Abstract
The present study examines the stratigraphy of two sandspits that both appeared and developed since the middle of the 17th century during the Little Ice Age. The Arçay spit is located along the macrotidal Atlantic coast in South-West France with a maximum tidal range of 6.5 m. The Pointe du Banc in the English Channel, North-West France, is located in a hypertidal coastal setting with a tidal range of up to 14 m. The evolution of the two spit systems has been compared using historical maps, ground penetrating radar data and facies analysis and geochronological data from sediment cores. The Pointe du Banc spit developed between 1650 and 1750 CE, in a dominant seaward direction while the main mode of construction of the Arçay spit was in a longshore direction. It is proposed that this difference relates to sediment supply and coastline morphology. At the Pointe du Banc spit, the large tidal range causes a long wind fetch and sustained aeolian sediment supply. Moreover, the spit is located at the apex of a large-scale embayment where sediment transport from north and south converges. Combined, these factors result in a positive sediment budget and seaward shoreline progradation. At the Arçay spit, high wave obliquity results in a large littoral drift and sustained longshore spit construction. At both locations, low gradient shorefaces may have favoured a net landward-directed sediment flux that supply sand to the foreshore.
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | Depositional Record |
| Vol/bind | 11 |
| Udgave nummer | 1 |
| Sider (fra-til) | 311-327 |
| ISSN | 2055-4877 |
| DOI | |
| Status | Udgivet - 2025 |
Bibliografisk note
Funding Information:This work is a contribution to the BLiNiS research project (2013\u20132014, PI B. Tessier, LITEAU programme). Financial support, including C. Poirier post\u2010doctoral grant, was provided by the French Ministry of Environment (Minist\u00E8re de l'Ecologie, du D\u00E9veloppement Durable et de l'Energie, MEDDE) through the LITEAU funding scheme. M.Fruergaard received funding from Carlsberg Foundation, Denmark (COASTEVENT; grant nos. CF14\u20100173 and CF15\u20100254). We warmly thank F. Lelong and S. Haquin from M2C Lab for managing and performing the vibracoring campaigns on both sites. We are grateful to Dr. Cornel Olariu and an anonymous reviewer for their careful and constructive reviews, which contributed to improve the manuscript. We also thank Peter Swart, the editor of the journal, for his kind assistance and helpful advice in improving the latest version of the article. Finally, we express all our thanks to Drs. Sergio Longhitano and Domenico Chiarella, the co\u2010organisers of the Tidalites 2022 conference in Matera and co\u2010editors of this Tidalites 2022 Special Issue in The Depositional Records.
Publisher Copyright:
© 2024 The Author(s). The Depositional Record published by John Wiley & Sons Ltd on behalf of International Association of Sedimentologists.