Paleoflood events recorded by speleothems in caves |
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| Authors: | Fernando Gázquez José María Calaforra Paolo Forti Heather Stoll Bassam Ghaleb Antonio Delgado‐Huertas |
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| Institution: | 1. Unidad Asociada UVA‐CSIC al Centro de Astrobiología, University of Valladolid, Valladolid, Spain;2. Water Resources and Environmental Geology Research Group, Department of Biology and Geology‐University of Almería, Almería, Spain;3. Italian Institute of Speleology, Department of Biological, Geological and Environmental Sciences, University of Bologna, Bologna, Italy;4. Department of Geology, University of Oviedo, Oviedo, Spain;5. Centre de Recherche en Géochimie et Géodynamique (GéOTOP‐UQAM)‐McGill University, Montreal, Canada;6. Instituto Andaluz de Ciencias de la Tierra, Armilla, Granad, Spain |
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| Abstract: | Speleothems are usually composed of thin layers of calcite (or aragonite). However, cemented detrital materials interlayered between laminae of speleothemic carbonate have been also observed in many caves. Flowstones comprising discontinuous carbonate layers form due to flowing water films, while flood events introduce fluviokarstic sediments in caves that, on occasion, are recorded as clayey layers inside flowstones and stalagmites. This record provides a potential means of understanding the frequency of palaeofloods using cave records. In this work, we investigate the origin of this type of detrital deposit in El Soplao Cave (Northern Spain). The age of the lowest aragonite layer of a flowstone reveals that the earliest flood period occurred before 500 ka, though most of the flowstone formed between 422 +69/‐43 ka and 400 +66/‐42 ka. This suggests that the cave was periodically affected by palaeoflood events that introduced detrital sediments from the surface as a result of occasional extreme rainfall events, especially at around 400 ka. The mineralogical data enable an evolutionary model for this flowstone to be generated based on the alternation of flood events with laminar flows and carbonate layers precipitation that can be extrapolated to other caves in which detrital sediments inside speleothems have been found. Copyright © 2014 John Wiley & Sons, Ltd. |
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| Keywords: | paleofloods aragonite speleothems flowstone cave sediments El Soplao Cave |
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