1847.] JUKES ON AUSTRALIA. 241 



Notes on the Paleozoic Formations of New South Wales 

 «/ic? Van Diemen's Land. By J. Beete Jukes, M.A., F.G.S. 



The PalcBozoic Rocks of the neighbourhood of Sydney, New South 



Wales. 



The county of Cumberland, in which the city of Sydney is situated, 

 and parts of the adjacent counties, are composed almost entirely of a 

 palaeozoic formation of great thickness and extent. The principal 

 materials of this formation are certain shales and sandstones, with a 

 few associated beds of coal. In the close of the year 1845 I made a 

 short excursion across a portion of this district, in company with the 

 Rev. W. B. Clarke. We carried with us a mountain barometer, and 

 by taking the means of the two sets of observations made in going 

 and returning, got such an approximate estimate of the heights of the 

 ground and the thickness of the rocks, as to enable us to construct a 

 section with a sufficient approach to accuracy to be relied on for my 

 present purpose. This section runs from Liverpool (a town just at 

 the head of the tidal waters of George's River, which falls into Botany 

 Bay) by a slightly winding line, first S.S.W. for about twenty miles, 

 through Campbelltown to Appin, and then about S.S.E. for about 

 eighteen miles to WoUongong in the lUawarra district. Wollongong 

 is on the coast about forty-five miles to the northward of Sydney. 



From Pariamatta by Liverpool to Campbelltown the country is low, 

 gently undulating, and composed (PI. VII.) almost entirely of (No .1) 

 black and brown shales, with a few thin interstratified beds of sandstone 

 in their lower portion. From Campbelltown to Appin the country rises 

 into bolder undulations, and on approaching the latter town thick 

 beds of (No. 2) sandstone show themselves, creeping out from beneath 

 the shales. Beyond Appin nothing but this thick-bedded sandstone 

 was to be seen for many miles, the ravine of the Cataract river show- 

 ing precipices 200 feet high entirely composed of it. It rose very - 

 gradually in a wide gently sloping plateau, furrowed 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 Bulli obliquely into the country, and 

 sweeps round the valley of lUawarra, 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 sandstone. These consisted of alternations of (No. 3) 

 thick beds of shales and sandstone, with some conglomerate, (No. 4) 

 shales with beds of coal, and lastly, of (No. 5) some beds of com- 

 pact 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, form- 



