Skip to Main Content
GEOREF RECORD

Tosudite in very low-grade metamorphic graywackes from the Malaga area (Betic Cordilleras, Spain)

Maria Dolores Ruiz Cruz and Bartolome Andreo
Tosudite in very low-grade metamorphic graywackes from the Malaga area (Betic Cordilleras, Spain)
European Journal of Mineralogy (December 1996) 8 (6): 1391-1399

Abstract

The regularly interstratified dioctahedral chlorite/smectite, tosudite, has been identified in Carboniferous greywackes from the Malaga region; it mainly occurs replacing large phyllosilicate grains, frequently intergrown with muscovite and dickite. XRD data show a basal spacing of 29.2 Aa that shifts to 31 Aa after treatment with ethylene glycol and contracts to 23.2 Aa after heating at 500 degrees C. TEM confirms the regular 1:1 interstratification and shows sequences resulting in 24 Aa periodicity, due to chlorite (14 Aa) and collapsed smectite (10 Aa). EPMA results indicate a high Si content and approximately 0.60 atoms of Fe + Mg in the octahedral sheets. The Malaga tosudite can be included in the very low-grade metamorphic association of the Malaguide complex, ascribed to the Alpine orogeny. Minimum P-T conditions of tosudite stability are estimated, on the basis of chlorite geothermometry and phengite geobarometry, at approximately 2-4 kbar and 150-170 degrees C.


ISSN: 0935-1221
Serial Title: European Journal of Mineralogy
Serial Volume: 8
Serial Issue: 6
Title: Tosudite in very low-grade metamorphic graywackes from the Malaga area (Betic Cordilleras, Spain)
Affiliation: Universidad de Malaga, Departamento de Quimica Inorganica, Malaga, Spain
Pages: 1391-1399
Published: 199612
Text Language: English
Publisher: Schweizerbart'sche Verlagsbuchhandlung (Naegele u. Obermiller), Stuttgart, Federal Republic of Germany
References: 33
Accession Number: 1997-018113
Categories: Mineralogy of silicates
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 3 tables, sketch map
N36°17'60" - N37°17'60", W05°30'00" - W03°45'00"
Country of Publication: Germany
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United KingdomTwickenhamUKUnited Kingdom
Update Code: 199706
Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal