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Marine Redox Conditions in the Early Cambrian Ocean: Insights from the Lower Cambrian Phosphorite Deposits, South China

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Journal of Earth Science 2016年第2期27卷 282-296页

作者： haifeng fan Hanjie Wen Xiangkun Zhu State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Institute of Geology Chinese Academy of Geological Sciences

It is generally considered that a significant change in oceanic redox conditions occurred during the Ediacaran-Cambrian transition. However, there are currently two major conflicting views on the degree of oxygenation of deep water（oxic vs. ferruginous） during this interval. To date, the oxygenation conditions of the Early Cambrian ocean have not been well constrained. The oxygenation magnitude and mechanism of the Early Cambrian ocean could be critical to the significant biological evolution of the ＂Cambrian Explosion＂. To constrain the Early Cambrian oceanic redox environment, we conducted an integrated study on iron and sulfur isotopes and redox-sensitive elements（Mo, U, and V） of Lower Cambrian phosphorite deposits from two shallow sections（Meishucun and Gezhongwu） and a deeper water section（Zunyi） from the Yangtze Platform, South China. The near zero δ^（56）Fe values from the two shallow sections studied here reflect oxic conditions in the lower phosphorite deposition. An obvious positive shift in δ^（56）Fe and redox-sensitive element content was observed in the middle parts of the two shallow water sections, which might reflect loss of light iron by dissimilatory iron reduction during early diagenesis under suboxic shallow water in the platform. However, the highly positive δ^（56）Fe values in the deep section could reflect a lower oxidation degree of dissolved Fe（II） under anoxic deep water. The data suggest redox-stratified oceanic conditions during the Early Cambrian, in which completely oxygenated shallow water（platform） coexisted with anoxic deep water（slope）. We propose that prolonged upwelling of dissolved organic carbon（DOC）-, Fe（II）- and phosphorus-rich anoxic deep water in a redox-stratified ocean could have increased exchange with the open ocean, resulting in major phosphorite deposition in oxic-suboxic conditions. The progressive oxygenation of the ocean may have facilitated the Early Cambrian biotic diversification.

关键词： Early Cambrian redox-stratified ocean southern China iron isotope phosphorite.

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Carbon combustion synthesis of lithium cobalt oxide as cathode material for lithium ion battery

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Particuology 2008年第2期6卷 81-84页

作者： Yongle Gan Li Zhang Yanxuan Wen fan Wang haifeng Su School of Chemistry and Chemical Engineering Guangxi University Nanning 530004 China

Lithium cobalt oxide （LiCoO2） was synthesized by carbon combustion synthesis （CCS） using carbon as fuel. X-ray diffraction （XRD） and scanning electron microscope （SEM） measurements showed that carbon combustion led to the formation of layered structure of LiCoO2 and the particle size could be controlled by carbon content. For the LiCoO2 sample prepared at 800℃ for 2 h, at molar ratio of C/Co = 0.5, the particle-size distribution fell in the narrow range of 3-5 μm. Electrochemical tests indicated this LiCoO2 sample delivered an initial discharge capacity of 148 mAh/g with capacity retention rate higher than 97% after 10 cycles.

关键词： Lithium ion battery Cathode material Lithium cobalt oxides Carbon combustion synthesis

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Precise and accurate Ga isotope ratio measurements of geological samples by multi-collector inductively coupled plasma mass spectrometry

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Acta Geochimica 2024年第6期43卷 1054-1064页

