REVIEWS 159 



A brief resume is given of the publications of the Geological Survey, 

 which consist of twenty-five annual reports and eighty-three bulletins. 

 Under the heading ''Economic Geology and Ore Deposits," the present 

 condition of knowledge relating to the economic geology of the state is 

 summarized. One of the concrete results of a quarter of a century's 

 work is a geological sketch map of nearly the whole of the state, summing 

 up graphically the work of the survey up to the date of publication, 1920. 



The ore deposits of the country are reviewed briefly under individual 

 headings: copper, lead, tin, etc. Aside from gold which, as is well 

 known, has been for many years the greatest mining product of Western 

 Australia, the most important of these appear to be the iron ores, not- 

 withstanding the fact that up to the present their exploitation has been 

 very limited. They are of all grades and of wide distribution. The 

 most noteworthy of the high-grade deposits are those of Yampi Sound, 

 Kimberley division. There are 97,300,000 tons of ore available, two 

 samples of which were found on analysis to contain 65 and 66.5 per cent 

 metallic iron respectively. The close proximity of this deposit to the 

 sea is greatly in favor of its development as a commercial project. 



Another important iron ore deposit is that at Wilgie Mia which is 

 almost pure hematite. Analyses of three samples give 68.37, 64.36, and 

 68.83 per cent metallic iron respectively. There are 27,000,000 tons of 

 ore in sight above the level of the plain and according to borings the ore 

 continues to a depth of 250 feet in places with no appreciable diminution 

 in quality. This deposit is within 40 miles of a railway, and about 200 

 miles from Geraldton, which is a seaport. Both the Yampi Sound and 

 the Wilgie Mia ores are very low in phosphorus and sulphur and contain 

 only traces of titanium. 



Other ores of importance in steel manufacture, namely those of 

 manganese, tungsten, and molybdenum, are present in commercial 

 quantities. 



Coals of different geologic ages are known, but mining has been 

 carried on extensively in only one district, the Collie Coalfield, from which 

 5,000,000 tons have been raised. The coals of the CoUie field are sub- 

 bituminous, non-coking coals, which approach very closely to lignite in 

 some parts. The principal consumer has been the railways department. 

 About 10 per cent of the production has been used as bunker coal. The 

 other known coal deposits are chiefly of lower grade. Considerable 

 search for coal has been carried on in the extensive areas of Permo- 

 Carboniferous rocks but unfortunately it has proved fruitless. Appar- 

 ently the future industrial development of Western Australia is handi- 

 capped by scarcity of high-rank coals. 



