52 W.S. GRESLEY—CLAY-VEINS INTERSECTING COAL MEASURES. 
veins are younger, as they seem to be, than the clay-veins and the exist- 
ing topography, and they bear no relation to one another, the clay-veins 
cannot possibly be very modern formations. 
ALLIED PHENOMENA IN OTHER REGIONS 
NOVA SCOTIA 
Figure 18* is a plan showing numerous masses of shale encountered 
some 30 years ago in mining the *‘ Block House” seam of coal at Cow bay, 
Figure 18.—Plan of Shale Masses in ‘Block House Coal Seam. 
Cape Breton island, Nova Scotia. Figure 19 is a vertical section across a 
fair sample of one of these masses. 
A comparison should be made of fig- 
ure 18 with figure 7 (page 40), which 
is a plan of part of the most promi- 
nent clay-veins in the Florence mine. 
From Mr Rutherford’s reference 
to these formations, it seems that in 
every case noted they did not ex- 
tend beyond the coal bed and its 
roof. They probably owe their ori- 
gin to currents of water channelling 
out the coaly material as soon as it 
had accumulated, which gaps or 
wants speedily became filled with 
Figure 19.—Vertical Section of Shale Masses in 
“* Block House”? Coal Seam. 
One-sixtieth natural size. 
* Copied from Trans. Nova Scotia Inst. of Nat. Sci., 1868-"69, vol. 2, pl. 3, kindly furnished by Mr 
John Rutherford, M, E,, of Stellarton, Nova Scotia. 
