2 
Tlic Wianamatta Shales consist chiefly of ai'g'illaccous shales, deposited 
in tlie denuded hollows and on the worn surfaces of the Ilawkcshury Sand- 
stone. The remains of ]>lants, fish, and traces of Lahyrintliodonts have heen 
found in them. The late Rev. W. R. Clarke, R.R.S., estimated the thickness 
of this series to he about 700 feet. 
The Ilawkeshury Sandstones arc descrilied hy Mr. C. S. Mnlkinson, 
T\(}.S., as “yellowish-white sandstones, with a few hods of shale and pehlile 
con g'lom crates of irregular thickness.” Plants and lish are plentifully met 
wit hi, and two Lahyrintliodonts have heen described from tliis series — one 
believed to lie identical with tlie Euro]iean Triassic J\[<(slo(l(ms((urns rob/isftif;,^^ 
and another named Flafi/cpps Jfllkiusoui, Stephens. f TTic Ilawkeshury 
Sandstone in the Berrima District rests directly on the Coal-Measures, hut 
at Coal Clilf there is an intermediate set of beds 809 feet thick. 1: These are 
included in the succeeding group. The entire thickness of the Ilawkeshury 
Series is estimated by Mr. TVilkinson to he 1,000 feet. 
The Xarraheen Shales, which may perhaps lie the equivalents of the 
Clarence Series, consist of purplish-red or cliocolate ferruginous clay-shales. 
Tdiey are visible in clilf section at Long Ptcef, to the north of Manly, hut 
liave, however, been studied more in detail from the core of the Ilolt- 
Sutherland Bore at Dent’s Creek. Here they were struck, according to 
Mr. T\ W. E. David, at a depth of 771 feet below the surface, and extended 
to that of 1,362 feet, giving a thickness of 591 feet. 
The Estheria Shales follow liclovv the Narrabeen in the above luire, 
from 1,462 feet to 2,000 feet, or, in round numbers, a thickness of 638 feet. 
They consist of tine greenish-gray shales and dark grey mudstones, with 71 
feet of purple and green-mottled cupriferous shale and tulf. The true Coal 
^Measures are believed by Mr. David to ajipear at a depth of 2,000 feet. 
Taking the Holt-Sutherland Bore at Dent’s Creek as a tyjiical section 
of the infra-llawkesbury strata, Mr. David remarks§ that it “ does not afford 
any evidence of unconformity from the coal seams upwards, through the so- 
called passage beds, into the Ilawkeshury Sandstone.” He adds — “ Strati- 
graphical evidence derived from a core 1^- inch in diameter is obviously not 
very reliable ; but, so far as it may be accepted, shows no break in the 
* Stephens, Froc. Linn. Soc., New South Wales, 18S(>, 1, pt. 3, p. !)31. 
t Froe. Linn. Soc., New Soutli Wales, 1887, II, pt. 1, p. 150. 
X Notes on the Geology of New South Wales, Department Mines, second edition, 1887, p. 74, 
§ MS. Report. 
