COMPARISON OF C-14 AGES OF HYDROTHERMAL PETROLEUMS

In order to set limits on the time frame of formation of hydrothermal petroleum, we have obtained C-14 ages on samples from three diverse re gions; Gulf of California (Guaymas Basin), Northeast Pacific Ocean (Es canaba Trough and Middle Valley), and the East African Rift (Tanganyik a Trough). The results date the source of carbon and therefore provide maximum ages for the formation and emplacement of the hydrothermal pe troleums. The youngest petroleum occurs in the Southern Trough of Guay mas Basin (3200-6600 yr, mean 4692 yr); in the Northern Trough the pet roleum is slightly older (7400 yr). Significantly older hydrothermal p etroleum occurs in Escanaba Trough (17,000 yr) and Middle Valley (29,0 00 yr). A continental example from the East African Rift has an age of 25,000 yr, comparable to the ages observed in the oceanic samples fro m the Northeast Pacific Ocean. These ages affirm that hydrothermal pet roleum formation is a very rapid process and took place some time betw een the latest Pleistocene and the present in these active hydrotherma l systems.