Abstract:

Paleo morphology resulted from tectonic movement controlled the sequence formation and development of continental basins,especially of rift basins.In the early spreading stage of a rift basin,incised channel fillings and fan deltas developed in front of uplifts;shallow lake bars or bioclastic banks developed on locally uplifted subaqueous platform.In the early middle spreading stage,base level rose,the uplifts turned to be the main provenances,three types of break in slopes developed on the basin margin,which resulted in three types of depositional systems.Nearshore subaqueous fan system resulted from faulted scarp type break in slope;slope fans system developed on faulted terrace type break in slope;fan deltas and sub lake fan system developed on steep slope type break in slope.In base level falling stage,the rift basin was gradually filled by fan deltas and fluvial delta systems.

Key words: paleo morphology, base level, stratigraphic sequence, break in slope, Bozhong Depression