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61.
赣南路迳似金伯利岩(金伯利质煌斑岩)锆石的特点和年龄及其构造意义 总被引：1，自引：1，他引：0
南岭以花岗岩广泛分布闻名于世,但也存在基性超基性侵入岩。位于赣南安远蔡坊镇的路迳似金伯利岩(金伯利质煌斑岩)就是其中之一。本研究在野外调研的基础上,利用高灵敏高分辨离子探针(SHRIMP)锆石定年技术对其成岩时代进行了研究,获得其U-Pb年龄为132.0 Ma(变化于128.7～135.4 Ma)。同时还发现了早期锆石捕获晶,其年龄为1945 Ma,意味着赣南地区存在古元古代的基底。这一结果一方面弥补了原先根据K-Ar法和Rb-Sr法将似金伯利岩定为新生代的不足,为探讨赣南地区大地构造演化历史提供了准确资料;同时也表明燕山晚期的构造体制转换与壳幔相互作用是有关的,似金伯利岩岩浆可能起源于富集地幔。 相似文献
62.
The Mesozoic porphyry assemblage in the Jinduicheng area is a special molybdenum area in China, the Mo deposits, including the Jinduicheng, Balipo, Shijiawan, Huanglongpu, are distributed. The emplacement age and geochemical features of the granites in the Jinduicheng area can provide essential information for the exploration and development of the porphyry molybdenum deposit. In this study, we report LA–ICP–MS zircon U–Pb age and zircon Hf isotopic compositions of granite porphyries from the Jinduicheng area, and provide insights on the petrogensis and source characteristics of the granites. The results show that the zircon U–Pb ages of the Jinduicheng granite porphyry (143±1 Ma) and the Balipo granite (154±1 Ma), agree well with the Re–Os ages of molybdenite in the Jinduicheng molybdenum polymetallic deposit (139±3 Ma) and the Balipo molybdenum polymetallic deposit (156±2 Ma), indicating that the emplacement of granite porphyries occurred between Late Jurassic and Early Cretaceous. Zircons granite from the Jinduicheng area give the εHf(t) values mainly ranging from ?10 to ?16, and ?20 to ?24, respectively, corresponding to two–stage model ages (tDM2: mainly focused on 1.86–2.0 Ga, and 2.2–2.6 Ga, respectively) of zircons of the granite from the Jinduicheng values. The ore–forming materials are mainly derived from crust, with minor mantle substances. Zircons of the granite from the Balipo area give εHf(t) values ranging from ?18 to ?20, ?28 to ?38, and ?42 to ?44, respectively, corresponding to two–stage model ages (tDM2: mainly focused on 1.88–3.0 Ga, and 3.2–3.90 Ga, respectively). the εHf(t) values of the Jinduicheng porphyry more than that of the Balipo porphyry, and two–stage model ages (tDM2) less than that of the Balipo porphyry, shows that he source of the porphyries originated from ancient lower crustal materials in the Jinduicheng area, and mixed younger components, more younger components contributed for the source of the Jinduicheng porphyry. 相似文献
63.
Previous studies have obtained some petrogenetic and metallogenic chronological data with SHRIMP (sensitive high-resolution ion microprobe) zircon U-Pb, zircon LA-ICPMS (laser-ablation–inductively coupled plasma mass spectroscopy) U-Pb, molybdenite Re-Os isochron and muscovite Ar-Ar methods in southern Jiangxi Province and its adjacent areas. Based on these, the purpose of this paper is to study the petrogenetic and metallogenic ages and their time gap for different genetic types of W-Sn deposits, and thus to research their numerous episodes, zonal arrangement and their geodynamic background. The result shows that the large-scale W-Sn mineralization in southern Jiangxi Province occurred in the middle to late Jurassic (170–150 Ma), the skarn W-Sn-polymetallic deposits formed much earlier (170–161 Ma), and all of the wolframite – quartz vein type, greisen type, altered granite type and fractured zone type tungsten deposits formed in the late Jurassic (160–150 Ma). In one ore field or ore district, greisen type tungsten deposits formed earlier than quartz vein type ones hosted in the endo- or exo-contact zone; and quartz vein type hosted in the endocontact zone formed earlier than that of exocontact zone. There is no significant time difference between tungsten-tin mineralization and its intimately associated parent granite emplacement (1–6 Ma). They all formed in the same rock-forming and ore-forming system and under the same geodynamic setting. Regionally, rock-forming and ore-forming processes of the W-Sn deposits in the Nanling region (include southern Jiangxi Province, southern Hunan Province, northern Guangdong Province and eastern Guangxi Zhuang Autonomous Region) exhibit numerous episodes. The mineralization in the Nanling region mainly occurred at (240–210) Ma, (170–150) Ma and (130–90) Ma. The tungsten-tin deposits in this region are centered by the largest scale in southern Jiangxi Province and southern Hunan Province, and become small in the east, west, south and north directions. This displays a zonal arrangement and temporal and spatial distribution regularity. Integrated with the latest research results, it is concluded that the W-Sn mineralization in southern Jiangxi Province and its adjacent areas corresponds to the second large-scale mineralization in South China. The Indosinian W-Sn mineralization formed under the extensional tectonic regime between collisional compressional stages, while the Yanshanian large-scale petrogenetic and metallogenic processes occurred in the Jurassic intraplate extensional geodynamic setting of lithosphere extension. 相似文献
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65.
