The Study On Sequence Stratigraphy And Sedimentary System Of Mid-Lower Jurassic In Southwestern Tarim

Based on comprehensively summarizing predecessors’ research results, focusingon southwestern Tarim basin, utilizing the field outcrop section, well logging, seismicand paleontological data, guided by the theory of sequence stratigraphy, in view of60wells in southwestern Tarim and field outcrop, I conducted sequence division andsedimentary system research. Southwestern Tarim lower-middle Jurassic stratumcould be separated into three sequence SQ1, for SQ2and SQ3, and according to lowstand system tract, transgressive system tract and high stand system tract, eachsequence was divided into3parts. SQ1is equal of J1s, SQ2is equal of J1k, and SQ3isequal of J2y and J2t. Through core, logging and field outcrop, conducting sedimentaryfacies recognition on the southwestern Tarim lower-middle Jurassic stratum.Southwestern Tarim lower-middle Jurassic stratum mainly developed alluvial fansystem, meandering river system, fan delta system, lake delta system, lake system andswamps, the sedimentary system in the isochronous stratigraphic framework withinthe space distribution research. The regularity of combination of the space betweensedimentary facies has been clear, and sequence, sedimentary depositing model hasbeen established. Also, through the analysis of sequence sedimentary filling controlfactors, and suggested that formation and sedimentary sequence in this area iscontrolled by structural factors and sediment supply and lake level fluctuation for thesecondary controlling factors.