DUNBAR. 



231 



often contains reddish-brown-coloured spots; and 

 these are sometimes so numerous, as to give the 

 rock a deep brownish-red tint of colour. 



Sometimes the deep red portions are in the 

 form of veins, which run in every direction, and 

 present a variety of curious appearances ; and in 

 other instances, the imbedded red sandstone is not 

 in veins, but in masses, that vary in size and shape. 

 When the softer yellowish-grey sandstone decays and 

 falls out, the remaining mass acquires a singular ca- 

 vernous or cellular aspect. This sandstone forms 

 low ledges of rock covered at high-water, which are 

 succeeded by rugged and lofty rocks of the trap se- 

 ries, on which are situated the ruins of the old Cas- 

 tle of Dunbar. These rocks are very steep, and in 

 some places completely perforated by the action of 

 the waves, forming beautiful natural arches. They 

 are not composed of one variety of the trap series, 

 but of several, viz. red-coloured trap-tuff, amygdaloid 

 and of a basalt, which contain red diallage and oli- 

 vine, which, by the action of the weather, has ac- 

 quired a red colour. They form one inclined bed of 

 great thickness, which rises above the lower super- 

 incumbent and subjacent red sandstone. 



Advancing along the shore from these high trap- 

 rocks, we find the sandstone forming a number of low 

 rocky ledges, which are partly covered at high-water, 

 and extend onwards to striking cliffs of red-coloured 

 trap-tuff. The strata have the same direction and 

 dip as those already mentioned ; and the sandstone 



