Weichselian Lateglacial environmental and vegetation development in the Moervaart palaeolake area (NW Belgium); implications for former human occupation patterns

Abstract

In this paper, a detailed vegetation and environmental reconstruction for the Lateglacial interstadial in the Moervaart area (NW Belgium) is discussed, in relation to former human occupation patterns. This reconstruction is based on a multi-disciplinary research carried out on calcareous deposits of a large palaeolake (~ 25 km2). The combination of physical (magnetic susceptibility, micromorphology, organic matter, calcium carbonate), botanical (pollen, macrofossils, diatoms), zoological (chironomids, molluscs, ostracods) and chemical analyses (stable carbon and oxygen isotopes) allowed for a highly detailed reconstruction of the lake ecosystem and vegetation surrounding the lake. The chronology of the lake record was provided by radiocarbon dating and comparison with the nearby Rieme sites and regional biostratigraphy. During the Bølling phase, the Moervaart palaeolake formed as result of a major rise of the groundwater table in the area. Water level rise continued during the early Allerød phase and a rich water flora and fauna developed in the lake. From this period onwards, the area provided a suitable landscape for the Federmesser Culture hunter–gatherers with fresh drinking water, extensive and fertile woodlands and lake edges for wild game hunting, plant gathering and fowling. Water levels rose to a maximum at the end of the early Allerød. Thereafter, an outlet for the lake was formed in the east. As a result, water levels gradually decreased during the middle to late Allerød and eventually the Moervaart lake turned into a swamp and ceased to exist. In combination with the prevailing colder conditions, this led to a marked population decrease with probably temporary abandonment of the region.