Environmental trace element geochemistry of sediments of the Buccaneer offshore oil and gas field: Factors controlling concentrations of trace elements in sediments
Wheeler, Richard Brian
Anderson, John B.
Master of Arts
Sediments are a sensitive record of recent, as well as ancient, physical and chemical paleoenvironmental conditions. In the marine environment, sediments are the ultimate sink for all types of contaminants and, therefore, can be used to indicate the presence of anthropogenic contaminants in the system. Evaluation of contamination levels in sediments, however, is critically contingent upon consideration of sediment physical and mineralogical properties which may profoundly influence chemical composition. This study of trace element contamination in sediments of the Buccaneer offshore oil/gas field attempts to take an objective approach towards this problem. Several trace element-sediment interactive processes are examined in order to evaluate their control over the occurrence of Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr and Zn. Although trace element-sediment interactions could not be quantified, Q-mode cluster analysis was used to classify the sediment samples into similar groups on the basis of the sediment texture, organic carbon and carbonate contents. The Q-mode cluster analysis includes samples collected near the production platforms, as well as control samples collected at some distance from the platforms and supplementary analyses.