The Late Triassic is almost everywhere represented by thick bedded, white to light grey dolomites. Laminated, fenestral facies generally alternate with bivalve- and gastropod-rich beds, indicating sedimentation in peritidal, low-energy environments. The fossil content (gastropods, foraminifers and algae) is typical of the Norian–Rhaetian. The dolomites grade upward to limestones with megalodontid shells, tens of centimetres in size, of latest Norian– Early Rhaetian age. In the Jurassic, a marked facies differentiation becomes apparent between the eastern and western outcrop areas. In the former, calcareous wackestones and packstones with Foraminifera, algae, ooids and oncoids are dominant, indicating a persistent shallow-water, lagoonal environment. As such, these successions are comparable with those of the Monte Pollino area. In contrast, resedimented, calcareous facies are dominant at Monte La Serra, Monte Ciagola and Aieta, indicating a lateral transition to a slope domain. The most complete succession is that of Monte La Serra, where the upper Triassic megalodontid limestones are replaced upward by mud-supported calcareous conglomerates rich in coral, gastropods, sponges and echinid fragments. The Jurassic age is confirmed in the lower part of the interval by the presence of Stylothalamia sp. At Monte Ciagola the conglomerates contain a marly, yellowish matrix and are generally strained.
A comparable facies distribution is recorded also in Cretaceous rocks, with the eastern area dominated by shallow-water facies and the western area mainly occupied by resedimented slope deposits. The former are represented by dark, well- bedded, generally cyclic limestones with characteristic shelf macrofossils of this age (requienids, radiolitids, hippuritids) and a rich assemblage of microforaminifera and algae. These resedimented deposits comprise graded coarse calcarenites, floatstones and rudstones with abundant bioclasts of marginal environments (rudists, gastropods, corals, echinoderms). The resedimented facies are more abundant in the upper part of the succession.
In the Pollino Massif the Cretaceous shallow-water rudistid limestones are disconformably covered by the brackish lagoonal to shallow marine Trentinara Fm (Fig. 7), followed by middle Aquitanian–lower Burdigalian open shelf calcarenites (Cerchiara Fm), and by siliciclastic turbiditic deposits that are not older than Langhian, which include ‘Numidian’ quartzarenites of the Bifurto Fm.
On the SE side of the Pollino massif the Cerchiara and Bifurto Fms directly overlie the Cretaceous limestones. In all other areas, instead, the Cretaceous shallow-water carbonates are followed by coarse calcareous breccias. The occurrence of Nummulites sp., in both the clasts and the matrix, indicates that these beds are not older than Palaeogene. These breccias rapidly evolve to thin-bedded calcarenites that are also strongly deformed and contain, in the upper part of the succession, Myogipsina sp. and other Miocene Foraminifera. The succession is topped by marls, pelites and rare quartzarenite intercalations, which can be correlated with the Bifurto Fm (Iannace et al., 2005; 2007).
Figure 8 – Paleogeographic reconstructions (Oligocene to early Miocene) of the western Mediterranean during progressive closure of the remnant ocean basin and onset of collision in southern Apennines (from Critelli, 1999; Critelli et al., 2011).
