What Would Cause Pieces Of Slab Rock

[Cariboo5]

We are clearing a path up the creek cutting out blow downs alders etc. It is a gentle incline grade and at the 1100 meter mark there are fair size pieces of slabs in different sizes. Below this mark are normal rocks. This is not a large steep mountain with any rock out cropping near the top (all treed).. Any thoughts on why these slab pieces are here and how formed... Thanks in advance to all...

 

[unclemac]

washed down from way upstream (and underground) during a real big rock moving flood....

 

[Cariboo5]

washed down from way upstream (and underground) during a real big rock moving flood....

Thanks unclemac......I was also thinking glacier movement. I hoping that these are an indication of bedrock not too far down...

 

[austin]

They were formed by erosion(water pressure, especially during floods) and cold weather. Ice formed in that stream, expanding and cracking the rock(seperating it).

 

[Mekong Mike]

a big flood.

 

[Eu_citzen]

Sedimentary rocks can break like that, slate comes to mind.