78 ON THE WAIANAMATTA SHALES. 
The tunnels have all manifested the same fact. If the Waiana- 
matta were one formation filling up a basin of the eroded Hawkes- 
bury sandstone, the tunnels and shafts should reveal in some 
. 
fine calcareous facing. Now this is exactly the character of nearly 
is best seen from the following records of the strata passed through 
in five shafts along the Nepean tunnel. 
Shaft No. 1, 631 feet above sea-level. 
Sandstone, white and false-bedded with 
rou ‘ains via eae 73 feet. 
Shale, with plant impressions 1345 
Sandstone as before ... iif 1244 ,, 
Tota thickness of strata --. 2104 feet. 
Shaft No. 2, 687 feet above sea-level. 
Clay and loose boulders _ ie vee’ IO: feet: 
ery impure shale, or jointed sandstone A 
Sandstone false-bedded ie wee ee 99 
Total thickness of strata ve 2144 feet. 
F 
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