Authors: Proust, D.; Caillaud, J.; Fontaine, C.

Source: Clays and Clay Minerals, Volume 54, Number 3, June 2006 , pp. 351-362(12)

Publisher: The Clay Minerals Society

Abstract:

The early stages of amphibole weathering result in the crystallization of several clay mineral species: tri- and dioctahedral smectites, interstratified dioctahedral kaolinite-smectite (K-S), and halloysite. Each clay mineral crystallizes into specific microsites which develop from etch pits along specific crystallographic directions in the host amphibole. Two types of microsites are recognized according to their location in the amphibole crystal and their clay mineral crystallizations. The first type is a plane surface related to the (110) amphibole cleavages where saponite particles crystallize in a characteristic honeycomb texture. The second type is a 'sawtooth' (001) fracture surface generated by etch-pit coalescence where (1) platy K-S particles crystallize directly in contact with the amphibole at the top of 'teeth', (2) halloysite particles with tubular habits crystallize directly in contact with the amphibole on the side of the 'teeth', and/or on the K-S particles, and (3) montmorillonite crystallizes in the central part of the (001) fracture as a layer with honeycomb texture in contact with the K-S platelets located at the top of 'teeth'. The microtextural relationships between the clay minerals and their host mineral suggest the following crystallization sequence: (1) saponite and montmorillonite crystallize first on the (110) and (001) surfaces, respectively; (2) as amphibole dissolution proceeds perpendicular to the (001) fracture planes, montmorillonites continue to form in the middle part of the widening fracture whereas K-S crystallizes on the 'sawtooth' termination; (3) in the last stage of weathering, tubular halloysite crystallizes on the side of the 'teeth', and/or on the K-S.

Keywords: AMPHIBOLE; HALLOYSITE; KAOLINITE-SMECTITE MIXED-LAYERS; MONTMORILLONITE; SAPONITE; WEATHERING

Document Type: Research article

DOI: http://dx.doi.org/10.1346/CCMN.2006.0540306

Publication date: 2006-06-01

More about this publication?

• The JOURNAL publishes articles of interest to the international community of clay scientists, including but not limited to areas in mineralogy, crystallography, geology, geochemistry, sedimentology, soil science, agronomy, physical chemistry, colloid chemistry, ceramics, petroleum engineering, foundry engineering, and soil mechanics. Clays and Clay Minerals exists to disseminate to its worldwide readership the most recent developments in all of these aspects of clay materials. Manuscripts are welcome from all countries.

  Clays and Clay Minerals is the official publication of The Clay Minerals Society.

  The Editor-in-Chief is Professor Joseph W. Stucki jstucki@illinois.edu

  Publications of The Clay Minerals Society
  Source Clays

• Editorial Board
• Information for Authors
• Membership Information
• Annual Meeting of The Clay Minerals Society
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Geology
• By this author: Proust, D. ;  Caillaud, J. ;  Fontaine, C.

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers