342 
DURNFORD I DEEP BORING NEAR SELBY. 
depths of 2,170 feet and 2,200 feet — showed distinct evidence 
of faulting. The cores obtained from the depths named were 
of a very crushed and dirty nature, and were very distinctly 
slickensided. The cores obtained from lower depths were 
sounder, but the apparent dip of the strata, which in the Coal 
Measures had steadily increased with the depth of the hole, 
was so high — as much as 70° to 80° — that a great deal of boring 
had to be done to prove very little thickness of strata, and 
as it seemed likely that further boring would only deepen 
the disappointment felt at not proving workable coal seams, 
operations were discontinued when a total depth of 2,371 feet 
had been attained. 
A rough survey of the hole was made, which proved a 
deviation of about 12° from the vertical near the bottom. 
Assuming that the deviation took place in the same direction 
as the dip of the strata — and to a practical man this 
seems most reasonable — the high inclination of the strata as 
shown in the cores would thereby to some extent be explained. 
As, however, the apparent dip was as high as 70° at depths 
where the proved deviation of the hole was only 12°, it is evident 
that the actual dip at that point would be 58 degrees. A some- 
what perplexing feature already mentioned was the increase 
of the apparent dip as shown in the cores with the depth of the. 
hole. Two explanations offer themselves, viz. : — (1) That the 
deviation of the hole in the line of the dip increased rapidly 
with the depth of the hole, and that the actual dip of the strata 
was constant, or (2) that the strata were folded, and that the 
hole went down through the limb of an anticlinal or monoclinal 
fold. The first explanation is not in accordance with the observed 
facts, inasmuch as near the top of the Coal Measures, where 
the hole was nearly vertical, the dip shown in the cores was only 
slight. The second theory is probably correct. The diagram 
(Fig. 2) has been prepared to illustrate the effect of an anticlinal 
fold on the dip of the strata as observed in the cores from a bore- 
hole, and the effect shown is very much in accordance with 
the observations made at Barlow. Professor Kendall, in his 
report to the Coal Commission, expounds his opinion on the 
question of northern boundary of the coalfield, and demonstrates 
