of Nettleton Hill, Lancashire. 563 



the chalk, which is about two miles distant, runs eastward a 

 course of about six miles to the alluvial flat between the Wolds 

 arid the Humber. 



The chalk and chalk marl appear in mineralogical cha- 

 racter to pass into one another. In general, however, the 

 higher beds are whiter, harder, and contain a few flints ; and 

 the lower are softer, without flints, and of a dead white colour. 



The upper beds are remarkably destitute of organic re- 

 mains ; from the lower beds we obtained the following fossils : — 



Remains of fishes. Inoceramus Cuvieri. 



Turrilites undulata? Pecten quinquecostata? 



Terebratula subundata. O'strea semiplana. 

 Inoceramus cordiformis ? 



The Red Chalk is very similar to that found at the base of 

 the Yorkshire wolds. In the district represented by the 

 map, the average thickness will not exceed 6 ft. ; but, at a hill 

 near Stenigott, a few miles further south, it appears as a bed 

 of some importance, and cannot be less than 30 ft. thick. 

 The upper bed is generally of a lighter or yellowish red, and 

 the lower of an even dull red colour. These subdivisions are 

 generally very distinct, but the fossils are the same in both: 

 a few of the quartz pebbles of the inferior sands are scattered 

 through both beds. On the road side, at the western ex- 

 tremity of Thoresway Valley, the following section is seen : — 



White chalk marl. Deep red chalk, 4§ ft. 



Light red-coloured chalk, 14 ft. Thoresway sand. 



The fossils we obtained from the red chalk were, — 



Inoceramus . Terebratula biplicata. 



Terebratula subundata. Belemnites Listen", in abundance. 



The Thoresway Sand has been so denominated because it is 

 shown most distinctly in Thoresway Valley : it may be traced 

 beneath the red chalk near 



Roth well, and through all 

 the ramifications of Nettleton 

 Vale, as will be seen on re- 

 ference to the map. The 

 best idea of its composition 

 will, however, be given by the 

 annexed natural section at 

 Thoresway springs. Fig. 68. 



68 



a a, White chalk and chalk marl. 



b, Red chalk. 



c, Bed of highly ferruginous sand and sandstone, composed of 



grains of quartz, of various sizes ; in some places cemented 

 together, and in others loose, - - - - 4 ft. 



t t 2 



