The term bedrock is usually applied to thicker rock layers. These rock layers can be granite, sandstone, limestone or whatever shelf layer is in the area. Sometimes that rock is very solid and sometimes it is fractured, interbedded with other materials, or it is much less solid than what one would imagine.
If we see any canyon in the west we see that rock is cut by water erosion just as earthen materials are cut. Gravely alluvial soil washes away in hours and rock can wash away in days.
Valuable information, thanks. I am in the Missoula flood plain of eastern WA so I have seen the cataclysmic effects that flowing water can have. On the other hand, the “normal” flow of the Columbia River during my lifetime hasn’t really resulted in much visible erosion.