Repercussions of the dolomitization of the fractured Middle Turonian succession of Bireno platform central part of Tunisia

Abstract

The aim of this paper was to reveal the mineralogical, geochemical, and magnetic repercussions of the dolomitization of the fractured Middle Turonian Bireno platform. The fractures are contemporaneous to the subaerial exposure of the Bireno carbonate platform during the global sea level fall SB 90.5 Ma. The meteoric waters would have been mixed with marine groundwater initiated in Jebel M’rhila area resulting in the precipitation of dolomite in the open fractures according to the mixing water dolomitization mechanism. In terms of mineralogy, the fracturing increased the percentage of dolomite. Geochemically, it increased the amount of iron and subsequently increased the magnetic susceptibility. The principal component analysis confirms the positive correlation between continent indicating chemical elements such as Fe and negative correlation with marine indicating chemical elements such as Na, Sr, Ca, and Mn. In this study, we find a link between the fracturing, dolomitization, and magnetic properties. In doing so, the magnetic susceptibility may be used as proxy to identify and evaluate the quality reservoir.