嘉禾县某地汞矿床地质特征

通过对1:50 000嘉禾—塘村墟幅溪流重砂异常检查,在石炭系桂阳组地层中发现了原生汞矿床。矿体呈似层状、透镜状,主要矿石矿物为辰砂、少量辉锑矿,人工重砂中见银汞齐。矿石含Hg0.0004～0.416%,Ag0.23～47.37ppm,伴生元素Se含量较高,达15～43ppm。矿化严格受石炭系桂阳组(相当于岩关组邵东段)深灰色厚层状细晶云岩、中厚层碎裂化灰质云岩及北西西向断裂控制。围岩蚀变简单,仅见白云石化、方解石化及微弱的硅化。整个汞矿化带的分布受区域性近南北向断层控制。在该区1:200 000重砂扫面中圈定了很多辰砂异常,对这些异常进行进一步检查有可能发现新矿体。

GEOLOGIC FEATURE OF A MERCURY DEPOSIT IN JIAHE COUNTY

Following-up for the anomalies detected by 1: 50000 scale stream panned concentrate survey in Jianhe-Tangcunxu area, a primary antimony deposit is found in Guiyang Formation strata of Carbonifferous System. The orebodies take stratiform and lenticular shapes. The main ore mineral is cynnabar, with a little amount of stibnite, and silver amalgram is found in artificial panned concentrates. The ore contains Hg 0.0004--0.416%, Ag 0.23--47.37g/t , and associated element Se content is high, which reaches 0.0015--0.0043%. The mineralization is strictly controlled by dark-grey thick-layer fine-grained dolomitite, mediumlayer fracturized calcium dolomitite of Guiyang Formation and NWW trending faults. The wall rock alteration is simple, only dolomitization, calcitization and weak silicification can be found. The distribution of the entire mercury mineralization zone is controlled by the regional meridinal faults. Many cynnabar anomalies were delineated through 1 : 200000 scale panned concentrate survey in the region, to follow-up those anomalies may result in discovery of new orebodies.