54 



(^n some Contorteti Strata m tf)t l^ovctrale 

 itocfes, near ^stjobcr. 



Bv John Ward. 



OR field-work in structural and physiographical geology, 

 perhaps no district in Derbyshire surpasses the Amber 

 Valley at Ashover. Its lessons are easily learned ; 

 the extent of that portion of it which is geologically 

 interesting is small, barely exceeding four miles in length ; and 

 from numerous points, comprehensive views of its salient features 

 may be obtained. It furnishes the student with a wide range of 

 rocks, and excellent examples of stratification and faulting, of 

 river action and tlie relation of geological structure to scenery, 

 all, it is true, of a homely character, but not the less valuable for 

 that. But it is needless, in the present paper, to enter into the 

 geology of the district beyond the requirements of our subject. 



In this portion of the Amber Valley — that is, the mile below 

 and the three miles above Ashover — the main characteristics of 

 mid and northern Derbyshire are reproduced upon a small scale. 

 In each case the strata form an arch or anticlinal curve, having 

 its axis approximately N.N.W. and S.S.E., and tending to die 

 out in the former direction, and abutting, by means of a fault, 

 against the newer strata in the latter. The likeness to an arch 

 may be carried further, if we confine ourselves to one constructed 

 of several rims or layers of voussoirs, one above another; these rims 

 representing the strata of the anticline. Suppose the summit of 

 such an arch to be planed off, without, however, quite cutting 



