Powell's Colorado River expedition and the Grand Canyon
Expedición Powell al río Colorado y el Gran Cañón
- Date
- 1869 · confidence high
- Place
- Grand Canyon, Arizona, United States
- Credited to
- John Wesley Powell
- Field
- Cosmos & Earth
What was discovered
John Wesley Powell, geologist and Civil War veteran, descended the Green and Colorado rivers in 1869 with nine men and observed how rivers cut through rock; from this he drew concepts such as 'base level' and 'antecedent' river. His reports opened the geological study of the American Southwest.
The first expedition, in 1869, started from Green River (Wyoming); the second, in 1871-1872, was more complete. Powell's estimates of the age of the rocks are far below the real ones. The coordinates mark the Grand Canyon, not the full route.
What it led to
- fluvial geomorphology of arid lands
- merging the western surveys into the USGS
- stratigraphy of the Grand Canyon (Dutton)