丁家山铅锌矿床稀土元素地球化学特征研究

Rare Earth Element(REE) Geochemistry of Dingjiashan Lead-Zinc Ore District

丁家山铅锌矿矿床的成因复杂,主要存在矽卡岩型与块状硫化物型两种争议。尝试从稀土元素地球化学的角度对其成因进行重新探讨。结果表明:矿床的主要矿源层为元古代龙北溪组上段大理岩地层,而非中新元古代东岩组绿片岩地层;所谓的"绿片岩"为燕山期中酸性岩浆侵入体与经过区域变质的钙质泥岩、钙质粉砂质泥岩、钙质泥质粉砂岩和泥灰岩发生双交代作用所形成的矽卡岩,而非绿片岩相遭受区域变质;成矿流体主要来源于大理岩地层,少量来自岩体,而非多来源;成矿时代为燕山期,故矿床成因应为矽卡岩型。

The complex genetic type of Dingjiashan with undergone regional metamorphism calcareous lead-zinc ore district evoked much controversy. There mudstone, calcareous silty mudstone, calcareous ar- was a main debate of skarn type and massive sulfide type. We attempt to reexamine the genesis of deposit using rare earth elements geochemistry. It was re- vealed that the main source bed of the deposit is upper part of Longbeixi formation marble, rather than Dongy- an formation greenschist and so called ＂greenschist＇ was skarn, which was formed by contact metasomatism of strong Yanshanian intermediate-acid magrnatism gillaceous siltstone and marlstone, rather than green- schist undergone regional metamorphism. The ore- forming fluid of the ore district were mainly derived from marble, a few from granite sources, and the mineralization hanian. So the genesis type of placed by skarn type , rather than muhiple took place in Yans- this area should be