Drilling investigations of a young magmatic intrusion beneath Inyo domes, Long Valley Caldera, California: The effects of pressure, volatiles, and thermal history on chemical heterogeneity in magma systems: Final report
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 that occur at the margins of the conduit and most of the lower portion of the dome are high-Ba, low-silica rhyolites, with two populations of phenocrysts, and represent commingled magmas. Whereas samples from the dike and upper portions of the dome are low-Ba, higher silica rhyolites, and 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 throughout the conduit.
- Research Organization:
- Michigan State Univ., East Lansing (USA). Dept. of Geological Sciences
- DOE Contract Number:
- FG02-85ER13321
- OSTI ID:
- 6025692
- Report Number(s):
- DOE/ER/13321-T1; ON: DE88000900
- Country of Publication:
- United States
- Language:
- English
Similar Records
Petrology and emplacement dynamics of the intrusive and extrusive rhyolites of Obsidian Dome Inyo Craters volcanic chain, eastern California
Drilling investigation of a young magmatic intrusion beneath Inyo Dome, Long Valley Caldera, California. Progress report
Related Subjects
580202 -- Geophysics-- Volcanology-- (1980-1989)
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
CALDERAS
CALIFORNIA
CHEMICAL COMPOSITION
DIKES
FEDERAL REGION IX
GEOLOGIC STRUCTURES
IGNEOUS ROCKS
LONG VALLEY
MAGMA
NORTH AMERICA
RHYOLITES
ROCKS
USA
VARIATIONS
VOLCANIC ROCKS