Trace metals in sediment cores from the Campeche shelf, Gulf of Mexico

Trace metals in sediment cores from the Gulf of Mexico, in the Campeche shelf area were studied to investigate possible variations in their vertical and/or horizontal sedimentary distributions. Possible links to petroleum sources were investigated as this area contains very productive oil explotation and transportation activities. Sediments were collected undisturbed using a vegematic type box corer. The upper 10 cm. were collected and cut in sections of 2 cm each. Incomplete, open vessel sediment digestion and atomic absorption was used for trace element determination. Particular interest was placed on vanadium and nickel concentrations as they have been associated to oil. Several metals were measured and representative distributions are presented. Horizontal distributions appear to conform to predominant current circulation patterns reported and closeness to sources of sedimentary materials. Vertical distributions are discussed. The vertical distributions were strikingly constant. Correlation among metals are also presented. Fe was used as a normalizing agent and the carbonate content was acting as a diluter of total trace metal content.