YAN Cheng-wen, ZHANG Xian-he, LI Hong-wei, XU Hao-xiang

(Guangdong Geological Survey, Guangzhou 510080, China)

Abstract：The Neihan granite pluton is located on the northwestern edge of the Yunkai block, spreading along the Luoding-Guangning fault. The exposed area is larger than 600 km2. The main lithology consists of fine-grained biotitic granite. This study applied LA-ICP-MS zircon U-Pb isotopic dating method and the results shows the age of crystallization is 246.7±7.1 Ma and the result of Indosinian magmatism. Based on the lithogeochemical analysis of and the regional structural background, we concluded that the mechanism of magma intrusion is closely connected with the wide-spread collision orogenesis and the earth crust thickening during the Indosinian. As well, the partial melting within the crust may be its dynamic cause.

Key words：zircon; U-Pb ages; LA-ICP-MS; lithogeochemistry; Neihan granite pluton

E-mail: ycwcumt@163.com

ACTA MINERALOGICA SINICA Vol. 34, No. 4, 2014, Page 481-486