SPECTRAL ANALYSIS BASED ON DATA OF DIFFERENT GEOCHEMICAL PARAMETERS OF A CORE FROM SEBKHA ENNOUAL, SOUTHEASTERN TUNISIA: HOLOCENE SUN-DRIVEN CYCLOSTRATIGRAPHY

The aim of this work is to investigate the sedimentary cycles recorded along a 160 cm core carried out at the Ennoual wetland. Sampling had taken place every 2 cm in order to reucperate 80 samples. The Holocene cyclostratigraphy is controlled by the solar activity. It is Sun-driven. The spectral analysis visualizes obvious cycles probably having astronomical, atmospheric and oceanographic origins. On the one hand, based on the spectral analysis of Na and K values, millennial cycles of ≈ 2500 yr, and 1000 yr related to solar forcing are found out. On the other hand, the 1500 yr cycle is related to thermohaline circulation is extracted from the spectral analysis of Ca values.