The Beacon Supergroup in the McMurdo Sound region is a flat-lying continental sequence about 2000 m thick and ranging in age from Early Devonian to Late Triassic (400 to 180 m.y. B.P.). It was extensively intruded by sheets of Ferrar Dolerite in the Early Jurassic. The ultimate objective of our programme - to determine a polar wander curve for Antarctica for this 200 m.y. period - has yet to be achieved. However the secondary aim - devising and carrying out a field programme of collecting oriented rock samples - was successfully accomplished.

The field programme was to take oriented samples at time intervals of no longer than 0.5 m.y., roughly one every 3 m. Coring is the only feasible technique, but to date coring attempts in the Antarctic had been unsatisfactory. The main problems had been the large quantities of cooling fluid needed, the inability to use water, and the weight and unreliability of the equipment.

A 22 cc TAS back-pack motor (Plate XVI) used for tree trimming and grass cutting was adapted by attaching a specially designed coring head (Plate XVII) to the flexible drive. The coolant, a glycol and water mixture, was metered by a stock drenching handpiece. The entire unit, including 5 litres of antifreeze, weighs 14 kg.

Under 'normal' operating conditions, at least 2 litres of water was used per core. The aim was to reduce this consumption to less than 1/2 litre per core. For 600 cores, approximately 150 litres of antifreeze with a 1:1 mix would be required. In the event, 30 gallons (135 litres) was taken since the motor was low powered, thin walled coring stems were obtained as they require less driving power. These would be more likely to wear than the normal heavier corers so 10 core stems were taken.