34 GEOLOGY OF THE LOTHIANS. 



part of the chain, decreasing as the ratio of the distance 

 from the axis increases, might lead us to infer, that the vio- 

 lence of the upraising agents decreased from the central part 

 of the chain to the exterior. 



By what means then, since in these circumstances the 

 age of mountain chains cannot, with certainty, be ascer- 

 tained, are we to fix the date of their upraisure ? To 

 this question there appears to be a satisfactory answer. 

 If, after having examined a wide extent of country, a se- 

 ries of strata, inclined at angles at which they might have 

 been deposited, is found reposing upon another, which is 

 in the greatest possible confusion, being vertical and con- 

 torted, there is almost as little reason to believe that the 

 inclined position of the former, has in any way been influ- 

 enced by causes operating on the upraisure and flexure of 

 the latter, as there would be if they were horizontally 

 arranged. When the examination of a mountain-chain, 

 however, shews formations anticlinally tilted up, and no 

 one more conspicuous for its alterations than another, the 

 only conclusion to be arrived at is, that all have been 

 upraised at one and the same time. On examining the 

 Lammermuir range, for the purpose of determining the 

 age of the chain, the result to which we arrive is, that 

 the much disturbed rocks of the transition class have been 

 upraised prior to the deposition of the slightly inclined 

 secondary formations. In every natural or artificial sec- 

 tion, where the transition rocks occur, they are either in- 

 clined at high angles, or are vertical and contorted in the 

 most fantastic manner. The secondary formations, which 

 form the low land, and which in many places occur in con- 

 tact with them, are, however, never so disturbed ; but, on 

 the contrary, are elevated at angles consistent with the 

 supposition that they are in their unaltered state. It is 



