藏北龙木错东部三岔口地区下奥陶统与泥盆系的不整合界面  

Unconformity between the Lower Ordovician and Devonian in the Sanchakou area in the eastern part of the Lungmu Co, northern Tibet, China.

作　　者：夏军[1] 钟华明[1] 童劲松[1] 鲁如魁[1] 

机构地区：[1]安徽省地质调查院,安徽合肥230001

出　　处：《地质通报》2006年第1期113-117,共5页Geological Bulletin of China

基　　金：中国地质调查局<西藏1:25万松西幅;温泉幅区域地质调查>项目(200213000007)成果。

摘　　要：在北羌塘三岔口一带采获丰富的腕足类:汉伯矮正形贝及比较种Nanorthiscf.hamburgensis(Walcott)。建立了早奥陶世岩石地层单位——三岔口组,是羌塘地区目前有化石控制的最低层位。中、晚泥盆世拉竹龙组与下伏志留系、奥陶系不整合接触关系的进一步确定,证明了羌北-昌都板块与扬子板块的亲缘性,为羌北-昌都板块属性的确定提供了重要证据。Abundant brachiopods （Nanorth/s cf. hamburgensis （Walcott）） have been collected from the Sanchakou area, northern Qiangtang, and according to the fossils the authors erect a new Early Ordovician hthostratigraphic unit--Sanchakou Formation, which is the lowest horizon controlled by fossils in the Qiangtang region at present. The further determination of the unconformable contact relationships between the Middle-Late Devonian Lazhulong Formation and its underlying Silurian and Ordovician has prove the affinity between the northern Qiangtang-Qamdo plate and the Yangtze plate. This provides important evidence for the determination of the nature of the Qiangtang-Qamdo plate.

关 键 词：早奥陶世地层 泥盆纪地层 不整合 北羌塘 西藏 

分 类 号：P534.42[天文地球—古生物学与地层学] P534.44[天文地球—地质学]