Details
| Original language | English |
|---|---|
| Pages (from-to) | 185-197 |
| Number of pages | 13 |
| Journal | Chemical Geology |
| Volume | 128 |
| Issue number | 1-4 |
| Publication status | Published - 7 Jun 1996 |
| Externally published | Yes |
Abstract
The viscosity of a synthetic andesite-like melt has been measured between 1010 and 1014 P for water contents in the range 0-3.5 wt%. The very slow kinetics of water exsolution over this viscosity range allowed the measurements to be made at 1 bar with a high precision. After a steep viscosity decrease of > 5 orders of magnitude for 1 wt% H2O, an additional 2.5 wt% H2O causes a further viscosity decrease of only 2 orders of magnitude. These viscosity decreases are qualitatively similar to those observed previously for more silica-rich compositions. The new data join smoothly with available high-temperature measurements made at high pressures on water-bearing andesite melts. Because the intrinsic effects of pressure are as small for water-bearing as for water-free samples, the depressing effect of water on the viscosity of natural andesite melts can be estimated. Changes in water speciation as a function of either temperature or pressure do not seem to have marked effects on the viscosity. Although quantitative applications are not yet possible, the configurational entropy theory accounts qualitatively for these features.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geology
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: Chemical Geology, Vol. 128, No. 1-4, 07.06.1996, p. 185-197.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Water and the viscosity of andesite melts
AU - Richet, Pascal
AU - Lejeune, Anne Marie
AU - Holtz, François
AU - Roux, Jacques
N1 - Funding Information: We gratefully thank F. Pineau for the vacuum fusion analyses; R.A. Brooker for his help with the IR spectrometry; M.R. Carroll for the treatment of the IR spectra; and G. Boudon for giving us the Montagne PelCe samples. This work was supported by the EEC grant 087 12 1 R3 “Magma degassing and fragmentation” and the PNRN CNRS-INSU program. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1996/6/7
Y1 - 1996/6/7
N2 - The viscosity of a synthetic andesite-like melt has been measured between 1010 and 1014 P for water contents in the range 0-3.5 wt%. The very slow kinetics of water exsolution over this viscosity range allowed the measurements to be made at 1 bar with a high precision. After a steep viscosity decrease of > 5 orders of magnitude for 1 wt% H2O, an additional 2.5 wt% H2O causes a further viscosity decrease of only 2 orders of magnitude. These viscosity decreases are qualitatively similar to those observed previously for more silica-rich compositions. The new data join smoothly with available high-temperature measurements made at high pressures on water-bearing andesite melts. Because the intrinsic effects of pressure are as small for water-bearing as for water-free samples, the depressing effect of water on the viscosity of natural andesite melts can be estimated. Changes in water speciation as a function of either temperature or pressure do not seem to have marked effects on the viscosity. Although quantitative applications are not yet possible, the configurational entropy theory accounts qualitatively for these features.
AB - The viscosity of a synthetic andesite-like melt has been measured between 1010 and 1014 P for water contents in the range 0-3.5 wt%. The very slow kinetics of water exsolution over this viscosity range allowed the measurements to be made at 1 bar with a high precision. After a steep viscosity decrease of > 5 orders of magnitude for 1 wt% H2O, an additional 2.5 wt% H2O causes a further viscosity decrease of only 2 orders of magnitude. These viscosity decreases are qualitatively similar to those observed previously for more silica-rich compositions. The new data join smoothly with available high-temperature measurements made at high pressures on water-bearing andesite melts. Because the intrinsic effects of pressure are as small for water-bearing as for water-free samples, the depressing effect of water on the viscosity of natural andesite melts can be estimated. Changes in water speciation as a function of either temperature or pressure do not seem to have marked effects on the viscosity. Although quantitative applications are not yet possible, the configurational entropy theory accounts qualitatively for these features.
UR - http://www.scopus.com/inward/record.url?scp=0029750675&partnerID=8YFLogxK
U2 - 10.1016/0009-2541(95)00172-7
DO - 10.1016/0009-2541(95)00172-7
M3 - Article
AN - SCOPUS:0029750675
VL - 128
SP - 185
EP - 197
JO - Chemical Geology
JF - Chemical Geology
SN - 0009-2541
IS - 1-4
ER -