CONTROL OF STRUCTURE ON THE SEDIMENTATION IN BAIYINCHAGAN DEPRESSION,ERLIAN BASIN

There is a larger subsidence rate on the steep slope in north Baiyinchagan depression than that on the ramp in the south.Huoen area and Dongwu area,both locate on the northern abrupt slope,are sustained depocenters.Converted tectonic belts in Baiyinchagan depression are all tectonic accommodation belts. The accommodation belt In Guer area and west Sanghe area, both lie on the northern slope of the depression,are transverse and sustained, and the topography here is ever-existing palaeohigh.Both Baiyinchagan accommodation belt and east Da-1 accommodation belt on the southern slope are watershed divides.The former is the watershed divide between the braid-river delta system of Xilinhaolai and Da'erqi and the latter between the sedimentary system of Da'erqi and Wengte.Baiyinchagan depression was a fault lake basin during Aershan stage and Tenggeer stage with rapid subsidence and converted into a downwraping lake basin after Duhongmu stage.