关键词: 陆相, 断陷盆地, 层序, 成因, 构造演化

Abstract: A preliminary genesis analysis about a stratigraphic sequence showed that the development of sequence in confinental rift basins is just controlled by episode tectonic subsidence,and not sea/lake-level changes.The second order tectonic cycles control the development of sequences while the third and the forth order tectonic cycles are the main control factors of the development of parasequence sets and most parasequences respectively.The ratio between the new space added by tectonic subsidence and the volume of supplied or filled corresponding sediment determines the type and the characteristics of parasequences,parasequence sets and depositional systems tracts.The development of the main sequence surfaces,such as the unconformity and hiatus,for dividing different order sequences in continental rift basins,is related to tectonic events.Moreover,the analysis of sequence genesis has also revealed that lake-level changes are not synchronized with or correlative with sea-level fluctuations.

Key words: continental facies, rift basin, sequence, genesis, tectonic evolution