东天山东段-北山地区三叠纪钼成矿作用广泛而强烈，新探明大中型矿床4处：花黑滩钼矿床、白山钼矿床、小狐狸山钼矿床、东戈壁钼矿床.这些钼矿床均分布在古生代板块缝合带附近，与造山后钙碱性花岗岩成因联系密切，成矿作用高峰期在235~220Ma.矿石中辉钼矿铼含量表明，成矿物质中有不同程度幔源组份的贡献.造山后伸展背景下，岩石圈拆沉、软流圈地幔上涌底侵，导致下地壳部分熔融，这是成岩-成矿作用重要动力学条件，也为成矿作用带来丰富热能、流体及成矿物质.区域性深大断裂是深部岩浆或流体上侵的有利通道和成矿有利部位.%Intensive magmatic activities and related Mo mineralization occurred throughout in the east part of Eastern Tianshan and the Beishan area,such as the newly explored Huaheitan,Baishan,Xiaohulishan,and Donggobi molybdenum deposits.Previous U-Pb and Re-Os dating suggested these Mo deposits formed during the 235~220 Ma interval.The Re content in the molybdenite,together with Sr-Nd-Hf isotopic composition of the granite,suggested that the ore-forming ma-terials derived from mixed crustal and mantle sources.The post-orogenic lithospheric extension and mantle-derived mag-mas underplating were important geodynamic controls on the Mo mineralization in the Beishan area,and provided abnor-mal heat flow,voluminous fluids of multiple sources and ore metals.It is significant to pay more attention to evaluation of the ore-forming potentiality in the Triassic granites in Beishan belt.
展开▼
