Continental faulted basins formed in specific depositional environment. No matter they are dust pan

half graben and complex types

they have distinct general characters in section configuration and the distribution of sediments.In section configuration

the depressions are either triangle or reversed trapezoid-fenestral structure.Every type of faulted basin possesses clear deep depressed center with fine grained sediments and the sediments around the center get coarse. In a complete ingression regression cycle

the boundary lines between fine grain sediments and coarse grain sediments are two polygons appeared as a rhomb

that is the "rhombic centre". The rhombic centres may occure in bunches

and their shapes may be variety.The rhombic centres are the main source rock areas of the faulted basins.