The Flemish Valley (NW Belgium) is a relatively flat and low-lying area situated at the southern limit of the lowland cover sand region of the NW European plain. During the Late Pleniglacial and the Late Glacial, numerous shallow lakes were formed. These depressions are important and sensitive ecosystems providing excellent continental archives to investigate past environmental changes since the last glaciation, making this area of particular interest. However, although previous pollen analyses have punctually been carried out in the Flemish Valley, studies employed in combination with other proxy records are rare, and temporal resolutions stay low and not suited to catch abrupt and short changes as climatic crises may be. In order to better understand the natural processes which occurred in these particular ecosystems, an integrated research program based on a multiproxy approach has recently been undertaken on the Late Glacial. The fundamental aim is to produce a detailed and quantified reconstruction of past environments at high temporal resolution in relation with climate variability by means of independent proxies. For that purpose a 70m long trench was dug at Moerbeke through the deepest part of the Moervaart Depression, one of the largest palaeolake of Europe. Several sequences revealing a contrasted stratigraphy (lake marl, gyttja, peaty deposits and sandy layers alternating) are investigated using biological indicators (pollen, NPPs, plant macrofossils, charcoal, diatoms, ostracods, mollusks, insects), sedimentological (LOI, magnetic susceptibility, granulometry, gamma-density), chronological (AMS 14C and OSL dating, tephra layers) and geochemical proxies (isotopes). Using multiproxy comparisons, we will try to assess if the vegetation and other environmental indicators have changed concomitantly and simultaneously and to decipher between the most sensitive palaeoenvironmental indicators to regional climatic conditions.

Abstract of an Oral Presentation or a Poster