长江中下游成矿带铜陵矿集区层控硫化物矿床成因研究进展     

陈一秀  杨丹 《矿床地质》2021,40(1):128-142

安徽铜陵矿集区是长江中下游成矿带内重要的多金属成矿区,该矿集区具有大规模的成矿作用和多种类型的复杂成矿系统演化,找矿潜力大,研究程度较高.区内广泛发育一系列层状硫化物矿床,其成因问题一直是中国矿床学界争议的焦点之一.文章从成矿年代学、成矿流体来源以及成矿物质来源等方面,对近半个世纪以来国内外学者对该矿集区内层控硫化物矿...  相似文献   

Origin of ore-forming fluids in Qinggouzi stibnite deposit,NE China:Constraints from fluid inclusions and H-O-S isotopes     

BAKHT Shahzad  SUN Fengyue  WANG Linlin  XU Chenghan  YE Lina  ZHU Xinran  FAN Xingzhu 《世界地质(英文版)》2021,24(2):80-88

The Qinggouzi stibnite deposit is located in Huashan Town, Jilin Province, in the northeastern margin of North China Craton(NCC). It is controlled by fault structures, hosted within structurally controlled felsic dykes, predominantly surrounded by phyllite, schist and quartzite. This study presents the results of fluid inclusions studies, intending to determine the source of the fluid responsible for ore-formation, hence exploring its metallogenesis. The aqueous biphase inclusions are identified in the stibnite-bearing quartz veins of the deposit. Moreover, aqueous biphase inclusions are further classified into(1) biphase liquid-rich inclusions(1 a) and(2) biphase gas-rich inclusions(1 b) depending upon liquid to gas ratio trapped within the fluid inclusions. Homogenization temperatures for(1 a) and(1 b) range between 114.8℃ to 422℃ and 128.3℃ to 267.5℃, respectively. 1 a and 1 b have salinities of 0.18% to 16.14% NaCl_(eqv) and 1.22% to 12.88% NaCl_(eqv), and density range from 0.43 to 1.02 g/cm~3 and 0.81 to 0.98 g/cm~3, respectively. Sulfur isotopic analysis indicates δ~(34)S_(V-CDT) from 4.4×10~(-3) to 6.5×10~(-3), with an average of 5.2×10~(-3), whereas H isotopes values on δD_(V-SMOW) standard are-100.8×10~(-3) and-107.5×10~(-3), while O isotopes data on δ~(18)O_(V-SMOW) standard range between 20.1×10~(-3) and 20.4×10~(-3). Fluid inclusions study, combining with sulfur and H-O isotopic data reveal that the ore-forming fluids originated from deep source and were subsequently contaminated by meteoric water. Hydrostatic pressure calculation shows that the minimum and maximum pressures are 11.65 and 42.33 MPa, and relevant depths of deposit are estimated to be 1.16 and 4.23 km. Finally, we inferred that Qinggouzi stibnite deposit is a medium-low temperature, low salinity hydrothermal deposit, which is formed by deep source and later contaminated by meteoric water, and is classified as epizonal deposit in terms of orogenic series.  相似文献   

Preliminary seismic anisotropy in the upper crust of the south segment of Xiaojiang faults and its tectonic implications          下载免费PDF全文

Ying Li  Yuan Gao  Yutao Shi  Peng Wu 《地震科学（英文版）》2021,34(1):64-76

The Xiaojiang faults,striking north-to-south(NS),and the Honghe faults,striking north-to-west(NW),are first-order block boundaries that intersect to form a concentrated stress zone at an acute angle in the southern part of the Sichuan-Yunnan rhombic block(SYB).It is also a crucial zone for material escaping from the Tibetan Plateau(TP)due to the collision between the Indian Plate and the Eurasian Plate.In December 2017,the Institute of Earthquake Forecasting of the China Earthquake Administration(CEA)deployed a linear temporary seismic broadband array,the Honghe-Xiaojiang temporary Seismic Array(HX Array),across first-order block boundaries in the southern SYB.By using the waveform data of small earthquakes recorded by stations in the HX Array across Xiaojiang faults from 2017 to 2019,and by permanent seismic stations of the China National Earthquake Networks from 2012 to 2019,this paper adopts the systematic analysis method of shear-wave splitting(SWS),SAM method,to obtain preliminary results for seismic anisotropy in the upper crust.The study area can be divided into two subzones according to the spatial distribution of the directions of polarization of the fast shear-wave(PFS)at the stations:the northern zone(zone A,where the HX Array is located)and the southern zone(zone B,to the south of the HX Array).The results show that the directions of the PFS at stations in zone A were highly consistent,dominant in the NE direction,correlated with the in-situ principal compressive stress,and were seemingly unaffected by the Xiaojiang faults.The directions of the PFS as recorded at stations in zone B were more complicated,and were dominant in the NS direction parallel to that of the regional principal compressive stress.This suggests the joint influence of complex tectonics and regional stress in this narrow wedge area.By referring to the azimuthal anisotropy derived from seismic ambient noise in the southeast margin of the TP,the NS direction of the PFS in the middle and lower crust,and its EW direction in the upper mantle,this paper concludes that azimuthal anisotropy in the upper crust differed from that in the lower crust in the south segment of Xiaojiang faults,at least beneath the observation area,and azimuthal anisotropy in the crust was different from that in the upper mantle.The results support the pattern of deformation of ductile flow in the lower crust,and the decoupling between the upper and lower crusts as well as that between the crust and the mantle in the study area.The crustal directions of the PFS appeared to be independent of the Xiaojiang faults,suggesting that the influence of the South China block on the SYB passed through the Xiaojiang faults to the Yimen region.The results of this study indicate that anisotropic studies based on data on the dense temporary seismic array can yield clearer tectonic information,and reveal the complex spatial distribution of stress and deformation in the upper crust of the south segment of Xiaojiang faults.  相似文献   

