498 
Proceedings of the Royal Society 
and the same cavity. After describing in detail the various appear- 
ances assumed by the dolerites, and the features exhibited by the 
associated palagonitic tuffs, the author gives some account of the 
intrusive basalts, which are of two kinds — one occurring in sheets 
intruded along the line of bedding, the other in mere thin dykes 
and veins. 
He estimates the thickness of the anamesites to he not less than 
4000 feet, and that of the dolerites as between 9000 and 10,000 
feet ; thus giving a total thickness for the bedded volcanic rocks of 
not less than 13,000 or 14,000 feet. As the dip of the strata is 
extremely regular, and there are no large dislocations to complicate 
matters, this estimate may he relied upon as approximately correct. 
He then enters into a lengthened discussion as to the origin of 
the strata, and combats the prevailing belief that the igneous rocks 
are relics of submarine eruptions. The conclusion come to is that 
the bedded basalt rocks of the Faroe Islands represent the heavy 
basic, and more liquid lavas which flowed from a cone or cones 
placed at some considerable distance, probably to the west of the 
present islands. The palagonitic tuffs, which sometimes contain 
small stones and grit, and are often laminated, represent partly 
fine volcanic dust (which the winds could carry considerable 
distances), partly volcanic mud, and to some extent they may also 
have been derived from the subaerial disintegration of the exposed 
lavas. They pass here and there into regular shales and tuffaceous 
clays, especially upon the horizon of the coal-seams. The coals are 
composed of land plants of Miocene age, and many plant remains 
occur in the associated clunch or clay and shale. None of these 
appear to have grown in situ — there are no roots penetrating an 
ancient soil. The coals are made up of the debris of plants carried 
down by freshets into shallow pools and marshy meres. Not a 
trace of marine organisms was observed in any strata throughout 
the islands. The coals and clays indicate a pause in the volcanic 
activity, during which the Miocene flora invaded the igneous area ; 
but whether from the direction of America or Europe it is 
impossible to say. The local seam of coal at Dalbofos which 
occurs low down in the series, proves that there were more than one 
such pauses, and its fragmentary condition leads to the suspicion 
that the Miocene flora may have again and again invaded the 
