Tuesday, February 21, 2017

Catastrophic Geology: Case 13 - Burlingame Canyon

In 1926, a diversion ditch exposed to relatively high water flowrate and volume produced a 1500-ft long 120-ft deep canyon in just 6 days through hardened fine-grained (silt, clay, fine sand mixtures possibly) and occasionally gravelly, sedimentary deposits characterized as the "Touchet" geologic formation".  These deposits are from "slackwater" produced after the massive Missoula flood.  The huge canyon exposed uniform thickness beds (layers) of the slackwater deposits, indicative of pulses of flood backwater from the catastrophic flood event.  The beds are also characterized as rhythmites or rhythmically bedded material.

The canyon is in the current Wall Walla river valley in Washington State.  The rhythmites are 330 feet thick, indicating the massive nature of the Missoula flood and the geologic consequences of such a catastrophic event.

This is another example of the power of water and the catastrophic impact it can have on geology.  The "Touchet" beds were formed from a catastrophic event, and the Burlingame Canyon through them was formed by a catastrophic event.  You do not need millions of years to produce the landscape you see around you.