Mineralogical and Geochemical Characterization of the Tamerza Area Upper Lutetian-Preabonian Successions (Southwest Tunisia)

Abstract

The Upper Lutetian-Priabonian series (Seugdal Formation), lying in the Tamerza area (southwestern Tunisia) is commonly represented by two facies, composed mainly of dolomite and gypsum. In this context, the present work is aimed to determine the mineralogy and geochemistry relating to two sampled sections, characterized with distinguished lithology and thickness, in a bid to follow the facies featuring distribution. The systematic specimen of Great Cluse (GC) and Little Cluse (LC) sections were investigated by means of X-ray diffraction (XRD), and Fluorescence X (XRF). The obtained data prove to indicate that the samples pertaining to the Little Cluse (LC) section are mostly made up of dolomite with an obvious prevalence of palygorskite minerals lying on the top. As for the Great Cluse (GC) section associated samples, they turn out to be predominantly composed of dolomite persisting at the lower part, and gypsum predominating the upper part. These mineralogical constituents are confirmed through geochemical analyses, whereby, both of the Little Cluse (LC) as well as the Great Cluse (GC) sections respective samples appear to display remarkable amounts of CaO and MgO. The upper part of the Great Cluse (GC) section related samples proved to reveal that they are characterized with the persistence of high SO₃ amounts. Both of the sections, under review, are separated with the N120 fault, which seems to contribute remarkably in the facies’ noticeable thickening and distinguishable distribution.