河南省南召县水洞岭铜多金属矿床地质特征及找矿潜力

Geological characteristics and prospecting potential of Shuidongling Cu polymetallic deposit in Nanzhao of Henan

水洞岭矿床为一中型铜多金属矿床,(332)+(333)+(334)铜铅锌金属量13万余吨。笔者在收集区内已有地质勘查、科研成果资料的基础上,对矿区的地质情况进行了实地调查。通过对成矿地质特征的总结和综合研究,对矿床的成因进行了探讨。该矿床成矿的大地构造背景、赋矿岩石特征、矿体形态、近矿围岩蚀变的主要类别、矿石构造类型分带、矿石矿物组合、主要成矿元素组合及主要伴生组分等地质要素均与黑矿(VMS型)的特征基本相同;同时,矿石组构(交代文像结构、交代残余结构及矿石中呈脉状—细脉状斜切赋矿岩石片理而出现的黄铁矿化及闪锌矿化)、细鳞片状绢云母化及深色鳞片状叶绿泥石化蚀变特征等联合表明,矿床具有后期热液弱改造的痕迹。因此,水洞岭矿床的成因类型应归结为海底火山喷流沉积-弱改造类黑矿型矿床。

Shuidongling deposit is a medium-sized copper polymetallic deposit with over 130,000 tons of indi- cated, inferred and predicted metal reserves of Cu, Pb and Zn. The authors conducted field investigation on geological conditions of the mining area based on the existed data of geological survey and scientific research results related to the area. After a summary and an integrated study of the metallogenic and geological char- acteristics, the authors discussed the genesis of the deposit. The geological elements which include tectonic background of mineralization, characteristics of ore-bearing rocks, forms of the orebodies, main types of near-ore wall rock alteration, zoning of ore structure types, composition of ores and minerals, major metallo- genic element associations and main associated components are basically the same as those of black ore （VMS-type）. Meanwhile, the deposit shows some traces of late-stage hydrothermal weak reworking process which is proved by a combination of characteristics like ore texture （metasomatic-graphic structure, meta- somatic relic texture and pyritization and sphaleritization caused by schistosity of beveled ore-bearing rock which occur in veined or fine veined forms in the ores）, fine flaky sericitization and dark color flaky pennin- itized alteration characteristics. In conclusion, the authors believed that Shuidongling deposit was a subma- rine volcano sedimentation-exhalation weak reworked black ore type deposit.