HOPKINS ON THE LAKE DISTRICT. 75 
between Whitbarrow Scar (a mountain limestone hill) and the great 
limestone fell immediately on the west of Kendal. This dislocation 
must have been posterior to the mountain limestone, since it affects 
the beds of that formation. 
8. Formation of the Lakes.—From the preceding descriptions it 
would appear impossible not to ascribe the origin of the lakes of 
Coniston and Winandermere to the dislocations with which they are 
so immediately associated ; nor does it indeed seem possible to ac- 
count for the existence of any of the larger lakes independently of 
similar dislocations. Taking Wastwater, for instance, its depth is 
found to be forty-five fathoms, so that its bottom is probably almost 
a hundred feet lower than the surface of the sea. It is evident that 
such a basin could not be scooped out by the action of water ; nor is 
its depth increased by an accumulation of detritus at the mouth of 
the valley, for the river by which its surplus water is discharged cuts 
into the solid rock. The lake could only be formed therefore by a 
relative subsidence of its bottom, such, for example, as that shown in 
the annexed diagram, which represents a transverse section of a valley 
Fig. 2. 
See 
with its lake: a6 is a section of the fault which runs along the valley, 
and on opposite sides of which the strata are relatively displaced 
through the space c’c. If this relative subsidence do not extend to 
the mouth of the valley, or be less there than in the upper part of it, 
a lake will necessarily be formed. It is probable that in some of the 
English lakes, the extension of the subsidence towards the mouth of 
the valley has been arrested suddenly by a fault transverse to the 
valley, as appears from the great depth in the case of Wastwater, for 
instance, at an inconsiderable distance from its lower extremity. 
This general explanation will apply to all the lakes of the district, 
and appears to me to be the only intelligible one which can be given 
of their origin*. The evidence thus obtained of great faults ranging 
along the lake valleys is scarcely less conclusive than that afforded 
by the discontinuities of the limestone band above described. 
It would be absurd to suppose that the ranges of the faults in these 
valleys are confined to those spaces only where we now find demon- 
strative evidence of their existence. There can be no doubt of their 
extension frequently along the whole course of such valleys, or, in 
* The probable origin of these lakes in diverging dislocations is too obvious to 
have escaped the notice of such an observer as Professor Sedgwick, who has 
spoken of it in his memoir on this district. I am not aware, however, that the 
argument in favour of this view of their origin has been hitherto placed in that 
more determinate and demonstrative form which I have given it in the text. 
