History of Arizona’s History of Arizona’s Colorado PlateauColorado Plateau

and Related Landforms and Related Landforms

GCU 221GCU 221

Game Plan:Game Plan: Cenozoic history of the Colorado PlateauCenozoic history of the Colorado Plateau

- - Time step 1 – Compression (Kaibab Plateau)Time step 1 – Compression (Kaibab Plateau)- Time step 2 – Extensive Ponding and Deposition- Time step 2 – Extensive Ponding and Deposition- Time step 3 – Local Ponding / Deposition - Time step 3 – Local Ponding / Deposition

(Bidahochi)(Bidahochi)- Time step 4 – Erosion (Grand Canyon)- Time step 4 – Erosion (Grand Canyon)- Time step 5 – Extension (Hurricane Cliffs)- Time step 5 – Extension (Hurricane Cliffs)

Cenozoic Cenozoic History of History of

the the Colorado Colorado PlateauPlateau

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau Time Step Time Step 11 - 60 to 40 million years ago - 60 to 40 million years ago

Compression formed a bunch of

broad domal uplifts, sags, and laccoliths

across the Colorado Plateau

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau Time Step Time Step 11 - 60 to 40 million years ago - 60 to 40 million years ago

Kaibab Plateau (Domal Uplift)

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau Time Step Time Step 11 - 60 to 40 million years ago - 60 to 40 million years ago

St. John’s Sag (Synclinal downwarp)

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau Time Step Time Step 11 - 60 to 40 million years ago - 60 to 40 million years ago

Navajo Mountain (laccolith)

Igneous Intrusion –Kind of similar to a Metamorphic Core Complex, but more related to compression instead of extension

Time Step 2Time Step 2 - 40 to 20 million years ago - 40 to 20 million years ago

Drainage northeasterly onto the Colorado Plateau from the Mogollon Highlands, leads

to wide spread lake and river deposition.

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Bryce Canyon and theClaron Formation

Time Step 2Time Step 2 - 40 to 20 million years ago - 40 to 20 million years ago

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Bryce Canyon and the Claron Formation

Time Step 2Time Step 2 - 40 to 20 million years ago - 40 to 20 million years ago

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Green River Formation and the Flagstaff Limestone

Time Step Time Step 33 – 20 to ~5 million years ago – 20 to ~5 million years ago

Extension breaks apart the Mogollon Highlands Extension breaks apart the Mogollon Highlands and disrupts drainage leading to deposition on and disrupts drainage leading to deposition on the southern edge of the Colorado Plateau.the southern edge of the Colorado Plateau.

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Time Step Time Step 33 – 20 to ~5 million years ago – 20 to ~5 million years ago

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Bidahochi Formation – Where was the Colorado River at this time?

Time Step Time Step 44 – ~5 to ~1 – ~5 to ~1Grand Canyon incision leads to dramatic drop in Grand Canyon incision leads to dramatic drop in base level.base level.

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Time Step Time Step 44 – ~5 to ~1 – ~5 to ~1

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

How did the Colorado River cross the Kaibab Upwarp?

Time Step Time Step 44 – ~5 to ~1 – ~5 to ~1

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Can you say KNICKPOINTS!?!

Time Step 5Time Step 5 – ~1 to the present – ~1 to the present

Extension is moving onto the Colorado PlateauExtension is moving onto the Colorado Plateau

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau

Hurricane Fault

Cenozoic History of the Colorado PlateauCenozoic History of the Colorado Plateau Time Step 5Time Step 5 – ~1 to the present – ~1 to the present

Extension is moving onto the Colorado PlateauExtension is moving onto the Colorado Plateau

Hurricane Fault

Things to know:Things to know:

Colorado Plateau HistoryColorado Plateau History- - Time step 1 – Compression (Kaibab Plateau)Time step 1 – Compression (Kaibab Plateau)- Time step 2 – Extensive Ponding and Deposition - Time step 2 – Extensive Ponding and Deposition northwest drainage (Rim Gravels)northwest drainage (Rim Gravels)- Time step 3 – Local Ponding / Deposition (Bidahochi)- Time step 3 – Local Ponding / Deposition (Bidahochi)- Time step 4 – Erosion (Grand Canyon)- Time step 4 – Erosion (Grand Canyon)

southwest drainage (Colorado River)southwest drainage (Colorado River)- Time step 5 – Extension (Hurricane Cliffs)- Time step 5 – Extension (Hurricane Cliffs)

Questions: Ask Dr. Douglass