slackwater

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I'm starting a series of documentary shots showing the nature of the area where I live. This canyon (about 10 miles, 16 kilometers, from my home) illustrates the tremendous depth of the lava flows which swept across this region in the ancient past. The flows were further modified by gigantic floods following the ice age which created many narrow lakes and canyons with a north-south orientation. 'Hole in the ground,' is one of those north-south canyons.

MORE: 'The Columbia Plateau province (including most of eastern Washington state) is enveloped by one of the worlds largest accumulations of lava. The topography here is dominated by geologically young lava flows that inundated the countryside with amazing speed, all within the last 17 million years. Over 170,000 cubic kilometers of basaltic lava, known as the Columbia River basalts, covers the western part of the province. These tremendous flows erupted between 17-6 million years ago.

Most of the lava flooded out in the first 1.5 million years -- an extraordinarily short time for such an outpouring of molten rock. It is difficult to conceive of the enormity of these eruptions. Basaltic lava erupts at no less than about 1100 degrees C. Basalt is a very fluid lava; it is likely that tongues of lava advanced at an average of 5 kilometers/hour -- faster than most animals can run. Whatever topography was present prior to the Columbia River Basalt eruptions was buried and smoothed over by flow upon flow of lava. Over 300 high-volume individual lava flows have been identified, along with countless smaller flows.'

Posted by Don Wiley on May 13th, 2008
Archived under: Color