29Si AND 27Al CPMAS NMR QUALITATIVE AND QUANTITATIVE ANALYSIS OF KAOLINITE AND DICKITE IN KOS ISLAND KAOLINS, GREECE
Résumé
The application of 27Al and 29Si CPMAS NMR spectroscopy to the investigation of selected /caolinite and dickite bearing samples from hydrothermally altered rhyolites of Kos island is tested using also XRD and analytical SEM-EDS data. Kaolinite and dickite, can be detected by both their tetrahedral Si and octahedral Al CPMAS NMR spectra. It was found that the interference of the peaks become less significant and the shape of the peaL· narrow when the pulse recycling delay is high (up to 10s). The octahedral Al / tetrahedral Si ratios of kaolinite group mineral forms from samples showing various degrees of alteration, calculated from the NMR spectra, were found to be very similar to these derived from the structural formulae of SEM-EDS microanalyses. In this work it is presented for the first time an approach to provide narrow CPMAS NMR peaks. The narrow shape of the peaks provides accurate measurements of the exact position of the peaL· and the octahedral Al / tetrahedral Si ratios.
Article Details
- Comment citer
-
Papoulis, D. (2007). 29Si AND 27Al CPMAS NMR QUALITATIVE AND QUANTITATIVE ANALYSIS OF KAOLINITE AND DICKITE IN KOS ISLAND KAOLINS, GREECE. Bulletin of the Geological Society of Greece, 40(2), 936–946. https://doi.org/10.12681/bgsg.16776
- Rubrique
- Mineralogy-Petrology-Geochemistry-Economic Geology
Ce travail est disponible sous licence Creative Commons Attribution - Pas d’Utilisation Commerciale 4.0 International.
Authors who publish with this journal agree to the following terms:
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution Non-Commercial License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g. post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. Authors are permitted and encouraged to post their work online (preferably in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work.