An area of about 12,000 square miles was mapped in the field seasons 1950-51. It contains four Pre-Cambrian rock groups ranging from Archaeozoic to Uppermost Proterozoic. The main groups in the area, the Mt. Isa and Lawn Hill Groups, are shallow-water geosynclinal sediments involved in a Proterozoic orogeny which resulted in fairly intensive folding along dominantly north-south axes, together with much faulting. The geological features discussed in this report include physiography, topography, stratigraphy, igneous activity, structure, mineral deposits and water supply.

These documents have been scanned by the GA Library. Please refer to the document for contents.

Samples from four bores in the Great Artesian Basin of New South Wales were submitted for micropalaeontological examination, by the Water Conservation and Irrigation Commission of New South Wales. These bores are Bore No. 8213, "Trenton" Coonamble, No. 8262, "Montrose", Dubbo, No. 8268, "Fair Oak", Dubbo, and No. 8272, Wanaaring, Bourke. The results of the detailed examination of these bores are given below.

The writer spent four days in 1949 in the Adaminaby-Kiandra Area with J. Glover mapping the country north-north-east of the present Tunnel Line. In 1951 a fortnight more was spent on the Tunnel Lines themselves by the writer under the guidance of senior geologist D.C. Moye and geologists K. Sharp and C. Wood, who provided a large amount of information not yet available in written form. All sediments in the Tunnel Area are Ordovician, and in the case of the Tumut Pond beds an even older age is possible.

This report is based on field work at Jervis Bay and in the surrounding area during the period 4th to 30th June, 1952. The purpose of the investigation was primarily economic, though no further attention was given to the deposit of firebrick clay previously described (Smith et al., 1948). Outcrops in the Commonwealth Territory at Jervis Bay consist almost entirely of sandstone of Permian age. The name Jervis Bay Sandstone is proposed for these rocks, which have been found to underlie the Wandrawandian Siltstone, and are tentatively correlated with the Conjola beds - all units of the Shoalhaven Group, which includes part of the former Upper Marine Series. Marine fossils having affinity with those found in the former Upper Marine Series have been found in the Jervis Bay rocks. The sandstones have been invaded in a few places by basic intrusive rocks, probably during the Tertiary Period. The only materials of economic significance found in the Territory are firebrick clay, and ferruginous gravel useful for surfacing roads. Additional supplies of the ferruginous gravel may occur in the areas delineated on the map as suitable for further prospecting.

In October, 1951, the Geological Section of the Bureau of Mineral Resources recommended a geophysical survey at the newly-developed Rye Park tungsten deposit. The purpose of the survey was the delineation of the main mineralised areas around a granite cupola. The geology of the area, survey methods, and field operations are described in this report. The result of the survey and of diamond drill hole testing are discussed.

This statement sets out the results of drilling in part of the Minmi Area, Newcastle District. The area covered by the drilling grid totals about 390 acres and includes parts of Portion 130, Ph. of Teralba and Portions 15 and 26, Ph. of Hexam. This statement refers to the western and central blocks of the area. Proximate analyses and calorific value determinations of the coal cores were made by the New South Wales Mines Department laboratory in Sydney. The analyses here quoted indicate a composition roughly equivalent to that which might be expected for cleaned or hand-picked coal from this area.

The purpose of a visit to the Cloncurry district, which lasted from 21st August to 30th September, 1951, was to see what aid geophysical work could give in the search for copper deposits in this field which is one of the biggest mineral fields in Australia. While the Cloncurry district in the past produced copper from many small but rich deposits, only a few exceeded 200,000 tons, and the search now is being conducted mainly with the idea of finding and developing huge but relatively low grade copper deposits with at least several hundred thousand tons, or perhaps millions of tons of copper ore containing at least 2.5 to 5 percent copper. It is possible that geophysics might help in this search, and consequently, a number of old copper mines were visited and some geophysical test traverses made. With the rather limited facilities available the tests were confined to self-potential measurements and to a few traverses with a new Atlas gravity meter, especially suitable for ore prospecting because of its lights weight and transportability and its high sensitivity and accuracy. This report gives an account of the survey and its results.

Existing sources of water supply are described. Proposals for improving the supply of town water are considered. Further investigations are recommended with respect to tapping the southern lobe of the local basin, surface conservation, underground water resources, and the selection of a possible dam site.

The Oaklands-Coorabin Coalfield in the Riverina Division of New South Wales has been known for many years. Coal is produced from a small colliery near Coorabin and a minor amount of exploratory drilling in the general vicinity of this mine has been carried out by New South Wales and Commonwealth Government authorities. This exploration has shown that coal seams extend over an area of a few square miles near Coorabin. The coal occurs in Permian rocks which do not crop out but are covered by Tertiary and younger sediments with a minimum thickness of 100 feet. Examination of the regional geology led to the conclusion that the coalfield is far more extensive than the limited area proved by drilling. Because of the Tertiary cover, normal geological methods cannot be used to map the boundaries of the Coal Measures and for this reason geophysical survey's, which have been used successfully on similar problems elsewhere, were undertaken to map the sedimentary basin. A gravity survey was carried out first and as the work proceeded it became obvious that a pronounced regional anomaly is present. Consequently, seismic methods were employed to try to obtain the thickness of the sediments at a number of critical places and to provide a control for separating the effect of the sediments from the regional effect. A residual gravity contour plan was obtained and indicates the general shape of the sedimentary basin. This plan provides a satisfactory basis for recommending drilling to test the potentialities of the basin. An area of approximately 1,450 square miles was covered by the geophysical surveys and, after correcting for regional effect, the residual gravity pattern suggests the presence of a Permian basin approximately 600 square miles in area, with a possible extension in a north-westerly direction. Recommendations are made for testing the geophysical results by drilling at five widely-spaced sites in the supposed basin. Five additional drilling sites are recommended and are designed to prove reserves near the known coal occurrences.