Abstract:

According to the results of regional geological survey in recent years and the latest exploration achievements of Xinjiang & Tuha oil fields, the Carboniferous sedimentary building patterns by the analysis of regional tectonic background and depositional filling process are concluded. The aim of this article is to clarify the Carboniferous stratigraphic sequence in northern Xinjiang and to point out the source rock-existing formations of Carboniferous as well as the main hydrocarbon generating areas. The effective source rocks mainly occurred in the marine sedimentary basins of passive continental margin and marine-continental transitional facies basins developed during extensional period of Early Carboniferous in the Derbute Piedmont,Bogeda Piedmont in west Junggar,and east Junggar basin-Wucaiwan district,and were widely distributed in Lower Carboniferous;on the contrary, these rocks in Upper Carboniferous were relatively limited distributed, which existed mainly in the Shiqiantan and Buerjin-Jimunai and Kupu-Santanghu marine facies basins of Kelameili Piedmont in east Junggar basin，respectively. Hydrocarbon accumulation process in Carboniferous strictly followed the “Source Control Theory”.Effective hydrocarbon generating areas controlled the effective hydrocarbon accumulation areas, whose enrichment degree was affected by associated volcanic rocks. Finally, we selected several important regions that are strategic areas for the oil & gas exploration of Carboniferous. These regions included the developed source rock area and the adjacent tectonic belts in the east and west parts of Junggar basin, the Kupu-Santanghu area, the Bogeda Piedmont and Buerjin-Jimunai.

Key words: stratum, tectonics, lithofacies paleogeography, source rock, Carboniferous, northern Xinjiang