171 



this zone of dislocation, or on the right-hand side of the Z, the 

 fells consist chiefly of Yoredale Rocks with just a capping formed 

 by detached remains of Millstone Grit strata left on the summits 

 of the higher fells; and with strips and interrupted patches of 

 Mountain Limestone turned up endways where this rock underlying 

 the Yoredale Series has been exposed to view by the removal of 

 the overlying strata along the lower flanks of the fell sides next 

 the faults. These beds are generally much folded and otherwise 

 disturbed, or even occasionally turned upside down for short 

 distances ; but they right themselves entirely within a short distance 

 of the faults, and gradually pass into strata that retain much of 

 their original position of horizontality. Consequently, regarding 

 the strata on the outer, or eastern, side of the faults as a whole, 

 they may be said to consist of beds so nearly horizontal that almost 

 any of the higher members of the series, the Main, or Great Lime- 

 stone for example, can usually be found at about the same general 

 level above the sea all the way up from near Ingleton to Brough, 

 or beyond. 



The rocks on the inner, or western side of the faults, represented 

 in place by the side to the left of the Z, lie, as a whole, in a very 

 different manner. To the south, at the part represented by the _ 

 block at the right hand extremity of the foregoing diagram, the 

 great dome-shaped aggregation of rounded eminences forming the 

 Howgill Fells is described by Professor Hughes, in the Survey 

 Memoir on 98 N.E. as consisting of contorted and highly inclined 

 rocks, mostly of Silurian age, whose dips, as shewn in the figure, 

 bear not the slightest necessary relation to either the form of the 

 surface or to that portion of their surface that slopes beneath and 

 is covered up by the Carboniferous strata. 



These rocks form ground rising somewhat higher than the base 

 of the Millstone Grit of Wilbert Fell in the part of the carboniferous 

 tract lying to the east of the Howgill Fells and separated from them 

 by the line of the faults ; so that the full extent of the dislocation at 

 this point cannot well be less than the vertical distance between the 

 general level of the summits of the Howgill Fells themselves and 

 the general level of the equivalent strata that form the floor of 



