青海成矿地质特征的特殊性及找矿布局探讨

青海处于秦祁昆造山系和古特提斯造山系两大构造体系之间,从元古宙至新生代地壳活动强烈,各类成矿地质作用丰富而强烈,具有良好的成矿地质环境。然而,成矿期后印支晚期以来,特别是喜山期以来,青藏高原受到强大的挤压推覆作用,造成地壳短缩、增厚,高原剧烈隆升,形成高原上矿体保存条件不好,尤其是处于推覆前缘地带的青海北部东昆仑、祁连山等成矿带矿体受后期构造作用支离破碎,成矿元素活化分散,矿体保存条件较差。因此找矿布局应注意到青海矿产的保存条件,避开成矿后新构造强烈活动的深大断裂。

Discussion on the Specificity of Metallogenic Geological Features and Prospecting Layout in Qinghai Province

Abstract:Located between the tectonic systems of Qinling-Qilian-Kunlun and Paleotethys,Qinghai possesses excellent metallogenic geological environment due to abundant and intense geological activities from Proterozoic Eon to Cenozoic Era. However,since the Late Indosinian epoch,especially from the Himalayan,the Tibet plateau has been suffering from intense compression and nappe action,which resulted in crustal shortening and thickening as well as rapid uplift of the plateau. Consequently,the conservation conditions of ore bodies appear to be very poor,making ore bodies fragmented and metallogenic elements activated and scattered in the plateau,especially in the metallogenic belt of the East Kunlun and the Qilian Mountains which lie at the frontal zones of nappe structures. Therefore,it is very important to pay much attention to the conservation conditions of the ore bodies in Qinghai for prospecting layout and avoiding major deep faults which were active after mineralization.