the corallian rocks of england. 333 



2. The Pickering district. 



The separation between this and the district first described is 

 most simply made by the assistance of stratigraphical features, which, 

 though not quite accurately coinciding with a change of type in the 

 rocks, coincide sufficiently for the purpose. In going westwards 

 from Brompton we find the Corallian beds thrust up by an anticlinal 

 curve having its axis apparently a little to the west of Ebberston*. 

 The general dip of the beds is still southerly ; but this slight dome 

 makes them fall away both to the east and to the west, causing 

 the Lower Calcareous Grit to form the base of the hills, and even 

 bringing up the Oxford Clay to the surface near Allerston. These 

 beds are brought against the Kimmeridge Clay of the vale by a great 

 fault running nearly east and west. The upper limestones are quite 

 thrown out; and, as we have noticed, the beds beloware already putting 

 on the Pickering type. The openings in the Lower Calcareous Grit 

 are abundant ; and the country is eminently a sandy one. With the 

 fall of the anticlinal we enter on our Pickering district, which extends 

 for us as far as the neighbourhood of Helmsley (see Map, fig. 10). 



Throughout this range, as in the Scarborough district, the highest 

 beds occupy the lowest positions, and must be sought, for the most 

 part, at the edge of the vale. 



In the gorge of Newtondale, at the outlet of which lies the town 

 of Pickering, we obtain a complete section of all the Corallian beds 

 in this district ; and as the upper and most interesting portion is 

 magnificently displayed in the numerous quarries near the town, 

 we shall commence with a description of the formation as here seen, 

 with which we may afterwards more clearly compare the develop- 

 ment in other portions of the area. 



The general Corallian section on the meridian of Pickering, as 

 proved in the deep gorge of jNewtondale, is nearly as follows : — 



ft. 



Supva-coralline beds 20 



Upper Limestones 50 



Trigonia-beds and Middle Calc-Grit 45 



)' Lower Limestones 60 



\ including Basement- or passage-beds 30 



Lower Calc-Grit — 



205 

 The Lower Calcareous Grit can hardly be less than 100 feet thick. 

 Towards the top occurs the usual ball-bed series. Doggers of gritty 

 limestone in soft yellow calcareous sand, much as at Filey Brigg, are 

 succeeded by hard tables of similar rock. This series of impure lime- 

 stones has a thickness of about 30 feet. The commencement of the 

 calcareous series is well seen at the base of the S.E. angle of Blansby- 

 Park woods, close to the railway, where it is by no means fossilife- 

 rous — rather a contrast to this horizon in some localities. The cha- 

 racter of its upper portions and also of the oolites of the Lower 

 Limestones is not well revealed at this spot, though the beds may be 

 more clearly seen just on the other side of the river in Little-Park 



* A determination due to Mr. Fox Strangways. 



