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陶锡湖锡多金属矿床是粤东锡多金属成矿带内一个与花岗斑岩有关的矿床。本文对与矿化有关的陶锡湖花岗斑岩进行了岩石地球化学、锆石U-Pb年代学和Hf同位素研究。LA-ICP-MS锆石U-Pb定年显示,花岗斑岩侵位年龄为141.8±1.0 Ma,是早白垩世岩浆作用的产物。岩石地球化学特征显示,花岗斑岩属于弱过铝质高钾钙碱性系列,强烈富集Rb、Th、U、K、Pb,亏损Ba、Sr、Ti、P、Nb、Ta,具有明显Eu负异常,属于高分异I型花岗岩。花岗斑岩成矿金属元素丰度值高,属于典型的含锡花岗岩。花岗斑岩锆石εHf(t)从-6.67变化到-2.32,二阶段模式年龄(tDM2)为1343~1615 Ma,表明其成岩物质主要来自古老地壳,可能有少量地幔物质的加入。根据所得地球化学和年代学数据,结合区域构造演化,陶锡湖花岗斑岩及相关的锡多金属矿床形成于古太平洋板块向欧亚大陆俯冲作用有关的区域伸展的动力学背景。
The Taoxihu tin polymetallic deposit is a granite-porphyry-related deposit within the eastern Guangdong polymetallic metallogenic belt. In this paper, the geochemical, zircon U-Pb chronological and Hf isotope studies of the mineralized Taoxianhu granite porphyry were carried out. LA-ICP-MS zircon U-Pb dating shows that the emplacement age of granite porphyry is 141.8 ± 1.0 Ma, which is a product of the Early Cretaceous magma. The geochemical characteristics of the rocks show that granite porphyry belongs to the weak permanganate high-K calc-alkaline series and strongly enriches Rb, Th, U, K and Pb and depletes Ba, Sr, Ti, P, Nb and Ta Eu negative anomaly, belonging to high-grade I-type granite. Granite porphyry metallogenic elements rich in abundance, belonging to the typical tin-containing granite. The porphyry zircon εHf (t) varied from -6.67 to -2.32, and the second-stage model age (tDM2) was from 1343 to 1615 Ma, indicating that the diagenetic material mainly came from the ancient crust and that a small amount of mantle material might be added. Based on the geochemical and geochronological data obtained and the regional tectonic evolution, the Taoxianhu granite porphyry and related tin polymetallic deposits formed a kinetic background of regional extension of the Paleo-Pacific plate subduction to Eurasia.