262 AN ENQUIRY INTO THE NATURE OF [Ch. XIII. 



In this case, also, we have another instance in which the 

 structure of the conglomerate accounts for the lines or 

 seams by which it is traversed, without referring them to 

 stratification. Here is an immense mass of detritus which 

 has been derived from granite, and, not having been trans- 

 ported far from its source, still resembles granite in compo- 

 sition. When consolidated, this rock, as might be expected, 

 being formed of the same ingredients, assumes the same 

 structure as granite. The learned authors, indeed, do not 

 state that the mass is traversed by parallel lines, as is com- 

 monly the case with granite, but if made up of an aggrega- 

 tion of prismatic concretions, it may be inferred, without any 

 great assumption, that the structure, in this respect, also 

 resembles granites and then we have, in this case, perpen- 

 dicular layers of strata of conglomerate. Many geologists, 

 indeed, have described similar phenomena in various parts of 

 the Alps, and of other countries, and have attributed them to 

 the elevation of horizontal strata. But may it not be fairly 

 doubted, in the instance before us, that the layers of conglo- 

 merate have been so raised, since this apparent movement 

 can be accounted for without having recourse to the agency 

 of such tremendous convulsions, as would be required to 

 produce this effect ? There are, besides, other objections, one 

 of which may now be mentioned; viz., that if horizontal strata 

 have been so upraised, all of them ought to exhibit the same 

 angle of inclination. In Caithness this does not hold good : 

 thus, the old red conglomerate, in the narrow valley which 

 separates the Scarabins from the Maiden Paps, dips at 45 

 towards the great northern plain ; but at Schmian, which is 

 farther removed from the central quartz-rock, the dip of the 

 same is not more than 10 or 12. So that it is arranged 

 fan-shaped ; and the upper sandstone and calcareous schists 

 follow the same order, being inclined, at various angles, from 

 30 to 40 till they become nearly horizontal.* 



* Geol. Trans., vol. iii. p. 138. (New Series.) 



