Abstract
The Lower Bandelier Tuff, erupted from the Valles Caldera at 1.51 Ma, is composed of a Plinian tephra and associated ignimbrite. Based on ion and electron microprobe analyses of melt inclusions (MI) in quartz, sanidine, and pyroxene phenocrysts, a strong volatile gradient was present in the upper portion of the magma chamber. The observed volatile gradient may have influenced the eruption dynamics of the magma, initially causing discrete layers of magma to be removed when the gradient was large, followed by chaotic eruption of the bulk of the ignimbrite when the gradient was small. -from Authors
Original language | English (US) |
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Pages (from-to) | 15,151-15,170 |
Journal | Journal of geophysical research |
Volume | 97 |
Issue number | B11 |
DOIs | |
State | Published - 1992 |
ASJC Scopus subject areas
- Geophysics
- Forestry
- Oceanography
- Aquatic Science
- Ecology
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Palaeontology