Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

The prospect covers an area originally enclosing three first order and one second order anomaly located by the Airborne Scintillometer Survey if 1952. Preliminary ground investigation was carried out in October 1952 and is contained in 'Preliminary Report on Airborne Scintillometer Surveys by N.H. Fisher and J. Sleiss'. Carborne equipment was first used to locate the anomalies and determine their extent in July, 1953. An Auster aircraft carrying a Halross scintillometer also flew over the area at the same time locating a high only near the first zone. This was carried out by the Territory Enterprise Limited. A survey grid was laid down to serve both the geological and geophysical work. The base line runs north-south for 3,300 feet and traverse lines run across it at 100 ft. intervals. The detailed radioactive survey covered the whole area. Traverse lines were read at 300 foot intervals in the outer sections where closer work was not warranted. The work commenced in August and was completed in October 1953.

This report deals with the results of 22,355 ft. of scout boring over an area of approximately 50 square miles on the western flank of the Muswellbrook (N.S.W.) Anticline. A traverse of overlapping bore-holes, located between the outcrops of the Upper Marine Series (Mulbring Beds) in the east and of the Triassic sediments in the west; provided a more complete section of the Upper Coal Measures in this area than has been previously available. Some 46 coal seams were encountered and tentatively numbered for correlation. Some of the coal seams exhibit very good qualities, but none could be classed as a good gas or coking coal. Igneous intrusions are numerous and of a fairly wide vertical and areal extent; their influence on the associated coal seams is generally destructive. The results of the above boring may be regarded as a basis, for any detailed future underground and/or open-cut mining investigations. No attempt was made to estimate coal reserves of any kind.

White's South prospect is situated on the southern bank of the Finniss River (East branch) about 400 feet south southwest of White's Deposit (Ward 1953). Rocks do not outcrop in the area, but low radioactive anomalies were located in this area by the Geophysical Section 1951 suggesting that the western continuation of White's Deposit after faulting might be beneath the soil cover. Low grade ore intersections were obtained in five diamond drill holes put down in the area in 1952. A plan of the area on a scale of 40 feet to 1 inch accompanies this report (Plate 1).

Brown's Deposit is the westernmost known area of mineralization in the Rum Jungle area. It is situated approximately two miles northeast of Rum Jungle Railway Siding and one mile southwest of White's Deposit in an area known as Brown's Workings, which was worked for copper in the early part of the century. In June 1950, preliminary geophysical investigations revealed that a radiometric anomaly was present at the eastern end of the old copper workings, and in October 1940, a self-potential survey (Allen 1950) indicated the presence of two distinct bodies of sulphide mineralization. During 1950 a geological map of the area on a scale of 100 feet to an inch was prepared, and in 1951 mapping of the area on a scale of 40 feet and 20 feet to an inch was commenced. This work at present remains unfinished due to other commitments. Three diamond drill holes, part of an extensive programme of diamond drilling planned for the area were drilled towards the end of 1951.

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 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.

Uranium mineralization at Coronation Hill is associated with rhyolitic rocks of Upper Proterozoic and sediments of Lower Proterozoic Age. The mineralization at and near the surface is in the form of Autunite and Torbernite; it occurs in a zone of strong fracturing, which effects rocks of both Lower and Upper Proterozoic age. Rubble and soil covers most of the area of interest at Coronation Hill and openings available to date do not allow a full appreciation of the geology of the prospect. A preliminary programme of diamond drilling is recommended to test and prospect and further testing should be guided by such information as is obtained from this drilling. The discovery of uranium mineralization in volcanic rocks of Upper Proterozoic age at Coronation Hill opens up an entirely new province for exploration for uranium in the Katherine-Darwin region of the Northern Territory. The linear belt of fracturing, the South Alligator Fault Zone, on which the Coronation Hill is situated, suggests an obvious zone to which future prospecting effort should be guided.