Basemental Attribution of the Fe-Cu-Au-W-Mo Polymetallic Ore Cluster in the Southeastern Hubei: Constraint from the Ages and Hf Isotopes of the Inherited Zircons

There are two different opinions about the basemental attribution of the ore cluster in the southeastern Hubei Province, Middle-Lower Yangtze Metallogenic Belt that all attributed to the Chuanzhong-type basement or the north part related to Chuanzhong-type basement and the south part classified to the Jiangnan-type basement. In this study, zircon U-Pb dating and Hf isotope analysis were conducted for diorite porphyrite in the western Lingxiang pluton. The results indicate that the zircons of diorite porphyrite show complex compositions and sources. The youngest four zircons yield a mean ²⁰⁶Pb/²³⁸U age of (141±4)Ma, which coincide with previous researches and interpreted as the crystallization age of the diorite porphyrite. In addition, The other 16 older zircons have varied ages (217～2 550 Ma) and Hf isotopic compositions (ε_Hf(t) = −11.2～11.7). Combined with the reported ages and ε_Hf(t) values of inherited igneous zircons from the ore cluster in the southeastern Hubei, we compared with the data from Chuanzhong-type and Jiangnan-type basements respectively. The results suggest that they are different from Kongling Complex of the Chuanzhong-type basement, but are similar to the Fanjingshan and XiaJiang Groups of the Jiangnan-type basements. Particularly, the ～1.5 Ga crustal accretion both record in the ore cluster in the southeastern Hubei and the Fanjingshan and XiaJiang Groups. Combined with the regional geophysics, bounded by the line from Lingxiang, Daye to Wanghu Lake, the north part of ore cluster in the southeastern Hubei belong to Chuanzhong-type basement and the south part relate to Jiangnan-type basement.