A buried valley system in the Strait of Dover

Abstract

A series of buried valleys situated south of the submerged Chalk outcrop of the Strait of Dover and eroded down to — 170 m n .g.f. || are recognized as infilled tunnel-valleys excavated subglacially during the Warthe Phase of the Saalian glaciation beneath an ice sheet that advanced up the English Channel from the west. Before the Saalian a Chalk ridge joined England and France. Later in the Warthe, ice withdrew from the English Channel and an ice lobe from the North Sea overrode the Chalk ridge to extend some distance down-Channel, eroding some deep NNE-SSW hollows associated with the tunnel-valleys and scouring out the present deep-water channel; this being probably the first physical opening of the Strait of Dover. The tunnel-valleys were infilled during the Eemian interglacial and finally during the Brorup interstadial as evidenced by palynological study of borehole V 050 cores. The authors propose to name the major northern buried valley described in this paper 'Fosse Dangeard’, to honour the doyen of English Channel geology, Professeur Louis Dangeard. We are happy to have received his gracious acceptance of this proposal.

Fault activity in the epicentral area of the 1580 Dover Strait (Pas-de-Calais) earthquake (northwestern Europe)

“…The origin of these buried palaeobasins is presently uncertain, although most authors agree that they were probably formed during the Middle Pleistocene. Initially, they were attributed to glacial processes (Destombes et al 1975). Nevertheless, most of the recent studies seem to agree that none of the Pleistocene ice sheets extended that far south (e.g.…”

“…3). This structure also traverses two significant Quaternary features situated in the centre of the Dover Strait (Figs 3 and 4): a broad palaeochannel known as the Lobourg Channel and a complex sediment-filled palaeobasin network known as the 'Fosse Dangeard' (see Destombes et al 1975;James et al 2002). Elsewhere Quaternary sedimentary features are mainly limited to a number of major (stable) and minor (mobile) Holocene sandbanks (Mellet et al 2013) separated by areas with thin or absent sedimentary cover (see James et al 2002).…”

“…Dating of the Fosse Dangeard is currently limited to pollen extracted from a 50 m borehole collected from one of its sedimentfilled palaeobasins (Destombes et al 1975). This dating suggests that these sediments were deposited during the Brørup interstadial of the Weichselian glaciation.…”

“…Destombes et al 1975;Smith 1985;James et al 2002). The origin of these buried palaeobasins is presently uncertain, although most authors agree that they were probably formed during the Middle Pleistocene.…”

Hydrostratigraphic modeling using multiple-point statistics and airborne transient electromagnetic methods

“…Many such pre-glaciated areas are dominated by buried valleys, which have proven important subsurface features in regard to groundwater flow (Jørgensen and Sandersen, 2006;Seifert et al, 2008). These noteworthy geological features have received a lot of attention in research through the years (e.g., Destombes et al, 1975;Jørgensen and Sandersen, 2009;Kehew et al, 2012;Ritzi et al, 1994).…”