360 MR. J. R. DAKYNS ON THE LIMESTONE-KNOLLS [Aug. 1 899, 



nearly everywhere alike the limestone is an amorphous 

 mass without a trace of bedding. 



On Keal Hill I was equally unsuccessful : at the northern end I 

 measured at the foot of the hill dips varying from 10° to 30°, mostly 

 towards the south-south-west, and at the southern end conflicting 

 dips of 45° north-eastward into the hill and of 35° south-south- 

 westward. The last-mentioned dip would take the limestone 

 naturally below the shale, which is to be seen on that side dipping 

 southward and extends all along Stanton Beck, the boundary of the 

 hill on the east side. On the main mass of the hill, however, I 

 found no measurable dips at all. 



I therefore considered that, owing to the amorphous character of 

 the limestone, it was quite uncertain whether the abrupt and detached 

 character of these remarkable hills, Keal Hill, Elbolton, and Stebden 

 Hill, was due to faulting or to a quaquaversal structure : but when 

 subsequently Mr. Tiddeman propounded his view that the limestone 

 had been originally formed in the shape of mounds or knolls, and 

 pointed out that the overlying shale contained fragments of lime- 

 stone after the same fashion as it does in the Clitheroe and Slaidburn 

 country, I readily accepted his idea as offering a simple and satis- 

 factory explanation of the evidence seen on the ground. 



I have not examined the limestone-knolls about Thorpe Fell 

 since the time when I was engaged there in my official work 

 for the Geological Survey ; but I have seen south of Grimwith 

 E-eservoir (east of the River Wharfe), on the same horizon as 

 near Thorpe Fell, shale similarly containing fragments of limestone. 

 About these there can be no doubt that they fell into the sea, 

 and were embedded in the shale while it was being deposited ; 

 for beyond having a northerly dip, conformable to the limestone 

 below and the Millstone Grit above, the shale is quite undisturbed, 

 and thus there can be no question here of faulting or crush- 

 brecciation. The idea, then, that the limestone-fragments in shale 

 near Thorpe Fell had fallen into the water from some reef or 

 shell-mound, and had thus become embedded in shale which was 

 being deposited round and over the mounds, seems quite reasonable. 

 This idea, too, affords a simple explanation of the geological features 

 of the country, and relieves us of the necessity of supposing either 

 faults or a quaquaversal doming-up, for which there is little or no 

 evidence. 



We have, moreover, independent evidence that the surface of the 

 limestone underneath the overlying shales and grits is uneven. 

 On Simonseat, a Millstone Grit fell on the east side of the Wharfe, 

 there are some swallow-holes, which show that limestone is 

 present at no great distance below the surface : but below Thorpe Fell 

 is a thickness of at least 450 feet of shale overlying the limestone, 

 and there may be in places much more ; and nearly 1200 feet 

 of sandstones and shales occurs between the base of the Kinder 

 8cout Grit and the top of the limestone. It does not seem possible 



