Ployphase Early Paleozoic Metamorphism in the Northern Qinling Orogenic Belt
详细信息
- 责任者：Zhang Jianxin (Institute of Geology ; Chinese Aecademy of Geological Sciences ; Beijing 100037 ; China) ; Yu Shengyao
- 刊名：Acta Petrologica Sinica
- 出版年：2011
- 卷期：27(4)
- 关键词：多期变质作用 ; polymetamorphism ; 秦岭 ; Qinling Mountains
- 页码：p.1179-1190
- 图表：13 illus., 4 tables, 35 refs.
- 分类号：0802
- 出版序号：864
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
In combination with petrological data, SHRIMP and LA-ICPMS U-Pb geochronology on two HP granulite samples in the Songshugou area of the North Qinling orogen yield ages of (504±7) Ma and (506±3) Ma, respectively, representing the time of high pressure granulite metamorphism. This implies that HP granulite-facies conditions in high pressure granulite and eclogite facies conditions in eclogites developed at the same time but they formed in different thermal environments. The results suggest that the North Qinling orogen experienced an Early Ordovician subduction and crustal thickening, followed by an Early Silurian widespread Barrovian-type metamorphic event as observed in many collisional orogen.