Tuesday, August 9, 2016

Bald Mountain from Lake Cavanaugh

I've posted about Bald Mountain before (see bald-mountain). This is just a different view. This time from the south side of Lake Cavanaugh.

Bald Mountain is a block of greenstone within the Helena-Haystack Melange. The melange is a mixed slice of ocean floor that was thrust onto the edge of North America. It is one of numerous tectonic terrains in Washington State. Makes the bedrock geology of northwest Washington interesting as rocks of wildly different histories and ages are juxtaposed. The bedrock under the south shore of Lake Cavanaugh is much younger and is of local derivation, but just up the hill behind where I took this picture is yet another completely separate terrain of rocks with yet another different history.    

1 comment:

Hollis said...

A striking mountain! I agree, reminiscent of Devils Tower.