An overview of the occurrence and testing of bauxite deposits in Australia.

The series of samples described in this report are from 900 to 1536 feet down in bore No.3843, and is a continuation of that reported upon on 23/5/44.

The geophysical test survey of this field was commenced on 5/6/45 and operations were terminated on 6/8/46 when it was considered advisable to await the results of the drilling campaign for guidance in planning the future geophysical programme. The most intense work was done on the south-east gossan area where the methods used included, electromagnetic, potential-ratio, spontaneous polarisation, magnetic and resistivity. This interim report is supplementary to a detailed report of the survey and refers in detail only to some of the results on the south-east gossan area.

In consequence of planning, by the South Australian Government, to develop and mine the coal seams it was considered that the outer limits of the seams should be known with reasonable accuracy so that neither railway lines nor other permanent structures should be built over coal-bearing ground. An accurate knowledge of these limits was desirable for another reason, namely that in the peripheral zone the ratio of overburden to coal was more favourable than elsewhere. At the request of the South Australian Director of Mines the Commonwealth Government agreed to carry out a routine survey of the periphery of the basin, following the completion of preliminary trial surveys. These were carried out between January and April, 1946. Magnet, earth resistivity and gravity methods were used, of which only the gravity methods proved useful. The history of the field, geophysical problem, gravity instruments, testing, and results are discussed in detail in this report. Accompanying geological plans are included.

A report on the results of a micro-examination of samples, submitted by the State Rivers and Water Supply Commission of Victoria, taken from a depth of 3 to 379 feet down. The report comprises a detailed description of the samples, notes on the stratigraphic sequence, notes on the fossils fauna, and a table showing the distribution and stratigraphic range of species.

Asbestos has been mined from an open cut in portions 122 and 12 of the Parish of Yulgilbar, County of Drake. There are a few outcrops of rock in the immediate vicinity of the known deposits, and this renders geological interpretation of the area difficult. Because of this an extensive programme of development has recently been undertaken including drilling, trenching, shaft-sinking and driving. The geophysical surveys made were intended to assist the development, where possible, by outlining the probable extent of asbestos deposits, elucidating structural features associated with the deposits, and providing any information that would assist the geological interpretation of the area. The objectives, survey methods, and results of the survey are discussed in this report. Seven accompanying plans are included.

It is considered that the future of the Mount Bischoff field depends on the success or failure attending efforts to find additional payable ore. The problem then is to locate large tonnages of replacement ore either as extensions of known orebodies or as new orebodies. The results of the campaign outlined in this report will be of paramount importance to the maintenance and development of the field, and the campaign should be conducted energetically by diamond drilling, supplemented by underground explanatory work. The geological interpretation, objectives of the drilling, and proposed drilling campaign are outlined in this report. Three accompanying geological plans are included.

The Pioneer tungsten-bismuth mine, Hatches Creek, was discovered in 1917 and worked on a small scale from then until a short time after the conclusion of World War I, when production ceased owing to a fall in tungsten prices. Prices rose again in 1937, and exploration resumed. The general geology, ore bodies, and working of the Pioneer mine are discussed in this report.

On June 20th King Island Scheelite N.L. asked for advice on the location of suitable drill holes north of their present 150 and 170ft. faces to determine the geology along the No. 3 fault. In this report a scheme of drilling is set out, which would determine the geological structure of the area and indicate tonnage of ore and overburden. A plan is attached to the report which shows the bench limits, the main geological features and selected diamond drill hole sites.

The operational history, orebody, workings, grade, tonnage, and financial considerations relating to the Chesney mine are discussed in this report. Two geological plans are included.