WOOD AND HOME LINCOLNSHIRE AND S.E. YORKSHIEE. 171 



When all the circumstances thus analyzed are weighed in con- 

 nexion with this southerly- current hypothesis, they seem to us to 

 form a conspiracy of facts so much in conflict with it as to render 

 that hypothesis, if not impossible, yet in the highest degree im- 

 probable. 



One explanation of this seeming inconsistency offering itself to us 

 is suggested partly by the denuded and embossed condition of the 

 surface of the chalky, or basement, clay of Holderness, upon which 

 the purple clay rests, and partly by the circumstance of a scarp to 

 the chalk having been formed in this part prior to the deposition of the 

 purple clay, so opposite to what we see to have been the case in part of 

 Lincolnshire previously to the deposition of the chalky clay. We might 

 infer from this that, after the deposition of the chalky portion of the 

 Upper Glacial clay, under the conditions of a partial submergence only 

 in the north of England, an Intraglacial elevation of Yorkshire took 

 place — an elevation altogether prior to that general one which in- 

 troduced the Postglacial period — accompanied by the sweeping 

 off by denudation, during the process, of all the chalky clay from 

 that area, and followed by the erosion of the chalk edge into the 

 scarped condition in which we see it enveloped in the purple clay 

 at Speeton; the portion of the chalky clay remaining under Holderness 

 having been deeply denuded under shallow-water conditions, which 

 gave rise to the gravels marked h in the coast-section (fig. 1), and to 

 the intermediate bands of clay that seem in parts to take the place of 

 the beds h. After this it would then seem that the resubmergence 

 (which was so great as to cover the loftiest Wold- summits where 

 denudation-sands exist, and within about 150 feet of which summit 

 an outlier of the purple clay remains) was either too rapid to permit 

 of the accumulation of chalk debris from the Wold, or else that it 

 took place after an amelioration of climate had occurred, sufficient 

 to melt the glacier producing that debris, but not sufficient to 

 prevent the formation of floe-ice adequate to the transport of the 

 large blocks which abound in the purple clay. 



Another explanation offering itself to us is suggested by a peculiar 

 feature-presented by the northern scarp of the Wold itself ; for, if the 

 Ordnance Map be closely examined, it will be seen that the northern 

 scarp of the Wold coincides, even to sinuosities, with the strike of the 

 moorland ridge (whose lower continuation runs down through Scarboro' 

 into the sea at PileyBrigg, and is intersected by the section, fig. 13); 

 and that the denudation which has formed the northern scarp has taken 

 its direction from the resistance offered by the unyielding strike of this 

 Oolitic hard rock of the opposite side. It does not seem improbable, 

 therefore, when read by the light of Dr. Sutherland's description of 

 the shores of Greenland, that the sea was, during the period of the 

 chalky clay, kept out of the northern Wold-foot and vale of York by 

 a glacier fiUing this great depression, and that this, confined between 

 the ridge of the Wold and that of the moorlands, did by its forward 

 motion towards Malton, and thence round into the great depression 

 of the vale of York and so south towards Central Lincolnshire, 

 scarp the Wold, and impart this striking identity to the two sides 



