The Jiama deposit,a significant porphyry-skarn-type copper polymetallic deposit located within the Gangdese metallogenic belt in Tibet,China,exemplifies a typical porphyry metallogenic system.However,the mineral chemistry of its accessory minerals remains under-examined,posing challenges for resource assessment and ore prospecting.Utilizing electron microprobe analysis and LA-ICP-MS analysis,this study investigated the geochemical characteristics of apatite in ore-bearing granite and monzogranite porphyries,as well as granodiorite,quartz diorite,and dark diorite porphyries in the deposit.It also delved into the diagenetic and metallogenic information from these geochemical signatures.Key findings include:(1)The SiO2 content,rare earth element(REE)contents,and REE partition coefficients of apatite indicate that the dark diorite porphyry possibly does not share a cogenetic magma source with the other four types of porphyries;(2)the volatile F and Cl contents in apatite,along with their ratio,indicate the Jiama deposit,formed in a collisional setting,demonstrates lower Cl/F ratios in apatite than the same type of deposits formed in a subduction environment;(3)compared to non-ore-bearing rock bodies in other deposits formed in a collisional setting,apatite in the Jiama deposit exhibits lower Ce and Ga contents.This might indicate that rock bodies in the Jiama deposit have higher oxygen fugacity.Nevertheless,the marginal variation in oxygen fugacity between ore-bearing and non-ore-bearing rock bodies within the deposit suggests oxygen fugacity may not serve as the decisive factor in the ore-hosting potential of rock bodies in the Jiama deposit.
YANG Yang;SUN Miao;QI Jing;TANG Juxing;ZHANG Zebin;TANG Pan;XIE Fuwei;RAN Fengqin;YANG Zongyao;YANG Huaichao;BAI Yun
School of Earth Sciences,Chengdu University of Technology,Chengdu 610059,ChinaSchool of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,ChinaMNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources,CAGS,Beijing 100037,ChinaThe Key Laboratory of the Ministry of Education on Solid Waste Treatment and Recycling,School of Environment and Resource,Southwest University of Science and Technology,Mianyang,Sichuan 621010,ChinaChengdu Surveying Geotechnical Research Institute Co.,Ltd.of MCC,Chengdu 610023,ChinaSichuan Tianfu Mining Investment Co.,Ltd.,Chengdu 610055,ChinaSichuan Institute of Comprehensive Geological Survey,Chengdu 610081,China
apatite;metallogenesis;mineral geochemistry;porphyry;Jiama;Tibet
《地质学报（英文版）》 2024 (002)
399-415 / 17
This study was financially supported by the National Key Research and Development Program of China(Grant No.2022YFC2905001),the National Natural Science Foundation of China(Grant Nos.42272093,42230813),and a geological survey project(Grant No.DD20230054).Additionally,we would like to express our sincere appreciation to the two anonymous reviewers and editors for their valuable suggestions and constructive comments,which have significantly improved the quality of this manuscript.
10.1111/1755-6724.15143
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