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.

Approximately fifteen shafts were sunk near the eastern end of the Portion to depths of about 30 feet or more. The shafts were sunk from positions along the boundaries of a right-angled triangle with the east-west zero line for base, the 200E meridian for perpendicular, and the hypotenuse formed by the diagonal from 00/600W to 800N/200E. Two or three shafts have been sunk outside the triangle and none near the centre. This work has served to test thoroughly an area of not less than 400,000 square feet, equivalent to about 25,000 tons per vertical foot. The results of the work to date are discussed in this report.

Overview of staff involvement and general, field and laboratory work carried out during the month of August, 1947.

Overview of general work, staff involvement, drafting, field work and laboratory work carried out for the month of October, 1947.

Overview of general work, sampling, mapping and levelling, drafting, and laboratory work carried out during the month of September, 1947.

Overview of staff involvement and the general tasks, field work, and drafting carried out during November, 1947.

Shortly after I took up the appointment of Mineral Economist, the high quality of the mica from the Harts Range came to my notice. Accordingly, I paid a visit to Harts Range between the 22nd September and 4th October. In judging the possibilities of developing the mica deposits of the Harts Range, the difficulty is the almost complete lack of reliable detailed mining data in the past - production data for the later war years only are available. However, by comparing the degree of areal concentration of the pegmatites, the type of deposits and the quality and sizes of the mica so far produced with those in India, a reasonable picture can be obtained of comparative possibilities. The method of approach throughout this report, therefore, will be comparison of the Harts Range with India mica. This report gives an account of the present state of the Australian mica industry, including descriptions of current trade terms, the grading and classification of mica, and the Harts Range Mica Belt deposits. Suggestions and recommendations for the development of the industry are discussed.

A visit was made to inspect the limestone and dolomite deposits at Cow Flat and Walls Siding. An overview of the working of these deposits, which includes details of the leases, production, prices, plant operations, future developments, and the present positions of the owner companies, is given in this report.

Results of a micropalaeontological examination of samples taken from 1460 feet down to 1619 feet. This series is in continuation of that reported upon on 19/3/46.