278 Notices of Memoirs — Dr. J. Oeikie on the FcBrbe Isles. 



shire. Mr. Carruthers has pronounced many of them to be forms 

 which, though known on the Continent, had been hitherto almost 

 unknown in this country.'] 



(To be concluded in our next JSfiimber.) 



nsroTicss oip :m:eivi:oie-s. 



On the Geology of the F^eroe Islands. By James GtEikie, LL.D., 

 F.E.S., ETC. [Trans. Roy. Soc. Edin. 1882, vol. sxx. part 1.] 



IN this Memoir the author gives an account of observations made 

 in company with Mr. Amund Helland of Christiania, during the 

 year 1879 ; while at the same time he reviews the work done 

 previously by other geologists and travellers. The islands are 

 essentially volcanic; only two of them, Myggenees and Suderoe, 

 containing layers of clay, shale, and coal, intercalated with the 

 basalts, which are the principal rocks. The coal (probably of 

 Miocene age) occurs as more or less lenticular layers in beds of dark 

 indurated clay and shale. The seams, therefore, are very incon- 

 stant, and thicken and thin out in the most irregular manner. 

 Indeed, Dr. Geikie observes that it is not difficult to trace the 

 passage from coal into shale — an appearance which, taken in con- 

 nexion with the general aspect of the beds, is strongly suggestive 

 of the aqueous formation of the coal-seams. He saw no traces of a 

 true underclay, and nothing resembling rootlets. 



The volcanic rocks consist of bedded basalts (chiefly anamesite) 

 with layers of tuff, among which are sometimes intruded veins and 

 sheets of basalt. This is the case in Suderoe, where the coal-bearing 

 beds appear to have been lines of weakness, yielding more readily 

 to the assaults of the intrusive basalt than the harder and less easily 

 divided anamesites with which they are associated, for nowhere 

 else in the island do such intrusive sheets occur. 



Discussing the origin of the volcanic rocks, the author comes to 

 the conclusion that they must have been erupted from a centre or 

 centres, removed some distance from the site of the present islands — 

 a conclusion which explains the absence of breccias and agglomerates, 

 of lapilli and bombs. 



The great series of basalt beds and tuffs (13,000 or 14,000 feet 

 in thickness) most probably accumulated on the outskirts of an old 

 volcanic area. They represent the heavier and more fluid lavas, 

 derived from foci which most likely ejected other materials unable 

 to reach distances attained by basalts. 



There seems no reason to doubt that these igneous rocks belong to 

 the same great series of which the basalt plateaux of Iceland, Green- 

 land, Spitzbergen, and the Scottish Islands form separate portions, 

 and which are I'eferred to the Miocene period. The author gives an 

 interesting sketch of the physical conditions under which the rocks 

 of the Fseroe Islands would seem to have been accumulated. 



The principal object of his journey, however, was to examine the 

 1 Vide Ilidland Naturalist, vol. iv. p. 122. 



