Geological Structural Features And Evolution Of The Paleo-tectonic Stresses Field Of Daliangdaoban,inner Mongolia Regional

Daliangdaoban in Inner Mongolia located between Erlianhaote-Hegenshan suture zone and Xilamulun fault, belongs to Mongolia organic belt(MOB).The study area experienced multiple phases of tectonic deformation and deformation feature is very clear.We have researched geological structure features and evolution of paleo-tectonic stresses field in this area. It will provide geological evidence for research of MOB. It will solve some geologic problems caused by the North China and Siberian plate docking.By stratigraphic correlation, structural analysis, isotopic date and so on, we have determined a set of shallow metamorphic rock formation. Its deformation is complex, and it belongs to upper carboniferous the Benbatu group, we divide it into three stages of fold deformation.Auther carried on 1:50000 regional geological survey and structural analysis, focused on geometry and kinematics feature of fold, fault, joint, cleavage and lineation. Analyses morphological feature, combination relationship and attitude date. Besides, we combined shear joint attitude date and fault slip vector date to determine evolution of paleo-tectonic stress field in the region, and set up a complete set of structural deformation sequence. They are NW trending recumbent fold(D1), NE trending liner closed fold and thrust fault(D2), NE trending large extensional fault and fore deep basin(D3), NS trending relief fold and pressure fault(D4), NW trending extensional fault(D5).Tectonic evolution in the area was divided into four stage:① early Paleozoic continental crust growth stage on the northern margin of the North China black;② late Paleozoic continental crust growth stage on the northern margin of the North China block and the southeastern margin of the Siberian landmass;③ the Circum-Pacific domain tectonic evolution stage;④ tectonic evolution of Cenozoic uplifting stage.