EXPLANATION OF PLATE 1. 3 



As it would encumber the section to express Diluvium, 

 wherever it is present, it is introduced in one place only, 

 which shews its age to be more recent than the newest of 

 the Tertiary strata; it is found also lodged indiscrimi- 

 nately upon the surface of rocks of every formation. 



Granite, 



In our early Chapters we have considered the Theory 

 which refers unstratified rocks to an igneous Origin, to be 

 that which is most consistent with all the known Pheno- 

 mena of Geology, and the facts represented in the Section 

 now before us are more consistent with the Postulates of 

 this Hypothesis, than with those of any other that has 

 hitherto been proposed. I have, therefore, felt it indispen- 

 sable to adopt its language, as affording the only terms by 

 which the facts under consideration can be adequately de- 

 scribed. 



Assuming that Fire and Water have been the two 

 great Agents employed in reducing the surface of the globe 

 to its actual condition, we see, in repeated operations of 

 these agents, causes adequate to the production of those 

 irregular Elevations and Depressions of the fundamental 

 Rocks of the Granitic series, which are delineated in the 

 lower Region of our Section, as forming the basis of the 

 entire Superstructure of stratified Rocks. 



Near the right extremity of this Section, the undulating 

 surface of the fundamental Granite (a. 5. a. 6. a. 7. a. 8.) 

 is represented as being, for the most part, beneath the level 

 of the Sea. 



On the left extremity of the Section (a. 1. a. 2. a. 3.) the 

 Granite is elevated into one of those lofty Alpine ridges, 

 which have affected, by their upward movement, the entire 

 series of stratified Rocks. 



Corresponding formations of Primary and Transition 



