The uranium prospect at Coronation Hill is situated on the south side of the valley of the South Alligator River, 75 miles from the town of Pine Creek, from which it is accessible by trucks in the dry season. The surface showings consist of discontinuous exposures of autunite over an area approximately 400 feet square upon the north-eastern corner of Coronation Hill, an isolated feature within the river-valley. The rocks present are of Proterozoic age. Mineralization is found within two deeply-weathered members of a sedimentary-volcanic complex which forms the basal member of the Upper Proterozoic: the rocks of the prospect may be in part of Lower Proterozoic age. Sulphide mineralization accompanied by a secondary uranium mineral has been found at one point by diamond drilling: the sulphides are principally pyrite and the nickel sulphide bravoite. Mineralization is associated with a partly crushed and highly altered zone adjacent to a mass of Upper Proterozoic sandstone which overlaps the older and lower rocks. The structure is imperfectly understood and the control over mineralization has not been established. Development work, including costeaning, pitting, diamond drilling (1006 feet in two holes) and geophysical surveys (Radiometric, magnetic and electrical) has found no mineralization of economic grade, although it has shown the presence of alteration and sulphide mineralization which indicate that the full potentialities of the prospect have not yet been determined. Further work sufficient to complete preliminary exploration would require a minimum of 2500 feet of diamond drilling on underground operations at least equivalent to 1000 feet of drifting and crosscutting. Diamond drilling is somewhat preferable, since it can reach more deeply below the weathered zone. Only after completion of this additional work can it be determined whether or not the prospect is of economic value.

In 1944, while Mr. H. B. Owen, geologist of the Bureau of Mineral Resources, was travelling by road from Port Lincoln, South Australia, to Norseman, Western Australia, he collected specimens of the Tertiary rocks for micropalaeontological examination. A detailed report on these samples has never been put on record, but, as the area is now being investigated for the possibility of oil accumulation, the samples have been examined and this report prepared. Some interesting observations made by Mr. Owen during the trip are incorporated here. The most important results of the micropalaeontological examination of these limestones are: 1. The discovery of extensive deposits of upper Eocene age both in outcrop and in subsurface sections; 2. The similarity of the upper Eocene to lower Miocene stratigraphical sequence in the coastal area of the Nullarbor Plains with that found in portion[s] of the Carnarvon Basin, Western Australia, in the Adelaide Basin, South Australia, in north-western Victoria, and in the Torquay area, central southern Victoria.

This record gives a brief account of the conditions encountered in a geological reconnaissance of the south-western portion of the Canning Basin - an area covered mostly by sand and seif dune, interspersed by scattered low rock outcrops.

On the 4th November, 1954, the first report of eruptive activity at Bam Island was received at the Observatory, Rabaul. Mr. M.A. Reynolds was at that time engaged on an investigation at Tuluman Volcano, Manus Sub-district. As he had most of the field equipment with him the writer signalled a request to him to proceed to Bam to investigate this report. On the afternoon of the 5th it was learned that the Lorengau radio was out of operation and that Reynolds had not received the signal. The writer departed Rabaul at 0700 hours 6th November, 1954, and arrived at Wewak at 1200 hours. The m/v. "Ella" was made available and the writer departed Wewak at 0300 hours together with Cadet Patrol Officer R.G. Noble for Bam Island, arriving there at 1300 hours that day. The writer spent a little over a day on the island and returned to Wewak on the 9th November. The recent investigation revealed that the present activity consists of only mild explosions, ejecting well crystallised lava, which though incandescent when ejected was solid. Seismic activity only accompanied the actual exposions and was not premonitory.

Samples from four cores from Cape Range No. 1 Test Well, Shothole Canyon, Exmouth Gulf were submitted for palaeontological examination, by West Australian Petroleum Pty. Ltd. Portion of each core was crushed, washed and examined for microfossils. Foraminifera of Lower Cetaceous age were found in all samples. Radiolaria, ostracoda and Inoceramus prisms were also present. A detailed list of microfossils recognised in each sample is given below.

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

The 1954 investigation was primarily concerned with examination of as many of the thermal areas as possible in the short time available, and to record temperatures which could be used as a basis for comparison in future investigations. The writer arrived at Talasea on the "Theresa May" on the 28th August after completing investigations in the Langila Crater area and on Vitu Island. Over the next three days thermal areas near Talasea and west of Pangala village on the north coast of Garua Harbour were visited and temperatures taken.

During the reconnaissance survey carried out in 1952 by Mr. J.E. Thompson, Senior Geologist of the Bureau of Mineral Resources, four traverses were made across the Island and established the following sequence: [see record for detail]. Because of the lack of good exposures, and unreliable dips, no stratigraphic thicknesses could be obtained. Samples of the limestones and tuffaceous siltstones were subsequently sent to Canberra and their microfauna examined by the authors. Following is the list of the faunal determinations.

In January, 1954, the Bureau of Mineral Resources began diamond drilling in the Edith River, N.T., to test the grade and extent of uranium mineralisation in two uranium-bearing deposits. The uranium mineral, mate-autunite, occurs in narrow siliceous reef formations. Surface and drill core samples all returned less than 0.1% U3O8. Radiometric logging of the holes showed no significant increase of radioactivity with depth. Shaft sinking proved the deposits to be small and lenticular.

This report deals with the application of geophysical methods (other than radiometric) to the Coronation Hill Radioactive Deposit. Results of radiometric gridding of the surface and costeans, field sludge assays, and radiometric drill hole logging are not treated as these are included in entirety in R.B. Allen's report "The Coronation Hill Uranium Prospect," Bureau of Mineral Resources Record 1954/17. Structural indications from magnetic evidence are discussed. These comprise several faults, or zones of weakness, one of which may coincide with the axis of the surface radio-activity. Several interesting magnetic features for which no cause can be proposed are also noted. The highly uncertain nature of the deductions made is emphasised. The method of approach to geophysical applications at Coronation Hill is detailed, and recommendations are made for possible future work.