Abstract: The Fushun Basin is located in the FushunMishan fracture zone, the later being the eastern branch of the northern extension of the famous Tanlu Fault. The oil shale is up to 200 meter thick and can be divided into the upper richer and the lower lean oil shale layer based on their oil yield. Horizontal beddings were developed in highgrade oil shale whose oil yield usually are between 5%~8% and up to 12%. There are little beddings in the lowgrade oil shale layers with oil yield of less than 3%. Geochemical analysis indicates that the organic carbon content is higher in the oil shale, with a maximum up to 13.1%. The oil shale contains Ⅰ-Ⅱtypes of kerogen with low maturity. The oil shalebearing succession in the basin underwent six stages of evolution: initial rifting, accelerated rifting, stably rifting, moderately rifting, slowly rifting and terminating rifting. Synthetic analysis indicates that both the lean and rich oil shale were formed in a shallow lake environment when the surrounding margins of the basin underwent higher leveling and when limited material was provided into the basin. However, the former was formed when the base of the basin subsided relatively quickly and when the organic material accumulation rate was not too high. The latter was formed when the base of the basin subsided slowly and when the organic material accumulation rate was very high.

Key words: Fushun Basin, oil shale, geological characteristic, ore-forming process