寒武系烃源古油藏油裂解气特征及成藏条件   总被引：4，自引：0，他引：4  

陈安定  刘德良 《海相油气地质》2006,11(2):41-46

在寒武系为母源的气藏中,普遍存在的固体沥青、25-降藿烷、氮气等三种物质,实际是古油藏残余油裂解的产物。25-降藿烷一般与氧化—降解油有关,氮气来自油藏水洗时溶入的大气,二者共同反映古油藏经历的抬升破坏作用。寒武系烃源一般经历过两次成藏:加里东—海西期形成“油藏”,燕山—喜马拉雅期裂解为“气藏”。寒武系油裂解气成藏的地质条件是:古构造聚油、后期改造适度、叠合盆地增熟、断层作为油气运移通道等。围绕加里东—海西期古油藏寻找原生、次生油裂解气是今后寻找寒武系来源油气的重要途径。  相似文献   

南黄海辐射沙洲附近海域悬浮体的研究   总被引：4，自引：0，他引：4  

宋召军  黄海军  杜廷芹  刘芳  倪金龙 《海洋地质与第四纪地质》2006,26(6):19-25

对2003年春季(3—4月)和秋季(9月)南黄海辐射沙洲附近海域的悬浮体样品进行了空间分布特征、有机无机组成、粒度特征及其季节变化分析。结果表明:(1)2003年春季研究区内悬浮体浓度要普遍高于秋季的悬浮体浓度。悬浮体浓度最高值区位于长江口-老黄河口之间的近岸区。陆源物质为主的无机组分是悬浮体的主体成分,特别是在近岸浅水区和接近海底的底层水中尤为突出;(2)研究区海水中的悬浮体主要来源于辐射沙脊区(老黄河-长江复合三角洲)沉积物再悬浮;(3)悬浮体分布是风浪、潮流及沿岸流等多种因素综合作用的结果,而风浪和潮流是影响本区悬浮体分布的主要因素,巨大的风浪和强大的潮流造成辐射沙洲海底的沉积物再悬浮、搬运和再沉积,并在苏北沿岸流的作用下向沙洲外缘输运。  相似文献   

浅水波长计算问题     

薛鸿超 《海洋工程》2006,24(2):95-99106

浅水波周期保持常值,而波长缩减时其计算需进行迭代。提出了两个精度较高的经验公式供计算应用。水深波长比差值ΔLD0的变化规律反映出浅水波长缩减为一复杂过程,并与波能密度加大相关。LD0≤0.14时,特别是LD0=0.056前后,其特征会更加显著,由此可探讨波长变化的内在机理。  相似文献   

山东省近50年海洋气象灾害特征分析   总被引：3，自引：0，他引：3  

刘敦训 《海洋预报》2006,23(1):59-64

本文通过大量的文献和资料查阅,系统的统计分析了近50a山东省沿海及责任海区海雾、风暴潮、风暴海浪、海冰等几种主要海洋气象灾害的海洋、气象及分布特征和灾害情况,进一步分析了它们的变化规律和产生原因,为海洋气象业务、服务、科研提供有益的参考。  相似文献   

MM5数值预报产品在舟山海域风力分区预报中的释用   总被引：1，自引：0，他引：1  

黄辉  陈淑琴 《海洋预报》2006,23(2):67-71

本文阐述了舟山海域地理气候特征及开展舟山海域风力分区预报的重要性,详细介绍了利用海岛测风站资料研究的MM5数值预报产品在舟山海域风力分区预报中的释用技术,实践证明该释用技术能为风力分区预报提供重要的技术支撑,并为研究同类数值预报产品释用技术提供重要的参考依据。  相似文献   

海浪数值模式研究回顾与进展   总被引：2，自引：1，他引：1  

闻斌  刘俊 《海洋预报》2006,23(4):76-81

本文简单介绍了海浪的生成、发展理论,以及海浪数值模式的分类;回顾总结了国内外在海浪数值模式研究方面取得的成果。  相似文献   

珠三角基塘系统研究回顾及展望   总被引：2，自引：0，他引：2  

龚建周  蒋超  胡月明  杨颢 《地理科学进展》2020,39(7):1236-1246

基塘系统是中国劳动人民独创的低洼地利用方式和生态循环农业模式,珠三角基塘系统在历史上曾起到重要的作用,但目前其面积萎缩、生态功能退化。为了推动珠三角传统农业文化遗产的保护、促进区域人地关系协调发展,论文结合文献计量学方法对珠三角基塘系统研究文献进行梳理和概括,发现在基(田)塘生产力、区域水陆生态农业循环模式规律、社会经济发展与传统农业文化遗产保护的关系等方面已经展开研究;但是珠三角基塘系统演变机理研究比较薄弱,区域特色的农业文化遗产保护途径探索还鲜见。建议未来加强珠三角基塘系统演变机理、系统重构技术、农业文化遗产保护价值与途径的研究,以此深化基塘系统理论及实践研究,为协同区域农业生产格局与农业生态系统耦合关系提供支撑。  相似文献