Samples from 46 deposits of the known 76 occurrences of diatomite in Australia have been micropalaeontologically examined, and 27 genera of diatoms represented by 48 species have been identified from them. The distribution of these species in the various diatomites is given in Table II. The following tentative conclusions with regard to the suitability of Australian diatomites for filtration purposes are based on a study of the shapes and sizes of the contained diatoms,' in accordance with English and Californian experience. Extensive deposits of diatomite, which are dominated by the diatom Melosira and which are suitable for purposes other than filtration, are available in Queensland and New South W ales. Nevertheless, this type of diatomite is used successfully by Davis Gelatine (Australia) Ltd., as a filter medium. The commercial value of a diatomite as a filter aid, which depends on the amount necessary to give a perfectly clear filtrate, the speed of filtration, and the character of the press-cake and similar criteria, can only be satisfactorily determined by actual experiment. It is also necessary to establish a correlation between the characters determined by microscopic examination and actual filtration tests before a final conclusion can be stated.

Foraminifera were first recognized in the Permian sediments of Australia in 1882. Some systematic work on these micro-fossils was done up to 1905, but there was no further investigation until. 1937, since when five papers on Permian foraminifera have been published. However, about ten years ago, systematic sampling of outcrops, cores and cuttings from bores was commenced with the object of determining whether micro-faunal zones could be established. Core samples and drill cuttings from these bores: and the various outcrops have been examined by the writer and a microfauna identified. Surface samples from localities in New South Wales were also submitted by the Geology Department, University of Sydney, for micro-examination. From the information presented in the following sections of this bulletin, it will be seen that, although a considerable amount of research is still necessary before a definite system of zoning, based on the microfaunas, can be applied to the Permian rocks of Australia, such a system is possible. In the extensive collections of Permian rocks examined from the Hunter River District of New South Wales, assemblages of foraminifera rather than restricted species have proved useful for zonal purposes, and it will be shown that correlation of deposits in other States can be made, by means of these assemblages.

The known bauxite deposits near the township of Ouse are No. 1 on Glen Dhu Estate, Nos. 2, 3,4 and 5 on Gladfield Estate, and Nos. 6, 7, 8, and 9 on Leintwardine Estate, Nos. 10, 11, 12, 13 and 14 on Lachlan Vale Estate and No. 15 on Lawrenny Estate. Examination of all the occurrences and testing of the more promising by shaft sinking and boring was conducted. The results of this work are discussed in the report.

This geophysical survey was undertaken as part of a campaign by the N.S.W. Mines Department and the Commonwealth Bureau of Mineral Resources to explore the ore possibilities of the Cobar Mining Field. Tests, made in January 1947, on specimens of ore from the operating mines showed that some of the ore from the New Cobar and Chesney Mines exhibited appreciable magnetisation due to its pyrrhotite and possibly magnetite content. The survey was commenced in March, 1947 using the magnetic method only as a first method of attack. Watts Vertical Force Variometers Nos. 15887 and 16128 were used, the field work being carried out by the writers. The geology of the area, object of the survey, results, and recommendations for future drilling are discussed in this report. Two accompanying plans are included.

Collie is the only developed coalfield in Western Australia. Between June 1946 and April 1947 a comprehensive geological and geophysical survey was carried out to determine the boundary of the basin, its general configuration and the depth (thickness) of the sediments overlying the basement. The aim of the survey was to define those areas where there was sufficient thickness of sediments to enable drilling to be carried out with a reasonable expectation of proving additional reserves of coal. The geology of the area, application of the gravity method, results and interpretations, and drilling recommendations are discussed in this report.

The material submitted for examination came from 35 bores which were drilled in the Adelaide Plains during 1945 and 1946. For comparative purposes, material has also been examined from several bores previously drilled in the area. The bores were sunk for water and the area drilled extended from Bore No. 69 at Royal Park northwest of Adelaide, to Nathan Brewery Bore on the Torrens River. The bores range in depth from 160 to 620 feet. This report comprises descriptions of stratigraphic sequence, fossil fauna, and the structure of the Adelaide Basin, with reference to the material examined. Two accompanying plans are included.

A request was made for an estimation of the ore reserves indicated to date in the King Island Scheelite Mine, and for a drilling campaign to be drawn up to prove a total of fifteen years supply of ore at an annual rate of consumption of 200,000 tons. These two matters are dealt with in this report.

The question of a geophysical survey of the Copperhead mining property at Bullfinch was discussed and it was stated that there was need for a geophysical survey to determine the detailed structure of the jaspilite bodies over a small area concealed by tailings at the eastern end of the jaspilite zone. Following preliminary tests, a detailed survey was conducted in December, 1946. The geology, nature of the problem, and results of the survey are discussed in this report. Two accompanying plans are included.

The Lakes Entrance Oil Shaft is situated in allotment 21, Parish of Colquhoun, about 2 miles north-east of Lakes Entrance township. The shaft was sunk with the object of developing, by means of low pressure mining methods, the oil-bearing beds known to exist in the lower portion of the Tertiary basin in the Lakes Entrance area. It is estimated that, during mining operations, approximately 12,000 tons of Tertiary sediments were excavated. Consequently a unique opportunity was afforded the palaeontologist and geologist to study the stratigraphic sequence of Tertiary beds in the Lakes Entrance area. During visits paid to the scene of operations, extensive collections of fossiliferous material were made by the author. This report comprises notes on the scope of the micro-palaeontological investigation, the stratigraphy and the palaeontology of the Lakes Entrance Oil Shaft.

For nearly nine months of the year the river proper is confined to a narrow channel two to three hundred feet wide. During the remainder of the year, however, the river is subject to periodical floodings resulting from heavy tropical rain on its water-shed and for periods of a week of more at a time the low level bridge is covered by flood water. The dislocation of rail traffic which results from these periodical floodings has been a matter of serious concern to the Queensland authorities for many years and a decision was made to construct a high level rail and road bridge to replace the existing structure. Construction was commenced, but before it proceeded far, it was considered desirable that the depth of the bedrock, previously examined, should be established without doubt. In view of the uncertainty of the depth to be drilled and the very considerable difficulty in drilling through alternating layers of drift sand and boulder wash, a request was made by the Co-ordinator General of Public works for Queensland for a geophysical investigation of the site. A survey was carried out by the geophysical section of the Commonwealth Bureau of Mineral Resources during August and September, 1947. The investigation of the results is far from complete but the seismic method gave such concise results that this preliminary statement is justified. Geology, geophysical methods, results, interpretation, and testing are discussed in this report.