396 NORTHERN OUTCROP, CUMBERLAND COAL FIELDS—GILPIN. 
remain practically unaltered, be reasonable ground for expecting 
to find the different seams better adapted for the miner’s work 
than at the Joggins. 
I have already spoken of the Ragged Reef sandstones forming 
the upper cover of the Productive Measures. This sandstone, 
occurring in massive beds, overlaid by red and gray shales and 
sandstones, has been traced into the eastern district. From the re- 
port of Mr. McOuat, already quoted, it appears that it crosses the 
Macean River below Athol, and strikes the Little Forks River 
about a mile below the Styles Brook, and follows the course of 
the river to a point about a mile beyond the post road. 
The vertical thickness of Productive Measures between the base 
of this sandstone and the Millstone Grit is, at the Jogoins, 4757 
feet; at the Styles Brook, 4500 feet, equivalent at the latter 
place to an interval of about a mile, measured horizontally. From 
the course of the conglomerate, which turns to the south about 
three miles beyond the Styles mine, it would at no great distance 
run under the sandstone. This is accounted for by the officers 
of the Survey on the supposition of a great fault, an upthrow to 
the east, probably of several thousand feet. There are other me- 
thods by which this apparent obliteration of the Productive 
Measures can be explained, but the discussion would make this 
paper too long. 
This district affords a capital illustration of the principle that 
Nature never yields her secrets to the efforts of individuals con- 
fined to limited districts. | Explorations had been carried on for 
years in ignorance of the fact that to the north of the Productive 
Measures the line of the Millstone Grit had been drawn clearly 
and distinctly ; and that to the south an equally distinct barrier 
defined the area in which the prospector would legitimately exer- 
cise his skill and perseverance. 
The work of the Geological Survey in this coal field, for some 
unexplained reason, was left incomplete, but so far as it has been 
carried in the Northern district, useful hints have been given to | 
the prospector, which I have endeavored to place plainly be- 
fore you. 
We have seen that at the Joggins, the workable seams and the 
