Karst Landscapes of Arizona

1
Karst Landscapes of Arizona

• What is karst terrain?
• Karst Landforms
• Collapse/Solution
• Doline/Sink
• Uvalas and Poljes
• Fluvial
• Allogenic valleys
• Disappearing/reappearing streams
• Cockpit and Tower
• Remnant hills

Palmer 1984
2
Typical Karst Development

• Solubility of the substrate
• Carbonate, gypsum, halite,
• Affected by partial pressure CO2, temperature,
  mixing of different fluids
• Porosity and Permeability
• Secondary porosity, fault breccias, bedding
  planes, joints
• Breakthrough point
• Hydrologic gradient
• Topography, misbehaving water tables, turbulent
  flow regimes

3
Three Major Types of AZ karst

• 1. Surficial karst in carbonate and gypsum
• Typically in Kaibab (Permian)
• 2. Surficial karst resulting from dissolution of
  salt beds
• Salt deposits in Supai Form.
• Initiates collapses in overlying Coconino and
  Kaibab (Permian)
• 3. Breccia pipes
• Magmatic fluids associated with intrusions
• Important ore deposits

Breccia Pipes
Supai Salt Basin
4
Carbonate and Gypsum Karst
Geomorphology of surficial karst
Typical subsurface patterns, network pattern not
as common in AZ karst
5
Supai Salt Basin

• More than 300 collapse features
• The Sinks, Dry Lake Valley, McCauley sinks
• Pliocene to present

6
Colorado Plateau Breccia Pipes

• 50-500 ft diameter subvertical pipes
• Formed from magmatic fluids rising
• Cemented by silica, solution collapse features,
  but can be exposed as knobs