关键词: 变质构造, 古生代, 地层厘定, 康马, 西藏

Abstract:

 The Kangmar region is located in the central southern Lhagoi Kangri tectonic belt of the Kangmar-Lhunze stratigraphic area. Large amount of work has been done  at the formation of Kangmar dome，but the sequence of Carboniferous and underlying strata is still obscure.  It causes the geological history of Lhagoi Kangri tectonic belt before Carboniferous being missing. Based on great deal of data on paleontology, stratigraphy, and rock assemblages obtained during the 1∶250,000 geological survey in Gyangze-Yadong region,   the present authors  restudied the Carboniferous and underneath strata in this region, and a new stratigraphic sequence has been set up.  It is in ascending order, the Ordovician Langba Group(POl), Ordovician Zeguo Group(Oz)and Lower Carboniferous Guzi Formation(C₁g). The Lower Carboniferous Guzi Formation(C₁g)is underlying unconformably the Early Permian Polinpu Formation(P₁p)by extensional unconformity contact, and overlying the Ordovician Zeguo Group(Oz)by a detachment fault.  Pre-Ordovician Langba Group(POl)contacts Ordovician Zeguo Group(Oz)by extensional unconformity, and separates the underlying Kangmar rock mass by a detachment fault.

Key words: metamorphic structure, Paleozoic, stratigraphic revision, Kangmar, Tibet