Magnetite beach-sands of Bougainville Island, Territory of Papua and New Guinea

Magnetite with combined titanium dioxide, the predominant heavy mineral of the Bougainville beach sands, is derived from the unconsolidated pyroclastic and alluvial aprons of recent-active andesitic volcanoes principally Mt. Balbi in the north, Mt. Bagana in the centre and Mt. Taroka in the south. The spectacular high concentrations of magnetite on the eastern coast are probably too small for consideration as iron ore deposits. Magnetite sand concentrations of economic importance may exist in the large areas of coastal plain, particularly on the western side of the island, which are obviously made up of a succession of old strands. Magnetic survey methods may be of value in delineating zones of magnetite concentration in these areas.