Considerazioni critiche sui “tufi calcarei” delle Murge. Nuovi dati litostratigrafici e paleoambientali

Critical considerations and new lithostratigraphical-paleoecological data on the “tufi calcarei” of the Murge, Apulia, Italy

Abstract

On this study are analysed several lithostratigraphic successions of the carbonatic deposits that lie at the base of the lower Pleistocene series in the Murge area. They correspond to those rocks which are known in Puglia as “tufo calcareo” or “tufi calcarei”. The petrographic study of these deposits has shown that: a) they consist mainly in biocalcarenites, biocalcirudites, organic limestones and, secondly, in biomicrites, pelmicrites, micrites and calcareous silts; b) these sediments were deposited in the basin itself; they are constituted almost completely by bioclasts included in micrite and/or in sparite, with a very few or no lithoclast at all, contrary to opinions accepted up to now. The lithostratigraphic and sedimentologic data have made it possible to define various lithofacies and to reconstruct the environments of deposition; it has been possible to recognize sediments of continental environments (eolic and lagoonal) and sediments of marine ones (littoral and of deeper sea, as far as the shelf transition). Besides it is clear that the areal distribution of the facies of Quaternary deposits was controlled by the paleomorphology of the Cretaceous substratum.