A survey in 1968 showed that 116 overseas firms were searching for or developing minerals in Australia. Fifty-two of these were from the United States, 20 from Canada, 18 from Britain, 16 from Japan. They include most of the large companies of the world. The survey also showed that 60 Australian companies were linked with oversees firms in joint exploration or development activities.

Overseas companies compete on equal terms with Australian concerns for rights to exploration areas. The Government departments administering the granting of such rights allocate them as freely to overseas companies as to local ones. The essential requirements are that the applicants should be bona-fide and capable of marshaling sufficient resources to carry out appropriate exploration programs. A considerable proportion of the high risk capital for exploration is also coming from these overseas sources, and this will be reflected in the ownership of the discoveries which inevitably will flow from their efforts.

There are many inter-related factors causing the growth of interest in mineral exploration in Australia at this time, including technological, economic and political ones. But the primary factor is geological— the recognition of the great potential for the discovery in Australia of a large variety of useful and valuable minerals. No matter how attractive the non-geological factors, exploration on this scale would be most unlikely unless there were sound reasons for believing that there were major mineral deposits still to be discovered.

This belief in the prospects of Australia is based only partly on the impressive empirical record of past and recent discoveries. To the exploration geologists who devise the exploration programs, the factor of even greater significance has been the gathering and publication of a sufficient body of scientific geological and geophysical information to illustrate the wide variety of geological environments which exist over most of the continent.

Although the information is not complete even on the smallest scale and is highly uneven and fragmentary at the larger scales, sufficient is available, when used imaginatively, to generate definite ideas about the favourable potential of many regions for the occurrence of mineral deposits. Of particular value has been the spectacular upsurge in basic geological mapping by both Bureau of Mineral Resources and the State Geological Surveys which has occurred during the past 20 years, and the regional aeromagnetic and gravity surveys made by the Bureau of Mineral Resources. These geological and geophysical maps form the basis for the selection of most areas that are taken up for exploration.

Probably the dominating concept influencing scientific mineral exploration in Australia at the present time is that of the controlling relationship between geological environment and the occurrence of mineral deposits.

In selecting areas for exploration for particular minerals those which have been productive in the