New dredging method sucks up archeological treasures

DEN BOSCH – Bringing up sand with a cutter suction dredger from a deep pit, layer by layer, is helping archeologists trace the location from where artifacts have been sucked up. The sand is pumped by huge pipes to an area where dredging firm Boskalis prepares the soil at a low-lying and drainage-problem site designated for a new subdivision of 6,400 homes near the Brabant capital of s-Hertogenbosch. The layer-to-layer approach allows Boskalis to separate the various types of sand it pumps up. Some of it is the typical low-quality sand suitable for raising the height of the low lying polder, other more valuable layers meet the criteria for mortar, concrete or as fill for drainage trenches. Archeologists have discovered a wealth of information in the sludge that is pumped to the site, including bones thought to have belonged to mammoths. When artifacts surface, archeologists (who are daily joined by private collectors) say they can trace the age by knowing the depth of their last resting place. Based on what has surfaced from such pits, academics think that the Netherlands once was a cold and dry tundra where mammoths, rhinoceros, wild horses and polar foxes roamed. The site also turned up the skull of a polar fox, thought to be the oldest ever found in the Netherlands.