2010•Journal of Chengdu University of TechnologyRequires access
The sequence-based lithofacies-paleogeography of Jialingjiang Formation and Leikoupo Formation in eastern Sichuan Basin,China
Yijiang Zhong
Open publisher page 3 citations
Abstract
Based on the method of sequence-based lithofacies-paleogeography mapping,this paper studies the sequence stratigraphy and lithofacies-paleogeography of Lower Triassic Leikoupo Formation and Middle Triassic Jialingjiang Formation in eastern Sichuan Basin.The Jialingjiang Formation is divided into two sequences(TSQ1,TSQ2),and the Leikoupo Formation into one sequence(TSQ3).Taking the system tract or sequence as the mapping unit,5 maps of sequence-based lithofacies paleogeography are drawn from Jialingjiang Formation to Leikoupo Formation in eastern Sichuan Basin.In TST of TSQ1 there mainly deposits limestone of open platform and in HST of TSQ1 there deposits in restricted platform facies gypsolith,gypsum-dolomite and pelitic-dolomite,showing the sea level falling and the evaporated environment in eastern Sichuan basin.In TST of TSQ2 there also deposits limestone of open platform.Then,with the water body shoaling,there deposits gypsolith,gypsum-dolomite and pelitic-dolomite of restricted platform in HST of TSQ2.With the Jiangnan old land enlarging,TSQ3 is incomplete and the upper stratum is absent.From east to west,in TSQ3 there deposits clastic rock to the carbonate and the beach-barrier coast to restricted platform in sedimentary environment.The most important factor of controlling sequence filling and paleogeography evolvement is the sea level fluctuation.