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Spatial Patterns and Controlling Factors of Soil Organic Carbon and Total Nitrogen in the Three River Headwaters Region,China

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Chinese Geographical Science 2025年第1期35卷 131-148页

作者： CUI Qiao LI Zongxing FENG Qi ZHANG Baijuan ZHAO Yue Observation and Research Station of Eco-hydrology and National Park by Stable {1. Tracing in Qilian Mountains/Key laboratory of Ecological Safety and Sustainable Development in Arid Lands Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China

The alpine ecosystem has great potential for carbon *** organic carbon(SOC)and total nitrogen(TN)are highly sensitive to climate change,and their dynamics are crucial to revealing the effect of climate change on the structure,function,and services of the ***,the spatial distribution and controlling factors of SOC and TN across various soil layers and vegetation types within this unique ecosystem remain inadequately *** this study,256 soil samples in 89 sites were collected from the Three River Headwaters Region(TRHR)in China to investigate SOC and TN and to explore the primary factors affecting their distribution,including soil,vegetation,climate,and geography *** results show that SOC and TN contents in 0-20,20-40,40-60,and 60-80 cm soil layers are 24.40,1..03,1..04,1..40 g/kg and 2.46,1.90,1.51.1.1. g/kg,respectively;with higher concentrations observed in the southeastern region compared to the northwest of the ***-way analysis of variance reveals that SOC and TN levels are elevated in the alpine meadow and the alpine shrub relative to the alpine steppe in the 0-60 cm soil *** structural equation model explores that soil water content is the main controlling factor affecting the variation of SOC and ***,the geography,climate,and vegetation factors notably indirectly affect SOC and TN through soil ***,it can effectively improve soil water and nutrient conditions through vegetation restoration,soil improvement,and grazing management,and the change of SOC and TN can be fully understood by establishing monitoring networks to better protect soil carbon and nitrogen.

关键词： controlling factors different soil layers soil organic carbon(SOC) soil total nitrogen(TN) alpine ecosystem the Three River Headwaters Region(TRHR),China

Formation mechanism of deep natural hydrogen in the Sichuan Basin

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Science China Earth Sciences 2025年第2期68卷 581-597页

作者： Xiaomei WANG Kun HE Chunlong YANG Hao XIE Xiaobo WANG Yitong LYU Linfeng XIE Shuichang ZHANG Research Institute of Petroleum Exploration&Development PetroChinaBeijing 100083China Key laboratory of Petroleum Geochemistry China National Petroleum CorporationBeijing 100083China International Center for isotope Effects Research School of Earth Science and EngineeringNanjing UniversityNanjing 210023China

As a potential renewable and clean energy source,the distribution and exploration prospects of natural hydrogen have garnered widespread ***,the limitations in understanding the formation mechanisms and accumulation patterns of underground natural hydrogen have significantly constrained its efficient exploration and *** study reports H_(2)content and isotopes in natural gas from deep formations in sedimentary basins through geochemical analysis of 58 conventional gas samples from the Sinian to Triassic strata in the central Sichuan *** discovered that H_(2)content in deep natural gas in central Sichuan generally exceeds 0.1.,with a maximum of 1.6%,and hydrogen isotopes(δ^(2)H_(H_(2)))range from-850‰to-586‰.Analysis of the geological conditions,hydrogen generation mechanisms,and isotope fractionation characteristics in the study area confirms that microbial fermentation or in-situ organic matter cracking are not effective pathways for deep H_(2)*** with helium content and isotope analysis of the natural gas,it is inferred that the volcanic basement in the central Sichuan area is the potential source rock for natural H_(2)in the Sinian to Triassic ***,H_(2)originates from the radiolysis of water and hydrothermal reactions of Fe(Ⅱ)in the basement ***,a diffusion fractionation model reveals significant isotope fractionation during the migration and accumulation of deep H_(2)into sedimentary reservoirs,which lead to anomalously light δ^(2)H_(H_(2))in deep natural gas in central *** indicates that the underground natural hydrogen accumulation is in a long-term dynamic process,with simultaneous H_(2)accumulation and dissipation in the gas *** research not only elucidates the formation mechanism of deep H_(2)but also provides insights for the resource potential of natural hydrogen in sedimentary basins.

