay minerals should be carefully clarified before they are used as climate indicators,especi

关键词： Quaternary Zoige Basin Lacustrine sediments Paleoenvironment Weathering

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Synthesis of carbon quantum dots decorating Bi_(2)MoO_(6) microspherical heterostructure and its efficient photocatalytic degradation of antibiotic norfloxacin

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Chinese Chemical Letters 2024年第8期35卷 373-378页

作者： Meijuan Chen Liyun Zhao Xianjin Shi Wei Wang Yu Huang Lijuan Fu Lijun Ma School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China key Lab of Aerosol Chemistry and Physics State Key Laboratory of Loess and Quaternary Geology(SKLLQG)Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China

In this study,three-dimensional microspherical CQDs/Bi_(2)MoO_(6)heterostructures were synthesized using a simple alcohol-thermal *** was found that the CQDs/Bi_(2)MoO_(6)had a large specific surface area of 56.0 m^(2)/g,and the introduction of CQDs extended the light absorption spectrum from 480 nm to 496 *** utilizing the synthesized CQDs/Bi_(2)MoO_(6)composite for photocatalytic degradation of antibiotic nor-floxacin in a water environment,complete decay of norfloxacin and effective removal of total organic car-bon(TOC)were achieved within 30 *** the optimization of material synthesis and experimen-tal conditions,the optimal CQDs loading amount was determined as 200μL,the optimal CQDs/Bi_(2)MoO_(6)dosage was 0.8 g/***,the CQDs/Bi_(2)MoO_(6)worked well under a wide pH range of *** co-existence of HCO_(3)−enhanced the norfloxacin decay,while the presence of Cl^(−),NO_(3)^(−),and SO_(4)^(2−)slightly retarded *** synthesized CQDs/Bi_(2)MoO_(6)had the great potential in removing and mineralizing nor-floxacin in real aquatic environments.

关键词： Bi_(2)MoO_(6) CQDs Heterojunction Norfloxacin Photocatalysis

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Revisiting the Mg isotopic systematics of siliciclastic components of sediments and sedimentary rocks:A new geochemical proxy of continental weathering in Earth's history

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Science China Earth Sciences 2024年第2期67卷 620-633页

作者： Tianzheng HUANG Bing SHEN Kangjun HUANG Meng NING Chao LI Jinzhuang XUE Yuanlin SUN Baoqi HUANG key laboratory of Orogenic Belt and Crustal Evolution MOESchool of Earth and Space SciencesPeking UniversityBeijing100871China State key laboratory of Continental Dynamics Shaanxi Key Laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an710069China Institute of Sedimentary geology Chengdu University of TechnologyChengdu610059China key laboratory of Rhenium-Osmium Isotopic Geochemistry Chinese Academy of Geological SciencesBeijing100037China

The Mg isotopic compositions of siliciclastic components(δ^(26)Mg_(sili))of sediments and sedimentary rocks have been commonly used to constrain the intensity of continental weathering,based on observations of,(1)an upward enrichment of26Mg in modern weathering profiles,(2)preferential uptake of26Mg in soil clays,and(3)general positive correlations between weathering intensities andδ^(26)Mg_(sili)***,not all weathering profiles display an upward increase ofδ^(26)Mg_(sili),and not all soil clays enrich in26Mg,complicating the interpretations ofδ^(26)Mg_(sili)data of sediments and sedimentary *** further explore the controls ofδ^(26)Mg_(sili)of sediments and sedimentary rocks,here we measuredδ^(26)Mg_(sili),mineralogical compositions and major element compositions of deep sea sediments from South China Sea(SCS)and carbonate rock samples from two late Paleozoic sections in South *** samples show decreasing trends of both normalized Mg concentration(Mgnorm)andδ^(26)Mg_(sili)values with the increase of weathering intensity,while SCS sediments samples do not show any correlation between Mgnormorδ^(26)Mg_(sili)values and weathering intensity.A three-stages weathering model is developed to explain the observed Mgnorm andδ^(26)Mg_(sili)*** the new model,weathering can be divided into three stages,(1)the preliminary weathering stage characterized by dissolution of primary minerals and formation of secondary clay minerals in saprolite,(2)the transitional stage with massive vermiculite and chlorite formation on the bottom of soil,and(3)the advanced stage showing dissolution of vermiculite and chlorite in the top of *** new model explains anδ^(26)Mg_(sili)increase and Mgnormdecrease with an increase weathering intensity in preliminary weathering stage and decrease of Mgnormandδ^(26)Mg_(sili)with increase weathering intensity in advanced weathering *** revised weathering model warrants the application of Mg isotope in the study of contin

关键词： Clay mineral Chemical weathering CIA Soil Weathering model

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Method to measure tree-ring width,density,elemental composition,and stable carbon and oxygen isotopes using one sample

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Journal of Forestry Research 2024年第3期35卷 167-174页

