BASALTS OF BATHURST AND NEIGHBOURING DISTRICTS, 311 
hundred feet from there to the base of the basalt near Bathurst. 
If the basalt flowed from Swatchfield, it must have been a very 
extensive lava flow to travel so far and arrive at the site of the 
Bald Hills with a thickness of over two hundred and fifty feet. 
Equally extensive flows of lava are known, however, in modern 
times, as, for example, that of Skaptor Jokul, in 1783.’ It is 
rather remarkable, however, that there appear to be no outliers of 
basalt along the valley of the Campbell or Fish Rivers. The 
whole of it appears to have been denuded away, except in the 
immediate neighbourhood of Swatchfield. 
It is true that boulders of basalt have been several times reported 
as existing near the lagoon, about ten miles from Bathurst, As 
this would be on the line of flow of the basalt, the lagoon being 
close to the Campbell’s River, I was anxious to obtain a specimen. 
At first I failed to find them, but afterwards Mr. Woolley, who 
has charge of the Public School at Lagoon, and knew the country 
well, kindly drove me to some boulders of dark rock, which were 
the only ‘ones he knew in that neighbourhood. They proved: to 
be near the summit of a hill, at a height of about four hundred 
feet above Bathurst, and were of several types. Some were 
moderately coarse grained rocks, probably diorite or dolerite. 
Others were more like basalt, and a slice was cut from one of 
these. Although not a satisfactory section, it is sufficiently clear 
to shew that it differs essentially from any of our rocks hitherto 
examined, and is hardly a typical basalt. A determination of the 
Silica gave 55 per cent. Specific gravity of two specimens 27 
and 2:8. These results indicate a basic rock, but not a Bathurst: 
basalt. It is hoped that the origin of these boulders may be 
traced, and indeed, the country between twenty and thirty miles 
from Bathurst offers a fine field for investigation. 
After endeavouring to trace the source from whence our basalts 
were derived, one would naturally like to find out where they 
ee 
1 Well described by Lyell—* Principles of Geology,” 12th Edition, Vol. 
Ih, p. 49. eh 
