Tamarugite-bearing paragenesis formed by sulphate acid alteration in Diana Cave, Romania

Autor(en)
Cristina M. Puscas, Bogdan P. Onac, Herta S. Effenberger, Ioan Povara
Abstrakt

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(en)
Institut für Mineralogie und Kristallographie
Externe Organisation(en)
University of South Florida, Babeș-Bolyai University, Romanian Academy
Journal
European Journal of Mineralogy: an international journal of mineralogy, geochemistry and related sciences
Band
25
Seiten
479-486
Anzahl der Seiten
8
ISSN
0935-1221
DOI
https://doi.org/10.1127/0935-1221/2013/0025-2294
Publikationsdatum
06-2013
Peer-reviewed
Ja
ÖFOS 2012
105113 Kristallographie, 1051 Geologie, Mineralogie
Schlagwörter
Sustainable Development Goals
SDG 14 – Leben unter Wasser
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/08ed74c1-d46b-4c17-ba03-51c3f0eea361