2001 年 16 巻 p. 19-25
Hydrothermally-altered organic-rich lake sediment was collected from Lake Usori, Osorezan. The biomarker composition and carbon isotopic composition of individual n-alkanes were examined on this sample, and the characterization was carried out to compare with reservoir petroleum and hydrothermal petroleum.
The studied lake sediment is characterized by odd dominant n-alkane, a little amount of isoprenoid alkane and alkylaromatic hydrocarbon, and lack of UCM. These characteristics are different to the composition of both reservoir and hydrothermal petroleum. A significant amount of heterocyclic compounds and 17β(H)-hopane in this sample are similar to the composition of hydrothermal petroleum, but the concentration of PAHs, hopene and sterene in studied sample are much lower than those of hydrothermal petroleum.
Carbon isotopic compositions of individual n-C17-C30 alkanes decrease with increasing carbon number. The decrement of δ13C value is about 10‰.