^' 



Fig. 3. Geographic dislribution of sediment extract nuorescence intensity from the study area (contour mdicates the highest 25'7c of the values, >300). 



(normal alkanes), "recycled" orexpo.sed immature sediments, 

 petroleum (natural seepage ), andpyrolytic sources. The relative 

 amounts and composition of hydrocarbons varied widely over 

 the area sampled. The presence of a complete suite of normal 

 alkanes and isoprenoids, an unresolved complex mixture, 

 petroleum related PAH"s, mature biological markers (hopanes 

 and steranes), and vertical distributions of hydrocarbons in 

 cores confirm the presence of petroleum related hydrocarbons 

 at several locations. This petroleum is most likely derived from 

 natural seepage from much deeper source rocks and/or 



reservoired tluids. Significant geographic variations were 

 noted in all parameters measured and definable regional highs 

 were apparent. The coincidence of fluorescence and GC 

 derived petroleum indicators provides confimiatory information 

 on the presence of mature petroleum hydrocarbons at several 

 locations. These regional highs were lower than previously 

 reported macroseepage to the south and southwest survey. 

 When present, mature biological marker distributions were 

 similar in general, suggesting acommon source forthe migrated 

 hydrocarbons. 



296 



