180 PEOCEEDIXOS OF THE GEOLOGICAL SOCIETY. 



infer that the Prse- and Intraeglacial countryTvas farrowed bya yallev- 

 system of its own, the present valley- system of the south has but 

 little connexion with that prior state of things, but is essentially of 

 Postglacial origin. To the north of Flaniborough, however, the con- 

 traiy stmcture prevails ; and we may find evidence of this in all di- 

 rections, a series of conspicuous examples meeting us immediately 

 north of that point along the coast towards Filey. 



The cliffs of Glacial clay, moreover, which extend north from 

 Piley along that part of the coast-section, instead of being, like 

 those of the south, sections of a solid clay sheet, which can with no 

 more justice than the older Tertiaries be called a superficial deposit, 

 are but the face of a coat of the purple clay which envelops the ancient 

 Oolitic ridge running from the moorlands out to Fileybrigg (which, 

 as before observed, seems to have induced the direction of the erosion 

 giving rise to the northern 'VVold-scarp), a similar coat covering the 

 inland slope of the ridge, as shown in the following approximate sec- 

 tion, fig. 13. The coast, moreover, north of Flamborough intersects 



Fig. Id.—Section of Gristhorpe Cliff. 



S.W. Stone-pits on top 'IS.'E. 



Inland slope. of Q-ristiiorpe Cliff. 



Inland. 



1. Kelloway rock. I 3. Calcareous grit. 



2. Oxford clay. | c. Purple clay. 



This section is intended to represent G-risthorpe Cliff intersected at right angles 

 to its sea-face. The beds 1, 2, and 3, free from any facing of c, present a mural 

 precipice in the cliff a short distance from this point. 



deep vaUeys, and shows them filled with the purple clay and partially 

 reexcavated * ; so that what forms an extremely rare exception in 

 the country south of Flamborough, becomes the rule north of it. 



In conclusion, we should mention that, although the extreme west 

 of Lincolnshire falls within the title of this paper, we do not here 

 intend to describe it, except at the parts touched by figs. 4 and 5. 

 This part .may be more conveniently considered in connexion with 

 the structure of the great valley of the Trent. 



^e desire to express our obHgations to E. H. Clarke, Esq., the En- 

 gineer of the Grimsby Docks, and to W. Allen, Esq., the late Engineer 

 of the Hull ^est Docks, for much valuable information and assist- 

 ance. Our thanks are also due to T. Dale, Esq., the Engineer of 

 the Hull Waterworks, to A. Atkinson, Esq., the Engineer of the 

 Ancholme Xavigation, to George Simpson, Esq., of !N'orth Burton, 



* Strictly speaking, two of these ralleys, by crossing the Cape of Flamborough, 

 come out also immediately on the south side between the Head and Bridlington, 

 and are filled with beds of hard chalk debris below the purple clay. See South 

 Sea and Danes Dvke in fig. 1. 



