NOTES ON THE GEOLOGY OF DUNBAR SHORE, 103 



Trap Dyke Sandstone Strata 



b 





E Section exhibiting reversal in lie of Strata, from upburst of Trap. 



A to B on Map. 



lying against the Trap Dyke e. 



Several huge boulders of Trap are to be found on the shore. There is 

 one of these a little eastward of Broxmouth burn^ considerably upwards of 

 eight feet high: it is visible at a great distance. 



Continuing our walk^ we suddenly discover that we have quitted the 

 red and grey non-fossiliferous Sandstones of the old Red series, and we 

 now tread over the ruins of an ancient forest. Flat masses of yellowish 

 Sandstone pave the shore, in horizontal slabs, and are full of the remains of 

 Calamitesy SigillaricB, StiginarioB, Lepidodendra, etc. Many of these are mere 

 impressions, and form alone guides to their recognition. Many however, 

 retain the coaly matter into which their cortices have been converted, and 

 attract by the contrast of colour, as well as form. They are there in myriads, 

 and are of every shape and size, from the graceful Calamite, to the more 

 sturdy Sigillaria. I may here remark, that in 1815^ even Professor Jamieson, 

 could thus write of these organic remains: — "In the Sandstone there are 

 numerous supposed vegetable moulds, and some varieties of the Sandstone 

 are entirely composed of them. This latter fact would intimate, that these 

 are crystallizations of the Sandstone, and not true casts of organic bodies." 

 So long was the very existence of organic remains questioned, by gQ(?logists 

 of the Plutonic school. ' 



Among the layers of Sandstone, we meet with Limestone beds, the burning 

 of which, for agricultural purposes, was long carried on here, and led on 

 more than one occasion, to shipwreck, the fires of the kilns being mistaken 

 for signal lights. A memorable instance of this occurred in the destruction 

 of the Pallas and Nymph frigates, in 1810. 



At one point, near some houses called the Vault, the superincumbent beds 

 of Fossiliferous Sandstone have been removed, and you descend over their 

 edges, eccentrically carved by the waves, into all sorts of grotesque and 

 varied form of pillar and capital, to a lower platform of Calcareous Sandstone, 

 containing worn fragments of encrinites, and from that again, to a still 

 lower series of beds of Black Shale, full of the stems and plates of encrinites, 

 and containing also, numerous nodules of Ironstone, with remains of productus, 

 spirifer, terehratulce, etc. From the Calcareous beds, I obtained specimens 

 of portions of encrinites, as stated, in a water- worn condition; and the idea 

 has suggested itself, that this bed may have been formed from the debris of 

 a portion of the lower one, broken and washed up by the force of the waves of the 

 sea in which the encrinites of the Shale beds flourished in such abundance. I 



