Distribution of moretene, sterere, fernene, hopene and dienoic carboxylic acid in marine sediments in sea area of the Southern Ocean

The soluble organic matters were extracted from marine sediments in the sea area of Southern Ocean by using organic solvents. The hydrocarbon and carboxylic acid fractions were separated with the thin layer chromatography. The organic compounds of 170(H), 21α(H)-bishomomoretene, cholest-5-ene, 24-methyl-cholestene, 24-ethylcholestene, hop-17(21)-ene, neohop-13(18)-ene, fern-8-ene, fern-7-ene, 170(H), 210 (H)-hop-22(29)-ene (diplotene), steranes, β, β-hopanes C₂₉-C₃₁ and unsaturated carboxylic acids C_18:2^Δ9.12, C_18:1^Δ9,C_18:1^Δ11, have been identi-fied in the hydrocarbon and carboxylic acid fractions by means of gas chromatography and gas chromatography-mass spec-trometry-data system. The distributions of 3, a-bishomomoretene, β,β-hopene and β,β-hopane are characteristic of immature organic matter. The sterane, C₂₉ 20S/20R epimer ratio 0.6 indicate that the organic matter had experienced a thermal evolution in the early sedimentation. The unsaturated fatty acids especially dienoic acids and fernene compounds indicare not only the origin from autochthonous bacteria but also the reducing environment in the Southern Ocean.