Piston Coring

Piston cores were obtained from 9 sites (Table 8). The corer, 1 m long by 47 mm in diameter, was loaded with 40 kg of lead. It was lowered on a 4 mm wire rope through a 25 cm diameter hole drilled in the sea ice by mechanical auger and triggered to free fall the last 5 m to the sea floor. Core was recovered in a plastic liner and held with a phosphorbronze cone core catcher, extended by plastic strips. Most cores obtained were less than 60 mm long and only one attempt in three produced any core at all. The reasons for non-recovery of core were not ascertained but it appears likely that when lowered rapidly the corer descends on a helical path induced by spinning due to unwinding of the hawser laid rope. In addition, there may have been core loss due to inadequate functioning of the core catcher.

Eleven piston core samples were examined. Most of the cores, (PC1-8) contain dominantly calcareous foraminiferal faunas, with several hundred well-preserved tests present. PC 9-11 contain dominantly finely agglutinated assemblages, and a lower number of tests. The preservation of calcareous tests in these three samples is very poor, indicating re-working or calcium carbonate dissolution.

Cores 4 and 5 consisted of live sponge and sponge spicule mat respectively. Core 4 had a sparse foraminiferal assemblage but species present were similar or identical to those in the other cores.

The sediment in the samples varies from very fine sand to granule and pebble size clasts. To date no sedimentologic analyses have been attempted on this material.