1 Whereas here, we are far from shore, deep water, very little 



2 sediment relative to California is entering these canyons, so we have I 



3 think the deposition in the canyons of probably, I would say, most of 



4 the coarse grain material is staying in there, whereas you might have 



5 some fine grain transport out towards the slope. But it is a much 



6 different situation than California. 



7 DR. BUTMAN: Is there evidence on the slope for mass movement of 



8 material from the canyons? 



9 DR. VALENTINE: In the Gloria side-scan survey, there are very 



10 large mass movements feature off the Middle Atlantic, off Georges Bank, 



11 too, but who knows how old they are. 



12 DR. BUTMAN: Right. 



13 DR. VALENTINE: Those might be involving the whole slope and there 



14 are conduits from the canyons to deeper water and you can see effluvial 



15 geomorphology out there, but there is no knowledge on the age of these 



16 things or whether they are even active now. 



17 DR. TEAL: It is true that you have to keep in mind that these 



18 canyons may have been more active conduits for mass motion than at 



19 present, so the fact that it has happened in the past, I think, can 



20 probably be documented, but how frequently it will happen under the 



21 present circumstances is really very much in question. 



22 DR. BUTMAN: Maybe Page has a better hypothesis that the sands 



23 stay there and in some canyons, the fines either stay or move, at least 



24 for the east coast canyons. 



25 DR. VALENTINE: We don't have good information on the sediment 

 25 texture in the deeper parts of the canyon axis out on the slope. 



27 DR. BUTMAN: That's right. That's a really good point.. I made 



28 that at the beginning. We really only have looked at the texture 



29 primarily in the axis. You've looked at the texture on the slopes, but 



30 for instance, that Lydonia stuff is primarily on the axis and it doesn't 



31 go much deeper than 500 to 1,000 meters. 



32 DR. VALENTINE: There's a way you could tell if there is sand 



33 coming out of the canyons. You could sample in the deeper parts of the 



34 axis. Knowing the size of the material in the silt and clay that 



193 



