Sedimentary Facies Of The Kumgerliemu Group In The Central And Western Paleogene In The Kuqa Depression, Tarim Basin

In view of the existing problem nowadays in the aspect of the strata and sedimentary facies of Kumugeliemu Group of Tertiary in the midwest of Kuqa depression, the thesis has made a detailed research about Kumugeliemu Group using the theory of sedimentology and tectonic geology, combining predecessors' research achievements and under the precondition of abundant data of the well drilling, seismic interpretation and etc.Based on the previous stratigraphic classification, aiming at Kumugeliemu Group of the research area, the thesis has made a new classification which divides Kumugeliemu Group into five lithologic section bottom-up:glutenite section, gypsum-mud section, dolomite section, gypsum-salt section which is divided into junior gypsum-mud section and junior gypsum-salt section, mud section. Thus, it could really unify the stratigraphic classification inside Kumugeliemu Group of the east and the west part of Kuqa depression. Meanwhile the thesis has made meticulous coenocorrelation for all the lithologic sections and junior lithologic sections and has illustrated their distribution in the research area.Ultra-thick evaporite rock was deposited in Kuqa Depression during Palaeocene-Eocene of Tertiary. Inside the strata of Kumugeliemu Group, the thesis has recognized and classified two evaporate sedimentary cycles in which evaporate sedimentary cycle I has three junior evaporate sedimentary cycles. At the same time, by means of correlation, the thesis has verified the uniformity of the evaporate sedimentary cycles in the whole research area.Through the intensive study of the vertical and horizontal distribution of sedimentary facies, the thesis considers that the glutenite section is the deposition of fan delta, the gypsum-mud section is the deposition of restricted lagoon, the dolomite section restricted lagoon-tidal flat, the junior gypsum-mud section saline lake, the junior gypsum-salt section salt lake, the mud section shore shallow lake. Based on the correlation of sedimentary facies between wells and the stratigraphic distribution, the thesis has done a further research about the sedimentary facies and provenance distribution in the plane. At last, the thesis has established sedimentary model of Kumugeliemu Group, confirming that during the early stage of Kumugeliemu Group the environment of the research area is lagoon-tidal flat by the advance of sea and during the middle-late stage is evaporable inland lake by the sealing of the sea.