张麻井铀钼矿床地质特征及沽源盆地找矿思路

燕山造山带形成于中生代,由于构造、火山活动,产生一系列断陷盆地,与隆起带相间出现,有等间距特点。张麻井大型铀钼矿床位于蔡家营—双脑包次级火山构造洼陷带内。主要为次流纹斑岩体控制,赋存于次流纹斑岩体顶部隐爆角砾岩中。在古太古代末基底发生强烈变质作用,成矿元素第一次富集。中生代的火山热液活动,成矿元素第二次富集。经多期次热液活动,在隐爆角砾岩部位形成富矿体。

Geological characteristics of uranium-molybdenum deposit in Zhangmajing and prospecting idea for Guyuan Basin

Yanshan orogenic belt was formed in Mesozoic era,a series of faulted basins and uplift belt appear alternatively with the characteristics of equal interval because of tectonic,volcanic activity.The Zhangmajing large uranium-molybdenum deposit is located in secondary volcanic-tectonic depression belt of Caijiaying-Shuangnaobao,and is controlled by the subrhyolite-porphyry to host in cryptoexplosive breccia on top of subrhyolite-porphyry.The strong metamorphism happening in basement at late early-archean resulted in the first enrichment for ore-forming elements.The Mesozoic volcanic hydrothermal fluid activities resulted in the second one.So the oreshoots were formed in cryptoexplosive breccia by multiperiodic hydrothermal activities.