32 NOTES ON THE OANNOOK CHASE COALFIELD 
connected with a search for coal would be confined to questions as 
regards workable depth, &e. 
The Triassic Rocks may rest on Permian, on True Coal Measures, 
or on the barren rocks of Lower Coal Measures, or on older 
rock, A very interesting example of this was proved at the Fair 
Oak Colliery where—about 35 years ago—a very large amount of 
money was wasted owing to the unconformity of the Coal Measures. 
The No. 1 pits at Fair Oak were sunk through the Bunter Beds 
to the Coal Measures, and the owners expected to find the same seams 
as were being worked at adjoining Collieries. After passing through 
300 feet of Bunter Conglomerates the shaft entered the Coal Measures, 
another 450 feet failed to prove any seam of coal over 3 inches thick, 
and the proof was continued by means of a borehole to a depth of 
1,000 feet without success, and the undertaking was abandoned. 
Afterwards pits were sunk 800 yards distant and the seams of 
coal were found of normal thickness, and in the usual sequence. 
This and other evidence go to prove the existence of a ‘ Wash 
Out” or denudation of the Coal Measures over an area the extent 
of which is not yet exactly ascertained. The probable explanation 
being that at this spot the Coal Measures were elevated above the 
surrounding district, and were thus particularly subject to the 
denuding influences which took place before the Bunter Beds were 
laid down, and consequently the Coal Measures were here removed to 
below the lowest workable seam. 
FOSSILS OF THE COAL MEASURES. 
There are two kinds of collectors of fossils—those who collect 
with a view to forming as large and as perfect a collection as possible 
without regard to the particular stratum in which the fossils were 
found, and those who collect in order to identify certain fossils with 
certain beds of strata which may be perhaps traced over large areas. 
It is in this latter way that horizons or zones may be established. 
In this light the fossils of a district carefully collected and marked 
become of great geological interest, and it is singular how very little 
