Results are given of a geophysical test survey made at three localities on the Newcastle coalfield in August, 1952, to determine whether intrusive doleritic dykes could be located by the magnetic method. Knowledge of the position of the dykes would assist in planning the lay-out of underground workings and of surface roads. The results showed only slight variations of the magnetic field, but some weak anomalies of less than 100 gammas were recorded. The position of these anomalies coincides with the inferred position of the basic dykes near the surface. The variation in the shape of anomalies suggests non-uniformity of the magnetic properties and shape of the dykes. The magnetic method might be helpful in determining the position and extent of the dykes beyond the areas where they are known, but supporting evidence from other geophysical methods such as the gravity of electric resistivity methods may be needed to verify the magnetic results.

A request was received in December, 1951, from the Director of Ordnance and Underwater Weapons of the Department of the Navy for assistance in selecting an area suitable for the electrical balance testing of the pistol-firing rod unit of the torpedo. It was desired that this site should be at the R.A.N. Torpedo Establishment at Neutral Bay, Sydney, New South Wales. The only condition laid down in the relevant specification is that "the rod may be supported in a suitable wooden structure or in such other manner provided that the complete rod unit is not less than ten feet from any ferro-magnetic materials". In order to arrive at a more specific definition of the requirements for the testing site, the problem was discussed with the Chief Superintendent and officers of the Torpedo Establishment. The appropriate test specifications were consulted and a series of measurements were carried out to determine the actual requirements. The magnetic investigations described in this report were carried out in August, 1952, and the overall results and conclusions were communicated verbally at that time to the officers concerned.

A declinometer survey was made over a proposed compass-swinging base at the R.A.A.F. Airfield at Point Cook, Victoria in January, 1952, to determine its suitability. The results show that there are local magnetic disturbances which cause deviations in excess of the permissible maximum of one quarter of a degree. The site is therefore unsuitable.

The two samples submitted for micropalaeontological examination, came from the depths of 290 feet and 320 feet respectively. They consisted of hard, grey, carbonaceous shale. Crushings of the rocks yielded a small assemblage of arenaceous foraminifera and pyritic casts of ostracoda of Permian age. A list of the forms in each sample is as follows.

Bore No. 8287, Mr. E.J. Riches, "Myrnong", Bourke - Thirteen samples were submitted for examination from this bore. A detailed examination of these is given below. Bore No. 4676, P. Mallon, "Avoca", Bourke - Fourteen samples were submitted from this bore and a detailed examination of them is as follows.

The Yenberrie uranium prospect is 3.5 miles east of the Stuart Highway, and 4.5 miles in a direction 15 degrees east of north from the bridge across the Edith River, which is 33 miles by road northward from Katherine, and 137 miles southward from Darwin. The prospect is 1.5 miles slightly north of west from the old Yenberrie wolfram and molybdenite mines. Geophysical investigations at the prospect during 1953 consisted of brief radiometric, self-potential and magnetic surveys.

White's Deposit, which is the original discovery at Rum Jungle, and on which exploration has been mainly concentrated, has so far proved to be the most important deposit in the area. It is situated 2.23 miles on a true bearing of 28 degrees from Rum Jungle Railway Siding and lies on the northern bank of the Finniss River (East Branch) halfway between Brown's Deposit and Dyson's Find. Following upon the favourable results obtained from diamond drilling and shaft sinking in 1950 work was continued at the deposit during 1951 and 1952. The development work and exploration activities are not yet completed, but available evidence has suggested a control of mineralization, which it is hoped will be substantiated by future field work. Geological and assay plans and sections of the mine workings have been prepared on a scale of 20 feet to an inch from theodolite and tape surveys and surface geological plans on a scale of 40 feet to an inch have been produced by plane table and telescopic aledade surveys. A description of the deposit based on results obtained to the end of 1952 is given in the following pages.

The prospect is an existing cooper lease (M.L.69B) held by Messrs. J.W. Watson and K. Cooper who carried out some mining in the area in 1950. The area was first visited in 1953 by I.A. Mumme whose interest was aroused by the pre-existing copper prospects and the close proximity of the Shoobridge granite. Further examination was carried out by Mumme and the writer early in November, and detailed mapping was done on a scale of 100 feet to the inch by the writer and D.N. Smith. Radioactive rocks and the secondary uranium mineral torbernite were discovered at this prospect, which is a copper mine, on October 25th 1953 by I.A. Mumme. A survey plan of the mine shafts, pits and costeans and lines of mineralization was prepared by I.A. Mumme on the 5th and 6th of November so that a suitable base line could be chosen for magnetic and self-potential test traversing. Three magnetometer traverses were completed. P. Rosenhain visited the area on the 5th November and inspected the shafts, stopes and costeans and carried out geological mapping from the 16th November to the 19th November. Further magnetic and self-potential traversing and some reconnaissance radiometric field work was carried out during the two periods 16th November to 20th November, and 24th November to 28th November.

Ella Creek radioactive prospect is one of the first order radioactive anomalies located during the airborne surveys conducted by the geophysical section of the Bureau of Mineral Resources in 1952. Geological, geophysical and geochemical ground surveys have been carried out to ascertain the type and cause of the radioactive mineralization. The geophysical programme was carried out by I.A. Mumme assisted by D. Pritchard and E.T. Hadley.

The investigation of the Fitzroy Basin and adjacent areas was commenced in 1948 when a detailed survey was made of the Nerrima Structure and a widespread reconnaissance by land, sea and air was completed. The Fitzroy Basin survey was completed in 1952 and during this period 24 months were spent in the field and the remainder in office preparation. Approximately 40,000 square miles were examined during the survey and detailed maps covering an area of 28,000 square miles have been prepared at 1 inch = 1 miles, 1 inch = 2 miles and 1 inch = 10 miles. The area has been examined in the past in varying detail by three geological parties on behalf of local and overseas oil companies. The purpose of this survey was to examine the complete sedimentary sequence in sufficient detail to solve the problems encountered by previous surveys and eventually to be in a position to assess to a reliable degree the petroleum prospects of the area based on the examination of surface outcrop. The assessment of the petroleum prospects of the area has very definite limitations in that the potential source rocks (Devonian and Ordovician) are limited to the extreme eastern margin of the basin and nothing is known about their distribution or facies elsewhere under the cover of Permian and Mesozoic sediments. The aerial photography of the area, which was conducted by the Survey Squadron of the Royal Australian Air Force, has been the basis of all mapping, as reliable topographic maps of the area were not available.