Aug. 28, 1873] 
map of Victoria, exhibited by the Mining Depart- 
ment at the late Intercolonial Exhibition, and which 
contains the results of the latest surveys made in the 
colony, will be embodied in the general map. It was 
compiled by Mr. Brough Smyth from surveys made some 
years ago under the direction of Mr. A. R. C, Selwyn, at 
‘present director-general for the Geological Survey of 
‘Canada, but who formerly held a similar position in 
this colony, and from surveys made since by the officers 
of the mining department. It has been described “as the 
“nearest approximation that can at present be made to 
a true representation of the rock masses which are ex- 
posed in this colony.” The New South Wales Govern- 
ment have in preparation a geological map, which, it is 
expected, will be available for use before the general map 
is published. 
The Queensland Government has been keenly alive to 
the importance of mapping out the immense mineral dis- 
tricts of that colony, and for some years has kept a staff 
of geological surveyors actively employed in the work. 
The information thus collected has been embodied in a 
series of elaborately-coloured and_beautifully-executed 
_ maps, which have proved of great service in the compila- 
_ tion of the general map of Australia. An excellent sketch 
map, covering a considerable portion of the colony, has 
been obtained from the Government of South Australia. 
It was compiled under the direction of Mr, A. B. Cooper. 
It is especially valuable, as it embraces a great part of the 
populated districts. The country north of Encounter 
Bay, the most extensive mineral district in the southern 
_ portion, was examined and reported on by Mr. Selwyn 
_ many years ago, and a sketch map prepared by him is 
being used in compiling the new map. Thesame district 
¢ 
the request of the Government, and his observations are 
_ proving of great assistance. 
Thanks to the energy of Mr. C. Gould, a son of the 
eminent naturalist, the geological characteristics of Tas- 
mania were very accurately delineated during the time he 
was geologist for the colony. An excellent map was 
published under his direction, and he voluntarily made a 
- number of additions to it a short time ago, when he 
learnt that a copy was to be transmitted to Victoria to be 
used in the preparation of the general geological map of 
Australia. 
A large portion of the vast territory of Western Australia 
has been surveyed by Mr. H. Y. L. Brown, Government 
surveyor, but who was once attached to the geoloyical 
staff of Victoria. This gentleman has produced a very 
beautiful sketch map of the S.W. portion of the colony, 
_ which has been extensively used by the compiler of the 
new map. It thus appears that every care has been 
taken to obtain the most accurate information at present 
: available. 
An examination of the map discloses facts of interest 
not only to geological students but to the public at large. 
The value of the map to men engaged in mining is too 
palpable to call for comment, as it shows at a glance the 
formations in which the precious metals occur. In rocks 
belonging to the primary or palzozoic group, gold, tin, 
antimony, silver, lead, and copper may be confidently 
searched for. The secondary or mesozoic rocks contain 
coal, while tin is frequently found associated with granitic 
rocks. Persons engaged in pastoral and agricultural 
pursuits will also derive advantage by consulting this 
map. A very little geological knowledge will tell them 
that in districts where the principal rock masses belong 
to the tertiary period they may look for well-grassed 
plains suitable for pasture. In areas where the volcanic 
rocks abound, rich soil, well adapted for agricultural pur- 
suits, may be expected. The slatey ridges formed by the 
_ older silurian rocks, and the sparsely grassed mountains 
of granitic rock which abound in Western Australia, also 
convey a valuable lesson to the intelligent observer. One 
3 
si. 
has beer very recently reported upon by Prof. Ulrich, at. 
NATURE 353 
of the most prominent geological facts which the map 
discloses is, that a great metalliferous belt lies on 
each side of the main Cordillera from Cape Yorke 
to the southern point of Tasmania. It is composed 
chiefly of metamorphosed schists and granite rocks 
overlain.in a considerable area by the newer palzo- 
zoic rocks and mesozoic coal-bearing strata. Another 
great belt appears to extend from Encounter Bay in South 
Australia towards the Gulf of Carpentaria. North of the 
30th parallel of latitude the schists are overlain by ter- 
tiaries, and what Mr. Daintree considers to be rocks of 
the cretaceous age up to lat. 20° to 23°, where a large 
patch of metamorphic schist occurs. The whole tract 
west of the eastern metalliferous belt is occupied by ter- 
tiaries. Wide treeless plains, and what are called desert 
sandstones, abound. The vast tract of country known as 
Central Australia will have to be marked “ unknown,” as 
geological surveys have not yet been made of it. What 
is at present known of the geological character of the 
northern portion of South Australia will be mapped out. 
The Government of South Australia have furnished a very 
good map showing the paleozoic tract of Port Darwin, 
and from notes made by explorers the department has 
been able to lay down a large granitic tract also, as well 
as a large area covered with rocks of volcanic origin. 
The coal rocks are seen extending all along the coast 
from Port Curtis, in Queensland, in an almost unbroken 
line to Eden or Twofold Bay. They are especially pro- 
minent at Newcastle and Wollongong, in New South 
Wales. They again appear north of Corner Inlet, at 
Cape Otway, and can be traced in broken patches along 
the coast up to Glenelg, where they apparently terminate. 
Another interesting fact established by the new map is, 
that within the tertiary era connection has existed be- 
tween Tasmania and the main land. There is a strict 
resemblance between the geology of Tasmania and the 
continent, and the chain of granite islands extending from 
Wilson’s Promontory, the southernmost point of Austra- 
lia, to Cape Portland, the northernmost point of Tasma- 
nia, have all their ridges capped with tertiaries, thus 
showing that within the tertiary period the island and the 
continent must have been connected. The main geologi- 
cal characteristic of Western Australia is the immense 
area occupied by granitic rocks, varied occasionally by 
patches of sandstone, especially on the southern coast 
line. A comparatively small part is occupied by a belt of 
metamorphic rocks to the east of Champion Bay. Vol- 
canic rocks are also visible. A large granitic tract occurs in 
the basin of the Shaw River, east of Dampier Archi- 
pelago. It appears that there has been a greater amount 
of denudation on the western side of the continent than 
on the eastern. Where the altitude is that of the Di- 
viding Range, which varies from about 1,500 ft. to 7,000 fer, 
either granite, metamorphosed schists, or silurian rocks 
are found. Underneath the basalt or volcanic rocks in 
Queensland, as well as at Ballarat, the deep leads occur. 
It is curious to note that the deep leads of Queensland 
contain tin as well as gold. Wherever the dark red 
patch appears indicating granite, tin may be expected to 
be found. The extraordinary richness of the tin deposits 
of Queensland and New South Wales will probably 
cause the immense granitic tracts of Western Australia 
to be thoroughly explored. The middle belt of meta- 
morphic schists which occurs in South Australia is as 
well known for its extensive copper mines as the eastern 
belt is for its gold. 
The Mining department of Victoria has established a 
high reputation for the general excellence of the geolo- 
gical maps it has produced. The last effort will reflect 
equal credit upon the officers employed upon it. The 
rocks are shown in a descending order, and are easily 
recognised by the distinguishing colours with which 
they are tinted. A system of lettering the face 
of the map has also been adopted, which will fa- 
