Constraints on magma ascent, emplacement, and eruption: geochemical and mineralogical data from drill-core samples at Obsidian dome, Inyo chain, California

Journal Article · Fri May 01 00:00:00 EDT 1987 · Geology; (United States)

DOI:https://doi.org/10.1130/0091-7613(1987)15<405:COMAEA>2.0.CO;2· OSTI ID:5276172

Vogel, T A; Younker, L W; Schuraytz, B C

Systematic chemical and mineralogical variability occurs in samples from drill holes through Obsidian dome, the conduit to the dome, and a nearby associated feeder dike. The drill-hole samples from the margins of the conduit and most of the lower part of the dome are high-Ba, low-silica rhyolites; they contain two populations of phenocrysts and represent commingled magmas, whereas samples from the dike and upper parts of the dome are low-Ba, higher silica rhyolites that do not reflect commingled magmas. Samples from the center of the conduit are low-Ba, higher silica rhyolites that are only slightly mixed. A major part of the variability within the drill-core samples of the dome and conduit reflects the juxtaposition and commingling of two distinct magmas during their passage through the conduit.

• Research Organization: Michigan State Univ., East Lansing (USA)
• DOE Contract Number: FG02-85ER13321
• OSTI ID: 5276172
• Journal Information: Geology; (United States), Vol. 15:5
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CALIFORNIA
VOLCANIC REGIONS
GEOCHEMISTRY
MINERALOGY
CHEMICAL ANALYSIS
DIKES
DRILL CORES
GEOLOGIC HISTORY
MAGMA
METALS
MIXING
OXIDES
TRACE AMOUNTS
VARIATIONS
VOLCANISM
CHALCOGENIDES
CHEMISTRY
ELEMENTS
FEDERAL REGION IX
GEOLOGIC STRUCTURES
NORTH AMERICA
OXYGEN COMPOUNDS
USA
580202* - Geophysics- Volcanology- (1980-1989)
580400 - Geochemistry- (-1989)