Zijinshan is a large porphyry–epithermal Cu–Au–Mo–Ag ore system located in the Zijinshan mineral field (ZMF) of southwestern Fujian Province, China. Although it is commonly accepted that the early Cretaceous magmatism and the metallogenesis of the mineral field are closely related, the tectonic setting for the ore-forming event(s) has been controversial and regarded as either extensional or subduction-related. New U–Pb zircon geochronology, Sr–Nd–Pb isotopic systematics, and geochemical data presented here from granites and volcanic rocks in the mineral field help to clarify this uncertainty.LA–MC–ICP-MS U–Pb zircon analyses yield weighted mean ages of between ca. 165 and 157 for the monzogranite, ca. 112 Ma for granodiorite, and between ca. 111 and 102 Ma for nine samples of volcanic units in the study area. These dates, integrated with previous geochronological data, indicate that there were two magmatic events in the area during the Middle to Late Jurassic and the Early Cretaceous. Major and trace element geochemistry indicates that these rocks are high-K, calc-alkaline granites, are enriched in LREE and Th, U, Ta, Nd, Sm and Yb, and depleted in Ba, K, Sr, P, Ti and Y. These features are characteristic of volcanic-arc granites or active-continental margin granites. The Middle to Late Jurassic monzogranitic plutons in the region have initial 87Sr/86Sr ratios of 0.7096 to 0.7173, εNdT values of − 10.1 to − 7.6, 206Pb/204Pb isotope ratios of 18.51–18.86, 207Pb/204Pb isotope ratios of 15.64–15.73, and 208Pb/204Pb isotope ratios of 38.76–39.18. The Early Cretaceous granodiorite and volcanic rocks are distinctly different with initial 87Sr/86Sr ratios of 0.7055–0.7116, εNdT values of − 8 to 0.5, 206Pb/204Pb ratios ranging between 18.49 and 19.77, 207Pb/204Pb ratios of 15.63–15.71, and 208Pb/204Pb ratios of 38.71–40.62. These characteristics suggest that the source for the Middle to Late Jurassic monzogranitic plutons is a partially melted Mesoproterozoic substrate, with a minor component from Paleozoic material, whereas the Early Cretaceous granodiorite and volcanic rocks may represent mixing of crustal and mantle-derived melts. It is therefore suggested that the Middle to Late Jurassic monzogranitic plutons, and the Early Cretaceous granodiorite and volcanic rocks in the ZMF are the result of an active continental-margin setting related to the subduction of the Paleo-Pacific Plate beneath the Eurasian continent. Given that the mineralization and the early Cretaceous granodiorite and volcanic rocks in the area are genetically related, the Zijinshan porphyry–epithermal ore system formed in the subduction-related tectonic setting. 相似文献
66.
