Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite
<p>Very-low-grade mineral veins investigated in the impure limestone massif of the Aravis (Haute-Savoie, France) yielded a rich mineral assemblage typified by dolomite, calcite, quartz, illitic mica, fluorite and three types of chlorite. The vein network extends over more than 5 km and was pro...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-10-01
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| Series: | European Journal of Mineralogy |
| Online Access: | https://ejm.copernicus.org/articles/35/831/2023/ejm-35-831-2023.pdf |
| _version_ | 1797666384873783296 |
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| author | B. Dubacq G. Bonnet M. Warembourg B. Baptiste |
| author_facet | B. Dubacq G. Bonnet M. Warembourg B. Baptiste |
| author_sort | B. Dubacq |
| collection | DOAJ |
| description | <p>Very-low-grade mineral veins investigated in the impure limestone massif of
the Aravis (Haute-Savoie, France) yielded a rich mineral assemblage typified
by dolomite, calcite, quartz, illitic mica, fluorite and three types of
chlorite. The vein network extends over more than 5 km and was
probably emplaced around peak burial of the limestone (<span class="inline-formula">∼7</span> km
depth, 190 <span class="inline-formula"><sup>∘</sup></span>C). The mineralogy has been investigated with electron
microscopy, mass spectrometry and X-ray diffraction, with emphasis on
chlorite types. The first chlorite type is a chamosite often interlayered
with illitic mica. The second type is a Mg-rich, Al-depleted cookeite. The
third type is a Li-rich sudoite. Presence of the three chlorite types shows
limited solubility between di-trioctahedral chlorite phase components
(sudoite and cookeite) and with tri-trioctahedral chlorite (chamosite).
Departure of the Li-rich sudoite and Mg-rich cookeite from the ideal
end-member compositions suggests solid solutions towards a Li-sudoite
component. The associated illitic mica does not contain Li in significant
proportion but shows pyrophyllitic and di-trioctahedral substitution,
without a Tschermak component. These results call for systematic studies of
the Li content of chlorite and for better modelling of di-trioctahedral
substitution in chlorite and mica.</p> |
| first_indexed | 2024-03-11T19:57:50Z |
| format | Article |
| id | doaj.art-c2c0dad2d9c34cfa9f3611985967503a |
| institution | Directory Open Access Journal |
| issn | 0935-1221 1617-4011 |
| language | English |
| last_indexed | 2024-03-11T19:57:50Z |
| publishDate | 2023-10-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | European Journal of Mineralogy |
| spelling | doaj.art-c2c0dad2d9c34cfa9f3611985967503a2023-10-04T14:49:08ZengCopernicus PublicationsEuropean Journal of Mineralogy0935-12211617-40112023-10-013583184410.5194/ejm-35-831-2023Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chloriteB. Dubacq0G. Bonnet1M. Warembourg2B. Baptiste3Institut des Sciences de la Terre de Paris, ISTeP, UMR 7193, Sorbonne Université, CNRS-INSU, 75005 Paris, FranceInstitut des Sciences de la Terre de Paris, ISTeP, UMR 7193, Sorbonne Université, CNRS-INSU, 75005 Paris, FranceInstitut des Sciences de la Terre de Paris, ISTeP, UMR 7193, Sorbonne Université, CNRS-INSU, 75005 Paris, FranceInstitut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, UMR 7590, Sorbonne Université, Muséum National d'Histoire Naturelle, CNRS, 75005 Paris, France<p>Very-low-grade mineral veins investigated in the impure limestone massif of the Aravis (Haute-Savoie, France) yielded a rich mineral assemblage typified by dolomite, calcite, quartz, illitic mica, fluorite and three types of chlorite. The vein network extends over more than 5 km and was probably emplaced around peak burial of the limestone (<span class="inline-formula">∼7</span> km depth, 190 <span class="inline-formula"><sup>∘</sup></span>C). The mineralogy has been investigated with electron microscopy, mass spectrometry and X-ray diffraction, with emphasis on chlorite types. The first chlorite type is a chamosite often interlayered with illitic mica. The second type is a Mg-rich, Al-depleted cookeite. The third type is a Li-rich sudoite. Presence of the three chlorite types shows limited solubility between di-trioctahedral chlorite phase components (sudoite and cookeite) and with tri-trioctahedral chlorite (chamosite). Departure of the Li-rich sudoite and Mg-rich cookeite from the ideal end-member compositions suggests solid solutions towards a Li-sudoite component. The associated illitic mica does not contain Li in significant proportion but shows pyrophyllitic and di-trioctahedral substitution, without a Tschermak component. These results call for systematic studies of the Li content of chlorite and for better modelling of di-trioctahedral substitution in chlorite and mica.</p>https://ejm.copernicus.org/articles/35/831/2023/ejm-35-831-2023.pdf |
| spellingShingle | B. Dubacq G. Bonnet M. Warembourg B. Baptiste Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite European Journal of Mineralogy |
| title | Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite |
| title_full | Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite |
| title_fullStr | Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite |
| title_full_unstemmed | Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite |
| title_short | Very-low-grade phyllosilicates in the Aravis massif (Haute-Savoie, France) and the di-trioctahedral substitution in chlorite |
| title_sort | very low grade phyllosilicates in the aravis massif haute savoie france and the di trioctahedral substitution in chlorite |
| url | https://ejm.copernicus.org/articles/35/831/2023/ejm-35-831-2023.pdf |
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