陕西双王金矿床角砾岩动力学成因探讨

A DISSCUSSION ON DYNAMIC GENESIS OF THE BRECCIA DEVELOPED IN THE SHUANGWANG GOLD DEPOSIT IN SHAANXI PROVINCE,CHINA

双王金矿可拼性含金角砾岩是流体致裂角砾岩,而不是构造角砾岩或隐爆角砾岩。该区的深源异常高压流体是角砾岩产生的必要条件。角砾岩的动力学成因主要是区域变质作用、地壳隆升剥蚀作用和地下岩浆活动等形成异常高压流体,在重力、浮力和地热梯度的驱动下,在能干性强的岩石中产生裂隙,并向浅部增殖,被碳酸盐矿物等充填胶结。周而复始的流体压裂—沉淀愈合作用,使金多次富集,形成矿体。

The gold-bearing breccias of the Shu angwang deposit in Shaanxi Province are a kind of fluid fracturing breccias,which are neither pressure breccias nor cryptoexp losion-breccias as they were regard ed before.The superhigh pressure flui ds come from depth in the area were the necessary condition which breccias could be formed.The dynami c genesis of breccia was the superhig h pressure fluids,drived by gravity,buoyancy,and thermal degree,which come from regional metamorphization,crustal recoil and dis-integration,and magmatic activity induced splitting in competent rock s and accretion upward,and the chops were filled by carbnate and other min erals sealant.The gold was concentr ated and at last the gold bodies were formed during fluids fracturin g and chops healing in the rocks times.