Petrogenesis of the Xihuashan Granite in Southern Jiangxi Province, South China： Constraints from Zircon U-Pb Geochronology, Geochemistry and Nd Isotopes

• Published in: Acta geologica Sinica (Beijing) Vol. 86; no. 1; pp. 131 - 152
• Main Authors: Jiehua, YANG, Jiantang, PENG, Junhong, ZHAO, Yazhou, FU, Chen, YANG, Yinglong, HONG
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.02.2012; Wiley Subscription Services, Inc; Graduate University of Chinese Academy of Sciences, Beijing 100049, China%State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China; School of Geosciences and Info-physics Engineering, Center South University, Changsha 410083, China%State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences,Wuhan 430074, China%State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China; State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
• Edition: English ed.
• Subjects: Geochemistry; LA-ICP-MS; Nanling region; Nd isotope; Nd同位素; petrogenesis of Xihuashan granite; U-Pb dating of zircon; 中国南方; 地球化学资料; 燕山期花岗岩; 西华山; 锆石U-Pb年代学; 黑云母花岗岩; Geochemistry; U-Pb dating of zircon; Nanling region; Nd isotope; petrogenesis of Xihuashan granite
• ISSN: 1000-9515; 1755-6724
• DOI: 10.1111/j.1755-6724.2012.00617.x

Mesozoic granitic intrusions are widely distributed in the Nanling region, South China. Yanshanian granites are closely connected with the formation of tungsten deposits. The Xihuashan granite is a typical representative of tungsten-bearing granite. The Xihuashan granite consists mainly of medium-grained porphyritic biotite granite, medium-grained biotite granite and fine-grained twomica granite, which correspond to LA-ICP-MS zircon U-Pb ages of 555.5±0.4 Ma, 553.0±0.6 Ma and 552.8±0.9 Ma, respectively. Rocks from the Xihuashan mining area displays high SlOe （73.85% to 76.49%） and NaeO＋K20 contents （8.09% to 9.43%）, belonging to high-K calc-alkaline series. They are metaluminous to weakly peraluminous with A/CNK values ranging from 0.96 to 5.06. All granites in this study area are rich in Rb, Th, U and Pb, and depleted in Ba, Sr, P, Ti, Nb and Eu, especially depleted in medium-grained biotite granite and fine-grained two-mica granite. The medium-grained porphyritic biotite granites usually have high LREE concentrations, whereas medium-grained biotite granite and fine-grained two-mica granite displays high HREE contents. Our geochemical data reveal that the studied rocks are highly fractionated I-type granite. The magma underwent strong magma differentiation with decreasing temperature and increasing oxygen fugacity, which may explain the formation of three types of distinct granites. Variations of Rb, Sr and Ba concentrations in different type granites were controlled by fractional crystallization of biotite and feldspar. Fractional crystallization of monazite, allanite and apatite resulted in LREE changes in granite, and formation of garnet mainly caused HREE changes. Granites from the Xihuashan mining area have relatively high εd（t） values （-9.77 to -55.46）, indicating that they were probably generated by partial melting of underlying Proterozoic metasedimentary rocks with minor addition of juvenile crust or mantlederived magmas.