A GLACIATED SURFACE AT FILEY. 
BY JOHN W. STATHER, F.G.S. 
Notwithstanding the enormous development of glacial deposits 
in East Yorkshire, glaciated rock surfaces were until recently com- 
paratively quite unknown. The chief reason for this is no doubt the 
lithological character of the Secondary strata, which constitute 
the solid geology of this part of the county. The soft shales and 
sandstones, of which the Jurassic rocks chiefly consist, could not 
be expected to stand sufficiently firm under the pressure of the 
ice-sheet to i*eceive such markings, nor yet to preserve them if 
by any accident such impressions had been made. The same 
remarks apply to the Cretaceous rocks, although some of the 
indurated layers of the Chalk with flints might possibly have 
taken strife, had the local conditions of glaciation been favourable. 
Almost the onl}^ rocks on which there was any probability 
of these markings being preserved are the harder limestones of 
the Middle Oolite, and the ironstone bands of the Lower Oolite 
and Lias ; and it is precisely on these rocks that such markings 
have at length been found. 
The first discovery was that recorded by Mr. G. W. Lamplugh 
in the "Proceedings" of this Society in 1891,-"" w^here he mentions 
that the highest bed of the Oolite series of Filey Brigg showed 
glacial striations having a direction N. 20°E, These markings 
occurred at the south side of the Carr Naze, at the spot where 
the solid rock disappears from the coast line under the drift, 
a few yards to the left of the section in plate LI. 
In 1896 Messrs. Sheppard and Muff recorded in the Glacialist's 
Magazine! similar striations on a surface of Estuarine Sandstone 
exposed in a quarry north of Robin Hood's Bay, the direction 
of the striations being given as due north and south. 
* Vol. XL, Part iii., page 401. 
+ Sept., 1896, pages 52, 53. 
