Ancient landscapes of the Colorado plateau

Foundations of the Colorado plateau: early proterozoic, 1,750 million years ago

Ancient sediments, unconformities, and rifting: middle and late proterozoic, 1,255 to 740 million years ago

Ancient shallow seas: Cambrian to Mississippian, 525 to 318 million years ago

Continental unrest and geologic cycles: Pennsylvania and Permian, 318 to 251 million years ago

Desert rivers and great dunes: Triassic and Jurassic, 251 to 145 million years ago

Mountains and continental seaways: cretaceous, 145 to 65 million years ago

The modern landscape emerges: Cenozoic era, 65 million years ago to present

Summary of historical geology: grand canyon and the grand staircase

Where to see the rocks

Appendix: Paleogeography, paleogeographic maps, and how they are made.