INVESTIGATION OF THE SOLID BITUMEN BY CHEMICAL DEGRADATION METHOD——A CASE STUDY OF THE SOLID BITUMEN FROM THE NORTHEASTERN SICHUAN BASIN

An investigation on the parent material and the genesis of the solid bitumen from the northeas-tern Sichuan Basin has been carried out by using the selective chemical degradation method combined with various organic geochemical analysis and measurement techniques.Compared with the soluble organic matter extracted from the solid bitumen sample,the biomarker obtained by the chemical degradation method has relatively lower thermal maturity,and can reflect the characteristics of the parent materials of the early evolution stage.The data of the biomarker parameters and the bitumen reflectivity indicate that the solid bitumen has experienced a relatively high thermal evolution,and possibly has under-gone a certain degree of biodegradation.Based on the biomarker distribution of the solid bitumen in the sample,it can be inferred that the precursor of the solid bitumen dominantly derives from the low-level aquatic biota such as the bacteria and the algae,which were deposited under a brackish or relatively deep water environment.