JIANG Yong-guo1,2, CUI Yin-liang1,2, LI Xiao-feng3,4,5, YANG Chang-hua2, DOU Song2, XU Heng2, LIU Wen-jia2, ZHENG Xiao-jun2, ZHANG Jin-xue2, WANG Yan 2, ZHANG Ya-hui6, ZHOU Jia-xi6*
(1. Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. Yunnan Nonferrous Geological Bureau, Kunming 650051, China;
3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
4. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
5. College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China;
6. Key Laboratory of Critical Minerals Metallogeny in Universities of Yunnan Province, School of Earth Sciences, Yunnan University, Kunming 650500, China)
Abstract: The Shiganghe-Zhibenshan large W-Sn deposit is located in the western part of the Caojian complex granite in the northern Baoshan block which is in the conjunction between the Nujiang fault zone and the Lancangjiang plate junction zone. It is an important part of the Western Yunnan W-Sn metallogenic belt. The orebodies of the Shiganghe-Zhibenshan deposit occurred in the inner part of the granite body and the outer contact zone between the granite body and its wallrocks. The medium- to coarse-grained granite samples are characterized with peraluminous values (A/CNK = 1.06–1.16), enriched silicon (SiO2 = 75.18%–77.59%), alkali (Na2O + K2O = 7.22%–8.46%), and large ion lithophile elements, but relatively depleted high field strength elements. They have similar geochemical characteristics of the S-type granite. Zircon U-Pb dating results of two granite samples yield respective ages of (475.6±3.7) Ma and (473.8±4.2) Ma, indicating that the medium to coarse-grained granite intrusion in the deposit was emplaced in the Early Ordovician. Zircon Lu-Hf isotopic characteristics show that the granite could be formed by magma derived from partial melting of the Mesoproterozoic metamorphic basement, suggesting a crustal source. Furthermore, the granite is characterized by high concentrations of ore-forming elements such as W, suggesting that granite is a W-Sn enriched granite whose magma might provide ore-forming materials to the Shiganghe-Zhibenshan W-Sn deposit.
Keywords: petrogenesis of granite; U-Pb dating; Lu-Hf isotopes; the Shiganghe-Zhibenshan W-Sn deposit; the western Yunnan
ACTA MINERALOGICA SINICA Vol. 43, No. 5, 2023, Page 613
