REVIEWS 669 
drainage, shaft sinking, and for development of transportation facilities 
to assist mining operations. A separate chapter, entitled “Assistance to 
Prospecting and Mining,” explains these various forms of governmental 
assistance in detail and also lists geographically and by minerals all 
available government reports and maps covering mining districts. 
Another chapter is a glossary of common terms in mining and geology. 
Among the major metals, iron ores though widely distributed in 
Western Australia have as yet been developed only on a small scale for 
the production of flux for copper and lead smelting and no detailed 
geologic surveys have been made of any of the iron deposits. Copper 
deposits, though widely distributed, have been developed only to a 
minor degree. The production of lead ores has been small. 
Among the steel hardening metals, the production of manganese, 
tungsten, and molybdenum has been so small as to be essentially neg- 
ligible. Among the rare metals, there has been little or no development. 
The small tin production has come mainly from alluvial deposits, 
but in the Wodgina tin field, tin and tantalum occur in pegmatite dikes 
which, together with granite, intrude metamorphic sedimentary rocks. 
The chief constituents of these pegmatitic dikes are albite and quartz, 
with occasionally scaly lepidolite and tourmaline; in addition, ortho- 
clase, mangano-tantalite, and tin occur in varying quantities, as well 
as some of the rare radioactive minerals. In the vicinity of and along 
the margin of many of the pegmatite dikes are bands and bunches of 
tourmaline, sometimes to such an extent as to make up fully one-third 
of the entire rock. One of the most conspicuous of the pegmatite veins, 
about half a mile in length and 30 feet in width, has proved to be suffi- 
ciently rich in tin and tantalum to be worked. 
The tin ore, cassiterite, is concentrated along certain lines in the 
pegmatites and does not appear to be generally disseminated in minute 
quantities throughout its mass. The tin occurs in all shapes, from | 
minute grains up to pieces weighing as much as roo pounds. 
The coal deposits of Western Australia range in age from Carbon- 
iferous, through Permo-Carboniferous to Mesozoic, Tertiary, and post- 
Tertiary. The only deposits which have been extensively mined are 
those of the Collie field of Permo-Carboniferous age. In this field the 
total thickness of the coal seams is about 137 feet. The coals are semi- 
bituminous, non-coking coals which are dirty to handle and deficient 
in volatile materials. It is interesting to note that the coals appear to 
be mainly of drift origin and to have been deposited by current action 
on an extensive basin or river valley. The banded appearance of most 
