印度尼西亚西加里曼丹省吉打邦县马拉乌铅锌矿床地质特征

马拉乌铅锌矿床为印度尼西亚西加里曼丹（Kalimantan）省吉打邦县近年来发现的铅锌银矿床。该矿矿体顶板为黄铁矿化含碳质泥砂岩,矿体底板为玉髓状硅质岩。矿体呈侧羽状、脉状及透镜状。矿区通常发育的蚀变有硅化、泥化和绿泥石化等。主要矿物组合有方铅矿、闪锌矿、黄铁矿、磁黄铁矿、黄铜矿、斑铜矿、辉锑矿以及自然金、银金矿、辉银矿等,通过对矿石组构等综合分析,表明该矿床的成因是岩浆期后热液充填交代矿床。

Geologic characteristics of the Marau lead-Zinc ore deposit in Ketapang of Kalimantan Province,Indonesia

The Marau deposit is a newly discovered lead-zinc ore deposit in Ketapang of Kalimantan Province in Indonesia.The deposit is distinctly controlled by fissures in the Mesozoic-Cenozoic volcanics.The hanging wall of the deposit is formed of pyritized carbargilites,and the bottom wall of chalcedonized silicalites.The ore bodies show pinnate,vein and lenticular shapes.The main wall rock alterations of the deposit are silication,argillization and chloritization.The mineral assemblages are complex and are composed of galena,sphalerite,pyrite,pyrrhotite,chalcopyrite,bornite,stibnite,gold,electrum and argentite.Basing on the analyses of mineral assemblages and chemical compositions of ores,it is clarified that the ore bodies obviously show a zonation in both horizontal and vertical directions,indicating that the formation of the deposit is related to the hydrothermal alteration,caused by intrusion（injection） of subvolcanic rocks,and the hydrothermal solution is derived from late calc-alkaline volcanic rock formations.