Abstract:

The lithologic-stratigraphic traps in lacustrine basins are controlled by slope-breaks. Beixi Slope in Hailaer Basin has the
characteristics of slope-breaks. It is important to study the features and genesis of slope-breaks, and the control mode of sedimentary facies and lithologic-stratigraphic traps to help identify favorable exploration area. By the genetic mechanism of Beixi slope-breaks, we can divide them into fault slope-break, flexural slope-break, sedimentary slope-break and erosive slope-break. According to the relationships between slope-break and subsag, we divide the slope-break into three cells-inner slope-break, middle slope-break and outer slope-break. The outer slope-break is characterized by erosion slope-break, controlling the stratigraphic overlap traps; the middle slope-break is mainly fault slope-break and flexural slope-break, controlling the block-lithologic combination traps; the inner slope-break is mainly sedimentary slope-break, controlling the lenticular lithologic traps.

Key words: multistage slope breaks, lithologic-stratigraphic traps, Beixi Slope, Lower Cretaceous