作者： Yuxu Zhang Pan Qiao Chuanwei Zhu haifeng fan Hanjie Wen State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of Sciences99 West Lincheng RoadGuiyang 550081Guizhou ProvinceChina School of Earth Sciences and Resources Chang’an University126 Yanta RoadXi’an 710054Shaanxi ProvinceChina College of Resources and Environment University of Chinese Academy of SciencesBeijing 101408China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Gallium isotope is a potential geochemical tool for understanding planetary processes,environmental pollution,and ore deposit *** reported Ga isotope compositions(δ^(71)Ga NIST994 values)of some international geological standards,such as BCR-2 and BHVO-2 basalts,exhibit inconsistencies between diff erent *** mass spectrometry analysis,we found thatδ^(71)Ga NIST994 values of geological standards with or without the correction of the interference of^(138)Ba^(2+)(mass/charge ratio=69)on 69 Ga show signifi cant isotope off sets,and thus effi cient separation of Ba and correcting the interference of^(138)Ba^(2+)are both crucial to obtain accurateδ^(71)Ga *** comparingδ^(71)Ga NIST994 values(relative to NIST SRM 994 Ga)of the same geostandards from diff erent laboratories,we suggest that the isotopic heterogeneity from NIST SRM 994 Ga is one of the key reasons for the inconsistencies inδ^(71)Ga NIST994 values of BCR-2 and *** facilitate inter-laboratory comparisons,we measured the Ga isotopic compositions of 11 geological reference materials(including Pb-Zn ore,bauxite,igneous rocks,and loess)and two Ga solution standards(NIST SRM 3119a and Alfa Aesar).Theδ^(71)Ga NIST994 andδ^(71)Ga IPGP values of these reference materials vary from 1.12‰to 2.63‰and−0.13‰to 1.38‰,respectively,and can be used to evaluate the precision and accuracy of Ga isotope data from diff erent laboratories.

关键词： Ga isotopes MC-ICP-MS Reference materials Chemical purification Ba interference

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Mo isotopes in the Lower Cambrian formation of southern China and its implications on paleo-ocean environment

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Chinese Science Bulletin 2009年第24期54卷 4756-4762页

作者： WEN HanJie ZHANG YuXu fan haifeng HU RuiZhong State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

Over the past decade, as one of nontraditional stable isotopes, Mo isotope has developed rapidly and now become an important geochemical proxy to trace paleo-oceanic and atmospheric evolution through geological history. In this paper, Early Cambrian formations in southern China are investigated. The results indicate that δ 97/95Mo values of Early Cambrian seawater may have been larger than 1.4‰, values that are close to those of the modern ocean. It was also found that the variations in Mo isotope composition in samples from two sections (Huangjiawan and Gezhongwu in Guizhou) were closely related to changes in redox conditions during sedimentary processes. Combining our results with existing data, a preliminary model for the evolution of seawater Mo isotope composition through geological history was provided. It indicated that Mo isotopic variations were generally consistent with the evolution of atmospheric oxygen.

关键词：稳定同位素海洋环境中国南部下寒武统钼同位素组成南方氧化还原条件

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Selenium and Sulfur Systematics of Mafic Dykes in Western Fujian Province,Southern China

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Acta Geologica Sinica(English Edition) 2008年第4期82卷 884-895页

作者： fan haifeng WEN Hanjie ZHANG Guishan HU Ruizhong State key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang Guizhou 550002 China The Graduate School of Chinese Academy of Sciences Beijing 100039 China College of Earth Science and Land Resources Chang＇an University Xi＇an Shanxi 710054 China

Fifteen samples from three study areas （the Bancun diabase dykes, the Bali hornblende gabbro dykes, the Linzifen gabbro-diabase dykes） were collected and analyzed for selenium （Se）, sulfur （S）, copper （Cu）, major and trace elements. In general, Se, S and Cu do positively correlate to each other. The concentration of S and Se and the S/Se ratio are higher than the corresponding value of primitive mantle （PM）, and the Cu/S ratio falls in a narrow range （0.04-0.29）, which is consistent with that of primitive mantle （0.05-0.20）. The Bancun diabase dykes and the Bali hornblende gabbro dykes were located in an intraplate environment during the Late Mesozoic. Oceanic subduction was closely related to magmatic activities. The magmatic activities play an important role in the transportation mechanism of Se and S. Because those two groups were closer to fault zones, which may affect the distribution of S and Se and other elements. In the two groups, no crustal contamination was observed, indicating that all analyzed elements may come from enriched mantle metasomtism associated with slab subduction. However, the Linzifen gabbro-diabase dykes were located in an intraplate rift environment, and its invading age is older than the other two groups, the primitive magma comes from mantle, and there is an anomalous relation between S, Se and Al2O3, （La/Sm）N, and all these factors could result in higher S and Se concentration.

