河南汝阳地区铅锌矿床地质特征及铅同位素地球化学特征

汝阳地区是河南省重要的铅锌(铜钼)多金属成矿区之一,其中靳村—王坪一带铅锌矿床多分布于中元古界熊耳群鸡蛋坪组中性—中酸性火山岩地层中,属于受燕山晚期及王屋山期两期岩浆活动影响显著、且受近东西向断裂控制的铅锌矿床。铅矿石中铅同位素多有兼具原始铅和现代铅、正常铅特征,为幔源铅与壳源铅的混合铅。寄料街南部铅矿床(点)多分布于寒武系辛集组和馒头组泥灰岩、白云质灰岩层及北北东向、北东东向裂隙、节理中。铅矿石中铅同位素具现代铅、异常铅特征,为造山带铅,有上地壳物质来源特征。本文在研究汝阳地区数个铅锌矿床的地质勘查成果的基础上,结合详细的野外地质调查和矿石学研究,并进行了铅同位素分析,提出了汝阳地区铅锌矿床地质特征及铅同位素地球化学特征的异同,并对成矿物质来源进行了讨论,对汝阳地区及外围寻找铅锌矿床具有一定的指导意义。

Geological characteristics and lead isotopit geochemistry of lead-zinc deposits in the Ruyang region of Henan Province

Ruyang region is one of the most important lead-zinc (copper-molybdenum) polymetallic mineralization areas in Henan Province. The lead-zinc deposits in the jincun-wangping area of Ruyang region are mainly distributed in the intermediate-intermediate acid volcanic rock strata of the middle Proterozoic xionger group Jidanping formation, which was influenced by magmatic activities of the late Yan shun and the Wangwushan periods, and controlled by the nearly east-west faults, the lead deposits (spots) in the south of Jiliaojie are mainly distributed in limestone beds of the Xinji and Mantou formations of the Cambrian and in the fractures and joints of the NE and Ne directions, the lead isotope in the lead ore has the characteristics of modern lead and abnormal lead, which belongs to the orogenic belt and has the characteristics of the source of upper crust material. Based on the results of geological exploration of several lead-zinc deposits of the Ruyang region, combined with detailed field geological investigations and mineralogical studies, lead isotope analysis have been carried out. The similarities and differences of geological characteristics and lead isotope geochemistry of lead-zinc deposits in the Ruyang region are put forward, and the source of ore-forming materials are discussed, which show guiding significance to the prospecting of lead-zinc deposits in Ruyang region and its periphery.