The Stratigraphic Correlation And Tectonic Affinity Of The Northern Qaidam And The Western Margin Of North China In Mesoproterozoic And Neoproterozoic

The Quanji Block is a micro-continent that located in the northern margin of the Qaidam Basin.It is surrounded by the North China Block,the Tarim Block and the Yangtze Block,so its tectonic position is particularly special.The Quanji Group is a set of stable sedimentary cap that began to deposit above the basement from the Mesoproterozoic.Since the last century,many scholars put forward their understanding of tectonic affinity in North Qaidam.Due to the lack of reliable experimental data to support or one-sided argument is unconvincing,there is still an unified conclusion.One of the most typical viewpoints is that the Quanji Block is a fracture of the Tarim Block,it is similar to the North China Block in the Paleoproterozoic,but it owns a close affinity with Yangtze Block in the Mesoproterozoic and Neoproterozoic.Experimental data make a great contribution to stratigraphic division and tectonic affinity analysis.This paper collected a large number of previous research results and geological reports,focusing on detailed research and analysis on the northern margin of the Quanji mountain in the North Qaidam,Oulongbuluke mountain,Shihuigou and the Alashan,Helan mountain,Longshou mountain and the west of Henan Province.Through the regional comparative analysis of stratigraphic sequence,contact relationship,volcanic event layer and special marker layer(moraine gravel and phosphorus layer),and this paper finally found that the North Qaidam and the western margin of North China have similar structural affinities and environmental in the Mesoproterozoic and Neoproterozoic,rather than contrasting with Yangtze Block,and that the formation of its cap deposits and its lithologic characteristics may have responded to the breakup of the supercontinent of Columbia.