广东金坑铜锡铅锌矿床成矿地质体研究

金坑铜锡铅锌矿区位于广东莲花山断裂带南西段,为中型热液充填交代铜锡铅锌矿床。文章在综合前人大量研究成果资料基础上,从成矿地质体与成矿的时空关系、物质来源方面进行系统分析研究。主微量元素与Hf同位素表明细粒黑云母花岗岩为高分异的I型花岗岩,并为成矿提供了巨量的物源和热源;硫、铅、氢氧稳定同位素证明成矿物质来源于深源岩浆,成矿流体以岩浆水为主并混入部分大气水,成矿环境为低盐度、中高温;岩浆岩LA-ICP-MS锆石U-Pb定年发现,细粒黑云母花岗岩成岩年龄为(141.0±0.3)Ma,矿床中与锡石毒砂共生的辉钼矿进行Re-Os同位素定年发现,成矿年龄为(141.3±1.0)Ma;由此初步认为该区成矿地质体为早白垩世细粒黑云母花岗岩。

Research on the mineralization geological body in Jinkeng copper-tin-lead-zinc deposit, Guangdong

Jinkeng copper-tin-lead-zinc property, located in the southwestern section of Lianhuashan fault zone, Guangdong Province, belongs to a medium-sized hydrothermal filling-metasomatism type deposit. Based on the former researches, this paper systematically analyzes and studies the time-space relationship between the mineralization geological body and mineralization, as well as the material source. The characteristics of major elements, trace elements and the zircon''s Hf isotope show that the fine-grained biotite granite belongs to the highly fractionated I-type granite, which provides massive ore-forming materials and heat source for mineralization. The sulfur, lead, hydrogen and oxygen isotopic characteristics prove that the ore-forming material is derived from deep-seated magma, the ore-forming fluid is mainly composed of the magmatic water mixed with some atmospheric water, and the mineralization was occurred in a low salinity and medium to high temperature conditions. The LA-ICP-MS zircon U-Pb dating results of the magmatite show that the fine-grained biotite granite''s diagenetic age is (141.0±0.3) Ma, and the Re-Os isotopic data of the molybdenite associated with cassiterite and arsenopyrite shows that the mineralization age is (141.0±1.0) Ma. Therefore, the paper preliminarily accounts that the early Cretaceous fine-grained biotite granite is most likely the mineralization geological body.