LITHOFACIES PALAEOGEOGRAPHY OF LOWER JURASSIC IN ORDOS BASIN

By use of the single factor analysis and comprehensive plotting method and combining with the geotectonic system and facies analysis of single profile,the lithofacies palaeogeography of Fuxian Formation of Lower Jurassic in Ordos Basin has been analysed quantitatively.It is recognitzed that during the end of Triassic the Ordos Basin is uplifted and denuded by the Indosinian movement,forming the rolling topography,and during the Early Jurassic the deposition is occurred in the ralative low-lying area,forming the main palaeogeographic landscape of denuded-eluvial facies and the auxiliary one of alluvial-limnetic facies,and on this background the large areal Middle Jurassic deposition is developed.