Speleogenesis of an exhumed hydrothermal sulphuric acid karst in Cambrian carbonates (Mount San Giovanni, Sardinia)
Article first published online: 14 JAN 2013
Copyright © 2013 John Wiley & Sons, Ltd.
Earth Surface Processes and Landforms
Volume 38, Issue 12, pages 1369–1379, 30 September 2013
How to Cite
De Waele, J., Forti, P. and Naseddu, A. (2013), Speleogenesis of an exhumed hydrothermal sulphuric acid karst in Cambrian carbonates (Mount San Giovanni, Sardinia). Earth Surf. Process. Landforms, 38: 1369–1379. doi: 10.1002/esp.3375
- Issue published online: 16 SEP 2013
- Article first published online: 14 JAN 2013
- Accepted manuscript online: 5 DEC 2012 08:52PM EST
- Manuscript Accepted: 26 NOV 2012
- Manuscript Revised: 19 NOV 2012
- Manuscript Received: 23 FEB 2012
- cave formation processes;
- hypogene caves;
In the past few years the systematic study of caves intercepted by mine workings in southwest Sardinia has permitted us to observe morphologies due to rare speleogenetic and minerogenetic processes related to ancient hydrothermal activity. These relic morphologies are slowly being overprinted by recent speleogenetic processes that tend to obscure the hypogene origin of these caves. A combined geomorphological and mineralogical investigation has permitted a fairly detailed reconstruction of the various phases of evolution of these caves.
Cave formation had already started in Cambrian times, but culminated in the Carboniferous, when most of the large voids still accessible today were formed. A key role in carbonate dissolution was played by sulphuric acid formed by the oxidation of the polymetallic ores present in the rocks since the Cambrian. During the Quaternary a variety of minerals formed inside the caves: calcite and aragonite, that yielded sequences of palaeo-environmental interest, and also barite, phosgenite, hydrozincite, hemimorphite and many others. These minerals are in part due to a phreatic thermal hypogenic cave forming phase, and in part to later epigene overprinting in an oxidizing environment rich in polymetallic ores. Massive gypsum deposits, elsewhere typical of this kind of caves, are entirely absent due to dissolution during both the phreatic cave formation and the later epigenic stage. Copyright © 2013 John Wiley & Sons, Ltd.