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shale, somewhat resembling the Tapley's Hill stone, but has 
more lime in it, and is overlain by beds of siliceous and 
earthy limestones, which, in weathering, show the earthy 
particles and layers in relief. Тһе beds rol slightly, but 
have a general dip varying from 15° to 20° south-west. 
Half a mile from the bridge, down stream, in Section 509, 
Hundred of Noarlunga, a quarry has been worked by Mr. 
Reynell for road metal, in a thick, siliceous limestone, with 
a quarry face 50 ft. in height. The stone shows markedly 
the vermiculate structure already referred to. When the 
stone is split along the planes of the wavy liues, they are 
seen to consist of broad, uneven films of earthy silicates, 
separated by siliceous limestone. Тһе lines often run nearly 
parallel, in pairs, which gives a striking resemblance to 
organic remains seen in section. 
In the adjoining section (519), a little west of the dis- 
triet road which crosses the river, is the most important 
quarry in the limestones of the Field River, and is worked 
by Mr. Pocock. It is clearly the same set of beds as occur 
in the quarries of the South Australian Portland Cement 
Company at Brighton. The siliceous limestones, blue lime- 
stone, pink limestone, and magnesian limestone follow each 
other in an ascending series in the same order in both locali- 
ties, which are separated by a distance of three and a half 
miles in a direct line. The limestone has been thrown into 
a series of anticlinal and synclinal folds across the strike. 
Pocock’s quarries have been opened near the crest of the 
most eastern anticline. "The eastern limb of the fold, as seen 
in the main quarry, has a dip of 25? south-south-east, and 
has suffered a denudation, which exposes the underlying, 
earthy, and siliceous limestone on its eastern side. 'The 
ground between Reynell’s and Pocock’s quarries 1s occupied 
by a shallow synclinal fold, which brings in a small outlier 
of the limestone, seen on the district road and paddock to 
the east, but makes no prominent feature. 
Pocock's quarry exhibits a fine face of good limestone, 40 
ft. in thickness, with a dip slope towards the valley. The 
stone varies in colour from bluish to pink, and is oolitic in 
structure. A large, V-shaped mass of rubbly, magnesian 
limestone has latterly been encountered, replacing the good 
stone and greatly affecting its quality. This intrusion neces- 
sitated the opening of a new quarry about a chain length 
to the west of the old one. Here the stone is found to be 
sound, and has a dip of 48° to south-east. Тһе west side 
of the hill (on which Pocock’s quarry is situated) forms a 
dip slope of the anticline, in its western limb. Near the 
centre of the fold the dip is at 80°, which rapidly decreases 
