Sequence-paleogeography of Late Triassic Xujiahe formation in the eastern Sichuan Basin
Abstract：Based on the Vail＇s theory from EXXEN Company,the Xujiahe formation of the Late Triassic were subdivided into 4 third-order sequences,corresponding respectively to the intervals of the member 1,member 2 to member 3,member 4 to member 5 and member 6 to member 7.The TST and HST in each sequence was taken as a mapping interval and,then,the palaeogeography was reconstructed.The paleogeographic units during the TST and HST of 4 sequences include fluvial plain,delta and shallow lake,in which the first two units constitute the basic framework in the area.The sediment provenances are mainly from the Jiangnan mountains in the southeast,follows by the Daba mountains in the north.In general,the fluvial plain is expanded westward by the tectonic impact.In the periods from the transgressive HST in the sequence I to one in sequence IV,the shallow lake is firstly narrowed,then expand with a westward migration.Coal is mainly formed in the interdistributary bays,pere-marsh and flood basin.
Keywords：eastern Sichuan BasinLate TriassicXujiahe formationsequence stratigraphypalaeogeography
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)