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.

A site for a National Park Reserve is proposed at the head of the Tidbinbilla River, and a Zoological Park is planned, within the city limits, between Yarralumla Nursery and the Molonglo River. The Department of the Interior has requested geological information on these sites with special reference to supply of building stone. The geology of the proposed sites is described in this report. Possible sources of building stone in the vicinity of these sites are considered.

The establishment of seismological and magnetic observatories at Heard Island is described. Brief descriptions and photographs of the huts and instruments are given. Earthquake phases recorded between April 1951 and February 1952 are listed, as are absolute magnetic observations made between July 1951 and January 1952. Although Heard Island has two active volcanic craters, the region is not very active seismically. Only two near earthquakes were recorded, both probably 2°.9 distant along the Kerguelen ridge. The absolute magnetic observations showed that the high rate of secular change in declination and horizontal intensity is continuing.

This report covers the work done by the author who was geophysicist with the Australian National Antarctic Research Expedition at Macquarie Island from April to December, 1953. It is a sequel to Records 1953/30 and 1954/32 and deals with observatory routine and maintenance and other general duties required of the geophysicist. The report contains the results of absolute magnetic observations and initial earthquake phases. Detailed tables of scientific results will be published separately in reports at present in preparation.

The four field parties and the Airborne Geophysical Section continued operations in the area during the quarter ending 30th September, 1953. This report provides a summary of the geological and geophysical operations carried out during this period, and an overview of the staff and housing situation.

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.

An area of about 300 square miles was geologically surveyed in the Upper Murrumbidgee - Tumut River area. The object of the work was to investigate dam sites and tunnel lines in connection with a Hydro-Electric Scheme by which it is proposed to transfer water from the Murrumbidgee River into the Tumut River. Two proposed dam sites were examined. A detailed account of the topography, general geology, and engineering geology of these sites is given in this report. Accompanying geological plans are included.

In March 1946 the Department of Works and Housing requested that a geological examination be made of the Upper Cotter Valley in the vicinity of Kangaroo Creek to determine whether a dam could be constructed near the junction of Kangaroo Creek with the Cotter River. A geological examination was subsequently made. This report deals primarily with a possible dam site, near the mouth of Kangaroo Creek, and includes only a brief addition to the general geology of the Upper Cotter Valley. The location, physiography, general geology, engineering geology, and recommendations for future work are discussed in this report.

This report has been prepared at the request of Engineers of the Department of Works and Housing. The writer spent a day with Mr. Crotty examining the site, and another day alone studying general geological conditions relevant to the proposed scheme. The visit and its findings are outlined in this report.

This report concerns a geological reconnaissance made of a portion of the Kosciusko area and the preliminary geological plan compiled from air photographs and field observations. General geology, engineering geology, water problems, and proposed works for the hydro-electric scheme are discussed in the report. Three geological plans are included.