1 swept out of the area and the distributions that are left a season later 



2 are the two group A and group B types of distributions. 



3 So, we're seeing dynamic implications for the hydrocarbon 



4 distributions in terms of these tar specks and in terms of the biogenic 



5 materials. 



6 There are some strong geochemical relationships that the 



7 hydrocarbons exhibit. Hydrocarbons covary very strongly with TOC and 



8 clay content throughout the study area. This is true on the bank, it's 



9 true on the slope and on the rise. 



10 To a large extent, the entire study area is one hydrocarbon 



11 province, it's just mixing, it's distribution, but this is a "^ery strong 



12 covariance. PAH's, which are small fractions of the hydrocarbons, also 



13 covary strongly with TOC. 



14 I'll show one slide. If we look at different study areas, not 



15 just from the Georges Bank area, but from other OCS sediments, there is 



16 similarity in the PAH to TOC ratio. 



17 We see that the PAH's vary somewhat with terrigenous plant 



18 material and, therefore, is either considered to be sourced on shore and 



19 distributed with the plant material, or is introduced by aerial 



20 transport, is deposited and then remixed with the plant material. 



21 In any event, there is a strong covariance with PAH's and plant 



22 material. As I demonstrated before, the fine-grained silt-clay 



23 fractions, especially the clay fraction, contains a strong anthropogenic 



24 signal, mainly this unresolved complex mixture. 



25 There are many such examples, as the next one, fairly good 



26 correlations of hydrocarbon parameters, in this case these are all four 



27 seasons of data, total hydrocarbons versus organic carbon throughout the 



28 study area, correlation coefficients about .9. 



29 If we look at individual aromatic hydrocarbons such as the three- 



30 ring phenanthrene compounds and we combine four seasons and a study that 



31 was funded by NOAA several years later, a strong, fairly constant 



32 relationship between these individual aromatics and total organic 



33 carbon, good correlation coefficients. 



81 



