Abstract:

Take western Jiuquan Basin in northwest China as an example, it is proposed in this paper that the basin undergone strong tectonism is termed "deformedbasin". In order to study sedimentary facies of the basin, following problems should be paid attention: 1.Guidish's relationship between deposition rate and age are used to calculate erosion thickness so as to reconvert the initial configuration in vertical. 2.According to the discordant relationship of strata thickness and deposition system in each portion of the basin, the autochthonous system and the allochthonous system are distinguished in plane. 3.The primary boundary of the basin is roughly reconverted in accordance with Johnnes Walther's phase rule, Sternberg's low, geometry or depression and isopach strike of sedimentary stratum. Finally, it is pointed out that the place where source and reservoir bedswere overlaped and superimposed are new areas for oil and gas prospecting inthe deformed basin.