Petrogenesis and thermal history of the Yulong porphyry copper deposit, Eastern Tibet: insights from U-Pb and U-Th/He dating, and zircon Hf isotope and trace element analysis
MetadataShow full item record
The Yulong porphyry copper deposit (6.5 Mt at 0.46 % Cu) in eastern Tibet was formed in a post-collisional setting. New zircon U–Pb and U–Th/He ages, apatite U–Th/He ages and in-situ zircon Hf isotopic and trace element data for the Yulong ore-bearing adakitic porphyries elucidate the thermal history and petrogenesis of the deposit. Zircon U–Pb ages range from from 41.2 Ma to 40.7 Ma, indicating an Eocene formation age. Combined with the zircon U–Th/He age of 37.5 ± 1.2 Ma, results suggest that magmatic-hydrothermal evolution lasted up to 5 m.y. The apatite U–Th/He age of 33.4 ± 0.9 Ma reflects Yulong deposit exhumation during the ~33–30 Ma Tibetan uplift. Moreover, the high εHf(t)-values (7.1 ~ 12.2) zircon yield the highest ΣREE content, higher Y/Hf, lower Ce/Ce* and higher Th/U ratios compared to inherited zircon or magmatic zircon suggesting that the high εHf(t) zircon crystallized from another magma, and that magma mixing probably contributed to the adakitic porphyries at Yulong. In addition, inherited and magmatic zircon with the lowest εHf(t) values (−20.6 ~ −4.4) suggest crustal contamination. The positive zircon εHf(t) values indicate a source in the juvenile arc lower crust. Significantly, the juvenile arc lower crust inherited arc magma characteristics (abundant F, Cl, Cu and high oxidation state), which are now found in the porphyry Cu–Mo deposits.
Showing items related by title, author, creator and subject.
Thermal-tectonic history of the Baogutu porphyry Cu deposit, West Junggar as constrained from zircon U-Pb, biotite Ar/Ar and zircon/apatite (U-Th)/He datingLi, G.; Cao, M.; Qin, K.; Evans, Noreen; McInnes, Brent; Liu, Y. (2013)Understanding postmineralization tectonic movements in porphyry deposits, is critical to interpreting the complete thermal-tectonic history. This study reports new zircon U–Pb ages, hydrothermal biotite 39Ar/40Ar age, and ...
Leng, C.; Cooke, D.; Hou, Z.; Evans, Noreen; Zhang, X.; Chen, W.; Danisik, Martin; McInnes, Brent; Yang, J. (2018)The Triassic Pulang porphyry Cu-Au deposit, located in the South Yidun terrane, is the oldest and one of the largest porphyry deposits in the southeastern Tibetan Plateau. The mineralization occurs mostly in the potassic ...
Thermal history of the giant Qulong Cu-Mo deposit, Gangdese metallogenic belt, Tibet: Constraints on magmatic-hydrothermal evolution and exhumationZhao, J.; Qin, K.; Xiao, B.; McInnes, Brent; Li, G.; Evans, Noreen; Cao, M.; Li, J. (2015)A complete thermal history for the Qulong porphyry Cu–Mo deposit, Tibet is presented. Zircon U–Pb geochronology indicates that the mineralization at Qulong resulted from brecciation-veining events associated with the ...