326 
Geology of Sydney, 
a quarry made for railway purposes close to the iron 
bridge on the Sydney side of the township. 
Travelling south from Sydney, the tourist passes 
from the Hawkesbury Sandstone to the Narrabeen 
Shales. Near Helensburgh we find the Coal Measures 
supporting a vegetation very different to that occurring 
around Sydney. At Clifton the workable coal seams 
rise from below sea level, and continue to rise till, at 
Mount Kembla, they reach nearly to the top of the 
Illawarra Range. 
At Kiama, and back to Robertson, extensive 
basalt flows occur, showing excellent columnar struc- 
ture in the “ blue metal ” quarries. (See Fig. 30.) 
At Flagstaff Hill, Wollongong, Upper Marine 
fossils are to be found to the left of the Basin. Large 
examples of Cleobis grandis are not uncommon here. 
At Blackhead, two miles south-east from Gerrin- 
gong Station, abundant Upper Marine fossils occur. 
Fenestella , Protoretepora , Stenopora, Spirifers (very 
abundant), Product us, Dielasma , M mania , Avicido- 
pccten , Ckoenomya, Astartila , Pleurophorus , Fluty - 
schisma, Mourlonui, Goniatites. 
Taking Nowra as a centre, a number of interest- 
ing geological trips can be made in many directions. 
Both Sedimentary and Eruptive rocks can be studied 
in the course of these trips. 
The Sedimentary rocks include : — 
(a) Recent deposits. 
(b) Rocks of the Hawkesbury Series. 
(c) Permo-Carboniferous. 