关键词： selenium and sulfur systematics mafic dyke Mesozoic Fujian southern China

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Effect of Fatigue Loading on the Mechanical Properties and Resistance of High-strength Straight-hole Recycled Pervious Concrete to Rainstorm-based Waterlogging

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Journal of Wuhan University of Technology(Materials Science) 2023年第1期38卷 141-148页

作者：朱平华 fan haifeng YAN Xiancui LIU Hui WANG Xinjie CHEN Chunhong Department of Civil Engineering Changzhou UniversityChangzhou 213164China

A novel high-strength straight-hole recycled pervious concrete(HSRPC)for the secondary highway pavement was prepared in this *** study aimed to investigate the effect of porosity(0.126%,0.502%,and 1.13%),vehicle loading stress level(0.5 and 0.8)and service life on the resistance to rainstormbased waterlogging of HSRPC under fatigue *** mechanical properties of HSRPC in terms of flexural strength and dynamic elastic modulus were *** waterlogging resistance of HSRPC was described by surface water depth and drainage *** microstructure of HSRPC were observed with scanning electron microscopy(SEM).Results showed that although the dynamic elastic modulus and flexural strength of HSRPC decreased with the increasing number of fatigue loading,the flexural strength of HSRPC was still greater than5 MPa after design service life of 20 *** 2.5×10^(5)times of fatigue loading,the permeability coefficient of HSRPC with a porosity of 0.502%and 1.13%increased by 18.4%and 22.9%,respectively;while the permeability coefficient of HSRPC with 0.126%porosity dropped to 0.35 mm/*** maximum surface water depth of HSRPC with a porosity of 0.126%,0.502%,and 1.13%were 8,5 and 4 mm,*** results showed that fatigue loading expanded the number and width of cracks around the tiny pores in HSRPC.

关键词： recycled pervious concrete porosity fatigue loading service life stress level rainstorm and waterlogging

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Determination of total selenium in geological samples by HG-AFS after concentration with thiol cotton fiber

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Chinese Journal Of Geochemistry 2008年第1期27卷 90-96页

作者： fan haifeng WEN Hanjie HU Ruizhong CHANG Bin State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China The Postgraduate University of Chinese Academy of Sciences Beijing 100039 China

Standard reference material and different geological samples were dissolved by system A (the mixture of nitric and perchloric acids) and system B (mixture of nitric, perchloric and hydrofluoric acids), and total Se in all samples was measured by hydride-generation atomic fluorescence spectrometry (HG-AFS) after concentration with thiol cotton fiber (TCF). The analytical results obtained by the two digestion method are in good agreement (within the limit of errors) for most of the samples, particularly for those having recommended values. The Se concentrations determined by the two methods are of no difference, and the correlation coefficient is 0.9986; the relative standard deviation (RSD) for the determination of 0.04 μg/g Se is 10.2%. The recovery rates of systems A and B by the stan- dard-addition method were 96%–106% and 99%–104%, respectively.

关键词：硒地理特征棉花纤维矿物

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Molybdenum isotopic composition as a tracer for low-medium temperature hydrothermal ore-forming systems:A case study on the Dajiangping pyrite deposit,western Guangdong Province,China

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Chinese Science Bulletin 2011年第21期56卷 2221-2228页

作者： SONG ShiMing HU Kai WEN HanJie ZHANG YuXu LI Kuang fan haifeng State Key Laboratory for Mineral Deposits Research School of Earth and EngineeringNanjing UniversityNanjing 210093China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550002China Wuxi Research Institute of Experimental Geology SINOPEC Exploration and Production Research InstituteWuxi 214000China

Little is known about the range or controls on the molybdenum isotopic composition of low-medium temperature hydrothermal ore-forming *** present molybdenum isotope data from 12 hydrothermal syndepositional silicalite and carbonaceous slate samples from the Dajiangping pyrite deposit in western Guangdong Province,South *** δ 97/95Mo values from Orebody III range from ?0.02‰ to 0.29‰,with an average of 0.18‰.In contrast,the composition values from Orebody IV display a larger variation from ?0.70‰ to 0.62‰.However,the five samples from the main ore bed all show strong negative *** indicates that the significant variation in molybdenum isotopic composition supports different hydrothermal ore-forming metallogenesis and a metallogenic environment between the two *** III is likely to have been deposited from submarine exhalative hydrothermal fluids under a relatively strong reducing environment and Orebody IV may have also been influenced by hydrothermal superimposition in a more oxidized disequilibrium *** addition,the δ 97/95Mo values of Orebody IV are clearly negative,together with the values increasing stratigraphically upward in the ore beds,suggesting that the metallogenic environment of Orebody IV is different from the open oceanic *** might be dynamic fractionation in this restricted ***,the molybdenum isotope can be used as an effective tracer for the ore-forming fluid and metallogenic environment.

