1 DR. KRAEUTER: You know what you just said, you have a flux of 



2 sediment going into the canyon, you've got a depositional area at the 



3 head of the canyon, where is the sediment coming from that's coming into 



4 the canyon? 



5 DR. BUTMAN: Where does it come from? I would guess it's coming 



6 from the shelf. 



7 DR. KRAEUTER: So it bypasses that depositional area to get in 



8 there? 



9 DR. BUTMAN: The depositional area is the first place that it 



10 comes to. The depositional area in Lydonia Canyon, if you call that a 



11 depositional area, is the shallowest part of the canyon head. 



12 So, if you think about stuff coming in from the sides--this data 



13 suggests that things come in from the sides, uniformly over the canyon 



14 rim, that some of it accumulates in the head and some of it is--what 



15 accumulates in the middle part of the canyon may be transported up the 



16 canyon and accumulate in that depositional area also. 



17 Some may leak out, but we don't have a good handle on how much 



18 that is. You've brought up a really question, though. This has really 



19 been a process-oriented study, trying to understand what processes are 



20 important, and the time scales that are important in moving sediment 



21 around. 



22 The question you ask is rates, how much is moving, how fast is it 



23 moving, and at what rate is it accumulating where? This kind of data 



24 addresses what processes might be causing those rates, but in terms of 



25 calculating those rates, that's a whole other ball game. 



26 As I say, I think the geochemical tracers tell us more about the 



27 rates and they may not tell us the whole story either. I think that's a 



28 real important question to keep in mind. With the hypotheses we've been 



29 asked to address, the rate is the important question. 



30 I think that we don't have a good handle on rates. 



31 DR. MACIOLEK: Our third speaker this morning is Dr. Page 



32 Valentine from the U.S. Geological Survey in Woods Hole. The title of 



33 his presentation is "Sedimentary Environments in Submarine Canyons and 



34 on the Outer Shelf -Upper Slope of George Bank." 



33 



