Main controlling factors of sequence development in lacustrine basins are tectonic uplift and subsidence

lake-level changes

and changes of sediment supply rates.Transformation of regional tectonic regimes in stacked basins is the basis for defining the first-order sequence.Sedimentary products of tectonic episodes consist of the second-order sequence

the third-and higher-order sequences chiefly reflect changes of paleogeography and depositional styles.Isochroneity of system tracts of lacustrine basin under various conditions is obviously different.System tracts defined above are isochronic when change ratios between compatible space of one "sedimentary field" controlled by one extrabasinal sediment supply or multi "sediment fields"controlled by several extrabasinal sediment supplies and sedimentation:rates are all more than 1 or less than 1.Lowstand sandstone and conglomerate bodies controlled by structural break(zone) in fault-depressed type lacustrine basin and delta-front sandstone bodies underlainl and overlain by two largest flooding acustrine mudstones in depressed-type lacustrine basin are main targets for explorating subtle pools.