lley of the
Hunter, Liverpool Plains, Wellington Valley, and Buree.

Vesicular lava and amygdaloid are the chief ingredients of some of the
best parts of Australia Felix. In that region volcanic phenomena are more
apparent than in other parts of Eastern Australia, especially where the
Grampians, consisting of a mass of sandstone 4000 feet thick, seem a
portion of the great formation covering the districts of the north. The
strata in these mountains are inclined to the north-west, as if in
obedience to the upheavings of Murroa or Mount Napier, an extinct volcano
in the very line of their outcrop.

Observation. We found in the interior, hills of sandstone only, but at
this extremity of the great Coast range granite is extensively exposed in
ridges, between which, in one extensive district, are round heights of
mammeloid form, consisting of pure lava, and in another, tabular masses
of trap reposing on granite occupy one side of a valley.

GRAVEL.

Beds of gravel are not common in these parts of Australia; but occur
partially in the basins of the larger streams on the interior side of the
Coast range where the pebbles in general consist of quartz.

SANDSTONE.

The prevailing geological feature in all Eastern Australia is the great
abundance of a ferruginous sandstone in proportion to any other rocks.
The sterility of the country where it occurs has been frequently noticed
in these volumes. It is found on the coast at Port Jackson and it was the
furthest rock seen by me in the interior beyond the Darling.

A deposit upwards of 1200 feet thick forms the Blue Mountains west of
Sydney, ranging thence, with the intersection of no other rock of
importance, to the Hawkesbury; and although declining towards the sea at
the rate of only 100 feet per mile, or 1 in 52, or at an angle of about 1
degree with the horizon; yet it is traversed by ravines which increase in
depth in proportion as the sandstone attains a greater elevation, and
present perpendicular crags and cliffs of a very remarkable character.

A region consisting of a sandstone deposit of so great thickness and so
slightly inclined necessarily presents a monotonous aspect in all
directions; and when it is compared with European countries composed of
many formations and presenting great diversity of scenery it proves how
much geological structure influences pictorial and physical outlines.
(See Plate 10 Volume 1, also Plate 38 above.)

In the eastern part of Austr