55 
ANNEXURE  H 
THE APPLICATION OF AERIAL PHOTOGRAPHS TO GEOLOGICAL MAPPING AND 
MINERAL RESOURCES SURVEYS IN AUSTRALIA AND TERRITORIES, 
Prepared by Bureau of Mineral Resources 
The value of aerial photographs in geological mapping, particularly on the 
regional scale necessary in the first stages of mineral exploration, is well known. 
The use of aerial photographs to assist and accelerate geological mapping was 
pioneered in Australia by the late Dr W, G, Woolnough, Commonwealth Geological Adviser 
from 1927 to 19441. It may be said that without aerial photographs the work of the field 
geologist in inland Australia would take three or four times as long. 
Investigation and development of Australia's mineral resources is carried out by 
Governmental agencies and mining companies, Prominent among the former is the Bureau of 
Mineral Resources, Geology and Geophysics, a division of the Commonwealth Department of 
National Development and the Mines Departments in each of the States, 
The Bureau's use of aerial photographs and photomaps is probably more extensive 
than that of the other agencies engaged in mineral exploration,. but may be taken as typical 
of what can be and is being done, 
As its title implies, the wark of the Bureau of Mineral Resources, Geology and 
Geophysics _is primarily concerned with the mineral resources of Australia as a whole, and 
particularly the application of geology and geophysics in exploration for oil and minerals, 
The Bureau also undertakes basic investigations to develop methods of exploration, main- 
tains geophysieal observatories throughout Australia, in New Guinea and in Antarctica, and 
carries out nation-wide surveys and assessments of mineral resources. 
Geological and geophysical surveys are carried out by the Bureau in Commonwealth 
Territories and in the various States by arrangements with the State Government concerned, 
The results of these investigations are published in the form of maps and reports, the 
latter almost always containing several maps and plans. Preliminary maps and plans are 
in many instances made available to leaseholders and State Mines Departments before the 
final document is published. 
Aerial photographs and photomaps are important not only when the results of a 
survey are being prepared for publication, but also during the course of the survey. In 
fact, some survey techniques are based to a very great extent on intelligent use of aerial 
photographs, and the provision of good photographs is essential before the survey can com- 
mence, 
Geologists of the Bureau rely heavily on aerial photographs and photomosaics 
which are studied before parties go into the field, so that a preliminary picture of the 
geology of the area to be mapped may be obtained, In the absence of maps, photomosaics 
also assist in the selection of possible access routes and in planning traverses across 
the area, 
In the field, the geologist lays out his traverses and plots his results on 
individual aerial photographs, and at the same time builds up the geological map using 
photomosaics, photomaps or planimetric maps (often on photo scale) as a base, The final 
map is produced on return to headquarters, and often represents the end-product of several 
years' work, 
The Bureau of Mineral Resources and the State Geological Surveys are partici- 
pating in an agreed scheme for the production of geological maps at a scale of L miles to 
: ^ 1 1 a 1 1 . : 1 : : 
1 inch, The basic unit in this scheme is a "h-mile area" - an area 12 degrees in longi-