Sand Mountain Volcanic Field
The Sand Mountain volcanic field consists of a group of 23
basaltic and basaltic-
andesite cinder cones and
lava flows at the western margin of the High Cascades in the upper McKenzie River watershed. The field covers 75 km
2 (30 mi
2) fed from two aligned groups of 42 distinct
vents that trend north-northwest and north-northeast and intersect near the largest
cinder cone, Sand Mountain (250 m or 820 ft high). The
vent alignments suggest that a complex system of dikes exists beneath the chain. A series of
lava flows originating from vents along the chain were erupted primarily from about 3,000 to 4,000 years ago. They traveled chiefly to the west, blocking local drainages and forming several small lakes. The Lost Lake
cinder cone group at the north-northeast end of the chain was active about 2,000 years ago. The extensive young, highly fractured lava flows from Sand Mountain, and others from
Belknap Crater, greatly disrupted the McKenzie River and create a landscape of
lava-filled canyons, lakes, disappearing streams, and numerous springs.
Location: Oregon
Latitude: 44.38° N
Longitude: 121.93° W
Elevation:
1,664 (m)
5,459 (f)
Volcano type: Cinder cones
Composition: Basalt, Basaltic Andesite
Most recent eruption: About 2,000 years ago
Threat Potential: Low/Very Low
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