20 meters under water! Under water landscapes, archaeology and Rhine‐Meuse delta, Maasvlakte 2, Rotterdam, 5 and 6 March 2015.

The Port of Rotterdam will host the 20 meters under water! international symposium on the 5th and 6th of March 2015.

The International Symposium presents the results of recent interdisciplinary research (geological, archaeological, palaeobotanical, archaeolozoological and paleontological) carried out in relation to the construction of the Maasvlakte 2 port extension into the North Sea near Rotterdam in the Netherlands.

Culminating in on-site research 20 meters under water in a drowned landscape, the research produced discoveries of hunter / gatherer’s activities from between 8,400 and 6,400 BC (Late Preboreal to Early Atlantic).

The first day of the symposium will focus on three subjects:

Geology session

The geology session will present the scientific results of geological research carried out in the Yangtze port in 2008 - 2011 that preceded the 2011 ‘excavation’, as well as the results of the geological research in the sand borrow area offshore. For both areas, a detailed landscape reconstruction is presented. In the Yangtze port, a relatively high aeolian river dune complex was present in a slowly drowning river delta from 9000 - 6500 BC. Previous research on river dunes in Rhine-Meuse deltaic settings further upstream showed that they were excellent locations for prehistoric hunter-gatherer hunting camps. In the sand borrow area stacked fluvial deposits of Rhine and Meuse (with a small Scheldt component) are present. Underneath a thin bed of young Holocene marine deposits, several different fluvial units were identified from 20 – 40 m below sea level. Estimated ages range from Early Holocene just underneath the active layer to approximately 250,000 years for the deepest deposits. At the time of writing, OSL dates are not available yet. From most fluvial sequences, only the lower part has been preserved due to erosion by younger fluvial action. In situ archaeological artefacts are not to be expected.

Archaeology session

More information will be provided in the near future.

The archaeology session will present the scientific results of archaeological research carried out in the Yangtze port in 2011 at a depth of approximately 20 meters under water, below the port floor. The results of geological, botanical, zoological and archaeological analyses of the retrieved remains allowed a reconstruction of the history of occupation of a relatively high river dune complex by prehistoric hunter-gatherers, and of the surrounding landscape as it was around 9,000 BC. The landscape yielded an abundance of food while gradually being transformed due to rising sea levels from a valley containing the rivers Rhine and Meuse into an estuary, until it was finally swallowed up by the sea.

Palaeontology session

The palaeontology session presents the work conducted in the North Sea sand extraction zone and on the artificially created Maasvlakte 2 beach. Most of this research was geological and palaeontological in nature but also included an archaeological component. In the sand extraction zone, fluvial sand deposited by the rivers Rhine, Meuse and Scheldt was extracted from a depth of up to 40 meters below the surface to supply the construction of Maasvlakte 2. The age of the deposits ranged from the Early Holocene to approximately 250,000 BP, or were even older. Many mammal bones and some Palaeolithic artefacts were retrieved, the latter out of context, however, due to fluvial transport.

On the second day the symposium will start with an interview session on “complex projects” and will end with an excursion to Maasvlakte 2.