[freebeard]

The Richat Structure in Mauratania was scoured down to the bedrock. it would be like Atlantis all over again. ....or Grand Coulee:

This mass of water and ice, 2,000 feet (610 m) high near the ice dam before release, flowed across the Columbia Basin, moving at speeds of up to 65 miles per hour (105 km/h). The deluge stripped away soil, cut deep canyons and carved out 50 cubic miles (210 km3) of earth, leaving behind areas of stark scabland.

Over nearly 2500 years the cycle was repeated many times. Most of the displaced soil created new landforms, but some was carried far out into the Pacific Ocean. In Oregon's Willamette Valley, as far south as Eugene, the cataclysmic flood waters deposited fertile soil and icebergs left numerous boulders from as far away as Montana and Canada. At present day Portland, the water measured 400 feet (120 m) deep. A canyon 200 feet (61 m) deep is carved into the far edge of the continental shelf. The web-like formation can be seen from space. Mountains of gravel as tall as 40-story buildings were left behind; boulders the size of small houses and weighing many tons were strewn about the landscape.

Icebergs in Eugene?