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.

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.

Bearing in mind Mr. Kitchin's statement that the mica has been recovered from a shallow depth of about six feet only it appears to be of really good quality, and in view of the shortage of clearer types of mica it seems desirable that the deposit should be examined. The four mica specimens submitted for examination are described herein.

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.

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.

Car traverses were made in several directions over an area of 30 miles square with Coorabin as a centre, with the object of delimiting, if possible, the margins of the coal basin. The results of the geological survey are summarised herein.

It was recently suggested by Mr. N. White, Superintendent of Minerals Production, N.S.W., that a geophysical survey be made of the Commonwealth Deep Lead near Glen Innes as part of a campaign to prospect for stanniferous wash beneath the basalt cover. In company with Mr. N. White and Mr. E. Dow, an inspection was made of the area on the 7th and 8th October, in order to determine in the first place whether the problem offers scope for geophysical methods. A geophysical survey, if carried out, would commence in the vicinity of what is known as the Commonwealth Mine and the inspection was made primarily of that area. At present there is no activity at the Commonwealth Mine, which is actually the site where some alluvial deposits were first dredged for tinstone in 1909 by the Commonwealth Tin Dredging Company, N.L., on PML 25, Ph. Wellington, Co. Gough.

The overburden (or non-scheelite bearing rocks overlying the ore-bearing rocks) at the mine of the King Scheelite N.L. at Grassy include: 1) A layer of windblown sand ranging in thickness up to 30 feet; 2) An irregular layer of non-mineralised rocks occurring in the north-western part of the present workings; 3) Non-mineralised rocks conformably overlying the lode in the southern part of the workings; 4) Overburden dumped on the southern side of the open cut. The problem of the dumping of the overburden is involved in that of the selection of a suitable site for the treatment plant. Under the proposed scheme to increase production a new site will have to be found for the treatment plant that is to be erected.

This lease is situated on the Dividing Range south-west from Musgrave Telegraph Station. The geological notes contained in this report refer to the geology and workings of the Looking Glass mica deposits.

Mount Kitchin lies about thirty miles west from Chillagoe in Northern Queensland and is 13 miles by bush-track south-west from the now deserted town site of Arbouin on Cardross copper field. Six claims embrace the mica deposits at Mount Kitchin, but only three of these could be examined, on the 8th October, 1942, in the short time at disposal. The brief examination of these three claims, namely, "Wonder", "Anniversary" and "Southern Cross" confirms the remarks of Mr C.C. Morton in his report dated 1/5/42 to the Chief Geologist, Brisbane, and it appears that the "Southern Cross" and "Anniversary" claims contain the only deposits which may become producers in the future. When compared with the mica deposits of Central Australia the pegmatite bodies at Mount Kitchin are very small.