IRONSTONE AND SANDSTONE. 95 



of the Gristhoi'p series, supplies large and durable blocks of stone 

 for the Scarborough piers. In more than one bed, however, we ob- 

 serve a mixture of the crystalline and oolitic structure. 



The very hard rocks, at the foot of the castle on the east side, 

 form the continuation of this series. They consist of grey calcareous 

 sandstone, pai'tly incrusted, partly intermixed, with portions of iron- 

 stone ; and contain numbers of shells, which, owing to the hardness 

 of the stone, it is very difficult to disengage or break off. 



Beyond the north sands, tlie ironstone and sandstone make a 

 conspicuous figure on the shore. The ironstone frequently covers 

 the sandstone, as a solid crust; and from this ferruginous coating, the 

 rocks in many places appear as if they had passed through the fire: 

 some striking instances of which may be seen beyond Scalby mill. 

 In other places, the ironstone is found in nodules, as on the Gris- 

 thorp shore; and a bed of this description is found in the face of the 

 clift", among the shale, in Burniston wyke. 



Before we arrive at Cloughton wyke, the extent of this series is 

 vastly diminished: for at the point on the south-east side of that 

 creek, we find nothing that can w ell be appropriated to it, except a 

 bed of rough sandstone, partly calcareous, immediately below the 

 shale; and a bed of hard calcareous sandstone, or coarse limestone, 

 incrusted or intermixed with ironstone, and abounding with shells, 

 like the rock at the foot of Scarborough castle. These beds also bear 

 a considerable resemblance to some of the harder strata at Filey 

 Bridge; and it is observable that, at each of these thi'ee places, there 

 are some of the same kinds of large shells; though the Filey rocks, 

 belong to a higher part of the strata. 



The ferruginous beds, having reached the upper end of Cloughton 

 Avyke, are discontinued with the strata over them; nor has their pro- 

 gress been traced any further along the shore. In the lofty Stainton 

 Dale cliff's, where the authors examined the whole series of beds with 



