湖南龙山地区金锑矿床成因分析——以谢家山金锑矿为例

通过湖南部分金锑矿床年代学特征研究表明,170~150 Ma为华南集中成矿的高峰期,谢家山金锑矿通过白云母Ar-Ar测得成矿年龄160±2 Ma,受燕山运动Ⅰ影响,剧烈的构造作用与岩浆活动为成矿作用提供了动力学基础和储矿空间。流体包裹体地球化学、硫同位素和氢氧同位素的研究表明,谢家山金锑矿的成矿流体显示中低温(153.8~270.0℃)、低盐度(0.88~5.71%)、低密度(0.90~0.95 g·m~(-3))的特征。换算出其成矿压力范围是50~100 MPa,计算成矿深度为1.82~3.78 km,显示矿床成矿深度不大。该矿形成于中低温、低压环境条件下,成矿溶液主要为大气降水,早期伴有深源物质,并经历了多期次的构造与变质作用。谢家山金锑矿属矿床成因应该属于沉积—变质热液充填金锑矿床。

The Genesis of Au-Sb Deposits in Longshan Aera--A Case Study in Xiejiashan Au-Sb Deposit

Through part of Hunan gold antimony mineral chronology characteristic research shows that 170~150 ma is concentrated mineralization peak, south China Xiejiashan gold antimony deposit through the white mica Ar-Ar measured ore-forming age 160±2 Ma, affected by yanshan movement No.I, the intense tectonism and magmatism provides a dynamic basis and mineralization ore storage space. Fluid inclusion geochemistry, hydrogen and oxygen isotopic studies have shown that the sulfur isotope and Xiejiashan gold antimony deposit ore-forming fluid shows that in low temperature (153.8~270.0oC), low salinity (0.88~5.71%) and low density (0.90~0.95 g?m-3). Figure out its metallogenic pressure range is 50~100 MPa, calculate metallogenic depth is 1.82~3.78 km, according to metallogenic depth is not big.The deposit formed in the low temperature and low pressure condition, main ore-forming solution for atmospheric precipitation, early with deep source material, and has experienced many times of tectonic and metamorphism. Xiejiashan gold antimony deposit is a deposit genesis should belong to sedimentary-metamorphic hydrothermal iflling gold antimony deposit.