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

This report is an account of geological and geophysical investigations of the Burrundie Radioactive Prospect, which is located three and a half miles west-south-west of Burrundie Siding on the North Australian Railway.

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.

This quarter, with its favourable climatic conditions, has seen the greatest activity in the field for the year. Thirteen geologists and five geophysicists, together with many assistants, have operated in the area on many prospects. The Darwin office and laboratory are well-established and providing many services to the public such as assaying, instrument repair, and geological and geophysical advice. Detailed geological and geophysical work has been commenced or continued at the following prospects: A.B.C., Edith River, Burrundie, Brock's Creek and Adelaide River, while minor investigations have been carried out at many other localities. Three drills have operated throughout the quarter. Regional geological mapping has been continued over a wide area. The amount of work being done will decrease during the coming quarter due to the approach of the "wet" season.

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.

The Ella Creek Prospect was a first order anomaly discovered by the Bureau of Mineral Resources airborne scintillometer survey in 1952. After a detailed examination by geologists and geophysicists, accompanied by intensive costeaning it was considered promising enough to warrant drilling. The three holes drilled were probed radio-metrically and high counts ranging from 1,000 to 3,000 per minute were obtained. No primary uranium mineralisation was encountered, and it is suggested that the source of the radioactivity, on chemical testing, may prove to be thorium.

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.

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.