390 ARRAN. GEOLOGY. SECONDARY STRATA. 



Screeb with little uncertainty. But in proceeding: beyond 

 Brodick, it is no longer possible to connect the separated 

 portions, either by following their continuity or comparing 

 their positions ; the interruption being here complete. 

 For the same reason, no connexion can be traced between 

 the northern upper bed at the Cock, and that which fol- 

 lows next in geographical order on the western shore 

 at Glen lorsa; the intervening schist occupying a great 

 extent and producing a large chasm. It is equally 

 impossible to follow the strata in the interior country. 

 It may perhaps fre reasonably supposed that these strata 

 are continuations of the upper one, since they resemble 

 it in the great proportion which the fine sandstone bears 

 to the conglomerate, and in the absence of the smaller 

 strata, which, were it the lower one, would be expected 

 to appear above it. 



A general question respecting the continuity of strata 

 arises out of this investigation. Every deposit of se- 

 condary strata must, to a greater or less extent, be con- 

 sidered partial ; there being no proof that they have 

 ever possessed universal continuity. For this reason, the 

 supposed identity of remote strata, derived from particu- 

 lar appearances, must be received with caution ; since, 

 both in practice and in theory, this supposition may lead 

 to erroneous conclusions; while, like other hasty gene- 

 ralizations, it impedes the progress of investigation. If 

 we examine the mode in which stratified rocks appear 

 to have been formed, there will be no difficulty in acceding 

 to this doubt, as well in the case of the more general, as 

 of the more limited strata; since the same circumstances 

 must, under certain variations, have attended the forma- 

 tion of both. These deposits have perhaps originated in 

 diluvian causes and remote times ; more probably from 

 the gradual action of rivers on pervious rocks. Be- 

 ing received in cavities or in seas of different forms 

 and capacities, they have been consolidated by pres- 

 sure, repose, the partial solution and crystallization 





