A series of fault terrace belts were found in Xujiaweizi fault depression

from the margin to the center of the depression

in late Juassic to early Cretaceous.The synsedimentary faults

controlling the generation of fault terrace belts

segmented the secondary geological units

such as uplift belt

slope belt and hollow zone.Xujiaweizi fault-depression can be divided into north and south regions:the former consists of west and east two half-grabens;while the latter is composed of three half-grabens.Each half-graben generally consists of basin-margin uplift

steep-slope fault terrace

hollow zone and gentle-slope fault terrace.There is a secondary uplift between two half-grabens. The development of fault terrace belts controlled the topographies from the margin to the sag in the basin

and hence controlled the types of depositional facies and their distributions

too. Moreover

volcanic activities induced by faulting or associated with faulting resulted in the infilling of volcanic materials in the basin

and the transformation of secondary tectonic pattern and topography in the basin

which would

therefore

controlled the types and distribution of sedimentary facies.It is susgested that the distribution of volcanic massifs and sedimentary facies have been controlled by the fault terraces in Xujiaweizi fault depression.Such control should have been affected by multiple factors

and cannot be easily explained with a single meachanism.