Saturday, July 6, 2013

Geo 365: July 6, Day 187: Folded Flournoy Formation

Folded beds of (I think) Flournoy Formation- very similar in appearance to the Tyee- along the Umpqua River, near Roseburg, Oregon. (Right click on the photo here for various size options) While this is near the suture between the Siletz (Coast Range) block and the Klamath-Siskyou Province, and it is tightly folded with some thrusting, the deformation does not seem to be tectonic in origin. It appears to be confined to a fairly small area, maybe a square mile, and though the boundaries have not been tightly constrained, the transition from deformed to undeformed is apparently quite abrupt. This is thought to be more likely something like an olistostrome, an underwater slump.

Photo stitched in Hugin, otherwise unmodified. July 2, 2013. FlashEarth location.

No comments: