Hydrocarbons Cored from Knolls in Southwestern Gulf of Mexico: ABSTRACT

Some of the piston cores from knolls in the southwestern part of the Gulf of Mexico contain either layers of solid hydrocarbons or scattered inclusions of this material. Geochemical analyses indicate that the hydrocarbons contain about 50% asphaltenes. Samples from within a 58-m thick tar layer, from the tar layers, and from the inclusions were compared. Paleontologic investigations on coccoliths and Foraminifera show that mixing of fossil assemblages is common suggesting upward movement of sediment with the hydrocarbons. These findings demonstrate that hydrocarbons can originate in deep-sea sediments and that their upward movement results in "oil seeps," which may account for some of the hydrocarbons found on modern beaches. End_of_Article - Last_Page 2043------------