摘要
北祁连中西段发育三套早古生代蛇绿岩及相应的基性、超基性岩,呈北、中、南三条带状分布。区内金的活化、迁移主要受控于超基性岩带和与其分布近于一致的两条韧性剪切带,金矿化主要发生在强蚀变超基性岩体内、岩体与围岩接触带、断裂破碎蚀变带内。根据包裹体测温及成分测定、稳定同位素特征资料及超基性岩中金丰度值等分析,金矿物质主要来自超基性岩,流体来源于深部,其成因属与超基性岩有关的韧性剪切带型金矿床。
Three suites of Early Palaeozoic ophiolite are distributed in three belts (north, middle, south) on the middle--western sector of North Qilian. The activation andmigration of gold were mainly controlled by the ultrabasic rock belts and two ductile shearbelts in same direction. Gold mineralization occurred chiefly in the strong alterated ultrabasicrock bodies, contact zones between ultrabasic rock bodies and country rocks and crushalteration zones. According to the temperature and content of inclutions, stable isotopefeatures and gold abundance in ultrabasic rocks, gold is mainly from ultrabasic rocks andmineralization fluid from the depth. The origin type of gold mineralization is belonged toductile shear zone related to ultrabasic rocks.
