Ch. XIV.] OF THE STRATIFIED ROCKS. 299 



alteration, whilst they are cut off and disappear in the wedge- 

 shaped mass, which circumstance, conjoined with the position 

 on the sand, indicates that the upper bed of debris has been 

 transported : the time may come when these deposits will be 

 converted into stone, and then would future geologists find 

 derivative rocks, associated with sandstone, containing organic 

 remains of the modern epoch, and yet passing by the most 

 perfect gradation into crystalline slates, which are in contact 

 with granite, and abundantly intersected by granitic veins. 



It will be again necessary to revert to this topic, when the 

 well-known observations of Hugi, Studer, Beaumont, and 

 others, on the alteration of the strata by granite in the Alps, 

 come under consideration ; and, after making allowance for 

 the distorted and disproportionate appearance of their 

 sections, the dissimilarity of these phenomena and those just 

 detailed is not so great but that it may be possible hereafter, 

 when we are more minutely acquainted with the facts, to 

 offer a plausible explanation, without having recourse to the 

 supposition that the crystalline slates were once sedimentary 

 deposits. 



By way of illustration, take the Botzberg in the Swiss 

 Alps, described by Hugi and Studer. It is stated that the 

 strata dip towards the granite, and that the latter rock, in 

 descending the mountain, is succeeded by gneiss, which, in 

 its turn, gives place to mica-schist, followed by limestones and 

 slates belonging to the lias group. De la Beche, from whom 

 we quote, remarks that, " assuming the section to be correct, 

 the superposition of the crystalline rocks, in this case, is evi- 

 dent * ; " and he offers two explanations of this unusual 

 position ; one referring it to the strata being thrown over, the 

 other to the granite overflowing the fossiliferous beds. Now 

 it has been already shown, that it is no uncommon occurrence 

 to find parallel seams or joints traversing the secondary rocks 

 as well as the primary, and dipping toward the granite, but 



* Geological Manual, Svo. p. 456. 