作者： Chenxi Xu Yaru Zhao Wenling An Qingyu Zhao Yucheng Liu Masaki Sano Takeshi Nakatsuka key laboratory of Cenozoic geology and environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029People's Republic of China CAS Center for Excellence in Life and Paleoenvironment Beijing 100044People's Republic of China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049People's Republic of China Graduate School of environment Studies Nagoya UniversityNagoya 4648601Japan

Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each ***,we developed a method by which each proxy can be measured in the same ***,the sample is polished for ring width *** obtaining the ring width data,the sample is cut to form a 1-mm-thick wood *** sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray ***,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,*** density and the element content are ***,cellulose is isolated from the 1-mm wood plate by removal of lignin,and *** producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)*** on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.

关键词： Tree-ring width Tree-ring density Tree-ring elemental composition Tree-ring stable carbon and oxygenisotopes

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Regulation effect of the grille spacing of a funnel-type grating water–sediment separation structure on the debris flow performance

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Journal of Mountain Science 2024年第7期21卷 2283-2304页

作者： LI Shuai GU Tianfeng WANG Jiading WANG Fei LI Pu State key laboratory of Continental Dynamics/Department of geology Northwest UniversityXi’an 710069China Chengdu Institute of Mountain Hazards and environment Ministry of Water Resources&Chinese Academy of SciencesChengdu 610299China

The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve the water–sediment separation ability of the *** new funnel-type grating water–sediment separation structure(FGWSS)combines vertical and horizontal structures and provides a satisfactory water–sediment separation ***,the regulation effect of the grille spacing of the structure on the debris flow performance has not been *** regulation effect of the structure grille spacing on the debris flow performance is studied through a flume test,and the optimal structure grille spacing is *** empirical equation of the relationship between the relative grille spacing of the structure and the sediment separation rate is ***,the influence of the water–sediment separation structure on the regulation effect of debris flows is examined from two aspects:external factors(properties of debris flows)and internal factors(structural factors).The experimental results show that the gradation characteristics of solid particles in debris flows constitute a key factor affecting the regulation effect of the structure on the debris flow *** optimum grille spacing of the FGWSS matches the particle size corresponding to the material distribution curves d85~d90 of the debris *** total separation rate of debris flow particles is related to the grille spacing of the structure and the content of coarse and fine particles in the debris flow.

关键词： Debris flow Water–sediment separation structure Grille spacing Performance regulation effect

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Physically modulated phytoplankton production and export at submesoscales in the oligotrophic South China Sea Basin

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Science China Earth Sciences 2024年第8期67卷 2681-2698页

作者： Zhonghua ZHAO Mengdi XU Bangqin HUANG Wenfang LU Hongshuai QI Feng CAI Yuwu JIANG State key laboratory of marine environmental Science Xiamen UniversityXiamen 361102China College of Ocean and Earth Sciences Xiamen UniversityXiamen 361102China Fujian Provincial key laboratory for Coastal Ecology and environmental Studies Xiamen UniversityXiamen 361102China National Observation and Research Station for the Taiwan Strait marine Ecosystem Xiamen UniversityXiamen 361102China School of marine Sciences Sun Yat-Sen UniversitySouthern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519000China laboratory of Ocean and Coast geology Third Institute of OceanographyMinistry of Natural ResourcesXiamen 361005China

Oceanic submesoscales can significantly influence phytoplankton production and export owing to their similar timescales of *** on two-year Biogeochemical Argo(BGC-Argo) observations,this study investigated the development of submesoscale instabilities,particularly symmetric and mixed-layer baroclinic instabilities,and their impacts on biological production and export in the oligotrophic South China Sea *** the northern basin,near-surface winter blooms consistently cooccurred with seasonally deepened mixed ***,significantly stronger and weaker winter blooms were observed over two consecutive winters within the BGC-Argo observation *** the first winter,symmetric-instability-induced upward nutrient entrainment played a crucial role in initiating the strong winter bloom in early December,when the mixed layer was approximately 20–30 m shallower than the *** bloom occurred approximately 20–30 days earlier than that anticipated owing to the contact between the seasonally deepened mixed layer and mesoscale-cyclone-induced uplifted *** symmetric instability also facilitated the export of fixed phytoplankton carbon from the surface to deeper ***,during the second winter,remarkably intense mixed-layer baroclinic instability associated with an intense mesoscale anticyclone led to more significant shoaling of the mixed layer compared to the nutricline,thus increasing the vertical distance between the two *** this condition,upward nutrient injection,phytoplankton bloom,and carbon export were *** contrast,the BGC-Argo float in the central basin revealed significantly inhibited seasonality of phytoplankton biomass and submesoscale instabilities compared to those in the northern basin,primarily owing to the significantly shallower winter mixed layer.

关键词： Submesoscale instability Phytoplankton Nutrient transport BGC-Argo South China Sea

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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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