Description
Summary:Taken from the scanned dataset: 1) Summary - Some observations on the geomorphology have been recorded. - Xenolithic ejectamenta collected from the tuffs of Rogers Head and Rogers Head Peninsula have been described. 2) Introduction Heard Island is in the South Indian Ocean in Latitude 53 S, Longitude 73.5 E, and some 2,400 miles south-west of Fremantle, Western Australia. It is a volcanic island, 25 miles long and about 10 miles wide, with its main axis E.S.E. It has rarely been visited, owing to its being situated in one of the stormiest regions in the world. During the summer of 1947, an expedition was despatched to Heard Island with the object of landing a party to spend about twelve months there. The writer worked in collaboration with the Magnetician, Mr N.G. Chamberlain, Bureau of Mineral Resources, and was able to undertake a little geological work. The results of this work are submitted in the following notes. 3) Geomorphology Heard Island has been formed by the accumulation of material extruded from several volcanic vents. These volcanoes are on a submarine ridge which extends north to Kerguelen, and possibly south-west to the Antarctic continent. The sketch outline of Heard Island, shows that the island is elongated in an east-south-easterly direction and along a probable fissure. The main volcano of the island is Kaiser Wilhelm Peak, named by Drygalski in 1908. This peak is some 10,000 feet high, and consists of a cone partly surrounded by a caldera. Adventive or parasitic cones are situated on its flanks. Towards the south-west the island narrows to a long tapering spit, covered with sand and beach boulders. To the north-east of Kaiser Wilhelm Peak are the volcanic peaks (approximately 2,000 feet high) of Cape Laurens Peninsula, Rogers Head Peninsula and Cave Bay, separated from the main island mass by the Atlas Cove Plain. The work was carried out by Mr J.F. Ivanac (geologist).