History of Arizona’s Basin and Range and Related Landforms

History of Arizona’s Basin and Range and Related Landforms GCU 221

Game Plan: • Cenozoic history of the Basin and Range - Time step 1 – Compression (Thrust Faults) - Time step 2 – Extension (Fault Block / Metamorphic Core Complexes) - Time step 3 – Basin filling (Playas) - Time step 4 – Drainage integration

Cenozoic History of the Basin Range

Cenozoic History of the Basin Range • Time Step 1 - 70 to 20 million years ago Arizona COMPRESSED from North America overriding the Pacific Plate

Cenozoic History of the Basin Range • Time Step 1 - 70 to 20 million years ago How compression works…

Cenozoic History of the Basin Range • Time Step 1 - 70 to 20 million years ago “Keystone Thrust Fault”

Cenozoic History of the Basin Range • Time Step 1 - 70 to 20 million years ago “Arizona Thrust Faults”

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Arizona EXTENDED because North America overrode a “spreading center”

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago “San Andreas Fault” http://www.youtube.com/watch?v=ZxPTLmg0ZCw

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago “Compression to extension” • Two major features: • Fault Block Mountains • Metamorphic Core Complexes

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Fault Block Mountains

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago “Little More Complicated”

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Arizona Fault Block Mountains

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago “Sierra Estrella Mountains”

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago “Camelback Mountain” – Red Tertiary deposits and very old granite, typical Fault Block

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Death Valley Normal Fault

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Metamorphic Core Complexes

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago South Mountain

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Tempe Butte – A fault block that rotated away from South Mountain

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Catalina Mountains

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Can you find a fault block mountain and a metamorphic core complex? How can you tell?

Cenozoic History of the Basin Range • Time Step 2 - 20 to 10 million years ago Harcuvar Mountains. Bonus, Bear Claw Mountains or a detachment fault.

Cenozoic History of the Basin Range • Time Step 3 – 10 to ~5 million years ago Extension shuts down, Arizona dominated by interior drainage

Cenozoic History of the Basin Range • Time Step 3 – 10 to ~5 million years ago Interior drainage in arid locations forms playas or dry lakes Arizona kinda looked like numerous Death Valleys http://www.youtube.com/watch?v=lEOYyjYVkR0

Cenozoic History of the Basin Range • Time Step 3 – 10 to ~5 million years ago Death Valley… again

Cenozoic History of the Basin Range • Time Step 3 – 10 to ~5 million years ago Arizona’s old Death Valleys

Cenozoic History of the Basin Range • Time Step 3 – 10 to ~5 million years ago Wilcox Playa

Cenozoic History of the Basin Range • Time Step 4 – ~5 to the present Arizona’s drainages become mostly integrated

Development and integration of the Salt, Verde, and Gila Rivers

Things to know: • Basin and Range History - Time step 1 – Compression (Thrust Faults) - Time step 2 – Extension (Fault Block / Metamorphic Core Complexes) - Time step 3 – Basin filling (Playas) - Time step 4 – Drainage integration (basin spillover) If you have questions, ask Dr. Douglass

History of Arizona’s Basin and Range and Related Landforms