3 8 Sedimentary Formations 
and 3,450 feet on the Blue Mountains; the lowest two stations 
and the highest being in the Hawkesbury, and the others in tho 
Wianamatta beds above the Hawkesbury ; whilst at Newcastle, 
tho Urosthcncs was the deepest below the sea. 
As necessary to explain still further the succession of strata, I 
introduce here some additional remarks on tho Supra-earbon- 
iferous rocks in the province of New South Wales. 
Over the uppermost workable coal measures of that Colony, is 
deposited a series of beds of sandstone, shale, and conglomerate, 
oftentimes concretionary in structure and very thick-bedded, 
varying in composition, with occasional false-bedding, deeply 
excavated, and so forming deep ravines with lofty escarpments, 
to the upper part of which scries I have given the name of 
Hawkesbury rocks, owing to their great development along the 
course of the river-basin of that name. These beds are not 
less in the coast region than from 800 t:o 1,000 loot in thickness, 
containing occasional patches of shale, with fragments of 
fronds and stems of ferns, a few pebbles of porphyry, granite, 
or slates, and assume in surface outline the appearance of 
granite, from the materials of which and associated old deposits 
they must in part have been derived. On the summit of the 
Blue Mountains, as along the Grose Biter, the thickness of the 
series is very much greater. Patches of very small area contain 
coal, carbonate of iron, and other representations of miniature 
coal measures. 
Towards the base, patches of purple shales are frequent, and 
many ferriferous veins, with specular iron, haematite, ilmenite, 
graphite and other minerals, sometimes occur. 
In places, as about the “Yellow rock,” near the Upper'Wollombi 
Biver, in Ben Bullen and above tho deep excavation of tho 
Capcrtee amphitheatre, salt and alum are found in cavities 
formed by decomposition, and in other places, as at Bundauoon 
Creek in the Shoalhavcn District, at A ppm, and on the Bullai 
escarpment of tho Ulawarra, and at Pittwatcr, north of Sydney, 
stalactites have been formed under similar circumstances. 
There is an enormous mass of brown iron ore highly carbonised, 
partly worked at Pitzrdy, near Nattai, another on Brisbane 
Water, and a smaller, on the coast, a few miles north of Sydney, 
and other similar patches in intermediate localities. These are in 
part associated with specular iron, which occasionally lines the 
joints of the sandstones close at hand with well-formed crystals. 
The uppermost beds of this formation, especially where they 
become conglomerates, exhibit isolated summits imitating ruined 
castles, and have thus been traced by me at intervals all along 
the escarpments to the westward of Sydney, from the latitude.of 
the Clyde Biver to that of the Talbragar, and in certain localities 
within the longitudes of that line and the coast. In the deep 
