Comprehensive Geophysical Study on Stratigraphic Distribution Regularities and Tectonic Frameworks in Barkol Basin

The Barkol basin is sandwiched between the Maqinwula Island Arc and the Harlic Island Arc. Until now, its internal stratigraphic distribution, fault structure, hydrocarbon accumulation and basin-mountain relationship are still not clear. In this paper, geophysical and geological methods such as magnetotelluric sounding, aeromagnetic, and seismic methods are adopted to carry out comprehensive research. The research results show that the Cenozoic sediments are relatively thin, and the Mesozoic and Upper Permian strata have the characteristics of thinning gradually from the center of the basin to the periphery. The Lower Permian and Carboniferous strata are characterized by thick Piedmont deposits and thinning southward. There are 12 faults in the basin, the strike of which is nearly east-west, most of which are thrust faults. These faults constitute the basic tectonic framework of the study area. The basin is divided into three secondary structural units:the northern slope, the Harlic thrust belt and the Barkol depression. The Dahe structure in the Barkol depression is a favorable area for hydrocarbon accumulation. The southern Mount Harlic is thrusting northwest into the basin that is bounded by the Harlic fault. The basin and the northern Mt. Maqinwula are bounded by the Mt. Maqinwula fault, and the western Mt. Bogda fault is bounded by the Dongwu fault.