Friday, February 09, 2007

I recently discovered a series of geologic maps of my county created by Russell C. Evarts. I have long suspected that the lowlands of Clark County were at one time or another covered by the Columbia River, and these maps prove it. Indeed, according to the current theory, several enormous floods were released from an equally enormous lake east of Idaho. The waters ripped through Eastern Washington, crushing bedrock into gravel and creating the Scablands. The mix of water and rocks then swept down the Columbia until it reached a narrow section at Kalama, Wa. The mile-wide gap was too small to let the water pass, so it pooled up behind the Coast Range in the Willamette Valley. As the water slowly spread across the area, it deposited gravel beds 300 feet deep in some areas. Because this is an obviously captivating topic, I have changed my Gileskirk research paper to discuss the geologic origins of Clark county.


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