In 1909, the Seattle teacher visited the University of Washington to see the U.S. Geological Survey’s new topographic map of the Quincy Basin, a large area on the west side of the Columbia Plateau. He was 27, with no formal training in geology, but when he looked at the map, he noticed a striking feature: a huge cataract (much like Dry Falls) on the western edge of the basin, a place where water appeared to spill out of the basin and into the Columbia River, gouging a canyon several hundred feet deep. The falls would have been bigger than Niagara, but there was no apparent source of water for them—no signs whatsoever of a river leading to the cataract.
Bretz asked faculty in the department about the feature, called Potholes Coulee, but they had no answers for him. Nor could they explain many of the other unusual features of the region. That’s when, as legend has it, Bretz decided to become a geologist.
Wednesday, March 15, 2017
The Mystery of the Scablands
National Geographic is running a good story by Glen Hodges on the mysterious geology of the Columbia Plateau in eastern Washington state. In the midst of this desert are what look like the remnants of great floods: huge gravel bars, mighty erosion channels, things that look like that the potholes that form in the bottom of rivers but are ten times the size. A feature known as Dry Falls looks for all the world like a gigantic waterfall, ten times the size of Niagra, except that there is not river anywhere in sight. Geologists call the region the Channeled Scablands.