218 GEOLOGICAL FACTS OBSERVED ♦_ H 



means of a line, and it was thus ascertained to be 1134 feet 



high. I 



Greatly as our admiration was excited by the stupendous ■ 



exterior of these islands, their internal structure did not fail " 



most powerfully to arrest our attention. 



The Faroe Islands are composed almost entirely of Trap, the 

 most common characters of which are amygdaloidal and por- 

 phyritic. Beds of coal occur in Suderoe, and, it is said, also in 

 Myggenaes, neither of which islands we could visit, on account of 

 the unfavourable state of the weather, at the time we were 

 about to make an attempt to land upon them. The beds of 

 Trap are inclined at a small angle, about 4° or 5°, and dip to- 

 wards the south-east *. Their thickness varies ; in some, it is 

 but a few feet ; and Landt states that of some columnar beds, 

 which we did not reach, to be from 100 to 300. 



The first striking resemblance between the rocks of Fa- 

 roe and those of Iceland, we observed in the separation 

 of many of the beds of Trap by thin layers of TufFa, re- 

 semblinji red sandstone. In both countries, this tuffa occurs 

 of a greyish and of a yellowish colour ; and sometimes assumes 

 the small columnar form, and then it has a tendency to the tex- 

 ture of Wacke. In Faroe it occurs also of a green co- 

 lour f. 



The 



* We had a view of Myggenses, near enough to distinguish that it was com- 

 posed of beds, which rose at an angle considerably greater. The coal is proba- 

 bly in the same position as that found in the Isle of Skye, near Talisker, where 

 it occurs between beds of trap. 



t I have preferred the term Tuffa to that of Trap-tuff, because I wish to em- 

 ploy a generic term, and one that has no allusion to theory. Trap-tuff is, 

 no doubt, used as generic by the Wernerians ; but it is in reality a spe- 

 cific term. It is a question whether the specific terms should be derived 



from 



