The Crater Line consists of a series of rock exposures outcropping in an arcuate pattern around the southwestern flank of the Rum Jungle granite. The exposed rocks are believed to represent part of the Brocks Creek group of Lower Proterozoic age. The Crater formation, the major mappable unit in the line of exposures, consists of metamorphosed clastic rocks totalling approximately 1500 feet in thickness. Significant radioactivity is restricted to three stratigraphic zones within the Crater formation. These have been mapped and are designate Crater Pebble Beds, Number One Pebble Bed, and Number Two Pebble Bed. Number One Pebble Bed appears to contain the most significant anomalies. The radioactivity is restricted to conglomerate beds. There may be a genetic relationship to the greater permeability formerly localized in the conglomeratic zones. The radioactivity is not localized by tectonic structures such as folds, faults, or changes in dip. No source of the radioactivity has been identified. The radioactivity probably emanates from members of the uranium disintegration series. Four areas containing significant anomalies and deserving further investigation were found along the Crater Line.

In January, 1951, samples of radioactive minerals stated to have been collected in the Mt. Kavanagh (Cavenagh) area, Central Australia, were submitted to the Bureau by Mr. Norman Ashmore. Two radioactive minerals were present, one apparently allanite, and the other a strongly radioactive mineral of composition similar to betafite. The opportunity was taken of the presence in Alice Springs of the geophysical party destined for Rum Jungle and the geological party destined for Maranboy to make a brief inspection of the area. Two days were spent in the area. This report gives an account of the investigations and their results.

This report records observations made during two brief visits to the area when reconnaissance was limited to the shores of Melville Harbour and to the immediate vicinity of Gove aerodrome. Pisolitic bauxite containing upwards of 50 per cent alumina was observed throughout a traverse of 5.5 miles easterly from the airstrip. This bauxite, which rests on tubular laterite, may exceed 5 feet in thickness. The bauxite and associated laterite near Gove are derived from sedimentary beds which overlie coarse garnetiferous granite. The geology of the area, characteristics and composition of the bauxite, and mineral rights, are discussed in this report.

The information presented in this paper was collected in 1947-8 by a combined scientific team composed of officers from the Commonwealth Scientific and Industrial Research Organization and the Commonwealth Bureau of Mineral Resources, Geology and Geophysics, who carried out a reconnaissance of the natural resources of the Barkly Region. The subsurface water supplies and the geological features which assist in determining the characteristics of water supplies are discussed in this report.

Attention has been directed to the cobalt workings at Carcoar as a possible source of radioactive minerals in two ways. During testing of museum specimens for radioactivity, it was found that cobalt ore from Carcoar was strongly radioactive. Also, the occurrence of uranium in the cobalt ores was reported by Mr. McKillop, formerly a land holder in the area, who submitted a copy of a report signed by Professor T.H. Laby, certifying the presence of uranium in samples examined by him, and at a later date, a sample containing an uranium mineral. A brief visit was paid to the area in 1948, and the presence of strong radioactivity on dumps was confirmed. A more extensive survey of the area was, therefore, undertaken by geophysicists during 1949-50 and 1950-51. This report gives an account of the geophysical operations carried out in the vicinity of the Carcoar cobalt workings and describes the results of these investigations.

Bearing in mind Mr. Kitchin's statement that the mica has been recovered from a shallow depth of about six feet only it appears to be of really good quality, and in view of the shortage of clearer types of mica it seems desirable that the deposit should be examined. The four mica specimens submitted for examination are described herein.

In conjunction with an engineer of the Works and Housing Branch, a brief examination of the limestone deposits at White Rocks was made on 2/11/50 to determine their suitability as a source of road-metal and aggregate. The location and characteristics of the limestone deposits are described in this report. The northern and southern outcrops are described in some detail, and recommendations are made for further investigation.

<p>This data package includes raw (Level 0) and reprocessed (Level 1) HyLogging data from 25 wells in the Georgina Basin, onshore Australia. This work was commissioned by Geoscience Australia, and includes an accompanying meta-data report that documents the data processing steps undertaken and a description of the various filters (scalars) used in the processed datasets. <p>Please note: Data can be made available on request to ClientServices@ga.gov.au

A deposit of weathered graphic granite at White Rocks, 2 miles south of Queanbeyan, was investigated and the limits of material in it suitable for easily quarryable road metal were determined. The area was divided into two sections: a northern one held for the most part by the Queanbeyan Council, and a southern section at present held privately as a grazing lease. "Indicated" reserves, based on the present quarrying level, of 170,000 cub. yds were established in the northern section. Most of this material will be of the same quality as that being quarried at present; some of the material towards the southern boundary of the lease will however be harder and require more blasting. In the grazing leases "inferred reserves" of 140,000 cub. yds. were delineated. It is expected that this material will be quite suitable for road making but may be slightly inferior in sizing to the material at present being quarried; also it may require more blasting in some portions than the material being quarried at present; it will carry a higher average overburden than the Queanbeyan lease.

In the search for deposits of radioactive minerals in Australia the area of the Barrier Ranges appears especially worthy of investigation on geological grounds because it is composed of highly mineralised pre-Cambrian rocks. Mines in this area comprise the major producing mines along the main Broken Hill lode, one developed mine of less importance (the Pinnacles), and a number of small silver, lead and copper mines scattered over the surrounding district. The present report deals with the results of a reconnaissance radio-active survey performed by the Geophysical Section of the Bureau during July and August, 1950. The work was confined to the smaller mines, attention being directed, in the first instance to the mines from which radio-active museum specimens were stated to have come. At each mine the following tests were performed: tests on dumps and residues to discover whether any quantity of stone carrying a significant content of radio-active minerals had been broken during mining operations, tests on accessible exposed faces, and tests on rocks surrounding the mines. The tests were made with portable Geiger-Mueller rate-meters. Readings taken are quoted as multiples of background count, which has been considered as a constant characteristic of the instruments, rather than as the general reading obtained on country rock in the area. In most areas these methods of defining background would lead to the same result. As mentioned later, however, in the Broken Hill area this is not the case. Generally, the schists and gneisses on this field are definitely radio-active, and a true background reading, indicative of the complete absence of radio-active minerals, is obtained only on basic rocks. A reconnaissance survey was also made over the Euriowie tin field. Tests were also made around felspar quarries at Egebeck.