324 
Geology of Sydney. 
A dyke, quite twelve feet across, can be seen 
cutting the exposed sandstones on the high ground 
at the eastern end of the old rifle range, Moore Park. 
This, like most of the dykes around Sydney, runs east 
and west. 
The Kensington dyke can be found by taking the 
Bunnerong Road past Kensington, where a quarry on 
the left will be noted. In excavating this quarry the 
dyke was discovered. 
The Pyrmont dyke can be traced travelling in an 
easterly and westerly direction at Saunders’ quarries. 
The three principal quarries are named Paradise, 
Purgatory, and Hell Hole. It is in the last-named 
that the igneous dyke occurs. 
At Peakhurst a basaltic dyke crops out not far 
from the Public School. This last is probably a con- 
tinuation of the Moorefields dyke. A railway cutting 
exposes a decomposing basaltic dyke at Beecroft 
(Fig. 11). Mr. Wilkinson drew attention, in 1879, to 
two igneous dykes laid bare in a railway cutting at 
Petersham. At Prospect, close to the Reservoir near 
Parramatta, basalt and dolerite occur in a mass that 
has been intruded into the Wianamatta Shales. 
The dyke at Rookwood may be found by taking 
the Banks town Road from the Railway Station towards 
Potts Hill reservoir. The quarry showing the basaltic 
dyke will be found close to the road just beyond the 
southern boundary of the Rookwood Park. 
The intrusive mass of basalt forming the Pennant 
Hills quarry is well worth a visit. The quarry is 
