CYCLICITY OF GRAIN SIZE PARAMETERS ALONG A CORE FROM THE GLEYSOL OF SEBKHA ENNOUAL, SOUTHEASTERN TUNISIA

This paper aims to investigate the climatic cycles within the gleysol of sebkha Ennoual. The descriptive grain size distribution (mean, mode, median) visualized two and a half low frequency cycles stretching on 65 cm. Each cycle starts with a dominant vertisol fraction. Then, the arenosol fraction takes the super voice. Simple spectral analysis highlighted the individualization of a 75 cm cycle. The REDFIT spectral analyses numerically showed the appearance of high frequency cycles. Genetically, the middle of the cycles are marked by the appearance of a coarse aeolian arenosol fraction centre (160 µm). From the top downward, the length of the cycles decreases from 53 cm to 20 cm due to an upward increasing aridity. Inspite of solonchaks phenomenon within the gleysol filling of sebkhas Ennoual, kastanozem and phaeozems were quite recorded.