CompuServe Messages

Jim >> However, if they existed prior to the opening of the Atlantic Ocean in the Mesozoic, the rivers would have continued headward erosion and never been submerged. Also, erosion can take place in a sub-aqueous environment. River currents can extend long distances into the ocean. There are freshwater currents associated with the Amazon that extend at least 50 miles past the mouth of the river. Similar currents are associated with the Mississippi, and Columbia, and the is anecdotal evidence for the same situation before the Colorado was dammed to nothingness. << The currents would seam to float however if they were laden with soil and particles they may be heavier than the salt water. On some of the larger sedimentary deposits like the Indus and Ganges Cones the canyons have diverted many times like you would expect in a delta formation. They still cut channels down to 4,500 5,000 meters. This seams like unlikely behavior. The soil must be falling out of the river to make the deposits yet it still cuts canyons.