This report covers the results of the experimental electrical logging of eight bore holes in the Maitland Coalfields, New South Wales. The theory of the single point resistance and self-potential methods is outlined and the reactions of the coal and other formations are described. The experiments were inconclusive in deciding whether or not electrical logging can be used for correlation. Because there are many vertical and lateral gaps in the stratigraphical sequence of the coal measures it is considered unlikely that electrical logging could be used for correlation in the Maitland Coalfields. However, electrical logging has been recommended for adoption as a routine procedure in the drilling programme to check the recovery of cores in the coal zone. This procedure may results in a saving on drilling costs.

The beach sands on which investigations were carried out, were mainly from beaches along the eastern coast of Australia and from islands adjacent to this coast. A high percentage of the mineral grains of the heavy mineral fraction in these sands have grain sizes within the range -100 to +200, referred to British Standard Sieves. The grain size of the minerals, combined with the fact that the grains are quite well rounded, makes the heavy mineral sands an ideal subject for separation using the inclined method with the Isodynamic Separator. The use of this method, and the results obtained, are described in this report.

Database containing analytical data and interpretations from the Geoscience Geoscience (GA) geochronology program. Includes some legacy methods and externally sourced data. A collection of analytical data to support geochronology data or ages used in other reporting and publications.

A major purpose of the study, as it appears to me at this time, is to ascertain the presence of geochemical anomalies in the area of (copper) mineralization. Such anomalies, if established, may be correlated with the dispersion train phenomena and with the dispersion halo of the ore, in an area known as mineralization. A comparable study may be undertaken then, depending on the advice of the team, in an area of suspected but not known, mineralization. Further investigations, beyond the reconnaissance stage, may be projected, in consultation with the team, on completion of the orientation study. This report contains the author's tentative remarks on a proposed reconnaissance in South Australia. Objectives, background to the work, methods, and proposed operations are discussed.

The features of the single-point resistance log, obtained in A.A.O. No. 2 Bore, Roma, are described. Single-point resistance, self-potential and geological logs of the lower section of the boreholes are shown. The results indicate that electrical logging can be effectively used for correlation problems and that salt water sands in the reservoir rocks can be detected with reasonable certainty.

Monitoring changes in the spatial distribution and health of biotic habitats requires spatially extensive surveys repeated through time. Although a number of habitat distribution mapping methods have been successful in clear, shallow-water coastal environments (e.g. aerial photography and Landsat imagery) and deeper (e.g. multibeam and sidescan sonar) marine environments, these methods fail in highly turbid and shallow environments such as many estuarine ecosystems. To map, model and predict key biotic habitats (seagrasses, green and red macroalgae, polychaete mounds [Ficopamatus enigmaticus] and mussel clumps [Mytilus edulis]) across a range of open and closed estuarine systems on the south-west coast of Western Australia, we integrated post-processed underwater video data with interpolated physical and spatial variables using Random Forest models. Predictive models and associated standard deviation maps were developed from fine-scale habitat cover data. Models performed well for spatial predictions of benthic habitats, with 79-90% of variation explained by depth, latitude, longitude and water quality parameters. The results of this study refine existing baseline maps of estuarine habitats and highlight the importance of biophysical processes driving plant and invertebrate species distribution within estuarine ecosystems. This study also shows that machine-learning techniques, now commonly used in terrestrial systems, also have important applications in coastal marine ecosystems. When applied to video data, these techniques provide a valuable approach to mapping and managing ecosystems that are too turbid for optical methods or too shallow for acoustic methods.

At the request of the Broken Hill Proprietary a geophysical test survey, employing gravity and magnetic methods, was carried out near Wollongong, N.S.W. by geophysicists of the Bureau. The area over which these tests were made is part of the Southern Coalfield of N.S.W. and plans are being made to develop a colliery in it. The subsurface geology is known in part from five drill holes, namely, Nebo No. 2, 5, and 6 and Wongawilli No. 7 and 8. Basalt sills of considerable thickness were encountered in Nebo No. 6 and Wongawilli No. 8. The proximity of sills to the coal seams has resulted, in parts of the Southern Coalfield, in the cindering of the coal, and for this reason it is a matter of considerable importance in planning a colliery to know the area occupied by the sills. The technical aspects of testing, results, and conclusions are discussed in this report.

The field season in the Kimberley Division of Western Australia for the year 1948 extended from May 2nd to October 15th. It is estimated that about four weeks of this time was spent in activities not directly related to geological work. Three distinct areas were covered during the season, these being Dampier Land, Mt. Ramsay Area, and Nerrima Structure. An account is given of the personnel involved and the work completed within each area.

The deposits of heavy-mineral sands which are at present being exploited along the East Coast occur on or within a few hundred feet of the ocean beaches. The occurrence of this deposit at a distance of nearly 1.5 miles from the beach suggests the possibility that other deposits may be found at some distance from the coast line. Of incidental interest is the possibility that the deposit, which presumably was formed by wave or surf action, may be at slightly higher level than the deposits adjacent to present day beaches. The locality, examination process, origin, and nature of the deposits are discussed in this report. The results, including estimates of the quantities of heavy mineral concentrates and the grades of the mineral bearing sands, are tabulated here.

Systematic testing of South Stradbroke Island was started on 5th January, 1948. The boring and concentrating of samples were carried out by Associated Minerals Pty. Ltd., Southport. Sitting, levelling and mapping of boreholes was carried out by the Bureau of Mineral Resources. Between January and June, boring was directed towards the high active dunes adjacent to the east coast, and the areas of fixed, vegetated dunes west of the active dunes. The results of the testing work are recorded in this report. The occurrence of heavy minerals has been tabulated. Eight accompanying locality, section, and contour plans are included.