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  • The Wallaroo-Moonta copper field offers a challenge to modern geological and geophysical ore-finding methods. After the production of some 338,066 tons of copper valued at over 20 million pounds, large scale mining ceased in 1923. In spite of the present urgent need for copper, investigators have agreed that no good purpose can be served by re-opening the old mines and that any further substantial production from the field depends upon the discovery of new ore-bodies. Since the ore-bearing rocks are almost completely covered by superficial deposits, it is not unreasonable to suppose that there are still undiscovered ore-bodies in the field. Nevertheless some 30,000 feet of diamond drilling have been carried out in the past and the results, generally speaking, have been very poor. This is not surprising, perhaps, when the local nature of ore occurrences and the vast extent of barren country rock is contemplated. It appears that there is a clear task for geological and geophysical methods to select sites where diamond drilling will have the maximum chance of intersecting ore. The masking of the surface geology immediately suggests the application of geophysical methods and in 1929 some work was carried out at Moonta by the Imperial Geophysical experimental Survey. After a limited amount of work this Survey was forced to the conclusion that the field presented greater difficulties to electrical prospecting, owing principally to the screening effect of the saline overburden. Since 1929, however, geophysical technique has progressed considerably, and more is known concerning the physical conditions of the field. In view of the possible prize at stake it was therefore decided early this year to re-open and carry out further geophysical surveys. The work was carried out in close co-operation with the South Australian Mines Department, which had previously made extensive investigations of the structural geology, and had recommended the use of the geophysical methods.

  • The most important phosphate deposits in South Australia are situated in the Kapunda-Angaston districts and of those the principal deposits which have been worked are: 1) St. Kitts, 11 miles easterly from Kapunda; 2) St. Johns, 4.25 miles south-east from Kapunda; 3) Tom's, 5 miles east-south-east from Kapunda; 4) Moculta or Klemms, 3 miles north-east of Angaston. Deposits Nos. 2, 3 and 4 were examined in company with Mr. S.B. Dickinson, Deputy Government Geologist of South Australia on the 30th March. The following notes are written to set out as briefly as possible, the salient features of the deposits and to indicate the prospecting which it is considered is immediately necessary.

  • In 1944, while Mr. H. B. Owen, geologist of the Bureau of Mineral Resources, was travelling by road from Port Lincoln, South Australia, to Norseman, Western Australia, he collected specimens of the Tertiary rocks for micropalaeontological examination. A detailed report on these samples has never been put on record, but, as the area is now being investigated for the possibility of oil accumulation, the samples have been examined and this report prepared. Some interesting observations made by Mr. Owen during the trip are incorporated here. The most important results of the micropalaeontological examination of these limestones are: 1. The discovery of extensive deposits of upper Eocene age both in outcrop and in subsurface sections; 2. The similarity of the upper Eocene to lower Miocene stratigraphical sequence in the coastal area of the Nullarbor Plains with that found in portion[s] of the Carnarvon Basin, Western Australia, in the Adelaide Basin, South Australia, in north-western Victoria, and in the Torquay area, central southern Victoria.