 |
| Titel |
Raman spectroscopic study of alunite occurrences in the Sapes porphyry-epithermal deposit, NE Greece |
| VerfasserIn |
Panagiotis Papazotos, Maria Perraki, Panagiotis Voudouris, Vasilios Skliros |
| Konferenz |
EGU General Assembly 2017
|
| Medientyp |
Artikel
|
| Sprache |
en
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250149574
|
| Publikation (Nr.) |
 EGU/EGU2017-13934.pdf |
|
|
|
|
|
| Zusammenfassung |
| The Sapes area, Northeastern Greece, represent a deeply eroded Oligocene volcanic edifice
built up of post-collisional intermediate-to-acidic intrusives and their volcanic equivalents.
The area hosts a telescoped porphyry-epithermal system and associated high-sulfidation
epithermal Au-Ag-Cu-Bi-Te mineralization within advanced argillic alteration lithocaps
(Voudouris, 2014). Alunite is a common mineralogical constituent among the advanced
argillic alteration assemblages and it is a hydrated aluminium potassium sulfate mineral with
a general formula KAl3(SO4)2(OH)6.
The objective of this work is to study the alunites samples in the Sapes porphyry-epithermal
deposit by means of Raman spectroscopy, as it has been shown to be a useful tool in studying
the alunite structure, either natural or synthetic (Frost et al., 2006; Maubec et al.,
2012).
Raman spectra were excited employing a 532 nm laser at a resolution of 2 cm−1 in the
range of 100-4000 cm−1. Raman spectra exhibit distinguished bands at 162 cm−1, attributed
to translational mode of cations and or librational and translational modes of SO42−, at
235 cm−1 suggesting framework deformations including the SO42− entities as a
whole or attributed to OH/O hydrogen bond stretching mode, a weak band at 385
cm−1 may corresponding to Al–OH stretching vibrations, a moderate band at 564
cm−1 assigned to Al-O and OH deformation modes, bands at 484 and 653 cm−1
respectively due to v2(SO42−) and v4(SO42−) bending modes, a very strong vibration
at 1025 cm−1 that is ascribed to the v1 stretching vibration of the SO42− bands
located at 1080 and 1186 cm−1 due to v3(SO42−) stretching modes and finally
two bands at 3480 cm−1 and 3502 cm−1 that are assigned to the OH stretching
vibrations (Breitinger et al., 1997; Frost et al., 2006; Maubec et al., 2012 and references
therein).
A Raman and FTIR spectroscopic future work will focus on the comparative study among
the alunites occurrences in Greece (Sapes, Limnos, Lesvos and Milos), so as to identify the
differences and similarities in their structural and chemical features reflecting the geological,
geochemical and depositional environment.
References
Breitinger D., Krieglstein R., Bogner A., Schwab R., Pimpl T, Mohr, J., Schukow H.
(1997). Vibrational spectra of synthetic minerals of the alunite and crandallite type. Journal of
Molecular Structure, 408/409, 287–290
Frost R., Wills R., Weier M., Maertens W., Kloprogge J. (2006). A Raman spectroscopic
study of alunites. Journal of Molecular Structure, 785, 123-132.
Maubec N., Lahfid A., Lerouge C., Wille G., Michel K. (2012). Characterization of
alunite supergroup minerals by Raman spectroscopy. Spectrochim. Acta A, 96,
925–939.
Voudouris P. (2014). Hydrothermal corundum, topaz, diaspore and alunite supergroup
minerals in the advanced argillic alteration lithocap of the Kassiteres-Sapes porphyry-epithermal
system, western Thrace, Greece. Neues Jahrbuch für Mineralogie, 191/2, 117-136. |
|
|
|
|
|
|