\06 On the basaltic Surface of the Counties 



emerging at their base ; the solid mass of dyke is seen cutting 

 down the precipice to the southward at 150 yards distance. 



Depression of the Strata, 



Soon after we have passed the last of our wbyn dykes at 

 Port Spagna, (a name derived from" a vessel belonging to the 

 Spanish armada having been driven ashore in that creek,) 

 we discover a new and curious circumstance, viz. that the 

 western half of the promontory has sunk or subsided be- 

 tween thirty and forty feet, without the slightest concussion 

 or derangement of the parallelism of the strata. 



Two other depressions appear as we proceed onwards, 

 one at Porlmoon, and the other at the angle where the pro- 

 montory begins to project from the rectilineal coast ; these 

 however are far less considerable in thickness than the pre- 

 ceding, neither of them exceeding five feet. 



Such depressions occur at the collieries near Balk/castle, 

 and generally on one side of a whyn dyke. We have also at 

 Seaport, two miles west from the Giant's Causeway, a dyke 

 oblique and undulating, with a depression of the strata of 

 about four feet on one side ; but on Bengore promontory 

 our dykes are unaccompanied by depressions of the strata, and 

 where we have depressions we do not find a trace of a dyke. 



The portions of tins extensive facade, which I have se- 

 lected for explanatnrv views, are Portmoon, in or near which 

 most of the strata emerge, and Plvskin, where the strata 

 culminate : each of these views, too, exhibits one of our de- 

 pressions ; but in that of Ple<kin the first apparent de- 

 pression is purely- an optical effect arising from the position 

 of my friend major O'Neal, of the 5Gth, who took his view 

 from the water. 



Enumeration of the sixteen Strata that compose the Promon- 

 tory of Bengore, taken in their regular Order, and count- 

 ing from above. 



The country immediately to the southward of Bengore is 

 like the promontory itself, a stratified mass, accumulated to 

 the summits of Craig Park and Croaghmore, the first five 

 hundred and the second seven hundred feet high; but with 



those 



