14 BAKERS NORTH YORKSHIRE. 



limestone, which in the Havves district attain a thickness of 430 

 feet, are only augmented to 150 feet, whilst towards the east 

 they are diminished to 30 feet, and towards the south and 

 south-east vanish altogether ; and in like manner the non- 

 calcareous beds below the middle limestone, which at Hawes 

 are 350 feet in thickness, in Coverdale are reduced to 150 feet, 

 and towards the lower part of Wharfedale, in a south-eastern 

 direction, cease altogether; a state of things plainly pointing to 

 the conclusion that in this district at this particular epoch the 

 deep sea was towards the south-east and its shores towards the 

 west and south-west. 



At the west end of Penhill we have the Yoredale Rocks 

 from 600 to 700 feet in thickness, with all the principal beds 

 of the Hawes section present, but the grits and plates above 

 the Middle limestone much reduced in thickness. On the 

 Coverdale side of Penhill the Main limestone has sunk to 1,100 

 feet above the sea-level, and the Hardraw limestone ranges from 

 the end of Bishopdale past West Witton and dips beneath the 

 surface in the bed of the Yore near Bolton Hall. By the time 

 we reach Middleham Moor the Main limestone has declined 

 to 850 feet, and at East Witton to 400 feet above the sea-level. 

 Here it is extensively quarried, and is about 20 feet thick. It 

 may be traced along the whole length of both sides of Cover- 

 dale, in the lower part of the dale forming a terrace, on the 

 surface of which the high road is carried in some places ; and 

 as we proceed from these points further east, the series is 

 altogether buried beneath the Millstone Grit. 



On the north side of the Yoredale valley, the Hardraw 

 limestone may be best seen at the waterfalls called Hardraw 

 Force and Mill Gill Force, the Upper limestone best at Leyburn 

 Shawl, and between Askrigg and Carperby, and most of the 

 lower members of the series may be examined at the lead mines 

 at EUerbank near Carperby and at the Keld heads near Pres- 

 ton-under-Scar. At the former locality the Main limestone 

 forms a double scar at an elevation of about 1,200 feet and 



