湖南省溆浦地区板溪群金矿成因探讨

DISCUSSION ON GOLD GENESIS OF BANXI GROUP IN XUPU AREA, HUNAN PROVINCE

溆浦地区位于江南古陆南缘的雪峰山“S”形隆起带中段,金矿化产于板溪群中,主要类型为含金石英脉型及含金锑石英脉型,受背斜及断裂构造控制。岩石化学成分及稳定同位素研究结果表明,该区金矿化属变质热液成因,成矿溶液中局部可能有加里东期后岩浆热液和大气降水的参与。金源主要来自邻近围岩。千枚状板岩、粉砂质板岩及凝灰质板岩是金矿化的有利围岩。

Xupu area is situated in the middle section of 'S'-shaped Xuefeng uplift at the southern margin of Jiangnan Old Land. Gold mineralizations occur in the Banxi group. Main types of mineralizations include gold-quartz vein and gold-stibium quartz vein which are all controlled by the structures of anticline and faulting. The study of petrochemistry and stable isotopie composition indicate that gold mineralizations in this area are of metamorphic-hydro- thermal origin and post-Caledonian magmatic hydrothermal solutions and meteoric water were partially involved in ore-forming solutions. The gold source is mainly derived from the country rocks nearby and the favourable ones for gold mineralizations are phyllitic, silty and tuffaceous slates.