A complete Late Weichselian and Holocene record of aeolian coversands, drift sands and soils forced by climate change and human impact, Ossendrecht, the Netherlands

Abstract

A stacked aeolian sequence with intercalated soils is presented from the southern Netherlands, which fully covers the Late Weichselian and Holocene periods. An integrated sedimentological (sedimentary structures, grain size), palynological (pollen) and dating approach (radiocarbon, optically stimulated luminescence (OSL)) was applied to unravel climatic and human forcing factors. The dating results of soils and sediments are compatible, and no large hiatuses between the radiocarbon-dated top of the soils and OSL-dated overlying sands were observed. It is argued that the peaty top of wet-type podzols can be used for reliable radiocarbon dating. This study reveals more phases than previously known of landscape stability (Usselo Soil and two podzol soils) and instability (Younger Coversand I and II, two drift-sand units) that are related to Late Weichselian climate change and Holocene human occupation. Regional aeolian deposition in source-bordering (river) dunes (Younger Coversand II) took place in the second part of the Younger Dryas, after 12.3 ka cal. BP, implying a delayed response to Younger Dryas cooling, vegetation cover decline and river pattern change of the Scheldt. The onset of podzolisation and development of ericaceous vegetation occurred prior to the introduction of Neolithic farming, which is earlier than previously assumed. Early podzolisation was followed by a short phase of local drift-sand deposition, at c.5500 cal. BP, that possibly relates to agriculture. Strong human impact on the landscape by deforestation and agriculture resulted in a second phase of widespread drift-sand deposition covering the younger podzol soil after AD 1000.

Source-bordering aeolian dune formation along the Scheldt River (southern Netherlands – northern Belgium) was caused by Younger Dryas cooling, high river gradient and southwesterly summer winds

“…On the Brabantse Wal, this peat layer is correlated with the Usselo Soil (Vandenberghe et al, 2004). The Holocene drift sands (unit 8; Boxtel Formation) are separated from the Late Glacial river dune deposits by the Holocene podzol soil (Kasse & Aalbersberg, 2019). Calcareous and organic Holocene lake deposits (unit 5) are highlighted in the depression between the Late Glacial dunes in the polder area and the Brabantse Wal escarpment.…”

“…2). These deposits are separated by a major unconformity from the overlying Late Pleistocene and Holocene coversand and dune deposits in the east (Boxtel Formation), at c.15 to 25 m above sea level (Vandenberghe et al, 2004;Kasse & Aalbersberg, 2019). An up to 15 m thick, sea-level rise related, Holocene sequence is present in the west (Nieuwkoop and Naaldwijk Formations), completely filling the Late Weichselian Scheldt Valley (Vos & Van Heeringen, 1997).…”

“…Therefore, the dunes are interpreted as sourcebordering dunes (river dunes) that have been formed a short distance downwind of the fluvial source area. The medium to coarse grain size, presence of fine gravel and moderate to poor sorting are connected to the short transport distance of at most 10 km (Kasse & Aalbersberg, 2019).…”

“…This start of river dune formation is in good agreement with previous palynological research in the area. According to Nelson & Van der Hammen (1950) and Kasse & Aalbersberg (2019: fig. 7A) organic deposits below the river dunes at Hoogerheide and Ossendrecht date from the Allerød period (Betula and Pinus phases) and early Younger Dryas.…”

“…Optically stimulated luminescence enables direct dating of the aeolian sand and revealed a Younger Dryas age of dune formation along the Scheldt (Vandenberghe et al, 2004;Bogemans & Vandenberghe, 2011;Crombé et al, 2018). The Younger Dryas river dunes were modulated into drift-sand relief in the late Holocene (Schwan, 1991;Kasse & Aalbersberg, 2019).…”