At the end of the Oligocene, the "long-range effect" of the India-Eurasia collision terminated the link between the Tarim basin and the Paiaeo-Mediterranean and the Tarim basin started a development of continental basin. A very thick continental sequence mainly of fluvial-lacustrine facies deposited in the western Tarim basin in the Neogene. This sequence, composed mainly of clastic rocks with intercalation of evaporites, and of varying thickness with maximum of 6050 m, is classified into the