Deschutes & Ochoco National Forests
Crooked River National Grassland

Oregon Volcanoes

Moffitt Butte Volcano

SUMMARY

Type: tuff ring
Activity: extinct
Last Eruption: 50,000 to 100,000 years ago
Rock Type: basalt
Eruptive Volume: ?
Latitude: 43.51 N
Longitude: 121.44 W
Location Maps: from TIGER Mapping Service

• State Level - shows state and communities
• County Level - shows county lines, highways, and communities
• Local Level - shows above plus lakes and local roads

Topo Map from TopoZone

Moffitt Butte Photo Menu

GEOLOGIC BACKGROUND:

Moffitt Butte is a dissected basaltic tuff ring, 1400 m (4600 ft) in diameter and 122 m (400 ft) high. Moffitt Butte is not associated with a lake basin, as is the case for Fort Rock and Hole-in-the-Ground, but rising magma probably encountered permeable aquifers beneath the cone. A line of tuff rings between Moffitt Butte and the Fort Rock Basin are located roughly along what would have been an early drainage route between the Fort Rock Basin and the La Pine Basin. The crater floor of Moffitt Butte is about 80 m (260 ft) above the surrounding plain. A smaller vent and small tuff ring, 520 m (1700 ft) in diameter, are located on Moffitt Butte's southwestern flank. The crater of the smaller vent is filled with lava that issued from a dike on its northwest edge.

HISTORIC ACTIVITY:

• None

DATA SOURCE:

• Jensen, 1995.
  

ADDITIONAL INFORMATION