Duration of the Banco Bonito rhyolite eruption, Valles Caldera, New Mexico, based on magma transport modeling
Benjamin R. Phillips, W. Scott Baldridge, Carl W. Gable, and James M. Sicilian
Finite volume calculations of the flow of rhyolite are presented to investigate the fate of viscous magmas flowing in planar fractures with length to width ratios of up to 2500:1. Heat and mass transfer for a melt with a temperature-dependent viscosity and phase changes are considered. Magma driving pressures and dike widths are chosen to satisfy simple elastic considerations. These models are applied within a parameter space relevant to the Banco Bonito rhyolite flow, Valles caldera, New Mexico. We estimate a maximum eruption duration for the event of ~200 days, realized at a minimum possible dike width of 5−6 m and driving pressure of 7−8 MPa. Simplifications in the current model may warrant scaling of these results. However, we demonstrate the applicability of our model to magma dynamics issues and suggest that such models may be used to infer information about both the timing of an eruption and the evolution of the associated magma source.
- Phillips, Benjamin R.; Baldridge, W. Scott; Gable, Carl W.; Sicilian, James M., 2007, Duration of the Banco Bonito rhyolite eruption, Valles Caldera, New Mexico, based on magma transport modeling, in: Geology of the Jemez Region II, Kues, Barry S.; Kelley, Shari A.; Lueth, Virgil W., New Mexico Geological Society, Guidebook, 58th Field Conference, pp. 382-387.