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of the world's most fertile valleys, blessed with temperate weather and incredibly good soil. It turns out that Willamette Valley was the happy recipient of some of the fertile volcanic topsoil ripped off the Eastern Washington plain. When the flood waters (approximately 400 feet more than a normal flood stage for the river) reached Portland, a backwater was created as they flooded the Willamette Valley and extended upstream through the valley all the way to Eugene, Oregon. When the waters retreated they left Missoula flood deposits that are 100 feet thick in some places. And they also left enormous house sized boulders that had been carried downstream encased in ice. Even so, only a very small amount of the debris was left in the valley and over 99 % of the debris carried in the raging waters was lost to the sea.
If you come to Portland, the Max (lightrail) station under the west hills for the Zoo and the Forestry Center has a 270 foot long core extracted from where the elevator shaft was drilled from the surface to the Max stop inside the tunnel. This core contains the geologic history of the west hills. The evidence of a number of Bretz floods are sandwiched between lava flows showing a cycle of volcanic eruption and ice dam failures. To me, this geologic story of the Pacific Northwest is as amazing as the tale of how the Grand Canyon came to be.
We humans are along for the ride on this incredible voyage of the earth through time. When the earth twitches, the consequences for humans can be tragic as the recent earthquake and tsunami showed. Yet, there is beauty in the relentless processes of the earth. We humans could not live without the exquisite dance of our lovely (and powerful) planet with its core of molten rock, its wandering continents, the frightening volcanoes and earthquakes, and the never-ending wind and water that seek to smooth out and grind down the indomitable rocks.
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