Friday, July 30, 2010

A Back from the Road Update with some Oregon Serpentinite

I've been without a good or constant internet connection for a couple weeks, so am just now getting caught up on the California serpentinite issue (#CAserpentine). While out and about, I drove by some serpentinite in eastern Oregon, including the greenish hills above, which are west of John Day and east of Mt. Vernon on U.S. Route 26 where it overlaps with a short segment of U.S. Highway 395 (Google Maps). It appears that aggregate is being mined locally from these rocks, which overall consist of weakly to strongly serpentinized mafic and ultramafic rock (dunite, peridotite, gabbro, diabase).
If you stop at the Strawberry Mountains rest stop and overlook (which has an oversized covered wagon as a tribute to pioneers that traveled the Oregon Trail), you can examine and read about three large boulders of weakly serpentinized gabbro and diabase (Google Maps Street View). My photo shows a couple white to pale green, fibrous veinlets that I presume are made of chrysotile. The serpentinized boulders weren't very photogenic; someone had splattered red paint all over them. And I didn't get a picture of the plaque that told something about their geology; the sun angle was lousy or I was impatient (or both?).

In the meantime, I'm trying to get caught up on my serpentine link fest. If you notice any missing links, let me know. I'm not linking to SB 624 propoganda (just like they aren't linking to me).


Ron Schott said...

It's remarkable how variable serpentine can look in the field. What sort of camera did you shoot the macro with?

Silver Fox said...

Ron, I use a Canon PowerShot A650IS. The rocks were weakly serpentinized for the most part, and most surfaces were weathered and covered with lichen or red paint.