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 oldest rocks found in this area are Pre-Cambrian and the youngest are Recent but on the whole the area is one of great stability and not many of the periods of geological time are represented. The Pre-Cambrian are found outcropping round the edge of the basin and for simplicity in field work have been divided into five divisions. These are Tennant Creek, MacArthur R., Buldiva, Helen Springs, and Barkly Downs. This report provides a field summary of geology by division.

An examination was made of a proposed dam site at Geehi in April, 1947. The report comprises notes on access, general geology, evidence gathered from aerial photography, and the suitability of the site. Three accompanying plans, and a petrographic report on rocks collected from the vicinity, are appended to 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 following report is based on an examination of the mine made by the writer in February, 1947, and on information gained from the Western Australian Geological Survey. The production history, geology, ore reserves, and prospects of the mine are discussed. Four accompanying plans are included.

A geological report on the Alexander, Halley's Comet, and Manolis' Workings mines. The production, grade, geology, mineralisation, ore reserves, and prospecting of the mines are discussed. Accompanying geological 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.

Notes on samples of limestone collected from three caves on the Nullabor Plains, the Koonalda, the Abrakurrie, and the Weebubbie, and from the surface crust in the vicinity of the caves.

The Blue Spec Mine, Nullagine, was visited from 20th to 24th September, 1947. An inspection was made of the mine. No. 3 level (depth 450 feet) was mapped and the antimony-gold occurrences on lease 196, and on the property known as "Blacks", were also briefly inspected. The present position regarding water supply was investigated and recommendations made. The ore reserves, workings, economic considerations, and water supply are discussed in this report.