LA-ICP-MS Zircon U-Pb Age of Metamorphic Basic Volcanic Rock in Gongyanghe Group of Southern Gaoligong Mountains, Western Yunnan Province, and Its Geological Significance
Gongyanghe Group is composed of epimetamorphic sandstone and shale. In this paper, the authors identified the stratigraphic sequence composed of several layers of metamorphic basic volcanic rock in Bangmai Village of Longling County. It is held that its original rock was basalt formed in an intra-continental tension environment and probably related to extension after the Pan-African orogenic period. The authors got for the first time the U-Pb age(499.2±2.1) Ma of zircon from metamorphic basic volcanic rock and thus provided a reliable chronological basis for the division of the Gongyanghe Group and the restriction of the age.