The influence of peripheral sabkhas on the geochemistry and sedimentology of a Tunisian lagoon: Bahiret el Biban
Article first published online: 14 JUN 2006
Volume 28, Issue 5, pages 679–688, October 1981
How to Cite
MEDHIOUB, K. and PERTHUISOT, J.-P. (1981), The influence of peripheral sabkhas on the geochemistry and sedimentology of a Tunisian lagoon: Bahiret el Biban. Sedimentology, 28: 679–688. doi: 10.1111/j.1365-3091.1981.tb01928.x
- Issue published online: 14 JUN 2006
- Article first published online: 14 JUN 2006
- Manuscipt received 25 March 1980; revision received 5 January 1981
Bahiret el Biban is a restricted lagoon in an arid climate. The general geological setting is briefly analysed, especially with respect to the relations between the water body and its evaporitic bordering areas, i.e. supratidal sabkhas.
The geochemical behaviour of the lagoon waters has been studied over a 2-year period following floodings. In spite of some exchange with the open sea, there is a general tendency towards increasing salinity, calcium sulphate impoverishment and a consequent increase of the Mg/Ca ratio. Thus, unless large floodings occur, the basin waters undergo an evaporitic evolution.
Sedimentation and early diagenesis are controlled largely by this geochemical pattern, but also by exchange with the open sea and by the water depth. Organic matter derived from the sea is deposited on entering this highly saline basin and locally produces sediments which could eventually become source rocks.
Bahiret el Biban is a possible model which may be of considerable interest in the reconstruction of the early stages of the evolution of evaporitic basins.