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Geothermal mineral equilibria

Abstract

The dominant reaction determining the chemistry of fluids in a geothermal system of the New Zealand type consists of the conversion of primary plagioclase by CO/sub 2/ to calcite and clays with log P/sub CO/sub 2// = 15.26 - 7850/(t + 273.2), temperature t in /sup 0/C. Subsequent reactions involving secondary minerals control relative CO/sub 2/-H/sub 2/S-contents. The distribution of mineral phases throughout a geothermal system reflects the stepwise conversion of thermodynamically unstable primary phases through a series of intermediate, metastable phases to a thermodynamically stable, secondary assemblage. The relative stabilities of these phases was evaluated on the basis of their solubilities, the least soluble aluminium-silicate representing the thermodynamically most stable phase under a given set of conditions. Observed assemblages of secondary minerals in geothermal systems represent indicators allowing mineral/fluid-interaction conditions to be evaluated on the basis of multi-component mineral stability diagrams.
Authors:
Publication Date:
Mar 01, 1981
Product Type:
Journal Article
Reference Number:
EDB-81-038249
Resource Relation:
Journal Name: Geochim. Cosmochim. Acta; (United Kingdom); Journal Volume: 45:3
Subject:
15 GEOTHERMAL ENERGY; GEOTHERMAL FLUIDS; WATER CHEMISTRY; MINERALS; SOLUBILITY; STABILITY; CARBON DIOXIDE; EQUILIBRIUM; EXPERIMENTAL DATA; FELDSPARS; GEOTHERMAL SYSTEMS; THERMODYNAMICS; CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; DATA; FLUIDS; INFORMATION; NUMERICAL DATA; OXIDES; OXYGEN COMPOUNDS; 150302* - Geothermal Exploration & Exploration Technology- Geochemical Techniques & Surveys
OSTI ID:
6658242
Research Organizations:
Dept. of Scientific and Industrial Research, Petone, New Zealand
Country of Origin:
United Kingdom
Language:
English
Other Identifying Numbers:
Journal ID: CODEN: GCACA
Submitting Site:
TIC
Size:
Pages: 393-410
Announcement Date:
Apr 01, 1981

Citation Formats

Giggenbach, W F. Geothermal mineral equilibria. United Kingdom: N. p., 1981. Web. doi:10.1016/0016-7037(81)90248-9.
Giggenbach, W F. Geothermal mineral equilibria. United Kingdom. https://doi.org/10.1016/0016-7037(81)90248-9
Giggenbach, W F. 1981. "Geothermal mineral equilibria." United Kingdom. https://doi.org/10.1016/0016-7037(81)90248-9.
@misc{etde_6658242,
title = {Geothermal mineral equilibria}
author = {Giggenbach, W F}
abstractNote = {The dominant reaction determining the chemistry of fluids in a geothermal system of the New Zealand type consists of the conversion of primary plagioclase by CO/sub 2/ to calcite and clays with log P/sub CO/sub 2// = 15.26 - 7850/(t + 273.2), temperature t in /sup 0/C. Subsequent reactions involving secondary minerals control relative CO/sub 2/-H/sub 2/S-contents. The distribution of mineral phases throughout a geothermal system reflects the stepwise conversion of thermodynamically unstable primary phases through a series of intermediate, metastable phases to a thermodynamically stable, secondary assemblage. The relative stabilities of these phases was evaluated on the basis of their solubilities, the least soluble aluminium-silicate representing the thermodynamically most stable phase under a given set of conditions. Observed assemblages of secondary minerals in geothermal systems represent indicators allowing mineral/fluid-interaction conditions to be evaluated on the basis of multi-component mineral stability diagrams.}
doi = {10.1016/0016-7037(81)90248-9}
journal = []
volume = {45:3}
journal type = {AC}
place = {United Kingdom}
year = {1981}
month = {Mar}
}