92 DISPOSITIONS, FRACTURES AND 



an imaginary plane, upwards to the perpendicular, or 

 from a similar plane downwards ; in which latter case 

 they have been called divergent strata ; in both, the 

 term radiated has been applied to them. 



Such a series is subject to change its inclination in 

 the course of its progress from the imaginary perpen- 

 dicular ; the angles gradually diminishing till they 

 become horizontal ; and, to this modification, the 

 term of radiated ought in strictness to be limited. It 

 is further not uncommon to find a series of this nature 

 exceedingly complicated ; the angles of convergence 

 and divergence occurring alternately, together with 

 intermediate horizontal portions. The western coast 

 of Argyllshire offers a very interesting and extensive 

 example, in a series containing Chlorite schist and 

 other rocks, which is described in another part of 

 this work. (Chap, xxvii.) 



The appearances under review are interesting, 

 whether we advert to their probable causes, or to the 

 condition of the strata before these changes took 

 place. It must also be evident, that they tend to 

 confound all our reasonings respecting the actual or 

 original alternations of the strata; as it is scarcely 

 possible, in complicated cases, to determine what 

 belongs to original position and what to disturbance ; 

 how far the succession is simple, or how far it has 

 been multiplied by the repetitions consequent on 

 change of place. 



To assume a simple case, it is evident that a series 

 of strata becomes doubled by one convergence ; and, 

 if these be multiplied, there is no limit to the apparent 

 repetitions that may ensue. Thus, for example, a 

 series of four rocks, alternately converging to points 

 above and below the surface, so as to form six com- 

 plete angles, will present the deceptive appearance of 



