Devonian basin-fill histories of the Spanish Cantabrian Mountains and the Belgian Ardennes; a comparison

Abstract

The evolution of the Pre-Devonian and the Devonian sedimentary basin in the Cantabrian Mountains (N.W. Spain) and in part of the Belgian Ardennes is traced and compared. Emphasis is on the palaeogeography reflected by lithofacies in the carbonate platforms in both basins. Lithofacies from the Devonian system have been chosen because the Devonian is the Period of relative tectonic quiescence between the Caledonian and the Variscan orogenies. It could be attempted for such a Period to characterise sediment patterns and the nature of carbonate in terms of the megatectonic and geodynamic frame within which they are formed. For Iberia a geodynamic mobile model has been proposed in the literature, whereas the tectonically imbricated Belgian Ardennes are geodynamically a stable area. The Belgian carbonate platforms appear to have a Pacific faunal/particle affinity, and they evolved from rimmed margin to knoll-reef rimmed ramp platforms. The Spanish carbonate platforms appear to have an Atlantic faunal/particle affinity and evolved from ramp type to reef-rimmed carbonate platforms