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Belknap

Shield(s) in United States

Last Eruption: 475

Key Facts

Elevation

2,094 m (6,870 ft)

Type

Shield(s)

Location

44.285°, -121.842°

Region

High Cascades Volcanic Arc

Rock Type

Andesite / Basaltic Andesite

Tectonic Setting

Subduction zone

Location

Loading map...

Overview

The Belknap Crater area near McKenzie Pass in Oregon, north of the Three Sisters volcanoes, was the source of one of the largest concentrations of youthful volcanism in the Cascade Range. The basaltic to basaltic andesite Belknap shield volcano, topped by the Belknap Crater pyroclastic cone and the Little Belknap shield volcano immediately to the east, have produced widespread late Holocene lava flows on all sides, much of which took place between about 3,000 and 1,500 years ago. Eruptions from the NE base of Belknap crater produced lava flows that traveled 15 km W into the McKenzie River valley.

Volcanic Hazards & Risk Assessment

Primary Hazards

    Risk Level

    Population at RiskModerate
    Infrastructure RiskModerate
    Aviation RiskSignificant

    Geological Composition & Structure

    Rock Types

    Primary
    Andesite / Basaltic Andesite
    Silica Content
    Intermediate (57-63% SiO₂)

    Tectonic Setting

    Subduction zone
    Formed by oceanic plate subduction, typically producing explosive eruptions due to water-rich magmas.

    Age & Formation

    Epoch
    Holocene
    Evidence
    Eruption Dated

    Eruption Statistics & Analysis

    MetricValueGlobal RankingSignificance
    Total Recorded EruptionsUnknownLowModerately active volcano
    Maximum VEIVEI UnknownMinorLocal impact potential
    Recent Activity1551 years agoHistoricalHistorically active

    Monitoring & Alert Status

    Monitoring Networks

    Global Volcanism Program
    International eruption database

    Current Status

    Normal
    No recent activity. Routine monitoring continues.

    Nearby Volcanoes in North America Volcanic Regions

    Regional Volcanic Activity
    The North America Volcanic Regions contains multiple active volcanic systems. Cross-regional magma interactions and tectonic stresses can influence eruption patterns across the entire arc. Monitor regional seismic activity and volcanic alerts.

    Quick Info

    • Smithsonian ID: 322060
    • Evidence: Eruption Dated
    • Epoch: Holocene

    About the Photo

    The McKenzie Pass area in the central Oregon Cascades contains one of the largest concentrations of recent volcanism in the United States. Belknap shield volcano, seen here from Black Crater to the SE, is capped by a smaller snow-covered cone. Lava flows from Belknap and the smaller Little Belknap shield volcano in front of it cover nearly 100 km2. Most of the largely unvegetated flows were erupted between about 2,900 and 1,500 years ago.

    Photo by Lee Siebert, 1995 (Smithsonian Institution).

    Basic Information

    This page shows basic data from the Smithsonian Global Volcanism Program. For more detailed information, visit the official Smithsonian page.