关键词：同位素组成黄铁矿矿床热液成矿成矿系统中国西部中高温广东省示踪

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Ga isotopic fractionation in sulfides from the Yuhuang and Duanqiao hydrothermal fields on the Southwest Indian Ridge

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Geoscience Frontiers 2021年第4期12卷 122-130页

作者： Yuxu Zhang Shili Liao Chunhui Tao Hanjie Wen haifeng fan Jing Wen Weifang Yang Wei Li State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Key Laboratory of Submarine Geosciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China University of Chinese Academy of Sciences Beijing 100049China

This study examines the Ga isotopic compositions of sulfides in the Yuhuang and Duanqiao hydrothermal fields on the Southwest Indian Ridge,mid-ocean ridge basalts(MORB),and calcareous sediments around the hydrothermal ***δ^(71/69)Ga_(NIST-994) values of theMORB samples vary little(+1.20‰to+1.23‰,with an average of+1.22‰)and are consistent with the δ^(71/69)Ga_(NIST-994) values of two standard basalt samples(BCR-2 and BHVO-2),indicating that Ga isotopes may either not fractionate or fractionate only slightly under high-temperature geological processes;therefore,the δ^(71/69)Ga_(NIST-994) value of oceanic crust may be+1.22‰.The sediments(+1.28‰to+1.47‰,with an average of+1.38‰)are rich in heavier Ga isotopes than the basalts,and the Ga present in the sediments may have originated from soluble Ga present in the seawater that was adsorbed by(Mn,Fe)oxides/*** Ga contribution of basaltic debris to the sedimentswas almost ***,wespeculate that theδ^(71/69)Ga_(NIST-994) value of seawater in the study area fell within a range from+1.92‰to+2.36‰.Theδ^(71/69)Ga_(NIST-994) values of the sulfides in the Yuhuang hydrothermal field range from+0.99‰to+1.57‰,with an average of+1.25‰,and theδ^(71/69)Ga_(NIST-994) values of the sulfides in the Duanqiao hydrothermal field range from+0.93‰to+1.55‰,with an average of+1.19‰.Theδ^(71/69)Ga_(NIST-994) ranges of the sulfides in the Yuhuang and Duanqiao hydrothermal fields are similar,with the Ga isotopic fractionation reaching 0.58‰and 0.62‰,*** averageδ^(71/69)Ga_(NIST-994) values in the sulfides are close to those in the *** suggests that Ga within the sulfides in the Yuhuang and Duanqiao hydrothermal fields mainly originated from MORBs,with seawater and sediments making only small *** Ga isotopic fractionation in the sulfides may be related to processes associated with the formation of sulfides,such as rapid precipitation or the admixture of different stages of *** st

关键词： Ga isotope Hydrothermal sulfide Yuhuang Duanqiao Southwest Indian Ridge

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Large selenium isotopic variations and its implication in the Yutangba Se deposit, Hubei Province, China

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Chinese Science Bulletin 2007年第17期52卷 2443-2447页

作者： WEN HanJie Jean CARIGNAN HU RuiZhong fan haifeng CHANG Bin YANG GuangShu State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China CRPG-CNRS 15 Rue Notre-Dame des Pauvres B. P. 20 54501 Vandoeuvre-les-Nancy Cedex France

The selenium isotopic ratios have been measured in the Yutangba Se deposit, Hubei Province, China. The results show that the δ 82/76SeNIST values vary from -12.77‰ to 4.93‰, which is the largest Se iso- topic variation found so far in natural terrestrial samples. The sample Ytb-5 of high-selenium carbona-ceous shale has the lightest Se isotopic composition with a δ 82/76SeNIST value of -12.77‰. On the basis of variations of Se isotope in the deposit along with other geological and geochemical evidence, the "redox model" is suggested to favor the explanation of the occurrence of native Se in the deposit. The application to the Yutangba Se deposit with the discovery of large Se isotopic fractionation for natural samples indicates the potential of Se isotope as a new geochemical tracer.

关键词：中国湖北硒同位素分馏法黑色页岩

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