ANNIVERSARY ADDRESS. 47 
The respective depths of these bores being seven hundred and 
thirty seven feet and four hundred and thirty-four feet.'| That 
the coal-measures improve in quality, at all events with respect 
to the top seam, is proved by the Liverpool Bore and by the Cre- 
morne Bores,? the latter on the shores of Port Jackson. (Plate 3.) 
The question here suggests itself, as the seams in the Cremorne 
Bores are dipping westerly, whereas the dip of the same seams in 
the Blue Mountains is easterly, so as to form a basin, ‘ where is 
the centre of the basin situated’? Probably, I think, in the 
neighbourhood of Parramatta. 
As the seams are rising seawards from the Cremorne Bores at 
the rate of one hundred and ten feet per mile (see diagram 1 of 
Plate 2), it is obvious that, if these dips continue for many miles 
seawards, the coal-seams must outcrop, unless covered unconform- 
ably by newer formations, in the continental shelf. Obviously, 
as the top coal-seam at Cremorne is about 2,850 feet below sea- 
level, and it is rising easterly at the rate of one hundred and ten 
feet per mile it should cut the surface of the sea, if its outcrop 
were produced, at a distance of twenty-five and three quarter miles 
east of the Cremorne Bore, [on the assumption that its inclination 
is uniform between these points| that is about twenty-three miles 
east of the entrance to Port Jackson. At this spot, however, 
according to the Challenger Reports,® the depth of the ocean is 
one hundred and twenty fathoms. This would therefore bring 
the outcrop six and a half miles nearer the coast, (if the depth at 
this second locality be the same as at the first), i.e., to sixteen and 
a half miles from the coast. The depth of the ocean, however, 
1 Annual Report ie: of eis 1884, p. 180. By Authority, 
Sydney, 1885. Loe. cit., 1885, p. 1 
2 For further description of the es Bore see Journ. Roy. Soc. 
N.S. Wales, Vol. xxvit., 1893, “‘ Notes on the Cremore Bore,” by T. W. E. 
David and E. F. Pittman, pp. 443 - 465. Also see, Records Geol. Survey 
N. 8. Wales, Vol. rv., pt. i, p.1-7, by E. F. Pittman, Government 
Geologist and T. W. E. David. 
3 Challenger Reports—Narrative of the Cruise, Vol. 1., part 1, p. 463, 
pl. 26. 
os 
