内蒙古赤峰市双尖子山银多金属矿床的基本特征

Basic characteristics of Shuangjianzishan sliver polymetallic deposit in Chifeng City, Inner Mongolia

赤峰双尖子山矿床是近年在大兴安岭南段新发现的一处超大型银多金属矿床,其规模很可能刷新中国银矿规模的记录。文章对该矿床的基本地质特征进行了初步研究,表明银多金属矿化主要分布在中二叠统大石寨组的泥质、粉砂质板岩中,呈脉状、细脉浸染状产出,矿脉成群分布,构成长大于2000 m、宽大于1500 m的矿脉群。矿化与燕山期花岗岩、闪长玢岩、隐爆角砾岩、大石寨组上覆侏罗系地层的底砾岩具有密切的时空分布关系。根据矿床产出环境及矿化和热液蚀变等特征的初步研究,认为该矿床为多期次成矿叠加形成的中低温岩浆热液矿床。

The Shuangjianzishan sliver polymetallic deposit in southern Da Hinggan Mountains is a superlarge deposit which is expected to exceed the record of the silver deposit with the largest silver reserves ever discovered in China. The silver mineralization, occurring as veinlets, veins and stockworks, is dominantly distributed in the siltstone and mudstone of the Middle Permian Dashizhai Formation. They constitute an ore vein group, --2 km in length and --1.5 km in width. The ore-forming process is spatially and temporally associated with Yanshannian granites, diorite porphyrite, cryptoexplosive brecciated rocks and basal conglomerates in Dashizai Formation. According to the characteristics of ore geology and hydrothermal alteration, the authors infer that the Shuangjianzishan deposit was formed at several stages, and belongs to the middle-low temperature magrnatic hy- drothermal-type deposit.