念青唐古拉弧背断隆东段古近纪大规模火山作用及找矿意义

探讨念青唐古拉弧背断隆东段古近纪火山岩的地质地球化学特征、成因机制、动力学背景以及找矿意义.通过对火山岩进行岩石学特征研究及全岩地球化学分析,结果表明该套火山岩相对富集不相容元素K、Rb、Th、Ce,而Sr、Ba、Ta、Nb、Ti呈现低谷,LREE富集且分馏明显,而HREE相对亏损且分馏不明显,稀土配分模式图呈以Eu为...

Paleogene large-scale volcanism and prospecting implication in the east sag-uplift of Nyanqentanglha arc-back in Tibet,China

The east sag-uplift of the Nyanqentanglha arc-back is demarcated by the Naqu-Dangxiong fault on the west,the Shiquanhe-Namucuo-Jiali suture zone on the north and the east,and the Shamole-Maila-Milashan-Luobadui fault on the south.The geochemical data of the Pana group volcanic rocks indicate that they are high K calc-alkali — shoshonitic volcanic rock series.This group of volcanic rocks is formed in the transition zone of soft collision to hard collision.They are the mixed products of the basic differential magma derived from the mantle and the acid magma derived from the remelting continental crust.The abyssal sediments on the subducting slab participated in this process.Therefore,it is quite favorable to find metal sulfide deposits related to the acidic volcanic rocks because the rhyolites occur in the area.