关键词： Natural H2 Sichuan Basin Hydrogen generation mechanism isotope fractionation

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Fresh insights into the onset of big mantle wedge beneath the North China Craton

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Acta Geochimica 2025年第1期44卷 145-162页

作者： Yingpeng Wang Xuance Wang Wen Zhang Xiaowei Yu Ligong Wang Jinhui Wang Peigang Zhu Yongbin Wang Shandong Institute of Geological Survey Ji’nan 250014People’s Republic of China Yunnan Key laboratory of Earth System Science Yunnan UniversityEast Outer Ring RoadChenggong DistrictKunming 650500Yunnan ProvincePeople’s Republic of China Key laboratory of Critical Minerals Metallogeny in Universities of Yunnan Province Yunnan UniversityKunming 650500People’s Republic of China Radiogenic isotope Facility School of Earth and Environment SciencesUniversity of QueenslandBrisbaneQLD 4072Australia

The onset of the big mantle wedge(BMW)structure beneath the North China Craton remains *** on the genesis of Late Mesozoic granites associated with gold deposits in the Jiaodong Peninsula above the BMW could provide fresh insights into this *** monzogranite from the Zhaoxian-Shaling gold district was intruded during 1.4-1.8 *** I-type granite has high-K calc-alkaline and metaluminous *** monzogranite formed at medium temperatures(71.-770℃)and was generated in a thickened lower crust at depths within the stability field of *** monzogranite’s high zircon Ce^(4+)/Ce^(3+)and Eu_(N)/Eu_(N)^(*)values and low FeOT/MgO ratios,suggest that it formed in a high oxygen *** variableε_(Hf)(t)values with T_(DM2)of 1.93-2.87 Ga imply that it originated from the melting of ancient crust basement,with contributions from mantle-derived *** granite’s enrichment in LREEs and LILEs,and depletion in HREEs and HFSEs,along with its trace element tectonic discrimination diagrams and medium Sr/Y,indicate an adakite affinity in an active continental margin *** transition from S-type granites to I-type granites and finally to A-type granites observed in the eastern part of North China Craton suggests a shift in the tectonic environment from compression to *** change is also reflected in the transition from flat subduction to steep ***,the monzogranite was formed in a tectonic transition setting triggered by a change in the subduction angle of the PaleoPacific Ocean slab during the Late *** event may have marked the initiation of the BMW above the North China Craton.

关键词： Zircon U-Pb age Hf isotopic composition Jiaodong Peninsula North China Craton

Interaction of Ca^(2+)and Fe^(3+)in co-precipitation process induced by Virgibacillus dokdonensis and its application

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Journal of Environmental Sciences 2025年第1期147卷 131-152页

作者： Huaxiao Yan Yuping Liu Haojuan Zhang Shengping Jin Zuozhen Han Jusun Woo Maurice E.Tucker Long Meng Xiangqun Chi Chao Han Yanyang Zhao Yueming Zhao Hui Zhao College of Chemical and Biological Engineering College of Earth Science and EngineeringShandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary MineralsShandong University of Science and TechnologyQingdao 266590China laboratory for Marine Mineral Resources Center for Isotope Geochemistry and GeochronologyQingdao National Laboratory for Marine Science and TechnologyQingdao 266237China School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826Korea School of Earth Sciences University of BristolBristol BS81RJUK Cabot Institute University of BristolCantock’s CloseBristol BS81UJUK Qingdao West Coast New District First High School Qingdao 266555China

Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional *** reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose amajor hazard in ***,the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme *** this study,free and immobilized halophiles Virgibacillus dokdonensis were used to precipitate these ions and the effects were compared,at the same time,biomineralizationmechanisms and mineral characteristicswere further *** results showthat bacterial concentration and carbonic anhydrase activitywere higher when additionally adding ferric ion based on calcium ion;the content of protein,polysaccharides,deoxyribonucleic acid and humic substances in the extracellular polymers also increased compared to *** ions were biomineralized into calcite and vaterite with mul-tiple *** to iron doping,the crystallinity and thermal stability of calcium carbonate decreased,the content of O-C=O,N-C=OandC-O-PO_(3) increased,the stable carbon isotope values became much more negative,andβ-sheet in minerals *** calcium concentrations facilitated ferric ion precipitation,while ferric ions hindered calcium *** immobilized bacteria performed better in ferric ion removal,with a precipitation ratio exceeding 90%.Free bacteria performed better in calcium removal,and the precipitation ratio reached a maximum of 56%.This research maybe provides some reference for the co-removal of calcium and ferric ions from the oilfield wastewater.

