--> Sequence Stratigraphic Framework and Sedimentary Evolution of Niubao Formation in Lunpola Basin, Central Tibet

AAPG/SEG International Conference & Exhibition

Datapages, Inc.Print this page

Sequence Stratigraphic Framework and Sedimentary Evolution of Niubao Formation in Lunpola Basin, Central Tibet

Abstract

Abstract

Lunpola Basin is one of the most significant continental basin of central Tibet in Cenozoic. Its principal target reservoir is continental clastic rock in Niubao Formation.

Based on an integrated investigation on well logging seismic data, cores and outcrops, the Niubao formation has been subdivided into seven third order sequences from base to top, namely SQ1, SQ2, SQ3, SQ4, SQ5, SQ6, SQ7. Each sequence consists of Lowstand system tracts(LST), lake progressive system(EST), and high stand system tract(HST). Based on the established sequence stratigraphy framework, sedimentary evolution of the depositional bodies and its spatial and temporal distribution was well studied.

And the results show that the primary sedimentary facies of the study area includes fan delta, braided river delta, and lacustrine facies, and the sedimentation of the study was characterized by multiple sediment source converged, and continuous development. SQ1(N-1) developed fan delta in the middle-north and braided river delta in the southwest of the basin; SQ2-SQ4(N-2) develops inherited fan delta deposits with the scale reduced gradually, braided river delta developed in the south and sublacustrine fan developed in the middle of the basin, those two facies became the dominate sedimentation of SQ3 and SQ4 relatively. And the sedimentation of the basin evolved from braided river delta in SQ5 to beach bar sandbody in SQ7(N-3).