Jukes on Australia. 
377 
in every direction by innumerable winding and precipitous ravines, 
and covered by a forest of gum-trees, till on approaching the 
coast it ended in an abrupt escarpment 1200 feet above the sea. 
This bold escarpment stretches from the sea-cliffs of Built obliquely 
into the country, and sweeps round the valley of Illawarra, uniting 
towards the south with some lofty ranges which come out of the 
interior of the country, and which are, according to Mr. Clarke, 
composed of volcanic and other igneous rocks. In descending this 
escarpment between Mount Kerar and the Hat Hill of Captain 
Cook, we get the lower beds coming out from beneath the sand¬ 
stone. These consisted of alternations of thick beds of shales 
and sandstone, with some conglomerate, shales with beds of coal, 
and lastly, of some beds of compact sandstone with calcareous 
concretions. These latter beds rose from the foot of the hills into 
a gently undulating country about the town of Wollongong. To 
the southward these latter rocks were cut off by a strong band of 
igneous rocks, principally greenstones, forming a tract of country 
two or three miles wide, to the southward of which again were 
other sandstones of a dull red color; but our time did not permit 
of our working out. their relations with any approach to accuracy. 
I will now briefly describe this section in an ascending order, and 
glance at the extension of the rocks over the adjoining district, 
and at the position in which they now repose. 
5. The lowest group of rocks, the Wollongong sandstones, are 
commonly thick-bedded, fine-grained, and either dark grey or 
reddish brown. They are often slightly calcareous, and contain 
many concretionary calcareous nodules, from two inches to two 
feet in diameter, which when broken open commonly disclose a 
fossil shell. Beds two or three feet in thickness often exhibit 
concentric bands of color, or sections of spheroidal coats, and the 
rock has more or less a tendency to decompose along these colored 
coats. This concretionary structure in one place exhibited itself 
on a much larger scale. A portion of the beds, twenty feet high 
by thirty feet long, and consisting of six or eight beds, exposed 
in the face of a cliff, showed on each side the colored edges of 
concentric coals enveloping the whole mass. The lines of lamina¬ 
tion of the beds passed through the enveloping coats without 
VOL. in. NO. V. 2 b 
