The Quaternary deposits in the Bethune-Bruay-Allouagne-Chocques area are exposed on two hills composed of marine and continental (Ostricourt sands) facies of Landenian sands. The Ostricourt sands are overlain by a podzolic paleosol which underlies sandy loams and clays previously considered as Sparnacian. However, the presence of such periglacial phenomena as ice wedges and mammilliform sandstones in the podzols, and pergelisol pebbles in the loams and clays suggests that these deposits may actually be very early Quaternary. Overlying these deposits is a series of three soilflows alternating with paleosols, and separated from the Mindel-Riss interglacial by a hiatus. Eolian sands compose the Mindel deposits which are overlain by numerous soilflows of the Riss. The Wuerm is represented by three loess deposits sometimes intercalated with flows of leached rubble.