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.

Several lines of evidence for former glaciation of the English Channel are considered. These include the following major geomorphical features: (1) extensive areas of flat featureless sea bed bounded by cliffs with residual steep-sided rock masses rising about 60-150 m above them, (2) terrace forms bounded by breaks in slope or low cliffs, (3) palaeovalley systems related to the present land drainage, (4) enclosed deeps (fosses); all except (3) may be attributed to a glacial origin. The distribution of erratics on the Channel floor and in the modern and raised beaches of its coasts are attributed to widespread Saalian glaciation. This glaciation was responsible for the deposition of morainic material at Selsey and the damming-up of glacial Lake Solent. The so-called ‘100 foot raised beach’ of west Sussex is now re-interpreted as a fluvioglacial deposit laid down at the northern margin of the English Channel ice. It is thought that at the height of the Saalian glaciation mean sea-level fell to between 90 and 180 m below o.d. and that for a time the ice was grounded near the western margin of the continental shelf. Possible reconstructions of the limits and main movements of the Weichselian and Saalian ice sheets covering the British Isles and English Channel are included.

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North-south sections across the eastern end of an east-west-trending pericline at different levels in the Bentaillou mine in Ariege, France, show that the Ordovician formations of the mine area have been deformed into a series of vertical segments at depth and that this deep compression diminished upward, with the result that the upper beds did not participate in rotational movements.

The Cambro-Ordovician age of the Akjoujt series in Mauritania is confirmed. It differs in composition from the equivalent pelitic-sandy series immediately to the east (Iriji). Its present form, an apparently thick synclinal series, is due to repetition in isoclinal recumbent folds and thrust slices of low dip that can be explained by gravitative gliding at the time of orogenic uplift. This structure is similar to that of areas to the south, in contrast to the less deformed structure of contemporaneous strata to the east. The folding may have occurred in the Caledonian. The geomorphology of the hills surrounding Akjoujt is explained by early burial in a deep graben of the entire folded series after the principal orogeny, and subsequent, relatively recent rejuvenation.