Zircon U-Pb SHRIMP dating of the Yematan batholith in Dulan, North Qaidam, NW China

• Published in: Chinese science bulletin Vol. 49; no. 16; pp. 1736 - 1740
• Main Author: WU, Cailai
• Format: Journal Article
• Language: English
• Published: Key Laboratory for Continental Dynamics of MLR, Institute of Geol-ogy, Chinese Academy of Geological Sciences, Beijing 100037,China%Department of Geological and Environmental Sciences, Stanford University, CA 94305, USA 2004
• Subjects: UHP; UHP带; 北边缘柴达木盆地; 花岗岩; 超高压; 野马台岩基; 锆石定年; UHPbelt of North Qaidam; Yematan batholith; zircon U-Pb SHRIMP dating
• ISSN: 1001-6538; 1861-9541
• DOI: 10.1360/03wd0347

The Yematan batholith crops out over 120 km^2 in the North Qaidam ultrahigh pressure (UHP) metamorphic belt. It consists of granodiorite, monzogranite and biotite granite and forms an irregular intrusion into Neoproterozoic gneiss that has undergone Caledonian UHP metamorphism. Zircons from the Yematan granodiorite yield a SHRIMP U-Pb age of 397+3 Ma. These granitic rocks have geochemical characteristics intermediate between I- and S-type granites, and are post-collisional. We suggest that the Yematan granitic rocks were formed during the last exhumation event of the North Qaidam UHP belt.