Unifying Division of Sequence Stratigraphy Unit and Framework Sequence Stratigraphy of Erlian Basin

Based on analyzing the previous problems relative to sequence stratigraphy researches on Erlian basin, this paper associated with the theories and methods of tecto-stratigraphy, genetic stratigraphy and sequence stratigraphy.We take the boundaries of basin generation and boundaries of basin prototype with regional correlative significations as first-order and second-orders in the scenario of framework sequence stratigraphy. And every cycle (para-type basin) representing rift and tectonic inversion within basin (or depression) type is divided as third-order sequences, and the subsidence-filling unit as fourth-order sequences. This paper is to analyze sequence stratigraphic framework based on the restriction of tectonic-sedimentation, and to analyze genetic stratigraphic framework under sequence stratigraphic framework. The merits in the scenario of framework sequence stratigraphy are that it inherits the analysis of chronostratigraphic boundary, sequence cycle and accommodation within marine sequence stratigraphy, and abandon part component of sea-level change and systems tracts in marine setting that are unsuitable in continental rift basin. Such scenario is convenient to construct the unifying sequence stratigraphic framework abroad entire basin, and to express sedimentary characteristics and developments of every sequence stratigraphic unit as well as hydrocarbon pool forming conditions located on different structure-lithofacies zones. In the meantime, this scenario will help to promote cognizing distributions and regional differences of favorable reservoirs and their facies belts so as to establish the significant model of hydrocarbon pool formation and accumulation. Based on practical analyses in all sags within Erlian basin, this paper has constructed correlative, obviously disciplinary and unifying boundary-ordered systems and correlative sequence stratigraphic framework.