Magnetic susceptibility correlation of km-thick Eifelian–Frasnian sections (Ardennes and Moravia)

Abstract

After briefly introducing the sedimentology of two Eifelian-Frasnian carbonate sections in Belgium and Moravia, this paper focuses on the comparison of the magnetic susceptibility (MS) curves. The Ardennes section shows highly variable facies, with an alternation of ramp, platform and mound environments. Detrital inputs are locally very important. Time-equivalent facies in the area of the Moravian Karst correspond to rather pure carbonate platform facies, mostly composed of Amphipora beds. This first analyse of long-term trends in Devonian MS in Belgium and Moravia shows a remarkable similarity, despite a very different background of palaeogeographical setting, facies, sedimentary rate and retrogradation-progradation history. However, a relative independence of the MS and the distal-proximal curves, deduced either from the microfacies record (Ardennes) or from shoreline shifts (Moravia) is observed. This questions the nature of the forcing mechanisms that must at least be active at the inter-regional scale. Moravia and the Ardennes are located along the same palaeolatitude, perhaps suggesting some climatically driven mechanisms, responsible for the input of the detrital fraction responsible for the MS in these sediments. Trade winds are potentially responsible for transportation of dust and its widespread distribution in intertropical areas.IGCP580 “Application of Magnetic Susceptibility on Palaeozoic Sedimentary Rocks