Stratigraphic Correlation and Its Significance of Xinjiang-Gansu-Inner Mongolia Join Area

The stratigraphic division of Beishan mountains and east Tianshan mountains,in the Conjunction Area of Xinjiang Uygur Autonomous Region,Gansu Province and Inner Mongolia Autonomous Region,is different,because they belong to different administrative regions.But the stratigraphic correlation indicates that the stratum of east Tianshan mountains and Beishan mountains is continuous,and this can provide an important basis for tectonic division.Theses tectonic units,such as Archean-Paleoproterozoic Beishan complex (Ar₂Pt₁Bc),mesoproterowic Changcheng system Xingxingxia group (ChX) and Gudongjing group (ChG),Jixian syst}n Kawabulake group (JxK) and Pingtoushan formation constitute the center of Xingxingxia-an sham micro-pant,and Dunhuang micro-lant ism ainly made up of Archean-PaleoproterowicDunhuang complex (Ar₂Pt₁Bc) and a little mesoproterozoic Changcheng system Qianluzi group (ChQ).The accessory basiswhat the Hongliuhe-Niuquanzi-Xichangjing ophiolite beltwas confirmed Eopaleowic suture wne is that there is Precambrian stratum of containing phosphorus-vanadium-uranium-manganese in the south side of this belt,which indicate the extension and shallow-subdeep water sedimentary environment before cracking of the south plate and the north plate This evidenceproves that Hongliuhe-Niuquanzi-Xichangjing ophiolite belt lies in the location where the south plate and the north plate was splined and aggregated.