TY - JOUR
T1 - Mineralisation associated with the fractionated Cretaceous Baoshan Monzogranite
T2 - Tectonic implications for South China
AU - Zhang, Zhiqiang
AU - Bagas, Leon
AU - Mao, Jingwen
AU - Chen, Maohong
AU - Fu, Bin
PY - 2018/11/1
Y1 - 2018/11/1
N2 - Jurassic and Late Cretaceous granites are spatially and temporally associated with mineralisation in the Paleozoic Dayaoshan Terrane in South China (also known as South China Block). The porphyritic Baoshan Monzogranite of Late Cretaceous is an example that is petrographically studied in this contribution. Sensitive High-Resolution Ion-Microprobe (SHRIMP) zircon U-Pb ages, in-situ zircon O-Hf isotopic analyses, and whole-rock geochemistry are here used to better constrain the genesis of the monzogranite, which is porphyritic, and located in the Baoshan Cu mining area. SHRIMP zircon dating yields a weighted mean 206Pb/238U age of 89 ± 1 Ma, interpreted to be the crystallisation age of the porphyritic monzogranite. Its geochemical data indicates it is derived from partial melting of the lower to crust, followed by fractionation, and emplacement in secondary faults related to the major Bobai-Cenxi Fault. The monzogranite has a Paleo- to Mesoproterozoic source in the crust, which was metasomatised during Neoproterozoic subduction. The rotation of Izanagi Plate's subduction from NW to NE resulted into the reactivation of NW and NE-trending thrust faults as transpressional or extensional ones. It was during this period that Late Cretaceous intrusions such as the Baoshan porphyritic monzogranite were emplaced in the terrane near the NW-trending faults and other intrusions at the edges of basins such as Yangchun, Luoding and Bobai basins near NE-trending faults.
AB - Jurassic and Late Cretaceous granites are spatially and temporally associated with mineralisation in the Paleozoic Dayaoshan Terrane in South China (also known as South China Block). The porphyritic Baoshan Monzogranite of Late Cretaceous is an example that is petrographically studied in this contribution. Sensitive High-Resolution Ion-Microprobe (SHRIMP) zircon U-Pb ages, in-situ zircon O-Hf isotopic analyses, and whole-rock geochemistry are here used to better constrain the genesis of the monzogranite, which is porphyritic, and located in the Baoshan Cu mining area. SHRIMP zircon dating yields a weighted mean 206Pb/238U age of 89 ± 1 Ma, interpreted to be the crystallisation age of the porphyritic monzogranite. Its geochemical data indicates it is derived from partial melting of the lower to crust, followed by fractionation, and emplacement in secondary faults related to the major Bobai-Cenxi Fault. The monzogranite has a Paleo- to Mesoproterozoic source in the crust, which was metasomatised during Neoproterozoic subduction. The rotation of Izanagi Plate's subduction from NW to NE resulted into the reactivation of NW and NE-trending thrust faults as transpressional or extensional ones. It was during this period that Late Cretaceous intrusions such as the Baoshan porphyritic monzogranite were emplaced in the terrane near the NW-trending faults and other intrusions at the edges of basins such as Yangchun, Luoding and Bobai basins near NE-trending faults.
KW - Highly fractionated
KW - Late Cretaceous
KW - Porphyritic Baoshan Monzogranite
KW - Proterozoic lower crust partial melting
KW - South China
UR - http://www.scopus.com/inward/record.url?scp=85055058577&partnerID=8YFLogxK
U2 - 10.1016/j.oregeorev.2018.08.008
DO - 10.1016/j.oregeorev.2018.08.008
M3 - Article
AN - SCOPUS:85055058577
VL - 102
SP - 791
EP - 810
JO - Ore Geology Reviews
JF - Ore Geology Reviews
SN - 0169-1368
ER -