Hydrothermal petroleum from lacustrine sedimentary organic matter in the East African Rift.

摘要: Cape Kalamba oil seeps occur at the south end of Ubwari Peninsula, intersection faults controlling morphology northern basin Tanganyika Rift, East Africa. Oil samples collected surface lake 3-4 km offshore from have been studied. The aliphatic hydrocarbon and biomarker compositions, with absence typical suite polynuclear aromatic hydrocarbons, indicate an origin hydrothermal alteration immature microbial biomass in sediments. These data show a similarity between tar sample beach petroleum seeps, confirm that source these oils is organic matter consisting mainly bacterial degraded algal biomass, altered by activity. compositions also demonstrate < 200 degrees C temperature for formation/generation this petroleum, similar to fluid identified Pemba site located 150 north Kalamba. 14C age 25.6 ka B.P. obtained ball suggests Pleistocene sediments could be rock. Hydrothermal generation may occurred slightly before 25 B.P., during dry climatic environment, when level was lower than today. results suggest activity did not connection increased flux meteoric water, higher water tables levels as demonstrated Kenya Rift site. formation facile process continental rift systems should considered exploration energy resources such locales.