Sequence stratigraphic framework and palaeogeography evolution of the Cretaceous in Kuqa Depression,
Tarim Basin
Mei MingxiangYu BingsongJin Weiguang
1 Key Laboratory of Lithospheric Tectonics and Lithoprobling Technology,Minist ry of Education Beijing 100083
2 School of Earth Sciences and Resources,China University of Geosci ences Beijing 100083
The Cretaceous in the Kuqa Depression was an arid intracontinental depression,in which only the Lower Cretaceous marked by a set of arid redbed was developed and could be divided into the Yageliemu Formation,the Shushanhe Formation,the Baxigai Formation and the Bashijiqike FormationSeveral types of sediments constitute this set of arid redbediepluvialfan conglomerates,intermittent river sandy conglomerates,aeolian sandstones and desertlake purple mudstones These sediments of the Cretaceous in the Kuqa Depression made up a typical desert sedimentary systemThe cyclicity in stratigraphic records are reflected by the alternation between the coarse clastic pluvial sediments in the lower part and the fine desertlake sediments in the upper partAeolian sandstones were formed in the initial stage and the regressive stage of the lakeforming periodAccording to the cyclicities in the stratigraphic records represented by the sedimentary facies succession,iethe succession constituted by pluvial coarse clastic sedi ments in the lower part and fine desertlake sediments in the upper part,the Lower Cretaceous in the Kuqa Depression could be divided into five thirdorder sedime ntary sequences,ieSQ1to SQ5Because the top and bottom boundaries of the Lower Cretaceous in the Kuqa Depression are obvious tectonic unconformities,the Lower Cretaceous in the Kuqa Depression makes up a secondorder tectonic sequenceThere is regularly ver tical sacking pattern for thirdorder sedimentary sequences in the secondorder tect onic sequence This feature is reflected by that more coarse pluvial clastic sedi ments were developed in SQ1 and SQ5,and the middle part of the Lower Cretace ous in the Kuqa Depression made up by SQ2 to SQ4 was always developed with more fine d esertlake sedimentsDifferent from marine strata,the cyclicities represented by sequence sin stratigraphic records in the Lower Cretaceous of the Kuqa Depression are mai nly caused by the episodic tectonic subsidenceDue to a high difference of toporgr aphy,more coarse clastic pluvial sediments were formed in the initial stage of sedimentary basin subsidence,corresponding to the isostaticsubsidence stage during which the lake was formed and more fine de sertlake sediments were developedOn the basis of sequence stratigraphy,the pala eogeographical visage as well as the evolution process of sedimentary facies and palaeogeography for the Cretaceous of the Kuqa Depression are clearly reflected by a series of the panel diagram of sequence stratigraphic frameworks and their corresponding outline maps of sedimentary facies and palaeogeography
About author: Mei Mingxiang,born in 1965,was graduated from China University of Geosciences in 1993,and obtained PhDdegreeNow he is a profes
sor
of School of EarthSciences and Resources,China University of Geoscien
ces (Beijing),and is engaged in sedimentology and stratigraphy
Cite this article:
. Sequence stratigraphic framework and palaeogeography evolution of the Cretaceous in Kuqa Depression,
Tarim Basin[J]. JOURNAL OF PALAEOGEOGRAPHY, 2004, 6(3): 261-278.
. Sequence stratigraphic framework and palaeogeography evolution of the Cretaceous in Kuqa Depression,
Tarim Basin[J]. JOPC, 2004, 6(3): 261-278.