西藏仲巴地区早古生代鹦鹉螺化石的发现及其地质意义  

The discovery of Early Paleozoic nautiloid fossils in Zhongba area of Tibet and its geological significances

作　　者：罗凯[1] 李祥辉[2] 王成善[1] 李亚林[1] 葛玉魁[1] 张宝森[1] 李龙[1] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院和青藏高原研究中心,北京100083 [2]南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室,江苏南京210093

出　　处：《地质通报》2012年第4期528-531,共4页Geological Bulletin of China

基　　金：中国地质调查局项目<西藏1:5万仲巴县城北区4幅区调联测>(编号:1212011086037)

摘　　要：新近在西藏日喀则地区仲巴新县城西北部发现了属于早古生代的头足类鹦鹉螺化石,归属内角石科。化石产于一套钙质片岩、片理化结晶灰岩中,这套岩层原属雅鲁藏布江缝合带中段仲巴微地体中—上二叠统的曲嘎组一段。鹦鹉螺化石的发现为仲巴微地体的地层多样化识别提供了证据,也为曲嘎组的解体提供了重要的支撑材料。进而认为,测区可能会有晚古生代泥盆纪、石炭纪地层,仲巴微地体、拉萨地体、特提斯喜马拉雅地体的早古生带地层可能具有对比性,仲巴微地体在早古生代可能与华北/扬子板块有亲缘关系。Fossils of Endociratidae of nautilaoid（cephalopods） were recently discovered in Zhongba area,southwestern Tibet.The fossils occur in calcareous schist and schistositized crystalline limestone dated as the Middle and Upper Permian Quga Formation and tectonically classified as the Zhongba microterrane of the Yarlung Zangbo suture.The discovery of nautiloid fossils provides evidence for diversified stratigraphic classification and disorganization of the Quga Formation within the microterrane.It is therefore inferred that there probably exist the Devonian and Carboniferous strata in the microterrane,the Lower Paleozoic strata might be correlatible among the Lhasa terrane,Tethys Himalaya and Zhongba microterrane,and the Zhongba microterrane might have had an affinity to the North China plate or/and Yangtze plate.

关 键 词：鹦鹉螺 曲嘎组 早古生代 仲巴微地体 雅鲁藏布江缝合带 西藏 

分 类 号：P534.4[天文地球—古生物学与地层学] Q915.2[天文地球—地质学]