﻿456 ME. E. H. EASTALL ON THE [Aug. 1905, 



the Wain stones, on Hasty Bank, there is an interesting exposure 

 of the Dogger, which is here very different from its eastern develop- 

 ment. The section is as follows : — 



Thickness in feet inches. 

 Massive sandstone, very thick. 



Ferruginous, thinly-bedded, dark shale 20 



Shale, with ferruginous nodules 5 



Flaggy ironstone, with shaly partings 2 



Irregular nodular ironstone 1 



Blue shale 3 



Ironstone-doggers, with scaly coats 2 



Shale, with belemnites and pebbles 2 



Liassic shale below. 



Here a thickness of about 25 feet, of rather variable shaly beds, 

 comes in between the usual nodular ironstone with scaly coats and 

 the massive sandstone above, whereas in most of the eastern sections 

 the Dogger ironstone is immediately succeeded by sandstone. 



It is evident, on the most casual inspection, that the distance 

 between the line of old workings (indicating the Jet-Rock), and the 

 escarpment of the Estuarine Sandstone varies greatly in this district, 

 and in the small valley which runs down the west side of Hasty 

 Bank into Bilsdale this is very clearly seen. In one place sandstone 

 in situ may be seen within 30 or 40 feet of the Jet-llock, and this 

 sandstone must lie in an eroded channel in the shale of the com- 

 munis-zone, which is usually at least 100 feet thick. This trough 

 is evidently of considerable length, as it can be seen also in Raisdale, 

 on the other side of Cold Moor, more than a mile to the south-west. 



In connection with the Pebble-Bed with rolled belemnites, at the 

 base of the Dogger at the Wainstones, Prof. P. F. Kendall l has 

 published an interesting and important note. He has observed a 

 very strong resemblance between the pebbles at the Wainstones 

 and the Middle Liassic ironstone of Kildale, and from this he 

 draws two conclusions : 



' (1) That, as there was an extensive denudation of the Lias during the 

 deposition of the Dogger, it is not improbable that the Dogger ironstone may 

 have derived much of its material from the denudation of the Middle Lias- 

 ironstone,' 



According to my view, denudation of the Lias took place before 

 the formation of the Dogger, during the period when the only beds 

 deposited in this neighbourhood were those of Blea Wyke, and 

 possibly some of the ironstone of Glaisdale. 



Prof. Kendall continues : — 



' The other reflection is that, as the lowest horizon of the Lias to which the 

 Dogger erosion-plane has cut in the Cleveland area is still above the Jet-Eock, 

 there must exist elsewhere some old axis of disturbance, along which the Lias 

 was folded and denuded before or during the Dogger time, actually down to 

 the Lower Lias. As the Upper Lias is practically intact right down to the 

 Humber, except for pre-Cretaceous erosion on the Market-Weigh ton anticline, 

 I think that the source of the Lower and Middle Lias debris in the Dogger 

 must be sought to the north of the Cleveland area, perhaps on some of the 

 folds which can be shown to have been produced in pre-Permian times, and 

 accentuated by subsequent movement.' 



x ' The Naturalist ' 1902, p. 216. 



