America's Volcanic Past -
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| "Though few people in the United States may actually experience an erupting volcano, the evidence for earlier volcanism is preserved in many rocks of North America. Features seen in volcanic rocks only hours old are also present in ancient volcanic rocks, both at the surface and buried beneath younger deposits." -- Excerpt from: Brantley, 1994 |
MORE America's Volcanic Past - Oregon
Visit A Volcano - Newberry Caldera
Volcanic Highlights and Features:
[This list is just a sample of
various Newberry volcanic features or events and is by no means inclusive.]
Newberry volcano is a broad shield volcano located in central Oregon.
It has been built by thousands
of eruptions, beginning about 600,000 years ago.
At least 25 vents on the flanks and summit have been
active during several eruptive episodes of the past 10,000 years.
The most recent eruption 1,300 years
ago produced the Big Obsidian Flow.
Thus, the volcano's long history and
recent activity indicate that
Newberry will erupt in the future.
Excerpts from: Sherrod, et.al., 1997, Volcano Hazards at Newberry Volcano, Oregon: USGS Open-File Report 97-513 |
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| Newberry National Volcanic Monument |
Newberry National Volcanic Monument:1
Within the Newberry National Volcanic Monument, one finds some
of the most unique attractions in the
nation. Cinder cones, pumice cones, lava flows, including
obsidian flows,
Lava Cast Forest, caves,
lakes, streams, and waterfalls all attract visitors to this marvelous area.
Newberry Volcano:3
Newberry Volcano, centered about 20 miles southeast of Bend, Oregon,
is among the largest Quaternary volcanoes in thee conterminous
United States. It covers and area in excess of 500 square miles,
and lavas from it extend northward many tens of miles beyond the volcano.
The highest point on the volcano,
Paulina Peak with an elevation of 7,984 feet, is about 4,000 feet higher than the terrain surrounding the
volcano. The gently sloping flanks, embellished by more than
400 cinder cones, consist of basalt and basaltic andesite flows, andesitic to
rhyolitic ash-flow and air-fall tuffs and other types of
pyroclastic deposits, dacite to rhyolite domes and flows, and alluvial sediments produced
during periods of erosion of the volcano.
At Newberry's summit is a 4- to 5-mile-wide caldera that contains scenic Paulina and East Lakes.
The caldera has been the site of numerous Holocene eruptions,
mostly of rhyolitic composition, that occurred as recently as 1,400 years ago.
| Newberry Places |
Big Obsidian Flow:1
The Big Obsidian Flow, created 1,300 years ago, covers 700 acres. The black, shiny obsidian field is easily accessible from good roads or a
new trail that traverses the flow.
Lava Butte:1
About 7000 years ago, a dozen or so lava flows and cinder cones erupted from fissures on the flanks of Newberry
Volcano. An excellent example is Lava Butte, a 500-foot-high cinder cone south of Bend along Highway 97. A
road spirals to the top providing a grand vista of volcanic country. Here, gas-charged molten rock sprayed volcanic
foam (cinders) into the air. These fell back into a pile to form Lava Butte. As the eruption proceeded, the amount of
gas (mostly water vapor) contained in the molten rock decreased and lava poured out the south side of Lava Butte
and flowed 6 miles downhill. The lava spilled into the nearby Deschutes River forming lava dams in some places and
shoving the river westward out of its channel in others.
Lava River Cave:1
Lavas from Newberry Volcano and a few other sources cover large areas east and north of Bend. Some poured
into canyons and flowed down them for tens of miles. Most of these lavas are a few hundred thousand years old
and retain original surface features such as tumuli (lava blisters), pressure ridges, and pressure plateaus. Many
contain caves called lava tubes. Lava once flowed through these tubes to feed the spreading front of the lava flows.
A good example is Lava River Cave along Highway 97 south of Bend.
Newberry Caldera:3
Williams (1935, 1957) first recognized that the 4- to 5-mile-wide depression
at the summit of the volcano is a caldera.
Paulina Peak:1
Before the Ice Age, Mount Newberry formed as a shield volcano,
the highest point of the Paulina Mountains, set apart
from the Cascade Range to the west. This peak may have
reached a height of ten thousand feet before it collapsed to
form a crater. Today, the highest point of the crater is 7,897 foot Paulina Peak.
| America's Volcanic Past - Oregon |
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