Reduction of Permeability in Granite at Elevated Temperatures
- 9 September 1994
- journal article
- other
- Published by American Association for the Advancement of Science (AAAS) in Science
- Vol. 265 (5178), 1558-1561
- https://doi.org/10.1126/science.265.5178.1558
Abstract
The addition of hydrothermal fluids to heated, intact granite leads to permeability reductions in the temperature range of 300° to 500°C, with the rate of change generally increasing with increasing temperature. The addition of gouge enhances the rate of permeability reduction because of the greater reactivity of the fine material. Flow rate is initially high in a throughgoing fracture but eventually drops to the level of intact granite. These results support the fault-valve model for the development of mesothermal ore deposits, in which seals are formed at the base of the seismogenic zone of high-angle thrust faults. The lower temperature results yield varying estimates of mineral-sealing rates at shallower depths in fault zones, although they generally support the hypothesis that such seals develop in less time than the recurrence interval for moderate to large earthquakes on the San Andreas fault.Keywords
This publication has 16 references indexed in Scilit:
- Internal structure and weakening mechanisms of the San Andreas FaultJournal of Geophysical Research, 1993
- Model for episodic flow of high-pressure water in fault zones before earthquakesGeology, 1993
- Creep, compaction and the weak rheology of major faultsNature, 1992
- An earthquake mechanism based on rapid sealing of faultsNature, 1992
- The role of fluids in syntectonic mass transport, and the localization of metamorphic vein-type ore deposistsOre Geology Reviews, 1987
- Water-rock interaction and chemistry of groundwaters from the Canadian ShieldGeochimica et Cosmochimica Acta, 1984
- Chemical reactions accompanying fluid flow through granite held in a temperature gradientGeochimica et Cosmochimica Acta, 1983
- Dissolution and deposition of monosilicic acid in suspensions of ground QuartzGeochimica et Cosmochimica Acta, 1969
- The solubility of quartz in water in the temperature interval from 25° to 300° CGeochimica et Cosmochimica Acta, 1962
- Solubility and heat of wetting of silica powdersJournal of Applied Chemistry, 1959