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.

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.

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.

Existing sources of water supply are described. Proposals for improving the supply of town water are considered. Further investigations are recommended with respect to tapping the southern lobe of the local basin, surface conservation, underground water resources, and the selection of a possible dam site.

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.

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.

The overburden (or non-scheelite bearing rocks overlying the ore-bearing rocks) at the mine of the King Scheelite N.L. at Grassy include: 1) A layer of windblown sand ranging in thickness up to 30 feet; 2) An irregular layer of non-mineralised rocks occurring in the north-western part of the present workings; 3) Non-mineralised rocks conformably overlying the lode in the southern part of the workings; 4) Overburden dumped on the southern side of the open cut. The problem of the dumping of the overburden is involved in that of the selection of a suitable site for the treatment plant. Under the proposed scheme to increase production a new site will have to be found for the treatment plant that is to be erected.

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.