Sunday, April 19, 2009

Yellow Bluff

These impressive bluffs on the southwestern shore of Guemes are readily seen from the San Juan Island ferry. The abundant oxidation of the old sands and gravels leads to their orange/yellow color. There were lots of fresh slides - not sure whether this is always the case, or if this reflects the widespread pattern of recent erosion we have been seeing the last three years (particularly in northern Puget Sound?)

I wish I knew the geologic story better, since there was lots of interesting stuff going on in these bluffs. A thick peat layer was often found collapsed on the beach - and it looked like it had burnt, giving it the look of low grade coal or charcoal. The gravelly layer above the peat - maybe 50' up - contained enormous clasts of other material - suggesting a violent past. I'll do some homework before I come back the next time.

There is a public access just south of here at Kelly Point - where, according to the guy on the beach, landing craft were built during the 1940s. There's lots of old iron scattered around and you can tell the area has a history - another reason to do some homework before the next trip.


Anonymous said...

check out Keuler's thesis from WWU library!

Anonymous said...

Just Googled Yellow Bluff, and this came up. I'm one of the 6 cousins that own the land. I'm with you, I'd really like to know the geological story. We've had the land dedicated as open space, so anyone can use it (and we pay lower taxes). Very glad to hear people enjoy the place.