Analysis of the material sources of Shanxi formation and Shihezi formation in North E'erduosi Basin

Because of discovering successively clastic rock gas reservoirs in Permian of Upper Paleozoic in North E' erduosi Basin, the special attention has been paid to the material sources of these reservoirs. By applying mathematical statistics and in combination with the distribution characteristics of light & heavy minerals and debris composition, the source areas of the Shanxi Formation and Shihezi Formation of Permian in the region are analyzed in contrast with native rocks. The analytic results show that 1. the material source system at west basin margin area is obviously different from that at Suligemiao area in the west part of the basin; and 2. the native rocks at Suligemiao area have a close affinity with those in the middle-east part of the basin, however there is still a certain difference, i. e. the native rocks in the west part are mainly composed of sedimentary metamorphic rocks (quartzite) and neutral-basic igneous rocks, and those in the east part are mainly composed of acidic intrusive rocks. Not only the problems existing in the research on the material sources of Upper Paleozoic in North E' erduosi Basin have been settled but also a new knowledge of the change law of dedris content in Shanxi Formation and Lower Shihezi Formation from west to east in the basin is achieved on the basis of these analyses and conclusions.