GEOPHYSICAL AND GEOCHEMICAL STUDY OF THE SILICO-EVAPORITIC SEDIMENTARY FILLING OF BOUJMAL WETLAND, EASTERN TUNISIA: INFERRING THE CLIMATIC SIGNAL WITHIN GROUNDWATER NOISE
ELHOUCINE ESSEFI *
Department of Earth Sciences, National Engineering School of Sfax, University of Sfax, Tunisia and RU: Sedimentary Dynamics and Environment (DSE) (Code 03/UR/10-03), National Engineering School of Sfax, University of Sfax, Tunisia
NAJOUA GHARSALLI
Department of Earth Sciences, National Engineering School of Sfax, University of Sfax, Tunisia and RU: Sedimentary Dynamics and Environment (DSE) (Code 03/UR/10-03), National Engineering School of Sfax, University of Sfax, Tunisia
CHOKRI YAICH
Department of Earth Sciences, National Engineering School of Sfax, University of Sfax, Tunisia and RU: Sedimentary Dynamics and Environment (DSE) (Code 03/UR/10-03), National Engineering School of Sfax, University of Sfax, Tunisia
*Author to whom correspondence should be addressed.
Abstract
This study aims to investigate the drowned record of the climatic variability during the last two millennia within the sedimentary filling of Boujmal wetland, eastern Tunisia. Once the core opened, different bands were identified based on the Visual Core Description (VCD). Nevertheless, sampling was carried out each 2 cm in order to obtain higher resolution. Added to the amount of CaCO3, the counting of quartz percentages and size, samples underwent an investigation of their magnetic properties. Six climatic stages were identified: the Warming Present (WP), the Late Little Ice Age (Late LIA), the Early Little Ice Age (ELIA), the Medieval Climatic Anomaly (MCA), the Dark Age (DA), and the Roman Warm Period (RWP) along the 72 cm core. The geochemical analysis of the bulk samples does not show an obvious signal of the climatic variability. Whilst, according to the amount of evaporites, the geochemical study of the tri-acid attacked samples highlights the six climatic stages.
Keywords: Climatic variability, magnetic susceptibility, geochemical study, evaporites, boujmal wetland, eastern Tunisia