CBICH CLIFF. 



where they occur, they of course divide the third limestone into two 

 beds. The irregularity of these beds of toadstone, and the distur- 

 bance of the regular strata which they have caused, compelled Mr. 

 Farey to call them chance beds, to avoid the admission of their igne- 

 ous origin. In the same manner he explained the protrusion of the 

 granitic range of rocks in Charnwood Forest ; he described them as 

 chance beds in the red marie ; it was surely an extraordinary chance, 

 which produced rocks that extend under every other rock formation 

 in the midland counties of England. There are, however, circum- 

 stances attending the stratification of the mountain limestone of Der- 

 byshire, that have not been noticed by any of the authors I am ac- 

 quainted with, who have described this country. There are evident 

 indications of an upheaving force acting on several parts, and bending 

 the strata into arches, the segments of large curves as represented 

 Plate II. fig. 1. and fig. 6. These curves are sometimes complete 

 in the same hill, but frequently their continuity is broken. The stra- 

 ta of Madock high Tor have been described by former writers as 

 plain, and when seen in face of the rock they appear to be nearly 

 so, but they are in reality curved, as shown Plate I. fig. 6. They 

 enfold the back part of the hill, and are continued into the oppo- 

 site hill, Masson, which they also enfold. The continuity of the stra- 

 ta is broken by the vale of the Derwent, which makes their true form 

 more difficult to trace : but the arched stratification of the lower part 

 of the same beds is distinctly displayed westward, and may be seen 

 from the road near Matlock toll bar, where a section is made by the 

 Derwent. 



A very remarkable instance of the arched stratification, complete- 

 ly formed in one situation, may be seen four miles east of Matlock, 

 in the isolated mountain called Crich Cliff, which rises about nine 

 hundred feet above the Derwent. The strata rise all round, and en- 

 fold it, forming nearly spherical segments, as represented in the an- 

 nexed cut. This section, through the hill, represents the arrange- 

 ment of the beds of limestone which dip all round the hill ccc, but 

 are somewhat flattened at the top ; the shale and gritstone surround- 

 ing the lower part of the hill are represented ah. The true structure 

 of the hill has been discovered by recent mining operations ; several 

 valuable metallic veins have been explored in it, and a gallery has 

 been driven into it, as represented in the figure/. It is obvious that 

 this arched structure can be formed only by protrusion, whereas the 

 elevation or inclination of plane strata may have been produced by 

 subsidence. Now, when we consider their near proximity to beds 

 of toadstone of igneous formation, we can have litde difficulty in as- 

 signing a cause for this protrusion ; but, fortunately, we are not here 

 obliged to have recourse to conjecture : in driving the gallery towards 

 the centre of the hill, a mass of toadstone was met with (e e,) which 

 was not cut through when I visited the place in 1830. The same 

 toadstone was found by sinking a shaft upon it, as represented in the 



