The following eleven holes have been drilled: holes Nos. 22-33. Ongoing drilling operations, and the results and conclusions that can be drawn to date are outlined in this report.

In company with Mr. L.A. Richardson an inspection was made of this deposit on Friday, December 4th. The workings were plotted and examined, though these sections off the main drives could not be inspected very thoroughly owing to having no lighting available except matches.

Plans Nos. 617, 618 and 619 are submitted herewith. These plans show no geophysical results. The resistivity curves have been examined and it is considered that certain conclusions can be drawn regarding the behaviour of the clay bedrock. A preliminary structural interpretation has been made on the basis of depth determinations to an interface, assumed to be the top of the clay bedrock. This involves the analyses of three and four layer curves.

A preliminary report on these samples was forwarded on 19/2/'42, the final report being delayed until the results of a mineralogical examination of two rock types, prominent in samples from 1542 feet down to 1549 feet was available. The results of this examination are now available.

The Coorabin coalfield bore and shaft sites are listed. A short description is given of each site.

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.

Following a request by the Premier of South Australia an inspection of the Leigh Creek Coalfield was made on December 5th to December 8th, 1941. My opinion was sought chiefly on the probability of there being a considerable tonnage of coal available which could be won by open cut mining, preferably from one section of the field, near Telford Siding.

Preliminary assessment of core recovered from drill holes Nos. 22, 23, and 24, King Island.

The following notes on the number of the mica mines in the Harts Range area were collected on a recent water survey. They are very incomplete but it is thought that they may be of interest in view of the possibility of stepping up production in this area. Complete data concerning production, etc. of the mines seems to be impossible to obtain.

The mica used in modern aircraft sparking plugs, of which the attached section is representative, serves a triple purpose, viz: (a) Insulation of the electric current; (b) Protection of the insulating layers from heat; (c) As an effective seal against gas leakage. The use of mica in the construction and manufacture of aero engine sparking plugs is decribed herein.