The Origin of Grand Canyon Part V: Carved by Late Flood Channelized Erosion

ABSTRACTS

The Origin of Grand Canyon Part V: Carved by Late Flood Channelized Erosion

Michael J. Oard*

Following the Great Denudation by sheet erosion, the Great Erosion ensued. Deep canyons, including Grand Canyon, were carved during this latter time by channelized currents flowing toward the west. A late-Flood channelized hypothesis is presented. The cutting through of the Kaibab Plateau was first initiated by the convergence of two currents, one from the northwest and the other from the southwest. The southeast Kaibab Plateau thus presented an obstacle in the flow, resulting in a horseshoe-shaped erosional pattern that persisted, carving Grand Canyon along the southwest edge of the Kaibab Plateau. That convergence of currents caused Grand Canyon to be cut toward the west of the Kaibab Plateau. The channelized current was diverted toward the south by volcanism on the Shivwits Plateau. Rising volcanic mountains to the south and southeast and the rapid sinking of the Grand Wash trough may have been responsible for the current turning 135° around the southern Shivwits Plateau. The Esplanade, Tonto Platform, Little Colorado River Canyon, and Marble Canyon would have been carved by narrowing currents.