Tamarugite-bearing paragenesis formed by sulphate acid alteration in Diana Cave, Romania
- Author(s)
- Cristina M. Puscas, Bogdan P. Onac, Herta S. Effenberger, Ioan Povara
- Abstract
An exceptional new occurrence of the mineral tamarugite, NaAl(SO4)2 6H2O, from a short karst cavity (Diana Cave,B?aile Herculane; SW Romania) is described. It was formed by corrosion of the bedrock (limestone and marls) by a SO24 -rich steamcondensate resulting from oxidized S2- ions escaping from the thermo-mineral water emerging from depth in the cave. Tamarugiteforms dull white earthy aggregates. Scanning-electron microscope (SEM) observations reveal tabular subhedral crystals neverexceeding 15 mm across. The cell parameters refined from the powder data for the monoclinic space group P21/a are:a ¼ 7.358(6), b ¼ 25.23(2), c ¼ 6.093(5)A ° , b ¼ 95.16(5)°, V ¼ 1126.98(1)A ° 3. The d34S values of the cave sulphates and the thermalwater confirm marine evaporites as the source of sulphur. The sulphate-acid alteration of limestone with contribution of Al3þ and Naþfrom the marls and the thermal water is responsible for the formation of tamarugite. The steam-condensate alteration paragenesisincludes native sulphur, bassanite, anhydrite, epsomite, pickeringite, halotrichite, apjohnite and alunite, as well as quartz and halite,all primary and secondary speleogenetic by-products.
- Organisation(s)
- Department of Mineralogy and Crystallography
- External organisation(s)
- University of South Florida, Babeș-Bolyai University, Romanian Academy
- Journal
- European Journal of Mineralogy: an international journal of mineralogy, geochemistry and related sciences
- Volume
- 25
- Pages
- 479-486
- No. of pages
- 8
- ISSN
- 0935-1221
- DOI
- https://doi.org/10.1127/0935-1221/2013/0025-2294
- Publication date
- 06-2013
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 105113 Crystallography, 1051 Geology, Mineralogy
- Keywords
- Sustainable Development Goals
- SDG 14 - Life Below Water
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/08ed74c1-d46b-4c17-ba03-51c3f0eea361