First data on tunisian speleothems
by
Christiane Causse
L.S.C.E., UMR CNRS-CEA, Domaine du CNRS, 91198, Gif-sur-Yvette Cedex (France)
Coauthors: M. Bakalowicz (ISTEEM, Hydrosciences, CNRS-UMII, C.C. MSE, Montpellier, France), N. Chkir (L.G.I.P. ENIS, Sfax, Tunisie), D. Genty (L.S.C.E., UMR CNRS-CEA, Domaine du CNRS, Gif-sur-Yvette, France), R. Karray (Dept. de Geographie, Faculté des Sci. H.et S.,Tunis, Tunisie, University of Tunis), M-A. Mélières (L.G.G.E.,UPR 5151,St Martin d'Hères, France), V. Plagnes (L.S.C.E., UMR CNRS-CEA, Domaine du CNRS, Gif-sur-Yvette, France), K. Zouari (L.G.I.P. ENIS, Sfax, Tunisie)

Despite the existence of perennial karstic springs in Northern Tunisia, the most famous being the "Temple des eaux" at Zaghouan which has provided Carthage for domestic water 2000 years ago and is still supplying part of Tunis needs, a true large karstic development is not documented in this area. Nevertheless, a few caves have been recognised in the Serj Djebel. Aïn el Tseb Cave (7°9'12" E, 35°54'26" N, 850 m asl) and Mine Cave (7°39' E, 35°56'55" N, 920 m asl) were recently visited and one of them sampled according to a french-tunisian research program. Mine Cave, so called because discovered during mining industry, is a large cave where tectonic origin is more important than a true karstic one classically developed through dissolution of calcareous bedrock below the correlative formation of an epikarst. Here the epikarst does not exist. Nevertheless, speleothems are abundant, some of them still active. An underground spring is present in the cave. Seepage waters and two stalagmites were collected. One of them, 20 cm long, was (U-Th) dated at around 20 ka at the base and 5.6 ka near the top. There is no lamination. Hiatuses are not apparent, that may offer a continuous record for this time. The second concretion, around 30 cm long, gave access to older periods, from 500 ka up to 22.2 ka. A few hiatuses, still to be dated, mark growing interruptions to be related to paleoclimatic variations. Stable isotope data analyses are in progress. Travertine formations probably contemporaneous of the humid periods having allowed the speleothem growing were also collected in the same area. The aim of this project is to provide new insights on the southern mediterranean climate variations through multidisciplinary study of speleothem and travertine records.

Date received: April 30, 2001

Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cahi-58.