The refraction seismic tests described in this report were made at the request of the Victorian Railways Department. The work was located within the railway reserve between the outskirts of Wodonga township and the River Murray, and consisted of the shooting of five refraction traverses, set out approximately parallel to the railway line and covering in detail a total length of 4,800 feet. The aim of the seismic work was two-fold. Firstly an investigation was required of the subsurface formations in the vicinity of the bridges which carry the railway across several creeks intersecting the Murray flood plain. The subsurface information is required in connection with the design of the foundations of new bridges which will be constructed to replace the existing ones. The second purpose of the work was to test whether the refraction seismic method would be suitable for adoption by the Railways Department engineers as a standard routine method for investigating foundation conditions. To fulfil this purpose ideally, the method would need to be applicable generally to all the foundation problems encountered by the Department and to completely eliminate the necessity for test drilling of sites. The flood plain of the Murray, on which the seismic measurements were made, is composed of Recent alluvium, probably underlain by Tertiary river deposits and is crossed by several creeks and anabranches of the main stream. The outcrops in the vicinity of Wodonga show the bedrock to be granite and metamorphic sediments. The field work was done between February 26th and March 12th, 1953. The field party comprised two geophysicists and three field assistants provided by the Railways Department.

A field party from the Bureau of Mineral Resources left Melbourne on 19th March, 1949, together with a relief party from the Australian National Antarctic Research Expedition. The objects of the party's visit to Macquarie Island were the establishment of a Seismological Observatory, the determination of the secular variation of magnetic declination, and the location of magnetically suitable areas for a proposed Magnetic Observatory. The present preliminary report is concerned exclusively with an accident which occurred during the construction of the Seismological Observatory and which caused injuries to A.B. Billan, R.A.N. The building plans and choice of the site are discussed.

An examination was made of a proposed dam site at Geehi in April, 1947. The report comprises notes on access, general geology, evidence gathered from aerial photography, and the suitability of the site. Three accompanying plans, and a petrographic report on rocks collected from the vicinity, are appended to this report.

It was requested that the Branch examine the Naronga site with a view to determining whether it was suitable from a geological point of view for the construction of a flood control dam. The area was visited and mapped in March, 1946. The topography, geology, possible site and capacity of a retaining wall are discussed in this report. Three plates showing the area and sections accompany this report.

Following a request from the Department of Works and Housing, the Bureau of Mineral Resources carried out a geological investigation of a possible dam site in the valley of Pierce's Creek, a tributary of the Cotter River. The general geology of the area, and aspects of engineering geology, are discussed in this report. A geological plan of the site is included.

For nearly nine months of the year the river proper is confined to a narrow channel two to three hundred feet wide. During the remainder of the year, however, the river is subject to periodical floodings resulting from heavy tropical rain on its water-shed and for periods of a week of more at a time the low level bridge is covered by flood water. The dislocation of rail traffic which results from these periodical floodings has been a matter of serious concern to the Queensland authorities for many years and a decision was made to construct a high level rail and road bridge to replace the existing structure. Construction was commenced, but before it proceeded far, it was considered desirable that the depth of the bedrock, previously examined, should be established without doubt. In view of the uncertainty of the depth to be drilled and the very considerable difficulty in drilling through alternating layers of drift sand and boulder wash, a request was made by the Co-ordinator General of Public works for Queensland for a geophysical investigation of the site. A survey was carried out by the geophysical section of the Commonwealth Bureau of Mineral Resources during August and September, 1947. The investigation of the results is far from complete but the seismic method gave such concise results that this preliminary statement is justified. Geology, geophysical methods, results, interpretation, and testing are discussed in this report.

The first geological reconnaissance of the proposed diversion of the Snowy River to the Murray Valley was undertaken in late 1946. This work was followed by more detailed work in the summer of 1947-8 when field parties carried out a reconnaissance of a strip of country covering the approximate route which the main tunnel is expected to follow. Part I of this report deals briefly with the geological work accomplished during the two field seasons and provides a summary of the engineering geology of the main and subsidiary tunnel lines. Parts II and III consist of the geological reports by the leaders of the two field parties. Part II covers the survey area from Waste Point to the Geehi River. Part III covers the survey area from the Geehi River to Khancoban. Accompanying plans are included.

In response to the proposal for a new administrative building to be erected, 1/4 mile east of Parliament House, nine test pits were put down by the Department of the Interior for the purpose of examining the sub-surface conditions. Four of the pits were used for engineering tests of the bearing power of the rock foundations. The geology of the site is discussed in this report.

On May 3rd, and again on June 1st, the author visited the Cotter dam to investigate a reported loss of water from the fault on the northern side of the wall. This report gives an account of these visits, together with the author's observations and conclusions in relation to the reported water loss.

Detailed geological investigations were made of two previously selected dam sites, B and A, in the Upper Cotter Valley. Site B1 is geologically suitable for the construction of a dam, but subsequent to the investigation it was found that the storage capacity of this site would be insufficient for Canberra's estimated requirements; hence the site is unlikely to receive further consideration. Site A appears suitable for the construction of a stable dam, though less suitable geologically than site B1. Five recommendations are submitted for consideration.