Geology of the Okanogan Highlands 2011 - Stop 2


Continue along Myers Creek road for 2.2 miles from the last stop; the second stop is at the Pine Chee wetland, at the corner of Myers Creek Road and Chesaw Road.  

Just before the Pine Chee wetland, you will see an outcrop on the righthand side of the road. This outcrop shows rock from a lava flow -- andesite, a common volcanic rock -- which contains feldspar, and a dark green/black, square shaped pyroxene. The outcrop is similar enough to nearby volcanic rocks that have been measured, that it is thought to be about 50 million years old (Eocene epoch age). Dawes explained, "This can be recognized as volcanic rock in several ways: it doesn't have sedimentary-type bedding layers in it, it's not composed of all big, visible crystals throughout like a granite has; and the white crystals in it have a nice crystal form with square and sharp corners." 

http://www.okanoganhighlands.org/education/geology-2011/g11-stop3