Miocene Disruptions of the Palouse River

John Bush and Pam Dunlap
March 22, 2018, 3:30-4:30pm, McClure Hall, Rm 209, University of Idaho
The presentation reveals the most up-to-date geologic history of the Miocene sequence. Rock chip chemistry from ten wells greater than 700 ft. (213 m) in depth was used to form a stratigraphic framework for the Grande Ronde, Wanapum, and Saddle Mountains Basalts and associated Latah sediments. Domestic well reports, test wells, outcrops, and regional comparisons were used to determine approximate time lines and develop paleogeographic reconstructions from early Grande Ronde to late Saddle Mountains time. Reconstructions include the distribution of basalt flows and the disruptions, obliterations, and reversals of drainages. The fact that the Palouse River once flowed through the basin, from Palouse to Pullman, should be of interest to those working on any phase of the geohydrology of the basin.