Key features of mixed carbonate-siliciclastic shallow-marine systems: The case of the Capo Colonna terrace (southern Italy)

The late Pleistocene Capo Colonna terrace (southern Italy) is composed of a mix of shallow-marine carbonate and siliciclastic sediments. Shoreface sandstones, dominated by a terrigenous component and by sedimentary structures related to waves and currents, pass seaward into shelf coralline algal frameworks and associated calcarenites. Siliciclastic sandstones and rigid bioconstructions are locally juxtaposed. Main features of the studied system include (i) a bipartition between mixed siliciclastic-bioclastic sedimentation in proximal settings and coralline algal growth in distal settings, (ii) an analogy between the stratal architecture of the clastic-dominated part of the system and that of siliciclastic shelf/ramp systems, and (iii) the control on the gradient of the shoreface-shelf by inherited physiography and transgressive processes rather than the carbonate productivity.