我国西南地区两个别具一格的成矿带(域)

Two Unique Mineralization Areas in Southwest China

西南大面积低温热液成矿域包括多种矿床类型 ,它们之间具若干重要共同之处 ,如成矿温度多小于2 0 0℃ ,物质组成常“你中有我 ,我中有你” ,蚀变方式和受构造控制格局相似。本成矿域跨越多个大地构造单元 ,成矿作用是本地区最晚热事件之一 ;南岭西段为含锡多金属超大型矿床密集区。矿床都具复合矿石类型 ,但以多层似层状块状硫化物矿石为主。有的矿床锡达超大型规模 (个旧、大厂 ) ,有的则其他金属达超大型规模 (都龙的锌 ,白牛厂的银 ) ,但也含较多锡。含矿地层不同 。

The huge epithermal mineralization area of SW China comprises many ore deposits types, which often show important similarities: low ore-forming temperature ( usually <200℃ ),similar alteration forms and structural control, and intimate relationship in ore constituents. This huge epithermal area covers a number of tectonic units and mineralization was the latest thermal event in geological history. West Nanning is a metallogenic belt with clustered tin and polymetallic ore deposits. Ore types are complex, but layered massive sulfide type predominates. In certain deposits, tin reaches superlarge scale ( Gejiu, Dachang ), while in others, resenves of silver or zine are superlarge ( Bainiuchang and Dulong respectively), but still with appreciable amount of tin. Ore-bearing stratigraphic horizons may be different, but all are superimposed by Mesozoic granite intrusion.