This report provides a summary of volcanic activity in the volcanic centres of New Guinea for the year 1951. Extended descriptions are given of ongoing investigations and the volcanological observations made at Rabaul, Mt. Lamington, and other significant volcanoes.

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 Treasure Mine, Hatches Creek, is believed to have been discovered in 1914 and has been one of the most consistent producers of wolfram to the present time. This report gives an account of the economic geology of the mine. The ore type, reefs and workings, ore localization, and ore reserves are described.

The Nunyerrie Asbestos Deposits are associated with a remnant of metamorphosed ultrabasic rocks in granite country, which is part of a group of Pre-Cambrian rocks of Archaean age. The ultrabasics form an east northeast trending ridge about 1 mile long and 250 feet average width, which rises to a maximum elevation of 300 feet above the general level of the surrounding country. The belt of ultrabasics is highly sheared and jointed and consists chiefly of serpentines, but talcose rocks, chlorite schists, authophyllite rock and what appear to be hydro-biotite schists also occur. The ultrabasics have an intrusive junction with the surrounding granite rocks, and they are intruded by quartz veins and granitic dykes. The deposits were investigated by the author. This report gives an overview of the deposits. Workings, production figures, reserves, grades, and prices are described.

Four days were spent in the area, observations being severely limited, firstly by lack of knowledge, on the part of the observer, of overall topography such as could be obtained from aerial photos or viewing the area from an aircraft and secondly by the dense fog which covered the area for the greater portion of the time spent there. Captain Fox of Q.E.A. had previously informed me that during the aerial inspection made by Mr. G.A. Taylor, three areas of "burnt" ground had been observed. Mr. Jones during his stay in the area had located two of those and in addition, two more minor areas. During my stay in the area those fumarolic areas were inspected and in addition, the third area located and inspected. The three major areas shall be referred to as the lower, middle and upper fumarolic areas.

These deposits were visited between the 3rd and 5th July, 1951. The investigations were carried out in order to obtain a first hand knowledge of the extent and mode of occurrence of the deposits, and to select a number of diamond drill hole sites to test the continuity of the deposits at depth. This report gives an account of the investigations and their findings.

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.

An earlier report (Record 1950/041) has described the geophysical survey carried out early in 1950 on the Renison Bell tin field. The present report deals with the work of a second field season which commenced in November 1950 and continued until June 1951. The methods used were again the magnetic and self-potential. The 1950 survey was extended to the south and east by continuing along the Renison Bell Hill base-line a further 1000 feet south and reading stations on both sides of this base-line along traverses extending from the main quartz-porphyry dyke to the headwaters of the Montana Creek. In addition, some of the traverses were extended over the saddle between Dreadnought and Stebbins Hills as far as the Boulder tramway. The report gives an account of the survey work and its results, and provides recommendations for future testing. The geological features of the area covered by the present geophysical survey are briefly described.

At the request of the Government Geologist of Western Australia some gravity observations were made near Bullsbrook, a small township on the Perth-Geraldton road, 27 miles from Perth. It was thought that the gravity observations would help resolve a problem connected with the water supply of the township on which the advice of the Geological Survey of Western Australian had been sought. Because the gravity method had proved successful elsewhere in determining the thickness of sediments overlying dense basement rocks, it was though that some estimate of the thickness of sediments underlying Bullsbrook could be made by using the method. This report gives an account of the operations and their results.

A provisional Isogonic Map of Australia and New Guinea for the epoch 1950.5 has been prepared by revising the observational material used in the Isogonic Map for 1942.5, and including observations made at various parts of Australia since 1942. The extensions of the Isogonic Lines beyond the coast line of Australia depend almost entirely on extrapolation from the earlier work.