30 JOANNES RASMUSSEN 



Geikie's works we find, besides the glacial geology, a comprehensive account 

 of the general geology of the Faeroes. Helland retains Forchhammer's 

 classification of the rocks, but he uses other terms, e.g. "Anamesite" instead of 

 "Trap without glassy feldspar'', and "Dolerite" instead of "Porphyritic rocks". 



While the papers by Mackenzie (1814) and Allan (1814) cannot be consider- 

 ed of essential importance to later geological works, this is, however, not the 

 case with the publications by Forchhammer (1824), Helland (1880), and 

 Geikie (1880). They have laid the basis for later studies even though points of 

 view have changed a great deal, especially thanks to work by Peacock (1928), 

 Walker and Davidson (1936) and subsequent investigators. 



The present short account of investigations on the geology of the Faeroes 

 in more recent years, is chiefly based on results obtained during the systemati- 

 cal geological mapping of the Faeroes under the auspices of the Geological 

 Survey of Denmark. 



This project was begun in 1939, but was suspended during the war. In the 

 beginning it was conducted by Professor Arne Noe-Nygaard, and later (from 

 1951) it was carried on by this author at a permanent station in the Faeroes, 

 and is now about to be concluded by both of us. 



It must be emphasized that the geological mapping of the Faeroes has 

 not been concerned solely with rock types, but also with geological develop- 

 ment, or rather, with development of the plateau basalt volcanism. Thus, 

 the series delimited by the mapping represent stages in volcanic development. 



Attempts were made to make the map on the basis of different types of 

 basalt, but in our experience, many difficulties arose and this system in several 

 cases proved quite impractical. Among the problems encountered, the follow- 

 ing may be mentioned: (1) the characteristic tapering out and overlapping of 

 strata in the plateau basalts; (2) the very thin lava flows of varying types in 

 certain series occurring in a large number; (3) the horizontal changes in the 

 same lava flows, consequential to the sinking of heavier minerals. 



The Faeroes belong geologically to the large Brito-Arctic, North Atlantic, 

 or Thulean igneous region and appear as a geographically bounded link 

 between the Scoto-Irish region and Iceland. 



The geological structure of the Faeroes is very simple : a regular alternation 

 of lava beds with pyroclastic materials, and very subordinate intra-basaltic 

 sediments. The whole series, having a total thickness of about 3000 m, 

 is traversed by intrusive bodies. No eruptive rocks are known from the 

 Faeroes — neither effusive nor intrusive — of a composition other than basalt, 

 and the substratum of these basalts is completely unknown. 



As far as the age of the Faeroes is concerned, it is difficult to determine, 

 even roughly. Only two definable species of plant fossils have been found 

 {Sequoia langsdorfii and Taxodium distichum). However, compared with 

 conditions in the Scoto-Irish region and in Iceland, it is reasonable to estimate 

 the age as Eocene-Oligocene. 



