Underwater sampling
Sampling prehistoric landscapes
Recovering material from prehistoric land surfaces is a task fraught with difficulties. Limited visibility, tides, currents and restrictions on the time divers can stay underwater necessitated the development efficient excavation methods. The answer was to bring sections of the seabed to the surface for analysis onboard the boat. Marine grade stainless steel trays measuring 15cmx25cnx50 were constructed within which to recover samples. The size was limited to the amount a diver could manage underwater and was strengthened at one end while being open at the other. This enabled the tins to be pushed into the deposit being excavated. The top was left open to reduce friction and reinforced with cross straps. The seabed was cleaned and sectioned before recovery of deposit by the trays which permitted regular units to be selected enabling systematic recreation of their relationship on the surface.
Diver recovering sample from Bouldnor Cliff
Monolith tins
Specialist monolith tins were necessary to recover environmental and sedimentary material from the seabed. The hostile conditions necessitated a robust structure that was large enough to support the range of samples necessary for palaeoenvironmental assessment and landscape reconstruction. The optimum size and shape was also dictated by the ability of the diver to handle the sample and the need for strength as it was teased into the sectioned face with a lump hammer, and a need to maximise sampling speed. The tins were made of marine grade stainless steel, they measured 8cmx8cmx60cm, were reinforced at the ends, contained slits on the back to release water and had built on handles for manoeuvrability.
Monolith tins with samples from Bouldnor Cliff