Howlock Mountain is a heavily eroded
shield volcano
A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more v ...
in the
Cascade Range of central
Oregon
Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idah ...
, located along the Cascade Crest just north of
Mount Thielsen
Mount Thielsen, or Big Cowhorn (Klamath: hisc’akwaleeʔas), is an extinct shield volcano in the Oregon High Cascades, near Mount Bailey. Because eruptive activity ceased 250,000 years ago, glaciers have heavily eroded the volcano's struc ...
.
Ice Age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...
glaciers
A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...
eroded away most of the flanks of the volcano, leaving numerous deep
cirques
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landf ...
surrounding a central ridge capped by several
horns. The summit of Howlock Mountain lies along the border between
Douglas County and
Klamath County.
References
Further reading
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External links
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Shield volcanoes of the United States
Subduction volcanoes
Cascade Volcanoes
Volcanoes of Oregon
Mountains of Oregon
Landforms of Douglas County, Oregon
Mountains of Klamath County, Oregon
Umpqua National Forest
Mountains of Douglas County, Oregon
Volcanoes of Klamath County, Oregon
Volcanoes of the United States
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