1 represent sediment transport from the shelf into the canyons, around the 



2 ■ margins of the canyons and off the shelf onto the slope, where warm-core 



3 rings affect this band of the upper slope eroding fine-grained 



4 sediments, which is then carried into deeper water or carried to a 



5 deeper part of the canyons, 



6 The shelf sand moves across the rims, down along the walls. If 



7 the canyon is being heavily bioeroded, it's mixed with silt from those 



8 outcrops and proceeds to the canyon floor. If the canyon floor is 



9 relatively tranquil, such as Heeltapper Canyon or some parts of Lydonia 



10 Canyon, then that silt and clay will remained mixed with the sand and 



11 not be winnowed out and will form a deposit. 



12 Superimposed on this are areas of much stronger current activity, 



13 for instance the east rims of these large canyons, at least in these two 



14 instances, experience a strong westward current for long periods of 



15 time, have this gravel development, which indicates strong current 



16 strength, and sand is being transported much more rapidly across those 



17 rims than the others. 



18 In addition, we have depositional areas of fine-grained sand 



19 around Oceanographer Canyon, and this is fine-grained sand around 



20 Lydonia Canyon. Now, Brad's data, he was showing data on silt and clay, 



21 which I'm not, I'm showing the fine-grained sand fraction, which is 



22 slightly coarser, but also travels in suspension. 



23 Then along the axes of the canyons, we have varied energy levels, 



24 Oceanographer Canyon being very energetic, showing large bedforms and 



25 coarse, clean sediment similar to--Heeltapper Canyon and Lydonia Canyon 



26 are, in some cases, similar in that their current activity is less, and 



27 they show more silt and clay. 



28 In the literature, there is some evidence that the shape of 



29 canyons, Brad alluded to this already, the shape of canyons affects or 



30 strengthens currents which are flowing in them. In some work done on 



31 Hudson Canyon, the authors hypothesized that long, straight, parallel - 



32 sided canyons would enhance tidal or internal tidal currents and 



33 strengthen them. 



40 



