Abstract: One super-long term stratigraphic base level cycle (the second-class sequence) and coresponding 5 long temm stratigraphic base level cycles (the third class sequence) are recognized in Lower Creataceous of Jiergalangtu sag, Erlian basin by using the ways and principles of high resolution sequence stratigraphy. The long-term cycles could be described as ISC, LSC, LSC, LSC, LSC, and their developed characters are analyzed in this paper. Within the correlation framework of the sag, the development and distribution of the source-reservoir-caprock assemblages and their inner relationship to the base level eycle. [t is pointed out that four sets of the assemblages (LSCI, LSCz, LSC:+LSCs and LSCs) are developed, of which LSC3+LSCs assemblages are the most favorable for hydrorarbon accumulation.

Key words: Erlian basin, Lower Cretaceous, sequence, stratigraphy, source-reservoir caprock assemblage