Abstract:The muddy source rock is divided into many density fractions by density fractionation. The palynofacies analysis and the laser particles detection results show that the free organic particle with bio-texture is dominant in the fraction of ρ<1.6 g·cm3, which accumulates the majority of organic particles with well shape and large size in the source rock. The organic matter combines with the mineral tightly in the fractions of 1.6 g·cm-3<ρ<2.2 g·cm-3 and ρ>2.2 g·cm-3, which are rich in the particle amorphous and spongy amorphous organic mater respectively, indicating the amorphous organic matter is preserved by combining with the mineral (especial clay) in the source rock.The preservation ways of different organic micro-components are different in the source rock. A lot of amorphous exists in the fraction of the organic matter combine with the minerals, indicating this fraction is important in generating oil and gas of the source rock.
