Buckland^s Formation of the Valley of Kingsclere, 2^ 



beneath the level of the main portion. In illustration is a 

 sketch of the strata near the edge of the mineral district of 

 Monmouthshire. (Jig. 111.) Accidents of this kind are more 

 frequent near the outcrop of the strata than deeper in the 

 interior. 



By elevation, where masses have been heaved upwards, ap- 

 parently by internal force. (Jig, 112.) This species of dislo- 

 cation does not appear to be of such common occurrence as 

 that arising from partial subsidence. Under the description 

 oi Jaults, the subject of disturbance in the position of rocks 

 will, with propriety, be resumed. 



112 



115 



The softer and later-formed strata present fewer instances 

 of disruption than the older and more indurated rocks, parti- 

 cularly those containing the coal-measures, the carboniferous 

 strata of some writers. The sections constructed by Professor 

 Buckland and the Rev. W. D. Conybeare, to elucidate the 

 geology of the district around Bristol, furnish interesting 

 examples of every variety of arrangement ; and, by selecting 

 our illustrations from these documents, we desire to manifest 

 our respect for authorities so accurate, we had almost said, 

 so indisputable. 



One of the simplest 

 forms, occasioned by 

 the disposition of the 

 strata, and by which 

 the external form of 

 the earth is modified, 

 is that arrangement de- 

 nominated the saddle- 

 shaped (Jig. 113.), in 

 which the uplifted 

 edges of the strata are 

 piled against each other, forming a steep ridge, like the roof of a 

 building. Our sketch shows the elevation of Black Down (b), 

 part of the Mendip chain of hills, and 1092 feet above the 

 ocean. 



s 4 



Old Bed Limestone. 



