HASWELL — ON THE DENUDATION OF AftTHUIt's SEAT. 95 



they would have collected in masses at the foot of the declivity, — a 

 state in which we do not now find them. 



The Lower Carboniferous Strata and Interbedded Traps of Arthur's 

 Seat, in their original position. 



Fig. 1. 



A Mass 

 of 



overlying 

 Carboniferous 

 Sandstones, 

 Limestones, 

 Shales, 

 etc. 



A group 



of 



Felstones. 

 Three Basalts 

 above Ash of 



Dry Dam. 



Ash of Dry Dam. \ 

 _ ) 



Ashy 



Sandstones, 4 

 Shales, and 

 Limestones. 

 Greenstone of the Long Row. 



Sandstones, 



Shales, 

 and fine 



Conglomerates. 



The Beds indicated by thin lines are Carboniferous strata ; those by thick lines are 

 Interbedded Traps. 



In this way the elevating processes continued their unceasing work, 

 stratum after stratum was deposited, sheet after sheet of lava ejected 

 and consolidated, until, when the last of the porphyritic felstones 

 had been produced, the igneous centre gave signs of cooling, and all 

 became comparatively quiet. Then the sediment of these Lower 

 Carboniferous seas accumulated over the solidified lavas, ganoid fishes 

 revelled undisturbed in the Burdiehouse Estuary, and plants peculiar 

 to the period were entombed in the mud ; while, as the result of all, 



