西藏克鲁-冲木达矿集区晚白垩世花岗岩类地质地球化学特征及成矿潜力浅析

克鲁-冲木达矿集区位于西藏南部扎囊-桑日之间.通过对其晚白垩世花岗岩类岩石学、地球化学特征、形成的大地构造环境以及成矿专属性等的综合研究得出以下两点认识:(1)晚白垩世花岗岩类的岩石组合为闪长岩、石英闪长岩和二长花岗岩,为准铝质高钾钙碱性Ⅰ型花岗岩,具弱的斜长石分异结晶,富集Th、Sr等元素,亏损Ba、Nb等元素,形成于造山带环境,是角闪岩部分熔融的产物；(2)晚白垩世花岗岩类成矿作用主要集中在似斑状黑云二长花岗岩和黑云二长花岗岩阶段,部分闪长岩和石英闪长岩岩体中也含矿,主要的矿化表现为Cu、Pb-Zn和Mo的组合.

Geology, geochemistry and metallogenic potentiality of the Late Cretaceous granitoids in the Kelu-Chongmuda ore district, Xizang

The Kelu-Chongmuda copper-gold ore district is sandwiched between Zhanang and Sangri in southern Xizang. The results of the geology, geochemistry, tectonic setting and metallogenic specialization of the Late Cretaceous granitoids in the Kelu-Chongmuda ore district led us to draw the following conclusions. (1) The Late Cretaceous granitoids consisting of diorite, quartz diorite and adamellite are assigned to the metaluminous highpotassium calc-alkaline I-type granites, and characterized by slightly differentiation and crystallization of plagioclase, enrichment of the elements Th and Sr, and depletion of the elements Ba and Nb. They are interpreted as the products from the partial melting of amphibolite in the orogenic zones. (2) The metallogenesis of the Late Cretaceous granitoids are mainly hosted in porphyroid biotite adamellite and biotite adamellite, locally in diorite and quartz diorite. The mineralization is chiefly manifested in the metallogenic potentiality of Cu, Pb-Zn and Mo.