The presence of a regional-wide notch (45 to 115. cm below present biological mean sea level [BMSL]) along the Adriatic coast of Croatia, at a string of sites between Zadar and Rijeka, provides evidence for a rapid but poorly constrained subsidence event(s) after Roman times. For more than a century, this geomorphological tidal level indicator has attracted rich scientific debate but many unresolved questions remain. In this paper, we present new results from Caska Bay (Pag Island) looking at notch morphology and Holocene salt-marsh stratigraphy to constrain the chronology of this crustal deformation on Pag Island. The typical salt-marsh stratigraphy comprises low to high salt-marsh muds interjected by an unconformable marine layer (which lies between - 50 and - 100. cm BMSL) consistent with an abrupt transgression. The palaeoecological record shows an abrupt shift in assemblages across the salt-marsh mud-sand sediment contact translating abrupt coastal changes. Geochronological data constrain this event to around 1000 to 1200. cal. AD. The altitude of the layer is coeval with the submerged notch attested on limestone cliffs around the bay. The U-shape of the notch profile, coupled with the sharp palaecological contacts and submerged Roman pier, implies that sea-level rise was episodic and not gradual as suggested by regional numerical models. Together, our findings shed new light on the chronology of the "enigmatic" Croatian notch on the island of Pag, and highlight the need to couple geomorphological studies of rocky coasts with high-resolution sediment records.
Bibliographical noteFunding Information:
This research was undertaken within the framework of the Franco-Croatian project “CissAntiqua”, jointly funded by the Ministry of Culture of the Republic of Croatia, the University of Zadar and the municipality of Novalja, the French Ministry of Foreign Affairs (MAE), the French National Centre for Scientific Reserch, CNRS-InSHS and the Centre Camille Jullian (Aix-Marseille Université, CNRS, UMR 7299). We also wish to thank OT-Med. AMS radiocarbon dates were funded by the MAE and the CNRS project Artemis. Further support was provided by the Ministry of Science, Education and Sport of the Republic of Croatia (project no. 119-1191306-1305). We thank C. Oberlin (CNRS, CDRC Lyon) for assistance with the radiocarbon dating. We also wish to thank J. Kirby, M. Megrauoi, P. Sabatier and an anonymous referee for constructive comments on an earlier version of the manuscript. We thank Andy Plater for kindly overseeing the editorial process.
- Holocene sea level
- Salt-marsh stratigraphy
ASJC Scopus subject areas
- Earth-Surface Processes