of the North Side of the Vale of Pickering. 247' 



ing almost as many feet, it continues by Wretton and Aislaby 

 on the long slopes of the same sandstone series to Pickering. 



It thus appears that from Helmsley to Pickering the effects 

 of denudation on the dipping edge of the oolitic series are 

 scarcely at all observable ; the beds declining regularly, and 

 almost without interruption, into the Vale of Pickering. The 

 denudation of Helmsley appears to be connected with the for- 

 mation of the valleys about that town ; but from Pickering east- 

 ward, a more extensive operation of similar causes has pro- 

 duced a long range of escarpments crossing the direction of 

 the little existing valleys, but parallel to the general line of the, 

 great Yale of Pickering. 



The valley descending to the south by the town of Picker- 

 ing, presents good opportunities of observation. The strata 

 on the western side are much lower than on the eastern, and 

 slope south into the Vale of Pickering, without presenting any 

 escarpment. On the eastern side calcareous grit is quarried 

 beneath the limestone, a thin covering of the upper sandstones 

 mixed with clay lies above that rock, and the whole series, 

 sloping south into the Vale of Pickering, has been subjected to 

 denudation parallel to the range and on the declining side. 

 The effect of this denudation becomes extremely evident as 

 we proceed further toward Scarborough. Before reaching the 

 village of Thornton we cross a hill which appears to me to be 

 formed of the Oxford clay. At Allerston, springs issue from 

 the top of it, beneath the calcareous grit which is found on all 

 the little risings to Ebberston, while the clay fills the valleys. 

 At Ebberston, as at Allerston, springs issue from beneath the 

 calcareous grit, and flow southward over the Oxford clay, in 

 which stratum Mr. Vernon and myself found Mya. V-scripta, 

 and a peculiar ammonite as at Scarborough (see section C). 

 At Parson's Houses, between Ebberston and Allerston, a well 

 was sunk twenty-one yards through the clay of Ebberston to a 

 brown freestone rock, which I suppose to be Kelloways stone. 



Above the line of springs at Ebberston, calcareous grit in 

 its usual characters with calcedonized ammonites occupies a 

 good height in the hill, and is surmounted as usual by the 

 coralline oolite, here full of Ostrece in the lower part, and of 

 Melanice and TurriteLlce at the top. This escarpment, showing 

 calcareous grit and coralline oolite, is very distinct above and 

 north of the village of Snainton ; and I think may be traced, 

 though less evidently, by Brompton and Wykeham to the old 

 Tower at West Ayton. After this, the long slopes of calcareous 

 grit, descending from Falsgrave Moor and Oliver's Mount, are 

 covered by parallel beds of oolite at Seamer, sloping down into 

 the Vale of Pickering without any denudated edge. 



Between 



