ALLUVIAL COVERING. 21 



among- a vast variety of stones washed down from the alhivial part of 

 the cliffs. Masses of the encrinite limestone, mountain lithestone, 

 white limestone; Avith various kinds of basalt, and even lava, have 

 been disengaged from the alluvium near Whitby. Agates, carnelians, 

 amethysts, calcedonies, and a great variety of jaspers and jasper- 

 agates, with various other precious stones, are found on the beach 

 all along the coast; and are sometimes picked up on the moors, 

 where the surface is laid bare.* 



Yet, while the alluvium presents a promiscuous assemblage of 

 all kinds of rocky fragments and nodules, it must be remarked, that 

 a large proportion of them belong to the rocks of this district ; such 

 as chalk, flint, blue limestone, grey limestone, sandstone in all its 

 varieties, aluminous schistus, coal, &c. Some also belong to ad- 

 joining districts. In the Whitby cliffs we find masses of.magnesian 

 limestone, such as occurs at Sunderland, and in other parts of the 

 county of Durham: and in the Holderness cHffs we often perceive 

 fragments of coal, of the same kind that is found in the neighbourhood 

 of Leeds. 



One thing more remains to be noticed, respecting these stones 

 imbedded in the alluvium; and that is, that the fragments which 

 abound most in any particular quarter of the district, generally be- 

 long to the rocks of that quarter. Thus, though we find aluminous 

 schistus in the Holderness alluvium, and chalk and flint in the 

 Whitby alluvium; yet the schistus is much more abundant in the 

 latter, and the chalk in the former. In some parts of the alluvial 

 <:lifrs between Whitby and Sandsend, fragments of schistus occur in 

 great numbers, and serve to deepen the colour of the lower beds of 

 clay, in which they are most abundant. On the other hand, the 



* A variety of the minerals belonging to the alluvial beds, though not described as siich, 

 are enumerated in the Scarborough Catalogue of Fossils. 



