Washington Geologic Survey Mapping in Kittitas County.

Geologists Andrew Sadowski and CWU Alumni Bodie McCosby with the Washington Geologic Survey are working on a multi-year project completing detailed 1:24,000 geologic maps of Kittitas Valley and surrounding areas. Andrew and Bodie are based out of CWU's Discovery Hall and are wrapping up the fall field around the Reecer Creek and north Ellensburg areas, with plans to expand across much of the county in the future.

The project aims to refine the local stratigraphy of the Columbia River Basalt group with new analytical data and refine the Quaternary history of the valley with new lidar imagery. The mapping project includes detailed field work collecting samples for major and tracce element geochemistry, for U-Pb analyses of ash and sedimentary rocks of the Ellensburg Formation, and for petrographic analyses of thin sections. The LiDAR imagery also aids the assessment of major landslide deposits scattered on the flanks of the Columbia River Basalt Group that, in some cases, preferentially slip along the Ellensburg Formation.

Bodie McCosby taking notes on an entablature zone on the basalt of McCoy Canyon, part of the Grande Ronde Basalt flows. View is to the south with Mt. Rainier in background. (Sadowski photo)

Gently dipping Grande Ronde Basalt Mv(g) seperated by continental Ellensburg Formation Mc(e). (Sadowski photo)