Ice thickness measurements carried out by field parties based on Mawson during 1957-59 consisted of: (:) regional traverses in the form of closed loops extending several hundred kilometres inland from Mawson; (ii) semi-detailed traverses in the vicinity of a line of ice flow stakes about 25 Km from Mawson. The regional traverses showed that, beyond about 175 Km inland, the area surveyed is influenced strongly by the Lambert Glacier - Amery Ice Shelf system situated some 200 Km to the East. Preliminary contour plans of the ice and rock surfaces show fairly close correspondence. A sub-glacial extension of a range of mountains outcropping through the ice 80 Km to the East of the traverses was found. Work along the semi-detailed traverses close to Mawson detected sub-glacial extensions of the outcropping mountain ranges in the area. These extensions may explain the general direction of the coastline near Maws on.

At the request of the Australian Atomic Energy Commission, the Bureau of Mineral Resources, Geology & Geophysics conducted a seismic refraction survey on the site chosen for construction of a nuclear power station. The purpose of the survey was to determine the foundation conditions at the site and the properties of the rocks in relation to excavation methods and support of the proposed structures. The bedrock of the area consists of Permian sandstone (Jervis Bay Sandstone) overlain in places by unconsolidated Quaternary beach and dune sands. During the seismic work it was found that the sandstone beds have a relatively wide range of seismic velocities; often a higher-velocity bed overlies a lower-velocity bed, and this makes seismic refraction work difficult and less accurate. This is confirmed by laboratory measurements of seismic velocities on drill cores. Thin beds of higher- and lower-velocity sandstones occur, some too thin to be resolved by the seismic method. The seismic profiles presented must be considered bearing in mind these difficulties, Haterial sufficiently consolidated for foundations is shallow, and the seismic velocities indicate that some blasting will be necessary to excavate to the desired depth of 10 feet above mean high water level.

The seismic survey was carried out at the request of the U.K. Ministry of Supply. The purpose of the survey was to disclose the geological structure and, if possible, the physical rock characteristics at the Maralinga testing ground. The 11,000 ft/sec layer at a depth of about 200 ft, probably a sandstone-shale formation, and the 19,000 ft/sec formation at a depth of about 1350 or 1800 ft (according to the method of computation used) were successfully mapped. The subsurface information to a depth of about 200 ft was derived mainly from shallow drill holes and up-hole shots. An experimental spread indicated a very low Poisson ratio for the sandstoneshale formation.

The report describes work carried out during an ice thickness survey by seismic and gravimetric methods made in the summer of 1957-58 in MacRobertson Land, Antarctica. Methods used during the survey are described and the equipment used is listed in detail. Results have not yet been analysed fully but preliminary profiles are given. The accuracy limits applying to these profiles are given and future extensions of the calcu18tions are discussed.

These notes deal with a brief experimental seismic survey undertaken by the Bureau of Mineral Resources for the Victoria Railways. The object of the survey was to determine whether the seismic refraction method was suitable for subsurface exploration in the area between Dynon and Footscray Roads, West Melbourne. The information desired by the Railways was concerned with the existence or otherwise of a "foundation" rock capable of supporting constructions associated with railway sidings and marshalling yards. Records of seismic refractions were obtained along three traverses.

The geophysical survey described in this report was undertaken at the request of the Snowy Mountains Authority for the purpose of investigating possible sites for the proposed Spencer's Creek dam. The area surveyed is about two miles above the junction of Spencer's Creek with the Snowy River, about six miles east of the summit of Mt. Kosciuszko, and at an average elevation of about 5,700 feet above sea level. The specific information sought by the survey comprised the following: depth and nature of the bedrock, contours of the bedrock surface, nature of the overburden, and in particular, variations in physical properties occurring either horizontally or vertically. The seismic refraction method was used in the survey. This report gives an account of the geophysical survey and its results.

Details and results are given of a seismic refraction survey made at the request of the Hydro-Electric Commission of Tasmania, to investigate the site of the western portal of the proposed Mossy Marsh Tunnel. The tunnel is part of the No. 2 Tarraleah Canal project to transport water from Lake King William to Tarraleah Power Station. The primary object of the survey was to determine the thickness of till overlying the dolerite bedrock, and hence contours of the bedrock surface.

At the request of the State Rivers and Water Supply Commission of Victoria, seismic tests using the refraction method were conducted over six well locations near Cobram in the Murray Valley Irrigation District of Central Northern Victoria. The purpose of the tests was to determine whether the depth of the water table in that area could be measured by seismic refraction methods. The problem of rising water tables is one which occurs commonly in irrigation districts. In some areas the problem is purely a local one in which only perched water tables, any within ten feet of the surface, are involved, but it is also possible that the level of the general water table over a large are may be raised by deep percolation. The State Rivers are Water Supply Commission have maintained a check on the water table depth in the Murray River Valley Irrigation District for some time by measurement in existing wells. These wells are not necessarily in the best positions, and some are falling in. The seismic method was considered as an alternative to expensive test boring for ground water measurement.

In October and November 1959 a seismic party from the Bureau of Mineral Resources carried out a seismic survey in the Surat Basin, Queensland at the request of Australian Oil and Gas Corporation Ltd. A traverse extending from Surat eastward to within 10 miles of Tara was shot in five-mile sections of continuous reflection profiling with approximately five-mile intervals between the sections.^In addition two refraction traverses were shot near Surat to record velocities and depths of as many horizons as possible. Reflections were of fair to good quality throughout the survey and it was possible to correlate bands of reflections from one five-mile section to the next with considerable certainty. Over most of the traverses four reflecting horizons were followed, and in a few places reflections were obtained from a still deeper fifth horizon. The reflection survey revealed a wide basin between Surat and Cabawin (about 70 miles east of Surat), with its maximum thickness of sediments under Meandarra. The sediments there appear to be at least 19,000 ft thick. A marked anticline was discovered near Cabawtin. The refraction survey, using the "Depth Probing" method, revealed a refractor with a calculated velocity of 20,180 ft/sec situated about 1000 ft below the fourth reflecting horizon.

A reconnaissance seismic survey was made in the area of Quilpie and Et.omanga in south-western Queensland. Traverses crossed the Harkaway, Pinkilla, and Tallyabra Domes. Reflection horizons were correlated with horizons within the Mesozoic sediments, and one persistent reflection was correlated with a horizon near the top of the Palaeozoic sediments. A thickness of sediments of up to 15,000 ft, including up to 11,000 ft of Palaeozoic rocks, was indicated on the flanks of the Harkaway and Pinkilla Domes. Results were compared with existing gravity data. Suggestions of faulting are based on seismic and gravity evidence taken together and also on gravity evidence alone in locations not covered by the seismic work.