Drowned landscapes of the Belgian Continental Shelf : implications for northwest European landscape evolution and preservation potential for submerged heritage

Ondertitel:Verdronken landschappen van het Belgisch deel van de Noordzee : implicaties voor noordwest Europese landschapsontwikkeling en bewaringspotentieel van onderwater erfgoed

The expansion and reduction of ice masses across the North Sea Basin has a profound impact on eustatic sea levels and glacio-isostasy across northwest Europe. The complex interaction between eustatic sea level and glacio-isostatic adjustment of the landscape, from the time of ice mass expansion to their deglaciation, exerts a major control on local/regional landforms such as rivers and how fast or slow relative sea level movement occurs on a local/regional scale. Proglacial lakes in the North Sea Basin may have been a common landform during glacial periods. They were fed by meltwater from the Fennoscandian and British-Irish ice- sheets causing their levels to rise and exert major pressure on their confining barriers. During ice mass disintegration major volumes of meltwater enter proglacial lakes and may cause them to burst out of their confinements resulting in catastrophic glacial lake outburst floods. A high-resolution depth-converted structure map of the pre-Quaternary surface combined with regional palaeogeographic reconstructions demonstrates that the late Middle to Late Pleistocene geological evolution of the Belgian Continental Shelf is very complex. The various regions in which different depositional environments are preserved testify this. The Coastal Plain-Inner Shelf comprise the buried incised-valley system of the palaeo-Scheldt River and is mostly controlled by local/regional-scale processes, whereas the Middle-Outer Shelf landforms are controlled by southern North Sea glacial lake outburst floods from the Penultimate and Late Glacial period. The formational process interactions of and the interactions between depositional environments control the preservation potential of submerged heritage. Preservation of archaeological artefacts and palaeontological and human bone material is different for each depositional environment. Landforms and local palaeotopography control deposition and erosion in the landscape, which in turn determine if any form of submerged heritage can be preserved or accumulated within a primary, secondary or tertiary context. The preservation potential for archaeology and palaeontology has been visualised for the first time. Profile type mapping was used as a technique. The maps can be used as a guidance tool for preservation potential assessment at sea. This helps commercial-industrial end-users and policy makers to determine the risk for damage to the submerged heritage. Vice versa this pro-active engagement helps them save time and money for offshore activities because unexpected delays are prevented this way.

Jaar van publicatie:2018

Toegankelijkheid:Open