348 
STATHER : A GLACIATED SURFACE AT FILEY. 
the directions of the striae at six points a few yards apart, are 
as follows :— (I.) N. 15°E., (11.) N. 15°E., (III.) N. lO^K, 
(IV.) N. (V,) N. 15^E., (VI.) N. 25°E.; giving a mean 
direction of N. 18°E. 
Two hundred yards eastward of the foregoing group, near 
the second " Doodle" (plate LV.), at four points twenty yards apart, 
the stride read thus :— (I.) N. 20^E., (II.) N. 30^E., (III.) N. 20°E., 
(VI.) N. 25'^E. ; mean direction N. 24°E. 
It will thus be seen that the general direction of the striae 
agrees closely with the direction noted on the south side of the 
Brigg by Mr. Lamplugh. It is also worth noting that the mean 
direction of the eastern group (2nd Doodle) is six degrees more 
to the east of north than the mean direction of the western group 
(Spa Nab). 
The striated surface is about 40 feet above high-water mark, 
and dips three or four degrees to the south-east. The overlying 
drifts are 70 feet thick, and consist of boulder-clays of the type 
usual on the Yorkshire coast (plates L. and LI.). 
Where the striae are seen there is a complete absence of the 
local rock rubble, which usually intervenes between the boulder- 
clay and the solid strata, and which is so abundantly developed in 
most of the adjacent sections. It is evident that for some reason 
or other the pressure of the ice-sheet at this place was sufficiently 
great to sweep away all the loose weathered material, and thus 
to reach the hard unbroken calcareous band on which the markings 
are preserved. 
Further evidence of the exceptional pressure exerted in this 
locality is furnished by the sections a few yards to the west of the 
striated surface (plates LIV. and LV.), where the beds are super- 
ficially contorted to a depth of eight feet. 
The reason for the extra pressure at this place may, I think, 
be readily explained. The high ridge formed by the Middle Oolites 
to the north (plate LVI.), which would necessarily constitute a 
barrier to the movement of the ice, sinks down at this point low 
enough to permit access to the wide pre-glacial depression of the 
Vale of Pickering. And the great mass of the drift deposits which 
