The Carboniferous Prototype Basin Analysis In Bogda Region, Xinjiang, North-west China

The Carboniferous of Xinjiang, Northern-west China is a new exploration target layer, and significant exploration discoverments have been achieved in Santanghu Basin and Junggar Basin. Because of the low study level of Carboniferous in Turpan-Hami basin and adjacent areas, Carboniferous oil and gas exploration progress here is very slow. Bogda Tectonic Belt, which mainly composed of the Carboniferous, is located between the Junggar basin and Turpan-Hami basin, and has an important significant study meaning to Turpan-Hami Basins. According the Plate Tectonics, Structural Geology, Sedimentology Theory as a guide, utilizing the stratigraphy, geochemistry, petrography Stratigraphy, Structural Geology, Sedimentology, the Carboniferous prototype basin of Bogda region is analysised by the article, which provides the oil and gas exploration and development basis to the Carboniferous of Turpan-Hami Basin.According to the rock association characteristics, biological group characteristics, stratigraphic contact relations, the Carboniferous in Bogda region could be divided into Lower Carboniferous: Tapujieerquan Group and Qijiaojing Group, Upper Carboniferous: Liushugou Group, Qijiagou Group and Aoertu Group from below. The C-P₁ tectonic sequence could be divided into sub-Carboniferous tectonic sequence, Upper Carboniferous Formation Liushugou tectonic sequence, Upper Carboniferous Formation Qijiagou-Aoertu tectonic sequence sub-groups and sub-Lower Permian tectonic sequence by the stratigraphic contact relations and interpretation results of seismic data in the basin.Petrography of volcanic rocks, mineralogical characteristics and major elements, trace elements, REE and other geochemical characteristics of volcanic rocks in the region show that volcanic rocks of Bogda region has the consistent characteristics of mainland rift valley.The characteristics of ancient flow and the mother rock in source region show that Carboniferous source of Bogda region were from Junggar ancient land and Turpan-Hami Ancient Land, Kelameili - Moqinwulashan Tectonic Belt which uplifted in the late Early Carboniferous and the uplift region within the basin in late Late Carboniferous. Based on facies marks, which is established by the field measured profiles analysis and laboratory-office analysis, Bogda Rift Valley, which is a framework combined with the characteristics of source area, the Carboniferous sedimentary pattern of prototype basin in Bogda region is completed. The deposition is littoral-neritic facies in most area of the Bogda region and most time of the Carboniferous. Semi-deep sea - the deep sea sediment was developed in the axis of Bogda Rift Valley of the Liushugou period, and in the western region of Bogda region of Aoertu period. The stratigraphic distribution was developed mainly by east-west. In the Aoertu period, Late Carboniferous, differences between East and West of Bogda regions came out. The potential source rocks of Bogda areas are dark mudstone which were mainly distributed in the north area of Qijiaojing County of Liushugou Formation and Shichengzi regions located to the north of Hami City of Qijiagou Formation. They are controlled by half deep - deep-sea and littoral-neritic environment respectively. The dark mudstone is mainly II kerogen type and belongs to good - poor source rocks, most of them had been over matured.