Petroleum Associated with Polymetallic Sulfide in Sediment from Gorda Ridge

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Science  05 Dec 1986:
Vol. 234, Issue 4781, pp. 1231-1234
DOI: 10.1126/science.234.4781.1231


A sediment sample, impregnated with asphaltic petroleum and polymetallic sulfide, was dredged from the southern end of Gorda Ridge (the Escanaba Trough) off northern California, within the offshore Exclusive Economic Zone of the United States. The molecular distributions of hydrocarbons in this petroleum show that it was probably derived from terrestrial organic matter in turbidite sediment filling the Escanaba Trough. Hydrothermal activity at the Gorda Ridge spreading center provided the heat for petroleum formation and was the source of fluids for sulfide mineralization.