Since 1949 a considerable amount of geological and geophysical investigation as well as diamond drilling and some underground development has been undertaken in the search for uranium ore in the Darwin-Katherine region, and in the course of this work information has been gained which, it is thought, may be of interest to prospectors and companies who are now beginning to pay considerable attention to the possibilities of the area, but have had little or no experience of prospecting for uranium in the Katherine-Darwin region. Investigations of the area by the Bureau, by private companies, and by prospectors [are] now proceeding more vigorously than ever, and without doubt a good deal more remains to be found out concerning the uranium deposits of this province. In these circumstances the notes supplied below are put forward tentatively as being some facts known to the present writer at this time (July, 1953) as well as some more controversial opinions. It is expected that more information will be made available as the investigation proceeds. (The following notes should be read in conjunction with Pamphlet No. 3 (Radioactive Mineral Deposits) of the Bureau of Mineral Resources, Geology and Geophysics and a copy of the Mineral Map (NT32B-4) would greatly aid in their understanding).

The air-borne scintillometer survey near Katherine during October, 1953, failed to cover a triangular area in the south-east corner of the Katherine sheet, as it was beyond the range of the Shoran beacons. The area is part of a Bureau of Mineral Resources reservation taken out to protect the ABC Prospect. Several trial flights were made over the area, however, in an attempt to detect the presence of any significant radiometric anomalies. During these flights, Geologist A.B. Clark acted as an observer to spot on photo-mosaics the positions at which anomalies might occur. A third order anomaly was recorded during a flight along Maude Creek at a point thought to be within 1 mile of the junction of Dorothy Creek and Maude Creek. A search was made later by D.E. Gardner with the object of finding the source of the anomaly and the results of this work are given below.

Iron oxide-copper-gold (IOCG) mineral systems occur globally and range in age from Archean to Mesozoic or younger. An assessment for IOCG mineral system potential has been undertaken in the southern Arunta Region, incorporating the southern Aileron and northern Warumpi provinces. The assessment has been undertaken in a GIS-based environment using a mineral systems approach. This approach recognises four key system components: (1) sources of metals and fluids, (2) fluid-flow drivers, (3) fluid-flow pathways and architecture, and (4) depositional sites and mechanisms. For each of these key system components, mappable criteria were developed as proxies for mineralising processes in order to identify potential IOCG mineral systems. The locations of known deposits and prospects were not used for generating the assessment of IOCG potential. However, they are used as a validation of the results. The assessment largely reproduces the locations of known IOCG-style mineralisation, and predicts additional potential in a number of other areas, many of which are obscured by recent sedimentary cover. An approximately east-west-trending belt of broad IOCG potential has been identified, along with local regions of high potential where favourable criteria occur.

The areas included in the geophysical survey, namely the Laloki, Moresby-King and Dubuna leases, are among those held by Mandated Alluvials N.L., and lie in the Astrolabe Mineral Field. The positions of the leases held by the Company are shown in Plate G73-1. Laloki, the main producer of copper, is situated 20 miles by road from Port Moresby, near the junction of Sapphire Creek with the Laloki River. The Bureau was requested by Mandated Alluvials to carry out a geophysical survey in the vicinity of the known deposits and in adjacent areas. Both Laloki and Moresby-King mines has been in production up to the time when the war in New Guinea caused a suspension of operations. During the war the mine workings and much of the plant were completely destroyed. When consideration was given to the best method of reopening the mines it was decided that, if a large enough tonnage or ore could be proved sufficiently close to the surface, it would be most profitable to continue open-cut mining, and possibly install a flotation concentrator to avoid the troubles that had always accompanied smelting. The aim of the geophysical survey was, therefore, to locate a body of ore large enough to justify the adoption of these mining and treatment methods.

This presentation summarises results of 3d petroleum systems modelling of the northwestern Ceduna Sub-basin, Bight Basin, offshore southern Australia, using Schlumberger Petromod software. The model builds on two 2D models for the northern and central Ceduna Sub-basin published in Totterdell et al. (2008).

Report on the activities of the administrative and technical sections in the Katherine-Darwin area, to August, 1954. A brief account is given of geological and geophysical operations. The results of prospecting and development work are summarised.

A car-borne radio-metric survey of the B-volcanic formation within the reservation surrounding the A.B.C. uranium prospect indicated 32 small areas in which the radio-activity was a little in excess of 1.5 times, and in places a little higher than twice the background count of the alluvium in the valley. Testing of each area with an Austronic P.R.M. 200 failed to reveal any sources of higher radio-activity. Most of the anomalies are due to a comparatively high background count given by exposed basalt. Four anomalies found in black or dark soil in damp portions of the valley are considered to be due to traces of radio-active elements absorbed by humus. One anomaly appeared to be due to traces of radio-active material contained in "lateritized" alluvium. The other anomalies are in alluvium, and are due either to the presence of basalt a few inches from the surface, or to traces of radio-active matter deposited from seeping ground-water. Radio-metric contouring, with a view to possible costeaning, has been recommended in a small area within exposed basalt, where counts of approximately 200 per minute were obtained. No additional work is recommended on any of the other anomalies.

In the course of geological investigation of the area included in the Katherine, Mt. Todd and Lewin Springs 1-miles sheets, carried out by J.H. Rattigan and A.B. Clark, Bureau of Mineral Resources, A.B. Clark found, in September 1953, uranium mineralization subsequently known as the A.B.C. Prospect, 11 miles north-north-east of the township of Katherine. This report is a record of the detailed investigation which followed the discovery.

Operations of the Radioactive Section have been restricted during this quarter due to the "wet" season and lack of staff. Drilling operations at the Ella Creek Prospect were completed and operations commenced at the Edith River Prospect. No encouraging results were disclosed at either prospect. Other work has been limited to inspection of reported new discoveries and geophysical work in the Rum Jungle area.

Report on the activities of the administrative and technical sections in the Katherine-Darwin area, to April, 1954. A brief account is given of geological and geophysical operations. The results of prospecting and field work are summarised.