The area described in the report lies between latitudes 12°48' and 12°56' S., and longitudes 130°56' and 131°11'E. Most of the mapped region lies between the Stuart Highway and the North Australian Railway. The investigation of this area is still in the early stages and has consisted of general geological mapping, and detailed investigation (including drilling) of areas found to have been radioactive during airborne scintillometer surveys carried out in 1952. At Brodribb and Ella Creek superficial hematite-rich deposits have been found to be radioactive to the extent of up to ten times background, but drilling of this type of deposit at Brodribb has not yet proved the existence of payable primary ore. Further drilling is proceeding. A new discovery at Ella Creek in July this year gave high radioactivity over a length of about 300 ft. and two pits sunk to a depth of 3 ft. of this line have shown counts of 5,000 per minute and 10,000 per minute respectively. The field geologists recommend further testing here. In the Frazer area, laterite, which contains a belt of radioactivity up to eight times background, is known to exist, but, apart from limited trenching, has not yet been adequately tested.

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 Capel and Faust basins are located on the northern Lord Howe Rise in water depths of 1300-2500 m. Geoscience Australia recently completed a geological study and assessed the petroleum prospectivity of the area, based on new seismic, potential field, multibeam bathymetry and rock sample data. The data sets were acquired under Australian Government initiatives aimed at providing pre-competitive information to industry. Existing data coverage in these remote frontier basins is sparse and the DSDP 208 drill hole provides the sole well control. The interpretation of seismic data has confirmed the existence of large depocentres containing a maximum total sediment thickness of over 6 km. The early syn-rift megasequence is inferred to Comprise Early Cretaceous volcanics and volcaniclastic sediments, with possible coal and lacustrine sediments. The late syn-rift megasequence is likely to be a Late Cretaceous non-marine to shallow marine clastic succession. The post-rift megasequence is a Late Cretaceous to Holocene marine succession that becomes increasingly calcareous. In some areas, the syn-rift sediments overlie an older (?Mesozoic) pre-rift basin succession. Two major extensional episodes are recognised and appear to be related to distinct breakup stages of the eastern Gondwana margin. Potential source rocks may occur in the pre-rift and syn-rift sections. Basin modelling indicates that the deeper depocentres have reached the oil or gas window and that expulsion could have occurred from the Early Cretaceous onward. Fluvio-deltaic, shoreline and turbiditic sandstones may provide potential reservoirs in the syn-rift and the lower post-rift sections. There is considerable potential for stratigraphic and fault-related traps, and large anticlinal structures have been identified. Similar large depocentres appear to also occur over the central and southern Lord Howe Rise, highlighting the exploration potential of this vast frontier region.

A point has been reached in the prospecting of this field where it is necessary to review results and consider future actions. The bore on site A has been completed and Mr. Knight has concluded his preliminary geological survey of the area. The information now available modifies some of our earlier views. The following statement summarises the position.

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 June, 1954. A brief account is given of geological and geophysical operations. The results of prospecting and development work are summarised.

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.