BASALTS OF BATHURST AND NEIGHBOURING DISTRICTS. 301 
about twelve years ago. This cut the drift at some distance from 
the opening, but the roof fell in, and although attempts have since 
been made to reach the lowest layers of drift they have not been 
successful. 
Near the top of the saddle-shaped hill above Perth (A), on the 
Evan’s Plains side, there is a very compact conglomerate, with 
siliceous cement. It occurs in large massess on the hillside, but 
cannot be followed far, as both basalt and drift have been denuded 
away from the depression where the road from Perth to Evan’s 
Plains crosses. On this same hill the granite occurs at a height 
of over five hundred feet, but a short distance away the basalt 
appears to be in situ at a much lower level. On following the 
five hundred feet level round towards Bathurst one again meets 
with the compact conglomerate, but again only for a short 
distance, and, as blocks of it may be found on the other side of 
the hills, it probably passes across as a band under the basalt. 
Although the basalt in some quarries appears to be lower than 
the drift close to it, I have never found basalt underlying drift, 
or any evidence of successive flows of lava at considerable in- 
tervals of time. 
Mr. Curran mentions! the varying number of sides shewn by 
the basalt columns, and measured the angles. So far as my ex- 
perience goes, regular hexagons are rare. He did not find any 
instance of the ball and socket arangement of jointing, so well- 
known in some basalts.. It is certainly uncommon, but a column 
in the Bathurst Technological Museum shews a very fair ball 
joint, and the corners seem to indicate the tenons also well known 
to occur. After twelve years searching, I have been unable to 
find a fossil of any kind, except specimens of silicified wood, in 
any of the Bathurst drifts. The silicified wood is dull and opaque. 
Thave not seen any examples of opalised wood, although good — 
specimens are obtainable from Orange. 
On following the basalt in its westerly trend, at the northern 
end, one passes off the basalt for a short distance, and then 
1 Geology of Bathurst, p. Bsa ee 