关键词： Calcium carbonate Calcium ion Ferric ion Biomineralization Co-removal Immobilization

Study of groundwater mixing using CFC data

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Science China(Technological Sciences) 2001年第S1期44卷 21-28页

作者：韩良丰庞忠和 1. isotope hydrology laboratory International Atomic Energy Agency P.O. Box 100 A-1400 Vienna Austria 2. isotope {1. Section International Atomic Energy Agency P.O. Box 100 A-1400 Vienna Austria

CFCs (Chlorofluorocarbons) are sensitive tools in the study of groundwater mixing. Based on results of CFC concentrations, the extent of mixing can be identified by three methods: 1. discrepancy between apparent ages determined by individual CFC compounds; 2. inconsistency between CFC concentration ratios and their respective apparent ages; and 3. correlation between the concentrations of two CFC compounds for a group of samples. The principle of determination of mixing ratios and apparent CFC water age in the case of a two component mixing of CFC-containing water with CFC-free water is described.

关键词： CFC groundwater mixing two-component

isotope hydrogeochemical models for assessing the hydrological processes in a part of the largest continental flood basalts province of India

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Geoscience Frontiers 2022年第2期13卷 200-213页

作者： Md.Arzoo Ansari Jacob Noble Archana Deodhar U.Saravana Kumar isotope and Radiation Application Division Bhabha Atomic Research CentreTrombayMumbai 400085India isotope {1. Section Division of Physical and Chemical SciencesInternational Atomic Energy Agency(IAEA)ViennaAustria

Continental Flood Basalts(CFB)occupy one fourth of the world’s land ***,it is important to discern the hydrological processes in this complex hydrogeological setup for the sustainable water resources development.A model assisted isotope,geochemical,geospatial and geophysical study was conducted to understand the monsoonal characteristics,recharge processes,renewability and geochemical evolution in one of the largest continental flood basalt provinces of *** modelling and stable isotopes were used to assess the monsoonal *** distillation model were used to understand the climatic conditions at the time of groundwater *** parameter models(LPM)were employed to quantify the mean transit time(MTT)of *** and geochemical models were adopted to understand the geochemical evolution along the groundwater flow path.A geophysical model was used to understand the geometry of the *** back trajectory analysis confirms the isotopic finding that precipitation in this region is caused by orographic uplifting of air masses originating from the Arabian *** isotopic data of groundwater showed its meteoric origin and two recharge processes were discerned;(i)quick and direct recharge by precipitation through fractured and weathered basalt,(ii)low infiltration through the clayey black cotton soil and subjected to evaporation prior to the *** data showed that the groundwater is a renewable source and have shorter transit times(from present day to<30 years).The hydrogeochemical study indicated multiple sources/processes such as:the minerals dissolution,silicate weathering,ion exchange,anthropogenic influences *** the chemistry of the *** on the geo-electrical resistivity survey,the potential zones(weathered and fractured)were delineated for the groundwater ***,the study highlights the usefulness of model assisted isotopic hydrogeochemical techniques for underst

关键词： Stable isotopes Groundwater recharge Hydrological processes Modelling Deccan Traps

New Potential Barite Reference Materials for LA-MC-ICP-MS Sulfur isotope Analysis with Application to Hydrothermal Barite in the Huayangchuan Deposit,Western China

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Journal of Earth Science 2025年第1期36卷 1-10页

作者： Jiali Fu Xinqian He Zhaochu Hu Shuo Yin Jian Ma Kaiyun Chen Wen Zhang National Key laboratory of Uranium Resource Exploration-Mining andNuclear Remote Sensing East China UniversityofTechnologyNanchang 330013China State Key laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth Sciences East China University of TechnologyNanchang 330013China State Key laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430078China State Key laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an 710069China

Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates ***,in-situ S isotope determination of barite is challenging without natural matrix-matched reference *** this study,we present two natural barite reference materials(1.YS and 294-YS)for in-situ sulfur isotopic *** LA-MC-ICP-MS laboratories were utilized to test theδ34S micron-scale homogeneity of 1.YS and 294-YS barites that have 2s repeatabilities of better than±0.45‰and±0.41.,***,the in-situ analysis results are consistent with the results of the bulk analysis by GS-IRMS within *** grand meanδ~(34)S values of 1.YS(1..37‰±0.42‰,2s)and 294-YS(1..38‰±0.44‰,2s)are the final recommended values obtained from four independent *** the results confirm the suitability of 1.YS and 294-YS barite used as calibration materials with respect to in-situ S isotopic ***,the new developed barite reference materials were used as matrix-matched standard to calibrate the barite samples from the Huayangchuan carbonatite-hosted U-polymetallic deposit(Qinling orogenic belt,western China)to obtainδ34S *** the temperaturedependentδ34S fractionation of barite-pyrite pair,we calculate the formation temperature of barite(i.e.,506 to 537°C)and theδ34S value of mineralizing fluid(i.e.,-7.1.‰to-7.59‰)in the Huayangchuan *** results indicate an involvement of sedimentary sulfur,presumably acting as a potential uranium source(e.g.,upper crustal materials)for the giant Huayangchuan deposit.

