Periglacial environments and climatic development during the Early Pleistocene Tiglian stage (Beerse Glacial) in northern Belgium

Abstract

The climatic development of the Early Pleistocene Tiglian stage has been studied in the Tegelen Formation (Rijkevorsel, Beerse and Turnhout Members) in northern Belgium. The sedimentology, paleoecology and periglacial structures of the Beerse Member indicate the presence of a cold period (Beerse Glacial: Tiglian C4) within the warm Tiglian stage. The climatic deterioration led to a drop in sea level, which is reflected by a change in sediment provenance and sedimentary environments. Rhine supply was replaced by a local supply from central Belgium and the interglacial estuarine environment changed into a periglacial eolian sand sheet environment. Gleysols (H-Cg and Ah-Cg profiles) developed in the Beerse Member during phases of land surface stability. During the Beerse cold phase, vegetation was reduced to herbs and pine (tundra and boreal coniferous forest), indicating a mean summer temperature of about 10°C. The periglacial structures (involutions, frost cracks, initial ice-wedge casts) point to a mean annual temperature between -1 and -4°C, which is comparable with the temperature of the Weichselian Pleniglacial.