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A model for cover sinkholes development in Salento Peninsula from geophysical and geomorphological surveys
by
Gianluca Selleri
University of Lecce
Coauthors: G. Leucci, L. De Giorgi
The Salento Peninsula (southern Apulia, Italy) is lengthened for about 100 km in the Mediterranean Sea. Calcareous and calcareous marls rocks referable to some separate sedimentary cycles of age Mesozoic, Tertiary and Quaternary age crop out.
This peninsula landscape is composed of low sediplains alternated with narrow ridges, NNW-SSE trending and up to 200 m a.s.l. high.
A number of karstic morphogenetic phases developed under different climates during the several continental periods occurred since the end of Cretaceous. A polyciclic karstic landscape marks the areas where carbonatic rocks crop out. It is mostly due to the presence of exhumed karstic surfaces produced by a morphogenetic phase occurred at the end of the lower Pleistocene - beginning of the Middle Pleistocene. These last surfaces have been reactivated during last years, in some cases in response of human activity.
The reactivation of the karstic system can locally produce the opening of old and new sinkholes posing a serious threat to the public safety and to the anthropic structures. The natural factors that control the reactivation of the karstik system are still little known.
Geophysical and geomorphological researches have been carried out in an area where the Quaternary karstic system is covered by Middle Pleistocene sediments. The results of these researches indicates that the reactivation of the karstic system is most likely connected to the dynamics of the present surficial aquifer, hosted within the sedimentary cover.
In fact, it is possible that reactivation of sinkholes is due to the action of the underground water that flows from the surficial aquifer to the deep, lower one feed the karstik system. This process produces on the topographical surface the formation of a number of cover sinkholes.
Date received: September 13, 2004
Copyright © 2004 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 # caon-47.