Corrensite; a single phase or a mixed-layer phyllosilicate in saponite-to-chlorite conversion series? A case study of Sancerre-Couy deep drill hole (France)

Other| February 01, 1997 Corrensite; A single phase or a mixed-layer phyllosilicate in saponite-to-chlorite conversion series? A case study of Sancerre-Couy deep drill hole (France) Daniel Beaufort; Daniel Beaufort CNRS, Universite de Poitiers, Poitiers, France Search for other works by this author on: GSW Google Scholar Alain Baronnet; Alain Baronnet Search for other works by this author on: GSW Google Scholar Bruno Lanson; Bruno Lanson Search for other works by this author on: GSW Google Scholar Alain Meunier Alain Meunier Search for other works by this author on: GSW Google Scholar American Mineralogist (1997) 82 (1-2): 109–124. https://doi.org/10.2138/am-1997-1-213 Article history first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Daniel Beaufort, Alain Baronnet, Bruno Lanson, Alain Meunier; Corrensite; A single phase or a mixed-layer phyllosilicate in saponite-to-chlorite conversion series? A case study of Sancerre-Couy deep drill hole (France). American Mineralogist 1997;; 82 (1-2): 109–124. doi: https://doi.org/10.2138/am-1997-1-213 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyAmerican Mineralogist Search Advanced Search Abstract Transmission electron microscopy (TEM), analytical electron microscopy (AEM), and decomposition-simulation of X-ray diffraction (XRD) patterns were used to characterize trioctahedral clay from Sancerre-Couy that had previously been considered to be a mixed-layer material of chlorite-smectite (C-S). Corrensite should not be regarded as a regular, 50:50 mixture of chlorite and smectite mixed layers but as a true phase in the thermodynamic sense with a discrete stability field and paragenetic relationships with saponite and chlorite. C-S was not found to exist; the clay is composed of saponite or mixtures of corrensite, chlorite, and minor amounts of chlorite-corrensite mixed layers (C-C). Corrensite layers from different samples have a constant AEM composition (except for Fe/Mg ratio). The b parameter of corrensite is not compatible with a simple association of chlorite and smectite layers. Chlorite-like and smectite-like sublayers of corrensite do not behave independently during crystal growth. Selected-area electron diffraction (SAED) patterns and decomposition of XRD profiles provide evidence of C-C mixed layers. The conversion of corrensite to chlorite occurred by two simultaneous processes: (1) intergrowth of coherently stacked layers of chlorite leading to a mixture of discrete chlorite and corrensite crystallites; and (2) chlorite-corrensite random mixed layering in the case of very intimate associations of chlorite and corrensite domains. Intergrowths largely predominate over mixed layers because the solubility between corrensite and chlorite layers is low. These C-C mixed layers cannot be considered as interstratified minerals sensu stricto as may be the case for the smectite-to-illite conversion series. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.