滇西石缸河—志本山早奥陶世富钨锡花岗岩成因:岩石地球化学和U-Pb-Hf同位素约束  

Petrogenesis of the Early Ordovician W-Sn eniched granite in the Shiganghe-Zhibenshan area,western Yunnan,China:Constraints from petrogeochemistry and U-Pb-Hf isotopes

作　　者：姜永果[1,2] 崔银亮 李晓峰[3,4,5] 杨昌华 豆松[2] 徐恒 刘文佳 郑晓军 张金学 王艳 张亚辉 周家喜 JIANG Yong-guo;CUI Yin-liang;LI Xiao-feng;YANG Chang-hua;DOU Song;XU Heng;LIU Wen-jia;ZHENG Xiao-jun;ZHANG Jin-xue;WANG Yan;ZHANG Ya-hui;ZHOU Jia-xi(Faculty of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,China;Yunnan Nonferrous Geological Bureau,Kunming 650051,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Critical Minerals Metallogeny in Universities of Yunnan Province,School of Earth Sciences,Yunnan University,Kunming 650500,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093 [2]云南省有色地质局,云南昆明650051 [3]中国科学院地球科学研究院,北京100029 [4]中国科学院地质与地球物理研究所矿产资源研究重点实验室,北京100029 [5]中国科学院大学地球与行星科学学院,北京100049 [6]云南大学地球科学学院云南省高校关键矿产成矿学重点实验室,云南昆明650500

出　　处：《矿物学报》2023年第5期613-626,共14页Acta Mineralogica Sinica

基　　金：第二次青藏高原综合科学考察研究项目(编号:2019QZKK0802);云南省科技厅基础研究项目(编号:2019FB-144);云南大学科研启动项目(编号:YJRC4201804);云南省技术创新人才培养对象项目(编号:202105AD160003)。

摘　　要：滇西石缸河—志本山大型W-Sn矿床地处怒江断裂带和澜沧江板块结合带之间的保山陆块北段漕涧复式花岗岩体西部,是滇西W-Sn成矿带的重要组成部分。石缸河—志本山W-Sn矿床矿体分布于花岗岩内部或外接触带。矿区中-粗粒花岗岩具有富硅(w(SiO_(2))=75.18%~77.59%)、富碱(w(Na_(2)O+K_(2)O)=7.22%~8.46%)和过铝质(IA/CNK=1.06~1.16)特点,同时富集大离子亲石元素,相对亏损高场强元素,与S型花岗岩地球化学特征相似。2件花岗岩样品的锆石U-Pb定年结果分别为(475.6±3.7)Ma和(473.8±4.2)Ma,表明其侵位于早奥陶世。锆石Lu-Hf同位素特征指示,该花岗岩可能为中元古代变质基底部分熔融形成,其源区主要为壳源。花岗岩中W等成矿元素明显富集,表明其为富W-Sn花岗岩,可能为石缸河—志本山W-Sn矿床富集提供了成矿物质。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(SiO_(2)=75.18%–77.59%),alkali(Na_(2)O+K_(2)O=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.

关 键 词：花岗岩成因 U-PB定年 LU-HF同位素 石缸河-志本山W-Sn矿床 滇西 

分 类 号：P579[天文地球—矿物学] P595[天文地球—地质学] P618.66