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GEOREF RECORD

Phengitization, sericitization and potassium-beidellite in a hydrothermally-altered granite

A. Meunier and B. Velde
Phengitization, sericitization and potassium-beidellite in a hydrothermally-altered granite
Clay Minerals (September 1982) 17 (3): 285-299

Abstract

X-ray diffraction, optical and microprobe studies of a kaolinized oligoclase-orthoclase-two-mica-granite (Southern Armorican Massif) indicated that low-temperature metasomatism had produced three series of minerals. 1. Partial alteration of muscovite resulted in the formation of ferrous-magnesium-phengite. Biotite was destabilized to a kaolinite-titanium oxide assemblage. 2. Phengite, unreacted muscovite and feldspars recrystallized to an aluminous, magnesian 1M sericite mineral ranging in composition from mica to illite. 3. Feldspars were entirely destabilized to produce the assemblage potassic-beidellite-kaolinite-Al-illite. Kaolinite was the predominant mineral in the most altered rock. A fourth stage of mineral equilibrium was also observed; this occurred after material from stage 3 had been reworked. In this environment, the potassic-beidellite was replaced by a calcic-montmorillonite. Potassic-beidellite was not stable under weathering conditions.


ISSN: 0009-8558
Coden: CLMIAF
Serial Title: Clay Minerals
Serial Volume: 17
Serial Issue: 3
Title: Phengitization, sericitization and potassium-beidellite in a hydrothermally-altered granite
Affiliation: CNRS, Fac. sci., Poitiers 86022, France
Pages: 285-299
Published: 198209
Text Language: English
Summary Language: French
Summary Language: German
Publisher: Mineralogical Society, London, United Kingdom
References: 18
Accession Number: 1984-001502
Categories: Igneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. table, anal.
N46°30'00" - N49°45'00", W04°49'60" - E00°00'00"
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, Mineralogical Society of Great Britain and Ireland. Reference includes data from PASCAL, Institute de l'Information Scientifique et Technique, Vandoeuvre-les-Nancy, France
Update Code: 1984
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