296 W. J. CLUNIES ROSS. 
NOTES on toe BASALTS or BATHURST np THE 
NEIGHBOURING DISTRICTS. 
By W. J. Cuiunies Ross, B.Sc., Lond., F.G.S. 
[Communicated by J. H. Maiden, F.1.s. | 
[Read before the Royal Society of N. S. Wales, November 3, 1897.] 
INTRODUCTORY. 
Att residents in Bathurst are familiar with the Bald Hills, which 
form a prominent feature to the south-west of the city. They are 
the sources of the blue metal used for making the streets, and the 
columns of basalt are used for kerbs for gutters and for corner- 
posts. Being so well-known as basalt-capped hills, they have not 
escaped the notice of geologists. The late Government Geologist, 
Mr. ©. S. Wilkinson, alluded to them, and said that the basalt 
came from Swatchfield. The Rev. J. M. Curran has described 
the petrological characters of the rock in his paper dealing with 
the geology of Bathurst, and also in his prize essay “On the 
Microscopical Characters of New South Wales Rocks.” Lastly, 
the writer dealt with their character in his paper ‘‘On the Geology 
of Bathurst.”* 
Although, however, a good deal of work has been done in con- 
nection with the petrological characters of the basalt, very little 
attention seems to have been paid to the chemical composition of 
that or of the other Bathurst rocks, especially in the way of com- 
parison with those of other centres. 
Now the microscopic characters of a rock are very important 
for giving one a knowledge of its structure and mineral constitu- 
2 ee 
1A Contribution to the Geology and Petrography of. Bathurst, N.5- 
Wales.” —Proc. Linn. Soc. N.S. Wales, ser. 2, Vol. x1., pp. 173 - 2845 
sep. copies pub. Angus and Robertson, Sydney, 1891. 
2«A Contribution to the Microscopic Structure of some Australian 
Rocks.”—Sep. copies, Angus and Robertson, Sydney, 1892. 
3 Q.J.G.S., Vol. u., 1894, pp. 105 - 119. 
