[tedstruk (OP)]

Bretz kind of proved that the Columbia River scablands were created by cataclymsic Glacial flooding.  I think that there was a bit more to it.
The environment at that time, whether it was colder or warmer makes no difference, was more temperate, and more ecological, that is to say there were more tall trees to block the wind, huge rock hillsides to pen up weather systems.  In my theory, mini-environments, which warmed cold areas, and froze warm areas, were in activity wherever a flood left a gully that they could build in.  Suppose, a solid rock wall, descimated by a glacial flood, becomes subject to a mini-environment that creates 150 mph gust of wind blown rain which fills the cracks and forces the rock into splinters...then another flood comes, or even an earthquake, and the cycle starts all over again, except the mini-environment has moved elsewhere, and is wreaking the same havoc on another unsuspecting slide... It wasn't all created by glacial flooding, there were mini-environments to blame for some of it!