4 THE HAWKESBURY SANDSTONE. 
which of course would be very great on a loose sandy deposit Tt 
is thus I explain all those appearances which have a attributed 
to ice action, Mr. Wilkinson, the Government Geologist, thus g 
ibes such appearances.* “In the sections exposed in the quar 
ries at Fort Macquarie, Woolloomooloo, Flagstaff Hill, and other 
P ay be seen angular boulders of the ‘shale, of all sizes, up 
to 20 feet in diameter, embedded in the sandstone in the most 
confused manner, some of them standing on end as et 
with very rounded pebbles of quartz. They are sometimes slightly 
curved, as though they had been bent whilst in a semiplasti 
condition, and the shale beds occasionally terminate a } 
though broken off. Had the boulders of soft shale been 
in their present position by running water alone, their form would 
have been rounded instead of angular. It would a appear that that the 
shale beds must have been partly disturbed by some such agency 
as that of moving rt the displaced fragments of shale buomnd 
commingled with the sand and rolled pebbles carried fy by ie 
currents. Occasionally in the beds above those which 
angular bo ra few rounded pebbles of shale, sho . od 
that the re ey swept along for some distance a few 
are usually oval in shape, and are embedded in 2 
that the longer axis of the pebble is nearly always inclined 
dips sowrnnte the south-west,—thus indicating that the transported 
hereas the angular 
boulders in the beds below are, as before sntintdoinll confusedly 
heaped together withont regard to size.” In another place 
Wilkinson says :—“ From their lithological character the Hawkes 
was bounded on the west by the mountains which hot the 
northerly direction from the Shoalhaven River to the 
se ‘ “te hore-line 
denudation, cannot so 
probably did not oniand north of the Hunter River; - the . 
the east its extension is lost beneath the waters wih . 
Pacifie Ocean.” Mr. Wilkinson compares these ¥ of Mess 
Bacchus Marsh sandstones, and cites the opin : oe 
Selwyn and Daintree as to those formations being mel 
action. 
