措勤县幅地质调查新成果及主要进展  

New results and major progress in regional geological survey of the Coqên County Sheet

作　　者：刘登忠[1] 陶晓风[1] 马润则[1] 石和[1] 朱利东[1] 胡新伟[1] 

机构地区：[1]成都理工大学,四川成都610059

出　　处：《地质通报》2004年第5期506-511,共6页Geological Bulletin of China

基　　金：中国地质调查局青藏高原1:25万措勤县幅(H45C001001)地调项目成果。

摘　　要：在二叠系坚扎弄组中新发现Glossopterissp.,Yuaniasp.等植物化石,证实所含植物群属华夏-冈瓦纳混生植物群。对达雄群、乌郁群进行了重新厘定,新建新近系布嘎寺组(N1b)、洁居纳卓组(N2Q1j)。识别出3个构造层序、12个层序和7类沉积体系,建立了晚古生代至新生代的构造沉积序列。查明措勤盆地性质为构造复合盆地。发现新生代碱性正长岩和富钾火山岩,初步认定其为地壳加厚、地幔拆沉的产物。确认麦堆蛇绿混杂岩带属班公湖-怒江带的一个分支。Fossil plants such as Glossopteris sp. and Yuania sp. were found in the Permian Jianzalong Formation, which confirms that the contained flora belongs to the Cathaysia-Gondwana mixing flora. The Dawaxung Group and Oiyug Group have been redefined; the Neogene Bugasi Formation (N1b)and Jijunazho Formation (N2Q1 j)are newly established. Three tectonic sequences, twelve sequences and seven types of sedimentary system are recognized; the Late Paleozoic to Cenozoic tectonic sedimentary sequences are established. It is ascertained that the Coqên basin has the nature of a tectonic composite basin. Cenozoic alkali syenite and high-K volcanic rocks are found and it is preliminarily confirmed that they are the product of crustal thickening and mantle delamination. It is confirmed that the Maidui ophiolitic mélange belt is a branch of the Bangong Co-Nujiang belt.

关 键 词：舌羊齿化石 混生生物群 构造复合盆地 新生代碱性正长岩 富钾火山岩 混杂岩 班公湖-怒江带 

分 类 号：P623.12[天文地球—地质矿产勘探]