NEWCASTLE COAL REGION. A75 
12 inches.—Bad coal. 
18 inches.—Good coal. 
ie taches.“tiietd of stone. Coal bed, worked; 4 feet 13 inches thick. 
18 inches.—Good coal. 
Below, hard blue stone. 
In this section, the two layers of coal are separated by fifty feet six 
inches of rock; they correspond to numbers IV. and V. in the first 
section. The lowest affords the best coal, and is at present the only 
one explored, excepting the small workings on Telegraph Cliff. 
The island of Nobby is capped by a layer of conglomerate eighteen 
feet thick. Below this there are two layers of coal, separated, accord- 
ing to estimate, by fifty-five feet. The view on page 511 shows their 
positions. The upper coal bed, with its shales, is eight feet three 
inches thick, and consists as follows :— 
18 inches.—Coal. 
18 inches.—Argillaceous shale. 
12 inches.—Coal. 
36 inches. 
Argillaceous shale, in part arenaceous. 
15 inches.—Coaly shale. 
The lower coal bed, which is near the water’s edge, is nearly eleven 
feet thick, and contains as follows :— 
15 inches.—Coal. 
20 inches.—Clay, indurated. 
23 feet.—Coal. 
8 inches.—Indurated shale. 
5 feet.—Coaly shale. 
The two layers in Nobby are separated by the same interval nearly 
as the layers I. and II., and also layers IV. and V. It is uncertain to 
which they correspond. The whole island of Nobby has been altered 
by the action of heat from a basaltic dike which intersects it; but we 
reserve our remarks on this subject for a following page. 
The coal of the beds we have been describing is of the bituminous 
kind, and the best of it is of fair quality. It is evident, however, from 
the facts, that it is quarried with considerable difficulty on account of 
the thinness of the beds, and the very soft nature of the rocks asso- 
ciated with it. It is, however, quite extensively worked, and is of 
great value to the country.* 
* The principal explorations at Newcastle are carried on by sinking shafts. Large 
excavations have been made in the cliffs; but the difficulties arising from the thinness 
