OF THE APPALACHIAN CHAIN. 527 



often overturned, so as to dip towards the east, thus exhibiting a 

 direction of flexure, nearly opposite to that of the strata near the 

 Berwyii chain. As examples of these phenomena, we would 

 refer to Plate 36, fig. 8, presenting a transverse section of the Mal- 

 vern and Sedbury hills, and figs. 9, 9*", 10, of the same plate, 

 exhibiting the structure of the Woolhope axis. 



The same general structural features, will, we confidently be- 

 lieve, be found to prevail in the perplexing stratification of those 

 parts of Devonshire and Cornwall, which, of late years, have 

 drawn out much earnest theoretical discussion among British 

 geologists. An inspection of the sections accompanying Sir H. 

 De la Beche's elaborate Report, those, for example, from Combe- 

 martin to Bolt-hill, and from Linton to Bideford, and a careful 

 examination of the descriptions of this region, given by him in 

 that work, and by Messrs. Sedgewick and Murchison, in their very 

 able memoir " On the Physical Structure and older Deposits of 

 Devonshire," induces us to venture the prediction, that, through- 

 out the region to which they refer, the phenomena of folded axes 

 will be found of very extensive occurrence, and that this folding 

 and inversion, together with the general law of steepening flex- 

 ure in a particular direction, will explain the frequent repetitions 

 of certain groups of strata, and assist in removing much of the 

 obscurity that stiU hangs round the intricate geology of some parts 

 of that district. 



Similar indications are, we think, presented in the structure of 

 the southern and southeastern parts of Ireland, as described by 

 Weaver, Griffith, Hamilton, and Austin. Among these may be 

 instanced the great predominance of southern dips, those to the 

 north being only occasional and of short continuance ; a result, 

 in our view, naturally arising from a succession of folded and 

 steeply normal flexures, due to a pulsatory movement propagated 

 from the south. The evidences of such foldings and inversions, 

 are, we think, quite observable, in the account given by Mr. 

 Weaver, of the parallel bands and patches, in echellon, of the 

 older limestones, while the steepened dip, and extensive folding 

 and inversion among the higher rocks, resulting from the same 

 forces, are sti-ongly implied in the section given by the same 



