Exploration is being actively carried on throughout the continent. By mid-1969 mineral exploration holdings covered 20 per cent. of the continent including a very large proportion of the 45 per cent occupied by igneous and metamorphic rocks which offer the best prospects for metallic minerals. The sedimentary basins are mostly covered by petroleum exploration and development titles, on which are superimposed mineral exploration holdings in regions favourable for the occurrence of coal, phosphate and other non-metallic minerals.

Until recently mineral exploration in many parts of Australia was inhibited by remoteness, severe climate, difficult terrain, lack of roads and absence of development, in various combinations. But as the map of the exploration holdings shows, these factors have practically disappeared as deterrents to exploration, although they still remain as formidable obstacles in the way of the development of discoveries. At the exploration stage the effects of these physical barriers have been minimized or overcome by the use of versatile land vehicles, light aircraft and especially helicopters for access and transport, by radio communication and by a steadily rising level in the standard of field accommodation and amenities. These facilities have opened the way into previously inaccessible regions which now may even have a special attractiveness on account of the lightness or absence of previous exploration.

They have not, however, diminished the high demands that working in these areas makes of the exploration geologist for personal qualities of resourceful leadership, self reliance and determination.

Rights to large holdings, with areas suitable for the application of modern prospecting methods, are issued by the Mines Departments of all States and by the Administrations of the Territories, except Western Australia. This State until recently also did so, but now has placed an embargo on them. The areas of individual holdings cover a wide range but are commonly hundreds of square miles in extent. The rights to them are issued subject to conditions which generally commit the holder to carry out defined exploration programs involving specified minimum levels of expenditure, and require him to provide reports periodically giving the factual results of the exploration work. These holdings are for short terms of years and usually the holder is required periodically to relinquish a large part of his area. As a result ground is being continually released but naturally this consists of the less attractive parts. Even with relinquishment a shortage of exploration areas is developing, and this will become more severe.

A great deal of this expansion in exploration has come about through the entry of foreign-based companies into Australia.