Skip to Main Content
Skip Nav Destination
GEOREF RECORD

The solubility of a low-Fe clinochlore between 25 and 175 degrees C and P (sub v) = P (sub H2O)

Stephen U. Aja and Joe S. Small
The solubility of a low-Fe clinochlore between 25 and 175 degrees C and P (sub v) = P (sub H2O)
European Journal of Mineralogy (October 1999) 11 (5): 829-842

Abstract

Solid mixtures of kaolinite-chlorite (+ or -quartz) and/or chlorite-gibbsite have been equilibrated in aqueous 1.0 M NaCl, 0.001 and 0.005 M MgCl (sub 2) solutions at 25, 125 and 175 degrees C and saturated vapor pressures. Reversibility of fluid-mineral equilibria was demonstrated by approaching final solution compositions from high and low log a (super 1/2) Mg (super 2+) /a (sub H) (super +) and from silica under- and super-saturation. At the end of the experiments, the solutions were separated using immiscible displacement techniques. The chlorite-kaolinite equilibrium suggests a temperature-dependent reaction mechanism which may partly reflect changes in speciation of aqueous ions as well as variations in reaction kinetics. Log K for the chlorite-kaolinite reactions have been calculated to be 52.43+ or -7.50, 62.33+ or -6.89 and 79.06+ or -2.60 at 25, 125 and 175 degrees C, respectively. A comparison of the measured Mg/H activity ratios at 25 degrees C with values predicted for (end-member) clinochlore-kaolinite equilibria indicates that the experimentally measured assemblage is more stable; this suggests a large value of Gibbs energy of mixing (Delta G (super o) (sub mix) ) for chlorite solid solutions.


ISSN: 0935-1221
Serial Title: European Journal of Mineralogy
Serial Volume: 11
Serial Issue: 5
Title: The solubility of a low-Fe clinochlore between 25 and 175 degrees C and P (sub v) = P (sub H2O)
Affiliation: Brooklyn College of the City University of New York, Department of Geology, Brooklyn, NY, United States
Pages: 829-842
Published: 199910
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 47
Accession Number: 1999-070063
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 3 tables
Secondary Affiliation: University of Manchester, GBR, United Kingdom
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute.
Update Code: 199924
Close Modal

or Create an Account

Close Modal
Close Modal