Abstract:
The studied area locates in the Guangmingco area of north Qiangtang Basin. On the bases of Rock-Eval pyrolysis simulation experiment, kerogen identification, vitrinite reflection, ethnic component separation, and carbon isotope analysis of source rocks in outcrop samples of Jurassic Bailongbinghe Formation, the organic matter characteristics of source rocks were studied. The results indicated source rocks of Bailongbinghe Formation were dominated by carbonate and with high organic matter abundance, the organic carbon content obtained from 0.01% to 1.21%, averaging 0.39%. The content of sapropel in the kerogen ranged from 70% to 92%, averaging 80%, consistent with type Ⅱ
1 kerogen. The main peak of carbon isotope, the ratio of (nC
21-/ nC
22+) and Pr/nC
17-Ph/nC
18 correlation diagram indicated that the organic matter came from lower aquatic organisms and the type of organic matter was well. The vitrinite reflection value was in the range from 1.409% to 2.423%, averaging 1.909%. The thermal evolution of organic matter is generally high, reaching high maturity-over mature stage.