U-Pb Geochronology, Elemental and Sr-Nd Isotopic Geochemistry of the Houyaoyu Granite Porphyries: Implication for the Genesis of Early Cretaceous Felsic Intrusions in East Qinling

• Published in: Journal of earth science (Wuhan, China) Vol. 29; no. 4; pp. 920 - 938
• Main Authors: He, Xiaohu, Zhong, Hong, Zhao, Zhifang, Tan, Shucheng, Zhu, Weiguang, Yang, Siqi, Hu, Wenjun, Tang, Zhong, Bao, Congfa
• Format: Journal Article
• Language: English
• Published: Wuhan China University of Geosciences 01.08.2018; Springer Nature B.V; University of Chinese Academy of Sciences, Beijing 100049, China%State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry,Chinese Academy of Sciences, Guiyang 550081, China%Kunming University of Science and Technology, Kunming 650093, China%Institute of Yunnan Geology Survey, Kunming 650051, China; Department of Geology, School of Resource Environment and Earth Science, Yunnan University, Kunming 650091, China%State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry,Chinese Academy of Sciences, Guiyang 550081, China
• Subjects: Biogeosciences; Composition; Continental crust; Cratons; Cretaceous; Earth and Environmental Science; Earth Sciences; Geochemistry; Geochronology; Geochronometry; Geology; Geotechnical Engineering & Applied Earth Sciences; Granite; Isotopes; Lead; Magma; Mantle; Mineralization; Niobium; Orogeny; Petrography; Petrology; Ratios; Silica; Silicon dioxide; Strontium 87; Strontium isotopes; Tantalum; Uranium; Zinc; Zircon; China; destruction of North China Craton; ancient lower continental crust; granite porphyries; East Qinling
• ISSN: 1674-487X; 1867-111X
• DOI: 10.1007/s12583-018-0788-2

The Early Cretaceous Houyaoyu granite porphyries are located in the south margin of the North China Craton. Field observations, petrography, geochronology, major and trace elemental and Sr-Nd isotopic compositions are reported to elucidate the genesis of the Houyaoyu granite porphyries. SIMS zircon U-Pb analyses for the Houyaoyu granite porphyries yield two concordant ages of 133.2±2.3 (2 σ ) and 131±1.1 (2 σ ) Ma, respectively. Major and trace elemental compositions indicate that these porphyries are high-K I-type granites with high contents of SiO 2 , K 2 O, Rb, U, Pb, low Nb, Ta, Ti, and P. Initial 87 Sr/ 86 Sr ratios range from 0.708 3 to 0.709 7, and ε Nd ( t ) values range from -9.13 to -12.3, with corresponding two-stage depleted-mantle Nd model ages ( T 2DM ) varying from 1.57 to 1.91 Ga. This suggests that the Houyaoyu granite porphyries were predominantly derived from ancient lower continental crust, with minor involvement of mantle-derived components. On the basis of the tectonic evolution of the Qinling Orogen and geochemical characteristics of the Houyaoyu granite porphyries, it is proposed that they were formed in an extensional tectonic setting related to lithospheric destruction of the North China Craton, and produced Mo and Pb-Zn mineralization in East Qinling Orogen.