SYDNEY SANDSTONE. 467 
These isolated observations indicate little more than the general 
fact that the variation in the dip is local, being often some way related 
to the position or direction of valleys or fissures. Major Mitchell 
remarks that from the Blue Mountains to the seashore, there is a 
general dip of one degree to the eastward. On this point, we had no 
means of judging. ‘The statement establishes the important fact, that 
the variation from horizontality is in general very small, and on this 
depends much that is peculiar in the topographical features of New 
South Wales. 
Fissures.—The sandstone is fissured in most places with remarkable 
regularity in two directions at right angles with one another, and pro- 
ducing rectangular blocks which occasionally look like an artificial 
pavement on a vast scale. The directions are nearly uniform, being 
SSS 
VIEW AT SOUTH HEAD, PORT JACKSON. 
north-by-east and west-by-north, compass courses, or, allowing for a 
point variation, north-northeast and west-northwest. ‘The various 
cliffs and quarries about Port Jackson and also the region of Para- 
matta afford abundant illustrations of the statement here made. I have 
also observed the same in the Illawarra range to the south, and north- 
ward at Greenhills, on the Hunter. These courses sometimes vary a 
point, inclining to north-by-east, (true course,) and west-by-north. I 
noted down the latter on the Hlawarra range near the Kangaroo 
Grounds. A northwest course is at times met with, and also a north- 
east. I observed the former in the sandstone between Newcastle and 
Maitland. 
The view above given, shows the rectangular pavement which 
borders the sea at the foot of the cliff at the South Head of Port 
