Sedimentation and vegetation history of a buried Meuse terrace during the Holocene in relation to the human occupation history (Limburg, the Netherlands)

During several archaeological excavations on a river terrace of the river Meuse near the village of Lomm (southeast Netherlands) information was gathered for a reconstruction of the sedimentation and vegetation history during the Holocene. Various geoarchaeological methods - geomorphological, micromorphological and botanical analyses - were applied, while accelerator mass spectrometry (AMS) C-14 and optically stimulated luminescence (OSL) dating provided an accurate chronology for the sediments. During the Early Holocene, many former braided river channels were deepened due to climate amelioration. Later, river flow concentrated in one main river channel to the west, at the location of the modern Meuse. The other channels were only active during floods, and infilling continued until the Bronze Age. Because of the higher setting of the Lomm terrace, it was only occasionally flooded and therefore formed an excellent location for habitation. Humans adapted to the changing landscape, as most remains were found on the higher river terraces or their slopes, a short distance from the Maas river. The Lomm terrace was more or less continuously inhabited from the Mesolithic onwards. During the Early Holocene, river terraces were initially densely forested with birch and pine. From the Boreal (Mesolithic) onwards, dense mixed forests with deciduous shrubs and trees such as hazel, oak, elm and lime developed. During the Atlantic (Meso/Neolithic), the deciduous forests became dominated by oak. Due to human activities from the Late Subboreal (Late Bronze Age) onwards, forests slowly became more open, yet remained relatively dense in comparison to other Dutch areas. The botanical data, however, show that within the Lomm study area there was a large difference in the composition, distribution and openness of the vegetation. The spatial variation in openness came into existence during the Late Bronze Age, as soon as the higher areas started to be used for human activities (i.e. habitation, agriculture and livestock herding). Due to human activities, the northern part of the study area became very open during the Early Roman period. In the lower-situated areas of the southern part, however, forests remained present much longer, until the Early Middle Ages. Due to large-scale deforestation in the Lomm area and hinterland during the Roman period and Middle Ages, the sediment load of the river increased, large floods occurred and overbank sediments were deposited, burying the archaeological remains. The largest increase in sedimentation occurred after the Middle Ages.