skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Duration of the Banco Bonito Rhyolite Eruption, Vales Caldera, New Mexico based on magma transport modeling

Abstract

Finite volume calculations of the flow of rhyolite are presented to investigate the fate of viscous magmas flowing in planar fractures with realistic length to width ratios of up to 2500:1. Heat and mass transfer for a melt with a temperature dependent viscosity and the potential to undergo phase change 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.

Authors:
 [1];  [1];  [1];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1237263
Report Number(s):
LA-UR-07-1581
DOE Contract Number:
AC52-06NA25396
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Phillips, Benjamin R., Baldridge, W. Scott, Gable, Carl W., and Sicilian, James M. Duration of the Banco Bonito Rhyolite Eruption, Vales Caldera, New Mexico based on magma transport modeling. United States: N. p., 2007. Web. doi:10.2172/1237263.
Phillips, Benjamin R., Baldridge, W. Scott, Gable, Carl W., & Sicilian, James M. Duration of the Banco Bonito Rhyolite Eruption, Vales Caldera, New Mexico based on magma transport modeling. United States. doi:10.2172/1237263.
Phillips, Benjamin R., Baldridge, W. Scott, Gable, Carl W., and Sicilian, James M. Mon . "Duration of the Banco Bonito Rhyolite Eruption, Vales Caldera, New Mexico based on magma transport modeling". United States. doi:10.2172/1237263. https://www.osti.gov/servlets/purl/1237263.
@article{osti_1237263,
title = {Duration of the Banco Bonito Rhyolite Eruption, Vales Caldera, New Mexico based on magma transport modeling},
author = {Phillips, Benjamin R. and Baldridge, W. Scott and Gable, Carl W. and Sicilian, James M.},
abstractNote = {Finite volume calculations of the flow of rhyolite are presented to investigate the fate of viscous magmas flowing in planar fractures with realistic length to width ratios of up to 2500:1. Heat and mass transfer for a melt with a temperature dependent viscosity and the potential to undergo phase change 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.},
doi = {10.2172/1237263},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Mar 05 00:00:00 EST 2007},
month = {Mon Mar 05 00:00:00 EST 2007}
}

Technical Report:

Save / Share:
  • A low-silica rhyolite eruptive sequence of 3 to 4 kmT (dense rock equivalent volume) forms the youngest volcanic event from the ring-fracture of the Valles caldera. STTh/STSTh - STYU/STSTh activity ratios determined for whole rock, glass, and mineral phases indicate that the magma system became closed isotopically approx.150 Ka. Other evidence from age dating supports an age for the eruption between 150 and 130 Ka. This event was of considerable duration with plinian and ignimbrite-forming activity preceding an effusive phase by a lengthy, but indeterminable, interval. The lava flow was emplaced onto a much-dissected surface cut into the E1 Cajetemore » and Battleship Rock pyroclastic deposits. Twenty-four bulk-rock samples from all 3 eruptive stages exhibit little significant compositional variation, and the 3 units are petrographically identical (apart from differences arising from contrasting eruption styles). Nonetheless, phenocrysts and glasses exhibit substantial compositional variations and complex textural relations throughout the sequence. Very few phenocrysts appear to have been in equilibrium with the matrix rhyolitic liquid. The petrologic relationships are interpreted to result from partial melting of a pre-existing crustal igneous rock, probably of dioritic to granodioritic composition, and subsequent eruption of the resulting liquid and ''restite'' crystals. Kinetic arguments suggest a time-scale for magma production and eruption of the order of thousands of years.« less
  • Short communication.
  • We have carried Out an extensive tensor CSAMT survey of the Sulphur Springs geothermal area, Valles Caldera, New Mexico. This survey, consisting of 45 high-quality sites, has been acquired by in support of Continental Scientific Drilling Program (CSDP) drillholes VC-2A and VC-2B. Two independent transmitter dipoles were energized for tensor measurements using a 30 kW generator placed approximately 13 km south of the VC-2B wellhead. The soundings in the Sulphur Springs area were arranged in four profiles to cross major structural features. The electric bipoles parallel to each profile were deployed contiguously to ensure against spatial aliasing of the impedancemore » response corresponding to current flow across structural trends. The frequency range of acquisition was 4096 Hz down to 1 Hz for the central line, but only down to 4 Hz for most sites of the other lines. Data quality is high overall and is established by repeatability of measurements. Agreement between the CSAMT and available natural field MT data is very good over almost all the period range of overlap indicating that we are free of calibration problems and that far-field results are generally being obtained. Non plane-wave effects in the CSAMT around Sulphur Springs are apparent at 1 to 2 Hz, and perhaps slightly even at 4 Hz, however, which is near the bottom of our frequency range. CSAMT and MT data taken outside the Valles Caldera to the west were modeled in an attempt to compare resistivity structure exterior to the caldera to that within. With the availability of tensor CSAMT and MT data both inside and outside Valles Caldera, assumptions and methods of CSAMT are tested. In the Sulphur Springs area, near-coincident CSAMT and MT data near well VC -2B indicate that non-lane-wave effects in the apparent resistivity and impedance phase occure at a frequency near to that predicted from the resistivity structure local to the wester caldera.« less
  • The Cerro Toledo Rhyolite comprises a group of domes and tephra which were erupted during the interval between two caldera-forming ignimbrites, the Tshirege Member and Otowi Member of the Bandelier Tuff, in the Jemez Volcanic Field, New Mexico. To provide a chronologic framework for geochemical and isotopic studies on these rhyolites, which record the evolution of the Bandelier magma system during this interval, a {sup 40}Ar/{sup 39}Ar geochronology study was undertaken. Pumice from major pyroclastic fall deposits within the rhyolite tephra and samples from the rhyolite domes were dated as well as the stratigraphically bracketing Bandelier Tuff. The {sup 40}Ar/{supmore » 39}Ar ages for the two members of the Bandelier Tuff Yield and interval of 380{+-}20 k.y. between these caldera forming eruptions. During this interval nine major pyroclastic pumice units were deposited in the sections studies, for which six yield isochron ages, one a weighted mean age, one a maximum age, and one no reliable age due to lack of sanidine. {sup 40}Ar/{sup 39}Ar dates on pumice fall units within the Cerro Toledo Rhyolite tephra indicate that eruptive activity occurred at > 1.59, 1.54, 1.48, 1.37 and 1.22 Ma. {sup 40}Ar/{sup 39}Ar dating of Cerro Toledo Rhyolite domes indicates these were erupted within the caldera at 1.54, 1.45, 1.38-1.34, and 1.27 Ma. The dates obtained indicate that eruptive activity occurred throughout the 380 k.y. interval between the two members of the Bandelier Tuff, but suggest that eruptions producing both tephra and domes occurred during discrete intervals at ca. 1.54, 1.48 and 1.38-1.34 Ma. 43 refs., 5 figs., 3 tabs.« less
  • The cooling history of the Valles caldera was studied by the electron spin resonance (ESR) dating method using Al and Ti centers in quartz grains which were separated from the youngest units of the Valles Rhyolite. The ESR apparent ages are much younger than fission track ages and {sup 39}Ar- {sup 40}Ar ages. Three possibilities are suggested, the first is that the ESR ages are real, the second is that ESR method did not work for these samples, and the third is that about 10--40 ka, the signal intensity was partially reduced by a thermal event such as proposed bymore » Harrison et al. (1986). Research on the first and second possibilities is continuing. The third possibility might explain the difference between ESR ages and those by other methods (fission track and {sup 39}Ar- {sup 40}Ar). ESR dating has produced new insights regarding the history of the Valles caldera.« less