The Paleocene-Eocene shallow water deposits of the Ionian Islands (Pre-Apulian domain, Greece)

We present a synthesis on ongoing research of the depositional sequences and the biostratigraphy of a carbonate ramp developed in Paleocene-Eocene times in the Ionian Islands, focusing on outcrop data and reworked clasts from Cephalonia and Zakynthos. An interpretation of the facies in terms of paleoecology and proximality-distality changes is presented, along with a discussion of regional hiatuses and depositional models. Two main patterns of facies distribution have been identified, corresponding to different depositional models. The transition from one to the other occurred in the late Thanetian, and corresponds to a conspicuous change in the biota and depositional profile of the ramp. During the Paleocene a low angle homoclinal ramp was characterized by a wide inner-middle ramp belt with flourishing red algae, coral and foraminiferal assemblages. A selection of facies and assemblages is presented for the lower Thanetian. In early Ypresian times, a sharp areal contraction of ramp environments occurs, with the demise of restricted inner ramp sedimentation and the development of thriving larger foraminiferal assemblages (Alveolina and Nummulites packstone-grainstone), close to emerged areas.