关键词： LA-MC-ICP-MS S isotope reference material barite geothermometry

Oxygen isotope stratigraphy and events in the northern South China Sea during the last 6 million years

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Science China Earth Sciences 2001年第10期44卷 592-960页

作者：翦知湣成鑫荣赵泉鸿王吉良汪品先 1. Key laboratory of Marine Geology Ministry of Education Tongji University 200092 Shanghai China

Based on the stable isotopic analysis of more than 1.00 samples of planktonic and benthic foraminifers from ODP Site 1.48 in the northern South China Sea (SCS), the oxygen isotope stratigraphy has been applied to the last 3 million years for the first time in the SCS. Furthermore, the paleoceanographic changes in the northern SCS during the last 6 million years have been unraveled. The benthic foraminiferal δ1.0 record shows that before ~3.1.Ma the SCS was much more influenced by the warm intermediate water of the Pacific. The remarkable decrease in the deepwater temperature of the SCS during the period of 3.1.2.5 Ma demonstrates the formation of the Northern Hemisphere ice-sheet. However, the several sea surface temperature (SST) reductions during the early and middle Pliocene, reflected by the planktonic foraminiferal δ1.O, might be related to the ice-sheet growth in the Antarctic region. Only those stepwise and irreversible SST reductions during the period of ~2.2-0.9 Ma could be related to the formation and growth of the Northern Hemisphere ice-sheet.

关键词： oxygen isotope stratigraphy Pliocene-Pleistocene Northern Hemisphere glaciation middle Pleistocene revolution South China Sea.

Abiotic aerobic oxidation pathways of stibnite revealed by oxygen and sulfur isotope systematics of sulfate

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Journal of Environmental Sciences 2025年第1期147卷 83-92页

作者： Ningjie He Shu Li Xiaoqian Li Yaning Tang Jiaxue Yang Jianwei Zhou School of Environment Studies China University of GeosciencesWuhan 430074China Key laboratory of Mine Ecological Effects and Systematic Restoration Ministry of Natural ResourcesBeijing 100081China State Environmental Protection Key laboratory of Source Apportionment and Control of Aquatic Pollution Ministry of Ecology and EnvironmentWuhan 430074China Institute of Geological Survey China University of GeosciencesWuhan 430074China

The environmental threat posed by stibnite is an important geoenvironmental issue of current *** better understand stibnite oxidation pathways,aerobic abiotic batch experiments were conducted in aqueous solution with varyingδ^(1.)O_(H_(2)O) value at initial neutral pH for different lengths of time(1.-300 days).The sulfate oxygen and sulfur isotope compositions as well as concentrations of sulfur and antimony species were *** sulfur isotope fractionation factor(△^(34)S_(SO4-stibnite))values decreased from 0.8‰to-2.1.during the first 90 days,and increased to 2.6‰at the 1.0 days,indicating the dominated intermediate sulfur species such as S_(2)O_(3)^(2-),S0,and H_(2)S(g)involved in Sb2S3 oxidation *** incorporation of O into sulfate derived from O_(2)(~1.0%)indicated that the dissociated O_(2)was only directly adsorbed on the stibnite-S sites in the initial stage(0-90 days).The proportion of O incorporation into sulfate from water(27%-52%)increased in the late stage(90-300 days),which suggested the oxidation mechanism changed to hydroxyl attack on stibnite-S sites promoted by nearby adsorbed O_(2)on stibnite-Sb *** exchange of oxygen between sulfite and water may also contributed to the increase of water derived O into SO42-.The new insight of stibnite oxidation pathway contributes to the understanding of sulfide oxidation mechanism and helps to interpret field data.

关键词： Sulfide oxidation δ^(34)S_(SO4) δ^(1.)O_(SO4) Oxygen source of sulfate