1918.] The N.Z. Journal of Science and Technology. 
359 
DEPARTMENTAL REPORT. 
Magnesite and Dolomite in Australia and New Zealand. 
By P. G. Morgan, M.A., F.G.S., Director, Geological Survey 
Department. 
In order that steel of good quality may be made from the more or less 
phosphoric iron-ores of New Zealand a plentiful and cheap supply of 
calcined magnesite or dolomite for the linings of the steel-furnaces is neces¬ 
sary. The Bessemer or acid-hearth process of steelmaking is inapplicable 
to the Parapara iron-ore or the Taranaki ironsand, both of which are now 
known to contain more than the permissible minimum of phosphorus. The 
Thomas-Gilchrist basic-hearth or some allied process must therefore be 
employed. At the instance of Mr. E. Parry, Chief Electrical Engineer, 
Public Works Department, inquiries were made as to the supply of magnesite 
or dolomite from several of the Mines Departments of the Australian States 
(South Australia, Victoria, New South Wales, Queensland, and Tasmania). 
The replies received were interesting and instructive, and, as it is considered 
that the wider dissemination of the information obtained is desirable, a 
summary is now presented. A statement of what is known regarding New 
Zealand occurrences of magnesite and dolomite follows. 
Western Australia. 
The annual Progress Report of the Geological Survey for the year 1915 
(published 1916) contains on pages 31 to 33 a report by F. R. Feldtmann 
entitled The Magnesite Deposit at Bulong, N.E. Coolgardie G.F.” 
Bulong is a mining township 19J miles east of Kalgoorlie, but is not con¬ 
nected with that town by rail. Mr. Feldtmann states that the magnesite 
occurs in serpentine as short irregular veins, of varying thickness, which in 
places are so numerous as to form practically a stockwork. The veins, being 
less subject to weathering than the surrounding rock, and of a dazzlingly 
white colour, stand out conspicuously above the surface of the ground. In 
a few instances the magnesite occurs as a surface deposit of “ cement,” 
and in that case probably corresponds in its mode of origin to travertine. 
The main area of magnesite-bearing country forms a belt about two miles 
long and 10 to 25 chains wide. The northern end of this belt is about 
two miles and a quarter east of Bulong. There are other smaller areas of 
magnesite-bearing rock, chiefly to the north of the main area. Feldtmann 
states that prospecting had disclosed veins up to 2 ft. in thickness, and 
that, although no estimate as to the quantity of magnesite could be made, 
there was undoubtedly a very large amount of material carrying over 90 per 
cent, of magnesium carbonate. He was of opinion that notwithstanding 
the distance of the magnesite deposits from manufacturing centres they 
could be successfully worked on a large scale. A parcel of 58 tons had been 
sent away during his visit to the district. The export of magnesite from 
Western Australia during 1915 was 688 tons, valued at £1,196 ; but in 1916 
the export fell to 12 tons, valued at £47. In the former year five men were 
employed in magnesite-mining at Bulong, and in the latter year three men.* 
**Report of the Department of Mines for the year 1916 (published 1917), pp. 5, 6, 21. 
