地质通报2017，Vol.36Issue(7)：1104-1117,14.
保山地体寒武纪基性火山岩及其大地构造意义
Characteristics of the Paleozoic metabasite in Baoshan Terrane:Implications for the tectonic evolution
摘要
Abstract
The Baoshan Terrane is located on the southeastern margin of the Tibetan Plateau. Previous studies of the magmatism of the Baoshan Terrane were mainly focused on the Mesozoic and Cenozoic periods, whereas the study of the Paleozoic magmatism was relatively insufficient. In this paper, zircon U-Pb geochronology, geochemistry and Sm-Nd isotopes are presented for metabasite of Pumanshao Group in Bangmai area, Baoshan, Yunnan Province. The metabasites can be divided into two groups:amphibolite and bi?otite-plagioclase amphibolite. Zircon U-Pb geochronologic study shows that the two groups were formed at 536.7Ma and 532.0Ma, respectively. Geochemical characteristics indicate that the protolith of amphibolite was basaltic andesites and that of biotite-plagio?clase amphibolite was alkaline basalt. REE and trace element distribution and diagrams for discriminating the tectonic settings reveal that the two groups have geochemical features of E-MORB and OIB, respectively. Combined with the regional tectonic setting, the authors hold that metabasites are products of Proto-Tethyan ridge subduction. During Late Neoproterozoic-Early Paleozoic, like things in the Lasha and Himalaya terranes, the Baoshan Terrane was situated on the margin of Gondwana too and experienced accre?tionary orogeny.关键词
青藏高原东南缘/保山地体/早古生代/变质基性岩/增生作用/冈瓦纳Key words
southeastern Tibetan Plateau/Baoshan Terrane/Early Paleozoic/metabasite/accretion/Gondwana分类
天文与地球科学引用本文复制引用
徐晓尹,蔡志慧,陈希节,李化启,曹汇,黄学猛,段向东..保山地体寒武纪基性火山岩及其大地构造意义[J].地质通报,2017,36(7):1104-1117,14.基金项目
国家自然科学基金项目《青藏高原东南缘点苍山水平与垂直韧性剪切带的关系及运动学启示》(批准号:41302166)、中国地质调查局项目《特提斯-青藏高原科技长廊和主要成矿带构造背景综合地质调查》(编号:DD20160022)和中国地质科学院地质研究所基本科研业务费项目《缅甸抹谷及滇西早白垩世岩浆作用及对特提斯演化的启示》(编号:J1621) （批准号:41302166）
