136 MIDDLEM1SS: PHYSICAL GEOLOGY OF SUB-HIMALAYA. 



decidedly mature age. If we wish to see the aspect of a comparative- 

 ly modern mountain, we have only to look at some cases which admit 

 of no doubt, such as the chalk wolds of Yorkshire and Lincolnshire, 

 which must have been elevated and slightly disturbed previous to the 

 Post-Tertiary deposits of the low country nearer the sea. There we 

 have an example of what can be accomplished in the lapse of time 

 between the beginning of the Tertiary period and that of the glacial 

 epoch. The Pennine Chain may next be cited as an illustration of a 

 mountain-range which is older than the chalk wolds, but which is prob- 

 ably still in the process of growing. It has been subject to the 

 elevatory forces of crushing and folding during Secondary and Tertiary 

 times;; and has been successively wrapped round on its east, west, 

 and south sides by new formations ; all of which have in turn been 

 elevated, in order and degree, more or less directly proportional to 

 their age. The Pennine Chain is more elevated and more folded 

 than the chalk wolds ; and this seems to be simply because the forces 

 have had a longer time for working in in the former than in the lat- 

 ter case. Finally, the older Palaeozoic rocks rise into the highest form 

 of mountain structure which we have in England. On the other 

 hand, much of the older Palaeozoic country of Wales and the Lake dis- 

 trict is lower than that of the Pennine Chain ; and the reason for this 

 is perfectly evident. High as are some parts of the Cambrian and 

 Silurian area, it is probable they are not so high as they once were. 

 These mountains would seem to be retrograding towards extinc- 

 tion ; denudation is gaining on the forces of upheaval, so that in parts 

 they have sunk to a lower level than the growing area of the Pennine 

 Chain. 



Let us now examine the next paragraph quoted by me. Mr. Mel- 

 lard Reade says — " it is impossible to point to a range of mountains 

 " which have been built up of old denuded rocks." I find it difficult to 

 understand the form of thought which could induce such a statement. 

 Unless there be some hidden meaning in the words " built," "old," 

 or u denuded," I should regard the very opposite of this statement 

 as the great residual truth. Using words in their plain significance, 

 ( 194 ) 



