The Northern Australia Development Committee (a Committee composed of representatives of the Commonwealth and the States of Queensland and Western Australia) has recommended that a series of regional surveys be made in Northern Australia with the object of providing data which will enable development of the region to be planned on a scientific basis. These surveys are being made under the direction of the Commonwealth Scientific and Industrial Research Organization. From June to September 1946 the writer accompanied the C.S.I.R.O. party which was engaged in a reconnaissance survey of the Katherine-Darwin region. Christian, ecologist and leader of the party; Mr. G. A. Stewart, soil surveyor; and Mr. S. T. Blake, botanist. The area examined consists of 27,000 square miles in the north-western portion of the Northern Territory, west of longitude 133° east and between latitude 12° and 15° south. (See Plate 1 for locality map and reference to Australian map grid.) The primary object of the survey was to determine pastoral and agricultural possibilities. A geologist was attached to the party mainly because the area to be surveyed had been very incompletely mapped and the existing geological records did not provide an adequate background for the soil and pastoral work to be undertaken. The primary function of the geologist was, therefore, to provide this background for soil interpretation, but it was also intended that he should gather as much information as possible on the stratigraphy and mineral possibilities of the area. During the course of the investigation it was found, that geological mapping provided the essential framework into which much of the other scientific data could be fitted, and a fairly complete investigation of the stratigraphy and geomorphology of the area became essential. An account of the stratigraphy and geomorphology are submitted in this report with a reconnaissance geological map of the region. This geological map is the result of the combined work of the party and could not have been completed without the full co-operation of the other members and particularly of Mr. G. A. Stewart. An area of approximately 27,000 square miles had to be mapped by a series of traverses in a period of approximately four months, and the geology of the areas between these traverses had then to be filled in from available geological maps and records, and from aerial photographs which covered only parts of the region investigated. (See Plate 2.)

This report describes the results of a micropalaeontological examination of three rock samples from the vicinity of the Watheroo magnetic observatory.

This report describes the results of a micro-examination of five rock samples from the vicinity of the Rocket Range.

This palaeontological report describes a collection of fossils from Fitzroy Crossing.

This note describes a sample of beach sand. The specimens of foraminifera found in the sample are listed.

Geological investigation by the Bureau commenced late in July, 1948, and continued until the end of October of that year. The objects of the survey were to lay the foundation for future detailed studies of the mining field, to study the factors controlling ore localization, to assess the quantity and value of ore exposed to date, and to estimate the potential value of the field. In the search for orebodies, a knowledge of the geological factors can be of great assistance, and it is felt that the information given in this report and in the accompanying plans should be of considerable help in this respect. However, the prospector's methods - loaming, dollying, panning etc. are still quite fundamental to success in a prospecting field such as Tennant Creek and the suggestions made in this report are intended to supplement this type of work. The climate, topography, vegetation, gold production, general geology, and gold deposits of the area are described in this report. Detailed descriptions are given of the individual mines examined to date.

A collection of fossils from Canowindra was sent to the author for examination. The results of the examination are recorded in this report.

At present a gravimetric survey of the area between Berrigan, Mulwala, and Corowa is being made by the geophysical section of this Bureau to show the southern continuation of the sedimentary basin between Oaklands and Berrigan which contains Permian coal. Reconnaissance mapping of the area was carried out on the 4th and 5th of July to find where the bedrock consisting of granite and pre-Permian sediments outcrops, in order to facilitate the interpretation of the gravimetric survey data. The accompanying plan showing outcrops in the Oaklands - Coorabin coalfield area is included.

In the recent past, geologists have been inclined to confine their study to the structural traps and openings which localize individual ore shoots and have tended to neglect most other features, including considerations of ore genesis. L.C. Graton has recently remarked that "the out-standing unfilled need lying ahead is the discovery of new mineralized districts". In this connection he speaks of "the all-important standpoint of genetic understanding". As a contribution towards filling this need, the following points, relating to mineralization in the Cobar-Nymagee province, are here presented for consideration.

The Cobar field was visited during the period 18th to 24th July, mainly in connection with the exploration programme which is taking place in that area. During this visit, however, some information was obtained concerning the operations of the mines controlled by New Occidental Gold Mines, N.L., which company is being assisted financially by the Commonwealth. Estimated operational costs, grade, and production figures are given. The development, exploration, and future of the field are discussed.