大兴安岭北段砂宝斯-老沟地区金成矿规律及找矿方向

摘要

大兴安岭北段漠河县砂宝斯-老沟地区是我国重要的金矿产出地.在系统总结前人研究成果的基础上,对上黑龙江盆地构造演化、沉积充填历史、砂宝斯-老沟地区典型矿床成矿规律综合分析,将上黑龙江盆地二十二站组时期沉积古地理环境与有利成矿位置叠合,并研究含矿砂岩的粒度和还原物质含量,提出赋矿围岩二十二站组中的辫状河三角洲沉积体系中三角洲前缘是该区域有利的成矿部位.结合本区岩浆活动、构造发育状况,指出了该区在砂宝斯-老沟环形构造与辫状河三角洲沉积体系叠合部位,以地球化学、大比例尺地质填图等为手段,找寻南北向断裂带,进而对发育其中的构造破碎蚀变带进行空间定位的找矿方向.%The Shabaosi-Laogou region,Mohe County in the northern section of Daxinganling is an important gold output area of China.On the basis of previous studies,the tectonic evolution and sedimentary filling history of the Upper Heilongjiang basin are analyzed with the metallogenic regularity of typical deposits in the region.By superimposition of the sedimentary paleogeographic environment with the location of favorable mineralization,together with the analysis on the granularity of the ore-bearing sandstone and the content of reducing matters,it is pointed out that the delta front of the braided river delta depositional system in the ore-wall rock of Ershierzhan Formation is the favorable ore-forming area.Combined with the magmatic activity and tectonic development situation in this region,the ore-searching direction is defined at the composite area of the Shabaosi-Laogou annular structure and the braided river delta sedimentary system.With geochemical techniques and large-scale geological mapping,the north-trending fault zone should be positioned for the altered fracture belt within it.