DUNBAR, 



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bedded in it are patches and spots of a white-co- 

 loured sandstone, which, at first sight, appear to be 

 fragments; but, on close examination, we find 

 them gradually passing into the basis in which 

 they are contained; and even the red-coloured sand- 

 stone, in some places, presents the conglomerated 

 character, — facts which shew that these are not 

 fragments, but cotemporaneous masses. The por- 

 tions of sandstone vary in size from half an inch 

 to several inches ; and they also differ in shape, 

 being roundish, ovoidal, blunt-angular, and mas- 

 sive, as represented in Fig. 6. PI. xii. This cu- 

 rious sandstone is succeeded by a greenstone rock, 

 which is partly porphyritic, partly tufFaceous. It 

 is much intermixed with the red conglomerated 

 sandstone, and is traversed by veins several inches 

 wide, of white quartzy sandstone ; — facts which 

 shew that here the sandstone and tuff are of co- 

 temporaneous formation. This tuffaceous rock is 

 succeeded by a red-coloured sandstone, which is 

 sometimes very clayey and soft, and even appears to 

 pass into a sandy red coloured slate-clay. All the 

 varieties are marked with beautiful celandine or 

 mountain-green coloured spots, from half an inch to 

 two inches and upwards in diameter. They vary in 

 shape, being either circular or oval, and sometimes 

 we observe them of an irregular form ; and not un- 

 often this red sandstone contains layers of a green- 

 coloured clayey variety of the same rock. As we 

 advance along the shore, the red sandstone be- 

 comes more compact ; and, in several places, is 



