一、矿床特征简介九曲弯铜矿属自然铜型砂岩铜矿床。矿区位于沅麻盆地中段东侧。在大地构造位置上,沅麻盆地属江南地轴的一部分,且位于地轴的西南缘,为中新生代侧迭式山间盆地。矿区内广泛出露自垩系地层,尤以K_1~3地层分布最广,含铜岩系为一套紫色层和浅 First, the deposit characteristics of Jiuqu Bending copper is a natural copper sandstone copper deposit. The mining area is located on the east side of Yuanma basin. In the tectonic position, the Yuanma basin is a part of the southern axis of the Yangtze River and is located on the southwestern margin of the epicenter. It is a Meso-Cenozoic side-by-side mountain basin. The mining area is widely exposed from the Cretaceous strata, especially the K_1 ~ 3 stratum is the most widely distributed, copper-bearing rock series is a purple layer and shallow