Abstract:

Ⅱb is the dominant type of organic in mudstone in Es₄ of Linnan sag, organic carbon of about 68% samples are more than 0.05%, and value of S₁+S₂ are more than 0.5 mg/g in mudstone with higher organic content. The organic doesn't reach a much higher degree of organic evolvement, however, organic in some samples do reach the state of hydrocarbon generating. In order to make clear if mudstone in the study area had ever generated hydrocarbon, two samples of mudstone and oil-containing sandstone were chosen from a near depth, the biomarkers in the samples all show better comparability, which means that the mudstone in Linnan sag has some hydrocarbon generating potential, and do have generated hydrocarbon.

Key words: Es₄ Member, hydrocarbon source rock, hydrocarbon generating potential, Linnan sag