USGS/Cascades Volcano Observatory, Vancouver, Washington
DESCRIPTION:
Brown Mountain, Oregon
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[Map,20K,InlineGIF]
Map, Major Volcanoes of the Southern Oregon Cascades
From:
Wood and Kienle, 1990, Volcanoes of North America: United States and Canada:
Cambridge University Press, 354p., p.199-200,
Contribution by James G. Smith
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Brown Mountain is a small (5 cubic kilometers), youthful-looking
shield
topped by a
cinder cone
whose central depression is still 15 meters deep. Much of the mountain is bare,
unweathered, dark-colored, block-lava and clinkery aa flows. The flows are
mostly olivine-bearing basaltic andesite and andesite in composition.
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At first glance Brown Mountain looks no older than a few thousand years.
However, a small glacial valley carved into the northeast flank and a cirque
gouged out of the summit cinder cone belie its youthful appearance. The
deposits left behind have features typical of glacial deposits from
approximately 13,000 years ago. Evidence of the next older glaciation is
missing, and the age of Brown Mountain can be bracketed between around 60,000
and 12,000 years.
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A climb to the summit of Brown Mountain is mostly a scramble over fresh talus as
there is no maintained trail to its summit. Because its summit is lower than
that of nearby peaks, views from Brown Mountain are not as spectacular.
However, it offers a close view of the south flanks of
Mount McLoughlin. ...
Return to:
[Brown Mountain Menu] ...
[Mount McLoughlin Menu] ...
[Oregon Volcanoes Menu] ...
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08/21/00, Lyn Topinka