Holocene formation and evolution of coastal dunes ridges, Brittany (France)

Abstract

International audienceHolocene coastal dune formation under a continuously rising sea level (SL) is an abnormal response to increasing storm frequency. The aim of this work is to understand the coastal sedimentary budget and the present-day sand starvation, controlled by climate and man. Dating in Brittany shows that Aeolian deposition initiated from ca. 4000 cal BP, with the slowing down of the SL rise. Pre-historical dunes appeared here from ca. 3000 cal BP, without SL regression. After, further building phases recycled the same stock of sands. Historical dunes I developed from ca. 350 AD. Major storms between 900 and 1200 AD resulted in the construction of washover coastal ridges, the Historical dunes II. A part of the sand was evacuated offshore. From ca. 1350 AD, the pre-existing ridges are reworked forming the Historical dunes III, leading to rapid coastal erosion and inland drift. Holocene dunes with a rising SL constitute a temporary anomaly, mostly forced by man, soon erased by storms in Brittany

Holocene development of the Vistula Spit (Baltic Sea coast) based on multidisciplinary investigations

“…Evidence of increased aeolian activity during this period are known from the coast of Denmark (Clemmensen et al, 2001; Pedersen & Clemmensen, 2005) and Great Britain (Sommerville et al, 2007; Wilson et al, 2001). The onset of dune formation occurred in a similar time span also in some regions of France, like Brittany (Van Vliet-Lanoë et al, 2016), Aquitaine (Clarke and Rendell, 2009) as well as in Belgium (Anthony et al, 2010) and the Netherlands (Jelgersma and van Regteren Altena, 1969). On the Polish coast, the phase of increased aeolian activity and the rapid expansion of the barriers are documented on the Świna Gate Spit (Reimann et al, 2011) as well as on Western Pomerania, east of Wolin island (Sydor, 2021).…”

Controls on late-Holocene drift-sand dynamics: The dominant role of human pressure in the Netherlands

“…NW-European Holocene storm periods (HSPs) after Sorrel et al (2012) and Dutch storms from written sources after Berendsen (1984) and Buisman and Van Engelen (1996, 1998, 2000). Light orange bars represent coastal dune sites, dark orange sites are inland drift sands: Portugal – Costas et al (2012); Aquitaine, France – Clarke et al (2002); Brittany, France – Van Vliet-Lanoë et al (2016); Ireland – Wilson et al (2004); Hybrides, NW Scotland – Gilbertson et al (1999); northwestern UK – Pye and Neal (1993) and Orford et al (2000); Brecklands – Bateman and Godby (2004); Denmark – Clemmensen et al (2009); eastern Germany and Lower Saxony – Tolksdorf and Kaiser (2012); Holland coast – Jelgersma et al (1970), Zagwijn (1984) and Pierik et al (2017b); and Pulle, Belgium – Derese et al (2010). Forest cover after Louwe Kooijmans (1995); PD and drift-sand intensity – this study.…”

“…Many of these studies focussed on coastal settings where marine-influenced factors also played a role (e.g. Van Vliet-Lanoë et al., 2016 ); nevertheless, these cold and stormy climates might have caused inland sand drifting as well. While the observed large-scale dune formation also coincided with increasing PD and enhanced human pressure in both inland and coastal landscapes, most of these studies consider the human factor only to a limited extent.…”

Climate control on late Holocene high-energy sedimentation along coasts of the northeastern Atlantic Ocean

“…Onshore, HSPs are associated with the widespread formation of massive aeolian dune fields and coversands stretching along the coasts of western Europe (Alexanderson and Bernhardson, 2016;Bateman and Godby, 2004;Clarke et al, 2002;Clarke and Rendell, 2006;Clemmensen et al, 1996;Clemmensen and Murray, 2006;Clemmensen et al, 2009;Costas et al, 2013Costas et al, , 2012Costas et al, , 2016Gilbertson et al, 1999;Jelgersma et al, 1995;Nielsen et al, 2016;Sommerville et al, 2007;van Vliet-Lanoë et al, 2016;Wilson and Braley, 1997;Wilson et al, 2004), also recorded as the deposition of thin windblown quartz layers over soils (Jackson et al, 2005) and peat bogs (Björck and Clemmensen, 2004;de Jong et al, 2006de Jong et al, , 2007Kylander et al, 2016;Orme et al, 2015Orme et al, , 2016Sjögren, 2009;Tisdall et al, 2013). Aeolian activity was initiated during the last glacial termination (Costas et al, 2016) that gave rise to the periglacial "European Sand Belt" (Zeeberg, 2008), the most recent phase of dune formation being the LIA.…”