Post-11,000-year volcanism at Medicine Lake Volcano, Cascade Range, northern California

Journal Article · Sat Nov 10 04:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JB095iB12p19693· OSTI ID:5195572

Donnelly-Nolan, J M; Champion, D E; Trimble, D A ^[1]; Miller, C D ^[2]; Grove, T L ^[3]

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1. Geological Survey, Menlo Park, CA (USA)
2. Geological Survey Cascades Volcano Observatory, Vancouver, WA (USA)
3. Massachusetts Inst. of Tech., Cambridge (USA)

Eight eruptions produced about 5.3 km{sup 3} of basaltic lava during an interval of a few hundred years about 10,500 years B.P. After a hiatus of about 6,000 years, eruptive activity resumed with a small andesite eruption at about 4,300 years B.P. Approximately 2.5 km{sup 3} of lava with compositions ranging from basalt to rhyolite vented in nine eruptions during an interval of about 3,400 years in late Holocene time. The most recent eruption occurred about 900 years B.P. A compositional gap in SiO{sub 2} values of erupted lavas occurs between 58 and 63%. The gap is spanned by chilled magmatic inclusions in late Holocene silicic lavas. Late Holocene andesitic to rhyolitic lavas were probably derived by fractionation, assimilation, and mixing from high-alumina basalt parental magma, possibly from basalt intruded into the volcano during the early mafic episode. Some eruptions have produced both tholeiitic and calc-alkaline compositions. The eruptive activity is probably driven by intrusions of basalt that occur during east-west stretching of the crust in an extensional tectonic environment. Vents are typically aligned parallel or subparallel to major structural features, most commonly within 30{degree} of north. Intruded magma should provide adequate heat for commercial geothermal development if sufficient fluids can be found. The nature and timing of future volcanic activity cannot be predicted from the observed pattern, but eruptions high on the edifice could produce high-silica products that might be accompanied by explosive activity, whereas eruptions lower on the flanks are likely to vent more fluid mafic lavas.

• OSTI ID: 5195572
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:B12; ISSN JGREA; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
ALKALINE EARTH METAL COMPOUNDS
ANDESITES
BASALT
CALIFORNIA
CASCADE MOUNTAINS
CHALCOGENIDES
CHEMISTRY
DEVELOPED COUNTRIES
ENERGY SOURCE DEVELOPMENT
EXTRUSION
FABRICATION
FEDERAL REGION IX
GEOCHEMISTRY
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOTHERMAL RESOURCES
IGNEOUS ROCKS
IRON COMPOUNDS
IRON OXIDES
LAKES
LAVA
MAGMA
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MATERIALS WORKING
MIXING
MOUNTAINS
NORTH AMERICA
OXIDES
OXYGEN COMPOUNDS
RESOURCES
RHYOLITES
ROCKS
SILICON COMPOUNDS
SILICON OXIDES
SURFACE WATERS
TRANSITION ELEMENT COMPOUNDS
USA
VOLCANIC REGIONS
VOLCANIC ROCKS
VOLCANISM
VOLUME