The Quaternary formations of the Belgium

Abstract

Article in French.

ORIGINAL TITLE: Les formations quaternaires de la Belgique

Belgium was not directly covered by an ice sheet, although possible traces of moraines may exist in the Hohe Venn area. Several Quaternary marine deposits are known: (1) - The Merksemian – the oldest Pleistocene marine transgression in Belgium, characterized by a distinctive mollusk fauna; its exact correlation with glacial periods remains uncertain; (2) - A second marine level – glauconitic sands with Cardium edule, probably pre-Riss in age, equivalent to the Holstein or “Corton Beds”, (3) - A third marine level – identified through drilling, attributed to the Eemian.

Additionally, the coastal region contains well-known Holocene formations, the Calais and Dunkirk levels. Correlations between marine and continental formations are unclear. Some deposits previously thought to be Pleistocene may in fact be Pliocene. Terrace sediments show several levels, though their interpretation (climatic vs. interglacial) is debated. Widespread cover sands and niveo-aeolian loess display several weathered horizons linked to various interglacial periods. Riss-age loess shows at least three subdivisions, and Würm-age formations likely also have three (though this is not universally accepted). At the transition from the Pleistocene to the Holocene, especially in Low Belgium, deposits from the Dryas periods occur along with warmer oscillations such as the Allerød and Bølling.