陕西略阳高山金矿床成矿流体特征

ORE FLUID ORIGIN OF GAOSHAN GOLD DEPOSIT, LUEYANG, SHAANXI PROVINCE

产于“勉略宁”三角成矿带的高山金矿床由 5个金矿体组成 ,该矿床的形成受区域构造活动所控制 ,其成矿作用可分为三个成矿期 :早期金的初始矿化、中期金的二次富集和晚期金的表生富集。中期成矿期为金的主要富集期 ,但晚期的表生氧化和风化淋滤作用对金的再次富集起了非常重要的作用。矿床流体包裹体以纯液态包裹体为主 ,成矿流体的温度介于 15 0℃～ 30 0℃之间。成矿流体很可能来源于中酸性钠长斑岩脉 ,但又不是典型的岩浆热液 ,具有多成因性。金的沉淀富集是在弱 -中等碱性热液、相对还原的环境中进行的。金矿的物质来源与矿区的超基性岩体、钠长斑岩脉、厚层状白云岩及各类碎屑沉积岩有密切的关系。

Located at the Mian\|Lue\|Ning triangle mineralization belt, the Gaoshan gold deposit consists of 5 ore belts. Systematic investigations indicate that the mineralization process controlled by regional tectonic processes involves three stages including the initial mineralization stage, the second enrichment stage and the third stage of supergene oxidation. The second stage is proven to be the main enrichment period, and the supergene oxidation and weathering\|leaching also are important for gold enrichment. Investigations on fluid inclusions demonstrate that pure liquid inclusions are the major fluid inclusions in the Gaoshan gold deposit. The ore fluid has a temperature range of 150\|300℃, probably derived from intermediate\|acid albite porphyritic dikes, but not typically of magmatic hydrothermal origin. The ore fluid seems to be of multi\|source. The deposition and enrichment of gold proceeded in a reducing, weakly alkaline hydrothermal environment. Source material of the gold deposit has close connections with the ultrabasic rocks, albite porphyritic dikes, thick\|layered dolomite and clastic sedimentary rocks.\;