The Mosquito Creek Wolfram Field was visited on 6th and 7th October, 1951. This report gives a brief account of the inspection. The general geology of the area, the ore-bearing reefs, and the mining leases inspected, are described.

The Palaeozoic rocks of the Bonaparte Basin outcrop at the head and along the western side of Joseph Bonaparte Gulf and extend across the border between Western Australia and the Northern Territory. The Bonaparte Basin is the least known Palaeozoic basin in Australia, due partly to the remoteness of the area and the discouraging results of early coal explorations, and partly to the fact that the stratigraphical extent of the Palaeozoic sequence was only discovered in the last ten years. The Palaeozoic sequence so far established includes Cambrian, Ordovician, Devonian, Carboniferous and Permian sediments which rest on a pre-Cambrian basement and which are overlain in places by a mantle of Lower Cretaceous sediments. The authors intend in this paper to give an account of Carboniferous and Permian sediments of the Basin, as far as present knowledge permits, with briefer mention of the Lower Palaeozoic and Mesozoic sediments of the area.

This map has been prepared to display the probable form of the Isogonic Lines in the regions surrounding Australia, the boundaries being the meridians 85°E and 180°, and the parallels of latitude 10°N and 60°S. This report contains explanatory notes to the isogonic map.

A geophysical survey was made in the Rum Jungle district in October and November, 1950, using self-potential and potential-ratio methods. This investigation formed part of a larger programme of geological and geophysical exploration for uranium minerals. Self-potential surveys were made over three areas, namely, Brown's Copper Mine Area, Intermediate Area, and White's Area. A potential-ratio survey was made over only the first of these. This report gives an account of the geophysical work conducted in each of these areas. The results of the survey are described, and recommendations for future drilling work are given, for each of the surveyed areas respectively.

The material described in this report was collected and forwarded for examination by Mr. M.R. Banks of the Geology Department, University of Tasmania. The report comprises notes on the lithology, fossil content, state of preservation, and correlation, of the samples.

This report is comprised of nine separate sub-reports, referred to as records nos. 1951/3a to 1951/3i. Micropalaeontological examinations were conducted on samples from various localities in the region of Mt. Gambier, South Australia. The results of these examinations, together with any accompanying notes, are recorded in the respective reports.

A sample of lignite from a new water bore on the Freud River was sent for micropalaeontological examination. The results of the examination are described in this report.

At the invitation of Prof. S.W. Carey, the author visited Tasmania during the period 15th November to 2nd December, 1950, to take part in discussions on Cambrian geology in Tasmania and to learn in the field the results of recent investigations on Tasmanian older Palaeozoic rocks. During the visit the author had the opportunity of expressing his opinions both on newly discovered fossils and on the age of some Palaeozoic units, and the main object of this report is to record these opinions.

For the purpose of obtaining further information as to favourable structural features in relation to brown coal seams within the Yallourn-Morwell-Traralgon area, a gravity survey is being carried out by the Bureau of Mineral Resources, Geology and Geophysics at the request of the State Electricity Commission of Victoria. In the following a preliminary interpretation is given of the results obtained by this survey to date. This interpretation includes a detailed correlation of the gravitational disturbances with the geological structures so far known. Practical experience to be gathered from the work so far done has been outlined.

As a result of abnormal rains in 1950, a considerable body of water has been impounded in Lake George, situated in New South Wales, but only 20 miles north of Canberra, Australian Capital Territory. Local reports claim a depth of water of 30 feet in the Lake and these reports have prompted the Advisory Council of the Australian Capital Territory to investigate the possibility of developing the lake as a recreational resort. As a first step in this investigation the Council has asked the Bureau of Mineral Resources, Geology and Geophysics for an opinion as to how long a considerable body of water may be retained in the lake.