NEWCASTLE COAL REGION. A77 
fault or subsidence, from A to E, is about fifty feet. Between Nobby 
Island and the shore (E) there is a fault of fifty or sixty feet, for this 
must have been the case whether the lower layer be number II. or 
number V. The character of the rock in the lower layers of Nobby 
(which must have been a fine clay before baking) inclines me to 
believe that the lower bed is probably number II. The dike inter- 
secting this island has produced a dislocation not exceeding three 
inches. 
Interesting examples of faults are brought out in the excavations of 
the coal pit, which have uncovered them laterally for three or four 
hundred yards. The following cut (figure 1) is a ground-plan kindly 
Fig. 1. Fig. 2. 
\i 
G 
A m | | 
at i B A 
, Ja r 
G HY _B 
fs G arcs 
furnished by Mr. J. Steel. It appears from the figure that in the 
short space of two hundred and sixty yards there are five faults fol- 
lowing the same course, that is, curving around gradually from a 
north-northwest to anorth direction. Along the transverse line A B, 
figure 2, (running east-northeast,) these faults are as follows :— 
1. E. : = = - - - 6 feet. 
2. F.—180 yards to the westward = c - 10 feet. 
3. G.—50 yards farther west = : - 2 feet, 
4,H.—20 “ es s - - - : 1 foot. 
5. 1—10 <“ $f Lae - - - - 1 foot. 
The rock here falls to the westward by a series of dislocations, and 
the inconvenience arising from water collecting in the natural basins 
thus formed, has prevented farther mining in that direction. Two 
hundred and fifty yards to the southward, along the line C D, the 
faults E and F cause a displacement of only a foot each. The other 
faults have not been exposed on this line. The rock at this place has 
a slight dip to the westward or northward and westward. 
ILLAWARRA Coat Districr.—The most convenient and instructive 
120 
