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Ch. XII.] NATURE OF STRATIFICATION. 24-5 



discrepancy ; and if not, to search for such an explanation as 

 will offer a more satisfactory solution of all the phenomena ? 



But let us enquire, whether the granitic rocks of Cornwall 

 do differ from those of other countries, as regards their struc- 

 ture ? the point now under consideration; 



In our sketch of the granitic rocks, in a former chapter, 

 some examples will be found, which show that different 

 kinds of granite do succeed each other, and assume, more or 

 less, the appearance of regular beds. Such an arrangement 

 is distinctly displayed at Zinnwald, in the Erzgebirge ; but in 

 this case, as in that of the Hartz, of the Alps, and of Norway, 

 the granitic beds may be generally considered as belonging 

 to the stratified rocks. If this view, however, be adopted, it 

 is equally applicable to the granite of Cornwall and other 

 countries ; for all granitic groups are connected with schistose 

 rocks in a similar manner, only differing from each other in 

 the form of their respective masses: these being disposed 

 sometimes in rounded insulated patches ; sometimes in veins, 

 dykes, layers, or beds ; in short, exhibiting every variety of 

 shape and size, both rounded and elongated masses of various 

 forms and dimensions. 



Although the examples adduced, and others which will 

 readily suggest themselves, may not be considered so well 

 defined as those of Cornwall, yet, it must be borne in mind, 

 that the facilities for investigation also preponderate in favour 

 of the latter locality. Can we, therefore, after what has been 

 said, agree with Lyell, that the alternation of beds, varying 

 greatly in composition, colour, and thickness, is a proof that 

 the primary slates are stratified ? 



In concluding, therefore, the examination of the analogies 

 between the primary slates and the secondary and tertiary 

 formations that have been adduced by Lyell, in order to 

 prove that the former are stratified, and have been formed 

 from aqueous depositions, we may, perhaps, be permitted to 

 express a hope, that the objections which have been advanced 

 are not without some weight ; and that, if not altogether con- 



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