GEOLOGICAL FEATURES.

If we strike a line to the N.W. from Sydney to Wellington Valley, we shall
find that little change takes place in the geological features of the
country. The sand-stone of which the first of the barrier ranges is
composed, terminates a little beyond Mount York, and at Cox's River is
succeeded by grey granite. The secondary ranges to the N.W. of Bathurst,
are wholly of that primitive rock; for although there are partial changes
of strata between Bathurst and Moulong Plains, granite is undoubtedly the
rock upon which the whole are based: but at Moulong Plains, a military
station intermediate between Bathurst and Wellington Valley, limestone
appears in the bed of a small clear stream, and with little interruption
continues to some distance below the last-mentioned place. The accidental
discovery of some caves at Moulong Plains, led to the more critical
examination of the whole formation, and cavities of considerable size were
subsequently found in various parts of it, but more particularly in the
neighbourhood of Wellington Valley. The local interest which has of late
years been taken in the prosecution of geological investigations, led many
gentlemen to examine the contents of these caverns; and among the most
forward, Major Mitchell, the Surveyor-General, must justly be considered,
to whose indefatigable perseverance the scientific world is already so
much indebted.

The caves into which I penetrated, did not present anything particular to
my observation; they differed little from caves of a similar description
into which I had penetrated in Europe. Large masses of stalactites hung
from their roofs, and a corresponding formation encrusted their floors.
They comprised various chambers or compartments, the most remote of which
terminated at a deep chasm that was full of water. A close examination of
these caves has led to the discovery of some organic remains, bones of