地质通报2016，Vol.35Issue(7)：1115-1122,8.
东昆仑大灶火沟-万宝沟晚二叠世陆缘弧火山岩的发现及意义
The discovery of Dazaohuogou-Wanbaogou Late Permian epicontinen-tal arc volcanic rocks in Eastern Kunlun Mountains and its significance
摘要
Abstract
The material composition in Eastern Kunlun area is complex with long tectonic evolution history. The building materials have been preserved to record geological events that have occurred since the Paleoproterozoic. The orogenetic phase from Middle Devonian to Middle Triassic was particularly important in many ocean-land transformations, thus being a major period of magmatism and mineralization in the Eastern Kunlun area. For a long time, records of Permian volcanic rocks in the Eastern Kunlun area were lacking. 1∶250000 regional geological survey was carried out recently in Dazaohuo area and, as a result, a volcanic rock group of inter⁃mediate-acid, high potassium, calc-alkaline series was discovered, and U-Pb age of zircon in the subrhyolite-dacite was obtained through LA-ICP-MS, which is 254.7 ± 0.6Ma. The eruption of volcanic rocks under the continental margin arc environment was newly named Late Permian Dazaohuogou Formation to accord with section research and regional correlation. The Dazaohuogou For⁃mation mainly located in the Dazaohuogou-Wanbaogou area is strictly controlled by southern Kunlun fracture, with the outcropping area more than 74km2. This discovery not only provides definite evidence for the existence or nonexistence of Permian volcanic rocks in the Eastern Kunlun magmatic arc but also fills the gaps in Late Permian volcanic strata. The northward subduction of Kunnan Ocean started from Permian in Eastern Kunlun area, and formed huge collision-type granites. Volcanic rocks of the Dazaohuogou Formation imply that East Kunlun area was still in the regional extrusion phase in Late Permian.关键词
东昆仑岩浆弧/晚二叠世/大灶火沟组/挤压环境/LA-ICP-MS锆石U-Pb年龄/次流纹英安岩Key words
magmatic arc in Eastern Kunlun/Late Permian/Dazaohuogou Formation/extrusion environment/LA-ICP-MS zircon U-Pb ages/subrhyolite-dacite分类
天文与地球科学引用本文复制引用
史连昌,常革红,祁生胜,陈广庭,赵明福,徐博..东昆仑大灶火沟-万宝沟晚二叠世陆缘弧火山岩的发现及意义[J].地质通报,2016,35(7):1115-1122,8.基金项目
中国地质调查局项目 （）
