264 
G-eology op Sydney. 
varying from a dense basalt to a coarse-grained liorn- 
blendic greenstone. At Prospect these rocks form a 
conspicuous and irregularly- shaped hill, which attains 
an elevation of 430 feet above sea level. From its 
summit, near Graystanes (the residence of Mr. Went- 
worth), a very commanding view is obtained of the 
surrounding country, embracing the City of Sydney, 
Parramatta, Liverpool, Campbelltown, and the Blue 
Mountains.” 
“On the south side of this hill a large quarry has 
been opened, immediately adjoining the site of the 
reservoir for the Sydney water supply. This quarry 
has been abandoned, as road-metal can now be 
obtained nearer to Parramatta, but the rock on it being 
less jointed and more uniform in texture than that in 
any of the other quarries in the district could be hewn 
in large blocks, and would be suitable for making into 
slabs for paving-stones.”’ 
“ For this purpose samples of the stone should be 
obtained, for I am of opinion that as regards cost of 
production and durability it might successfully com- 
pete with the basalt flag-stones imported from Mel- 
bourne, though the stone from Prospect is somewhat 
the harder of the two. On the west side of Prospect 
Hill, on the Lawson Estate, and also on the north side of 
the hill, in a small Reserve, some dense basalt is being 
quarried yielding good road-metal ; it occurs in 
unlimited quantity.” — (Wilkinson.) 
At the head of an indentation on the coast, between 
Long Bay and Maroubra Bay, a dyke enters the sea. 
