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Unformatted text preview: area of the Palouse Falls. The basalt has low porosity but porosity none the less, because of fractures in the rock. This fracture porosity makes the Columbia River Basalt group the largest aquifer in Eastern Washington. Since the region is mostly all basalt, there are very little aquitards around the area. Thus the aquifers are unconfined. The water table in the region has been dropping at a rate of two feet per year. The rivers of the region have eroded and carved out the entire basalt group, causing the bends and turns in the deep canyons in which the rivers reside. At some points, the cliffs are up to fifty feet high. Some of the more winding rivers display large point bars and cut banks at the bends, clearly showing the erosion and deposition of sediment along the stream....
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This note was uploaded on 03/28/2012 for the course GEO 101 taught by Professor Wilkie during the Fall '08 term at Washington State University .
- Fall '08