Ironsand deposits offshore from the west coast, North Island, New Zealand

Abstract

Surface sediment samples have been obtained from the near-shore portion of the shelf off the west coast of the North Island, New Zealand, from depths between 5 and 50 fathoms. The percentage of magnetic ironsand in the sediments has been determined by magnetic separation. The highest percentages (30 per cent by weight) are found close to the shore; at the 50-fathom line — the maximum depth of the samples considered here — ironsand percentage is very low. The concentration of ironsand is ascribed to processes operating in the present and late Pleistocene wave zones.