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拉尔玛硅岩型金—铜—铀建造矿床的海底喷流沉积特征及找矿方向 总被引：1，自引：0，他引：1
西秦岭南亚带中的拉尔玛硅岩型金-铜-铀矿床,是一个比较典型的与海底喷流作用有关的金矿床。矿床赋存于寒武系太阳顶群中。太阳顶群地层由硅岩、板岩组成,厚度近千米。现已发现的矿体,80％以上产于硅岩中。硅质岩的地质地球化学特征表明,它是海底喷气沉积作用的产物,拉尔玛金-铜-铀建造矿床也具有海底喷流的沉积特征。 相似文献
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晚古生代期间，粤北半地堑式裂陷盆地受控于华南板块内的三叉张裂盆地系统。沉积演化阶段包括基底上隆、张裂、沉陷（三角洲充填）、下沉和封闭阶段。海西盆地演化史中的沉陷至稳定早期阶段对热水成矿有利。热水（喷气）矿床一般具有“三明治”式的矿石序列；底板蚀变（脉状矿石）→整合块状硫化物矿体→顶板蚀变和／或喷气盖层，以及底部爆发和沸腾特征。热水沉积（喷气）岩具有负的δ１３Ｃ和δ１８Ｏ值以及低于正常海相硅岩的δ１８Ｏ值，具有强烈的Ｅｕ正常ＲＥＥ模式。海西旋回可识别出４个与矿化层位有关的热事件：中泥盆统、上泥盆统、中－上石炭统和二叠统。区内绝大多数块状硫化物矿床是盆地扩张早期产物，而某些矿床（Ａｕ、Ａｇ、Ｃｕ）则是盆地封闭阶段──印支运动（Ｔ３－Ｊ１）的产物。 相似文献
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吉林省延边地区天宝山-天桥岭多金属成矿带的成矿物质来源 总被引：1，自引：0，他引：1
作者依据获得的直接证据(首次发现的含矿喷气岩等)和间接证据(组构标型、矿物标型及同位素标型等),并应用活动论的观点确认天宝山岩块、早二叠世庙岭组、红叶桥组是主要的含矿层,每一岩浆单元晚期的中小斑岩是含矿岩.其中的成矿物质在火山喷气、岩浆爆破和断裂构造的热动力驱动下活化并参与成矿,这样就使富含成矿物质层(岩)真正变成矿源. 相似文献
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《Geodinamica Acta》2013,26(3):117-137
In the Ligurian Alps (South-Western Italian Alps), Zn-Pb deposits occur within late Palaeozoic meta-sedimentary units belonging to the Briançonnais Zone near Casario (Tanaro valley). Different types of sulphide-rich, lens-shaped mineralizations are recognized: sphalerite-galena massive sulphide bodies, pyrite-rich lenses and sulphide-rich quartz–carbonate-chloritoid granofels. Sulphide lenses and host rocks are affected by at least three ductile deformation phases and by a polyphase alpine metamorphism, whose climax conditions are estimated, based on P-T pseudosection calculations, at T = 300-325 °C and P = 0.55-0.60 GPa. In all the mineralized lenses the ore minerals are represented, in variable amount, by Fe-poor sphalerite, galena, pyrite and arsenopyrite (± tetrahedrite, chalcopyrite and pyrrhotite); the gangue consists of quartz, carbonate (sideritemagnesite ± rhodochrosite s.s.), Fe-chloritoid, muscovite-phengite and chlorite. The mineralizations are associated with chloritoid – carbonate micaschists displaying a finely bedded texture, with sharp between-bed compositional contrast, which suggests their exhalative origin. In spite of the tectono-metamorphic overprint, some pre-metamorphic features of the hydrothermal system are still recognized, like relics of the hydrothermal feeding system, primary growth textures and sulphide-rich microbreccias. These massive sulphide lenses, which share many characters with the SEDEX deposits, testify to the occurrence of an exhalative event of Upper Carboniferous age previously unrecognized in the Ligurian Briançonnais Unit. 相似文献
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