• 责任者：Jiang Junhua (Institute of Mineral Resources ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Wang Ruijiang
• 刊名：Earth Science
• 出版年：2011
• 卷期：36(6)
• 关键词：地壳演化 ; crustal evolution ; 伸展作用 ; extension ; 青藏高原 ; Qinghai-Tibetan Plateau
• 页码：p.1021-1032
• 图表：8 illus., 2 tables, 29 refs.
• 分类号：0400
• issnNo：ISSN1000-2383
• isbnNo：CN42-1233/P

Based on petrochemical analyses and zircon U-Pb LA-ICP-MS dating combined with field investigation, the authors propose that these dykes represent a crustal extension event of the Bangong Lake arc zone after the closure of Bangong Lake middle-Tethys oceanic basin. The granite porphyries occurring only in NS-strike and the diorite porphyrites occurring both in NS- and EW-strike respectively yield a weighted mean age of (79.59±0.32) Ma (MSWD=1.08) with 13 zircons and (76.9±1.2) Ma (MSWD=2.8) with 6. The results indicate that the crustal extensional process of the Bangong Lake arc zone occurring in Late Cretaceous epoch was initialed only in EW-trending and slightly later also in NS-trending.