青海野马泉矽卡岩铁锌多金属矿区侵入岩、交代岩及矿化蚀变特征 总被引：1，自引：0，他引：1
野马泉铁锌多金属矿床位于柴达木盆地西南缘和青海祁漫塔格山之间的盆山结合部位.矿区出露有印支期及海西期侵入岩.矿区内矽卡岩呈层状、似层状产于上石炭统四角羊沟组中,矽卡岩矿物主要是石榴子石、单斜辉石、角闪石、绿帘石、符山石等;金属矿物主要有磁铁矿、黄铜矿、黄铁矿、闪锌矿等.文章基于详细野外地质调查、剖面和钻孔岩芯观察结果,开展了侵入岩和交代岩的岩石地球化学及矽卡岩矿物学的系统研究.结果表明,野马泉矿区闪长岩具有低w(SiO2) (51.90％～59.03％)、高w(MgO) (2.04％～3.44％)、w(TFeO)(5.33％～11.67％),高REE[(318.57×10-6～327.67×10-6)],低LREE/HREE比值(7.36～7.48)的特点;二长花岗岩具有高w(SiO2) (77.36％ ～77.41％)、低w(MgO)(0.04％～0.10％)、w(TFeO) (0.76％～1.08％)的特点,LREE/HREE比值较高(9.14～9.37).透辉石-钾长石交代岩比原岩低w(MgO)(1.17％ ～ 2.86％)、低w(TFeO)(3.89％～7.76％),且具有更强的Eu负异常(δEu=0.07～0.52),LREE/HREE比值更低(3.19～7.87).透辉石-钠长石交代岩相对原岩具有低w(MgO) (0.36％～0.92％)、高w(TFeO)(3.05％ ～8.13％)的特点.野马泉矿区的矽卡岩包括钙矽卡岩和锰质矽卡岩,钙矽卡岩主要产于接触带附近,组成矿物主要为单斜辉石和石榴子石,接近岩体的单斜辉石中透辉石端员组分较高,石榴石主要分布在接触带附近,内环带钙铁榴石组分高于外环带.综合矿物学、岩石地球化学结果,推断野马泉矿区闪长岩具有较大成矿潜力,野马泉矿区钙矽卡岩主要形成于氧化条件,锰质矽卡岩形成于还原条件. 相似文献
67.
Huang Jixian Mao Xiancheng Deng Hao Liu Zhankun Chen Jin Xiao Keyan 《Natural Resources Research》2022,31(4):2181-2196
Natural Resources Research - Spatial non-stationarity is a common geological phenomenon, and the formation of orebodies is a typical non-stationary process. Therefore, a quantitative study of the... 相似文献
68.
希特伦峡湾(Citronen Fjord)铅锌矿是处于储量扩展和可行性研究阶段的世界级原生铅锌矿床,也是目前所知世界上最北端的铅锌矿床。希特伦峡湾的褶皱和逆冲断层较发育,矿化区主要有迪斯卡弗里(Discovery)区、比奇(Beach)区和伊斯茹姆(Esrum)区,矿体呈NW-SE走向,主要赋存在晚奥陶世—早志留世泥岩和页岩中,主要的硫化物是黄铁矿、闪锌矿和方铅矿。硫化物δ34S值变化于+7‰~+35‰间(CDT),多数在+10‰~+25‰间,铅同位素具有放射铅成因特征。成矿流体温度在80~160℃之间,属中低温热液型。希特伦峡湾铅锌矿在成因上为喷流沉积型(SEDEX)矿床。格陵兰岛赋存和产出许多铅锌矿,尤其是北格陵兰古生代的富兰克林阶盆地,其东西向延伸超过2 500km,这个未充分开发的盆地将是勘探铅锌矿的优良靶区。 相似文献
69.
华南深部找矿有关问题探讨 总被引：14，自引：0，他引：14
华南是我国目前最重要的有色金属矿业基地之一。该地区矿业发达但危机矿山也多,研究程度高但多数矿床的勘查工作在20年前就完成,成矿条件好、已发现矿产地点多面广但进一步找矿难度也大。因此,在华南开展深部找矿势在必行,而且受到了国家、地方政府和企业界的共同关注。中国地质调查局设立了湖南瑶岗仙、康家湾、玛瑙山,江西大吉山、荡坪、岿美山,广西佛子冲、铜坑、栗木、泗顶,广东瑶岭、石人嶂、大宝山等一批危机矿山项目,力争在这些矿山深部实现找矿突破。华南地区开展深部找矿需要研究成矿物质来源、矿床分类、成矿区带划分及其在一定深度（距离地表3000m）的变化情况,需要明确地表的战略性选区与点上的攻深找盲、探边摸底同样重要,需要加快中深钻（1000-3000m深度）钻探及相关测量技术的研究,需要通过对“物质不灭”、“能量守恒”和“时空无限但有序”三原则的把握来评价矿产资源的潜力。 相似文献
70.
赣南淘锡坑钨矿的石英中子活化分析研究 总被引：1，自引：0，他引：1
对赣南淘锡坑矿区V11号王牌矿脉不同中段的石英进行了中子活化分析,发现W主要与Sm、Lu、Yb、Mn、Sc、Ta、Fe等元素相关性比较好。在矿体的纵投影面上,识别出156中段和106中段各有3个浓集中心,并有从地表往深部W含量逐渐升高的趋势,显示矿液由南东往北西富集。预测枫林坑深部找矿前景较好。尝试性地进行了矿脉深部储量的预测研究,获得了 106m和56m两个中段的储量共10275.6t,加上156中段—356中段,合计V11号脉体的储量为19851.93t,与探明储量接近。可见,利用石英中子活化分析资料,有助于矿体深部储量的估算。 相似文献