Colorado Plateau Uplift

Mechanism

Tectonic setting: Continental interior — uplift mechanism remains debated. Hypotheses include lithospheric thinning, mantle upwelling, lower-crustal flow, low-angle subduction effects from the Laramide, and combinations of these. The Plateau is unusual in having risen substantially without significant internal deformation.

No single mechanism cleanly explains the Plateau's uplift history. Current models invoke a multi-phase process spanning ~70 million years.

Effects

• river incision (Grand Canyon, Cataract Canyon, Glen Canyon, Black Canyon of the Gunnison)
• integration of the Colorado River system into a single drainage
• exposure of the layered Mesozoic and Paleozoic sedimentary stack
• exhumation of Precambrian basement in the Inner Gorge of the Grand Canyon
• preservation of laccoliths (Henry, La Sal, Abajo Mountains) as the surrounding Plateau eroded
• ongoing canyon deepening at measurable modern rates