The Trough Area extends parallel to and 200 to 300 feet west of the eastern beach from approximately 4800 feet north of the zero line shown on the locality plan, to 6000 feet south of the zero line. It has a flat sandy floor 150 to 200 feet wide, and a foot or two below water level. The "trough" is bounded on the east by the fore-dunes, and on the west by an area of shifting sand which rises sharply to elevations of 25 to 35 or 40 feet. Deposits of heavy minerals occur at or near the surface at several localities along the western edge of the trough. This report gives an estimate of the quantities of heavy minerals occurring from 2100 feet north to 1100 feet north.

A geological field party was engaged in this area from 9th May to 30th September, 1948. This report provides an account of the field operations undertaken throughout this period and describes personnel involvement.

The area under review in this report comprises a large territory located in south-western Victoria and south-eastern South Australia. The scope of direct geological information in the areas underlain by marine Tertiary rocks is severely limited, by very poor exposure of the underlying rocks at the surface. Under such conditions, once the scattered exposures have been examined and recorded on the map, little more can be done by surface work; the geologist is thrown back on a study of well and bore records and of the results of geophysical measurements. Considerable literature has been read and records of the principal bores in the area have been examined in detail. It has been recommended that a geophysical survey of the area be conducted, to determine, if possible, any structural features which might exist at depth in this southern-most extension of the Murray River Artesian Basin, which is made up of Tertiary to Recent formations, resting, in the area under review, on a basement of Pre-Cambrian or Jurassic Rocks. This report comprises an overview of the general geology, geological history, stratigraphy and topography of the area under consideration. Geological, bore-hole and well data has been compiled and tabulated. A geological sketch map is included.

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.

The "Trough" area extends parallel to and 200 to 300 feet west of the eastern beach from approximately 4800 feet north of the zero-line shown on the locality plan, to 6000 feet south of the zero line. A previous report (Record 1948/067) has given an estimate of the quantities of heavy mineral occurring from 2100 feet north to 1100 feet north. The following report deals with the remaining areas. The area was sampled during 8th and 9th September, 1948. Where the heavy minerals were at or close to the surface, samples were obtained from shovel holes. Where the mineral was at some depth below the surface, the samples were obtained from bores put down with a post-hole digger. Estimates of the quantities and grades of heavy mineral concentrates, the quantities of overburden, and the quantities of each of the heavy minerals are tabulated in this report. The data sets from which these estimates are derived are appended.

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 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.

The object of my trip to the United States of America was to discuss problems of micropalaeontology with various authorities in that country, to visit the palaeontological laboratories of the United States Geological Survey and National Museum, State Universities, Museums and laboratories of oil companies and to enquire into the latest techniques used in oil-field laboratories. I was also to attend the joint Annual Convention of the American Association of Petroleum Geologists, Society of Economic Palaeontologists and Mineralogists and Society of Exploratory Geophysicists at St. Louis. This report gives an account of the institutions visited by the author and the principal results of the visit.

This report presents the results of a gravity reconnaissance survey which was carried out under the writer's supervision during the last quarter of 1950. The report describes in some detail the methods adopted in carrying out the field work and the errors to which the results are subject. The results are discussed only briefly and the interpretation given must be regarded as a preliminary one subject to modification as further data are accumulated in extending or otherwise adding to the reconnaissance.

Widespread use of radio-active tracer elements in medicine, and the increased interest in the search for radio-active minerals, have led to the development of a variety of instruments for the detection of ionising radiations, and their general use by scientists who may have had no training in physics or electronics. While these instruments present a great diversity in appearance, the functioning depends on general principles which apply to all such equipment. The aim of these notes is to present these general principles in a simple form. For details of design, which are often highly complex, and require great skill and experience, reference should be made to the works listed in the bibliography.