BY Michael J. Oard
Uniformitarian explanations of the origin of Grand Canyon all appear improbable. Thus, we turn to published catastrophic options. The most popular of these today is the dam-breach hypothesis. There are three versions of this general hypothesis, but all face major problems, of which two appear especially critical: (1) the lack of evidence for the existence of the breached lakes, and (2) the presence of the long Kanab and Havasu tributary canyons that enter Grand Canyon at the level of the Colorado River. There are no diagnostic bottom sediments, shorelines, raised deltas, or other geomorphological features at the proposed sites of the breached lakes, despite their common occurrence at the sites of other Ice Age lakes. Also, the erosion of the Kanab and Havasu canyons, a mile deep and a quarter mile wide at their mouths, would require vast quantities of rushing water over a wide area to erode these tributaries along with Grand Canyon, since the heads of the tributaries lie about 50 miles from Grand Canyon and over 100 miles from each other. This area seems too large for a breached lake to have flooded with sufficient energy to erode the canyons. Another catastrophic alternative is needed.