U-Pb and Ar-Ar geochronology of the Fujiawu porphyry Cu-Mo deposit, Dexing district, Southeast China: Implications for magmatism, hydrothermal alteration, and mineralization

作者：Li, Xiaofeng^*; Hu, Ruizhong; Rusk, Brian; Xiao, Rong; Wang, Cuiyun; Yang, Feng

来源：Journal of Asian Earth Sciences, 2013, 74: 330-342.

DOI：10.1016/j.jseaes.2013.04.012

• Geochronology
• Zircon
• Apatite
• Rutile U-Pb age
• Biotite Ar-Ar
• Cooling history
• Porphyry Cu-Mo deposit
• Fujiawu
• SE China

The Fujiawu porphyry Cu-Mo deposit is one of several porphyry Cu-Mo deposits in the Dexing district, Jiangxi Province, Southeast China. New zircon SHRIMP U-Pb data yield a weighted mean Pb-206/U-238 age of 172.0 +/- 2.1 and 168.5 +/- 1.4 Ma from weakly altered granodiorite porphyry and quartz diorite porphyry, respectively. Two hydrothermal biotites from granodiorite porphyry give an Ar-Ar step-heating plateau age of 169.9 +/- 1.8 and 168.7 +/- 1.8 Ma. Hydrothermal apatite exsolved from altered biotite yields an isotope dilution thermal ionization mass spectrometry isochron age of 164.4 +/- 0.9 Ma. The apatite age is similar to the ages obtained from hydrothermal rutile (165.0 +/- 1.1 and 164.8 +/- 1.6 Ma) and indicates that the magmatism and hydrothermal activity in the Fujiawu deposit occurred in the Middle Jurassic. Hydrothermal fluid circulation related to multiple stages of magma emplacement resulted in Cu-Mo mineralization in the Fujiawu porphyry deposit. The zircon SHRIMP U-Pb ages and the published molybdenite Re-Os age (170.9 +/- 1.5 Ma) represent the timing of magma crystallization and Mo mineralization, whereas the rutile and apatite U-Pb ages reflect the timing of Cu mineralization following quartz diorite emplacement. The data suggest slow cooling after emplacement of the quartz diorite porphyry.

• 出版日期2013-9-25
• 单位中国科学院; 矿床地球化学国家重点实验室; 桂林理工大学