关键词: 树脂, 有机岩, 生物标志物, 烃源岩, 莺琼盆地

Abstract: The kerogens in Meishan group of Yacheng basin are typical Ⅲ type.The saturated and aromatic hydrocarbon fractions of Meishan group are predominately cadinene series compounds that originated from polycadinene,which present in dammar resins produced by angiosperm trees.According to optical microscopical analysis results,there are quite low amounts of resinite in organic matter of Meishan group,less than 4% in organic maceral quantitatively,average content ranging from 1.5% to 2%.Resinites are characterized by the very small size of grains which are commonly about 1-3 μm across.Organic matter of Meishan group consisted mainly of amorphinite vitrinite and inertinite.Transmission electron microscopy (TEM) analysis of kerogen ultrathin sections confirmed that submicroresinite were finely disseminated in.amorphinite,vitrinite and mineral-bituminous matrix widespreadly in low maturity (<0.70% R_o) samples of Meishan group,occured in less than 1 μm level in grains size,average content ranging 5%~10%.There are widespread micrinite and submicrinite disseminated in high maturity kerogen.Plant resin materials of Meishan group are mainly in ultrafine size,including submicroresinite and resin compounds.A great contribution to the hydrocarbon generation to plant resin material the rather than resinite is source rock.The results have indicated that Meishan group was good gas source rock,abundant plant resin material enhanced gas-generation potentials in the light of organic matter composition and abundance of Meishan group.

Key words: resin, organic rock, biological marker, hydrocarbon source rock, Yingqiong basin