BIOSTRATIGRAFIA A NANNOFOSSILI CALCAREI DELLA PARTE BASALE DELLA SUCCESSIONE DEL M. MODINO (NELL'AREA DEI FOGLI 234 E 235) ED EVOLUZIONE STRUTTURALE DELL'UNITA' OMONIMA

Abstract

This work deals with the basai part of the Mt. Modino "succession" cropping out in the Emilian sector of the 234 and 235 maps (1: 50.000 Fivizzano and Pievepelago). In the geologie literature this part of succession was interpreted in different ways, namely: - as allochtonous slices alternating with tectonic elements pushed off the Tuscan Nappe; - as olistostromes and olistolites stratigraphically interposed between the Macigno and the uppermost part of the Mt. Modino succession (Fiumalbo Shales - Marmoreto Marls -Mt. Modino Sandstones); - as an "Emilian" sedimentary sequence thrust from east over the Tuscan Domain; - finally, as a sedimentary-tectonic melange, of south­western origin, tectonically emplaced onto the Tuscan Units.