182 
Geology of Sydney. 
The Narrabeen beds can be studied along the 
cliffs on the coast, north of Long Reef. Here they are 
found rising from below the Hawkesbury Sandstone 
(Fig. 47), and show that chocolate-coloured hue that 
gives the name chocolate shales to these particular 
beds. The same shales were reached in a boring at 
Moore Park at a depth of 1000ft. below sea level. 
At Sutherland they are 520ft. below sea level. “ On 
the side of the hills near the Metropolitan Coal 
Company’s shaft, at Camp Creek, on the Illawarra 
Railway, 28 miles from Sydney, the chocolate shales 
crop out at 410ft. above sea level. Thence they may 
be traced along the face of the coast range as far 
south as Saddle Back Mountain, near Kiarna. Their 
thickness has not been definitely ascertained, but it 
is probable that the whole of the strata, including 
shales, sandstones, and fine conglomerates, 1573ft. 
thick, lying between the Hawkesbury Sandstones and 
the top seam of coal passed through in the Sutherland 
Bore, should be regarded as one series. At Camp 
Creek these strata have thinned out to about 920ft. 
in thickness, and at Bulli to about 700ft., gradually 
diminishing towards the south; whilst to the west, 
in the Berrima district, they have disappeared, and 
the Hawkesbury Sandstone rests directly on the coal 
scam.” 1 
. In the section shown (Fig. 46) the Hawkesbury 
Sandstones are seen resting directly on the Permo- 
1 0. S. ‘Wilkinson, F.G.S. “Handbook of Australian Association for the 
Advancement of Science.” 1888. 
