- 1Parthenope University of Naples, Department of Science and Technology, Napoli, Italy (andrea.gionta001@studenti.uniparthenope.it)
- 2University of Naples Federico II, Department of Earth Sciences, Environment and Resources, Naples, Italy
- 3CNR – IGAG, Rome, Italy
This study investigates the Holocene Relative Sea Level (RSL) fluctuations and their impacts on coastal landscapes in the Fondi Coastal Plain. This typical low-lying coastal area, spanning approximately 95 square kilometers along the Central Tyrrhenian Sea in Italy, is characterized by significant portions of its surface lying below mean sea level. This geomorphological configuration makes the plain particularly sensitive to sea-level changes and associated processes, including flooding and sedimentary dynamics.
The Upper Pleistocene to Holocene geomorphological evolution of this plain derives from a complex interplay between tectonic subsidence, glacio-eustatic sea level change, and sedimentary inputs coming from surrounding carbonate reliefs.
The research integrates a comprehensive geodatabase of RSL markers with new high-resolution stratigraphic, sedimentological, paleoecological, and geochronological datasets, alongside reinterpreted previous data. Overall data provide morphostratigraphic and geochronological constraints to the late Upper Pleistocene to Holocene evolution of the Fondi Plain coastal areas.
Two boreholes were drilled in the area according to the PRIN 2022 GAIA project goals. Sedimentological analysis, radiocarbon dating (¹⁴C), and Optically Stimulated Luminescence (OSL) dating allowed to reconstruct the main moments of coastal flooding and progradation/aggradation since the Late Pleistocene.
In detail, concerning the Holocene, the coastal evolution was influenced by an initial rapid rise from approximately −19 m MSL to −5 m MSL between 9 and 7 ka BP, followed since the mid-Holocene by a deceleration up to near present-day level.
Lagoonal environments in the new core, constrained approximately between 7 Ka to 4 Ka, testify a substantial stability of the coast. This behaviour was confirmed also by new Roman geoarchaeological SLIP data along the coast running from Fondi to Formia, indicating a relative sea level positions during the 1st century CE at approximately -0.55 ± 0.29 m MSL. These findings align with regional GIA models, confirming tectonic stability and subsidence rates of approximately 0.03 mm/yr over the past 2.0 ka.
These findings contribute to the coastal vulnerability analysis related to sea level rise induced by climate change.
How to cite: Gionta, A., Aiello, G., Amodio, S., Barra, D., Parisi, R., Mattei, G., Valente, E., and Aucelli, P. P. C.: Coastal Responses to Holocene Sea Level Rise in the Fondi Plain (Central Italy) by means of new borehole and geomorphologic data. , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19290, https://doi.org/10.5194/egusphere-egu25-19290, 2025.
