Scandinaua and Finland. '^Ol 



lie elsewhere refers to similar phenomena in the porphyry rocks 

 westward of Lake Siljan ("An Investigation," etc., pp. 112-3). 

 In regard to the same phenomena, Murchison says that in travelling 

 between Upsala and Sala, one is suddenly immersed in a chaos of 

 angular blocks, some of them of gigantic size. Seeing that they were 

 all composed of granitic gneiss, and no proof that these millions of 

 angular blocks were deposited on asar, and from their linear 

 arrangement, he concluded that they must be simply fragments 

 in situ, the subjacent rock being hidden by their great profusion. 

 He noticed that whenever an elevation presented itself, some- 

 times not exceeding 15 or 20 feet high, it was covered with angular 

 blocks of all sizes accumulated on a substratum of clay. " On 

 entering Dalecarlia we passed," he says, " a true granitic plateau 

 covered in parts with angular blocks, the mass of which, like those 

 above alluded to, forcibly reminded us, by its superficial aspect, 

 of the broken volcanic cheires of Auvergne .... they 

 were fragments in situ, the subjacent rock from which they had 

 been broken off appearing here and there. On passing the 

 low hills south of Fahlun the angular blocks and the underlying 

 parent gneiss were clearly exposed. Without such an explanation, 

 the sea of wild and irregular fragments dotted over the plain 

 immediately south of the copper-mines of Fahlun would indeed 



seem marvellous In passing from the Siljan to the 



Wenjan lake we passed through a country of low wooded porphyry 

 peaks, the parent rock of which is also almost entirely obscured 

 by vast quantities of local angular blocks, and on approaching 

 Johannisholm the observer is suddenly struck with great quantities 

 of sandstone debris, and on traversing the Wenjan lake all other 

 detritus disappears, and the whole mass consists of angular blocks, 

 occasionally of enormous size, composed of hard red, purplish, 

 greenish, or whitish sandstone, which constitutes the cover to a vast 

 expanse of horizontal sandstone, which further to the north^ is 

 detected beneath this chaos .... this Felsenmeer or cheires 

 consists of enormous angular blocks of purely laminated sandstone 

 and occupies a tract many miles in length, no part of which is more 



than 100 or 200 feet above the lake In numerous spots, 



indeed, the blocks of sandstone, though completely disjointed and 

 widely separated, conform on the whole to a horizontal arrangement, 

 and it was only at very rare intervals that we could detect the 

 subjacent horizontal rock from which they had been dislocated." 

 Whatever cause, says Murchison, is assigned for the produc- 

 tion of this chaos in situ, there can be no sort of doubt that 

 the same agent has operated over several degrees of latitude in 

 Sweden, effecting exactly similar results on innumerable low ridges 

 of hard rock, whether composed of granite, gneiss, of quartz rock, 

 or porphyry, or of finely laminated sandstone. Murchison proceeds 

 to entirely dispute that such a condition of things could possibly 

 result from any kind of subaerial denudation, and appeals to some 

 powerful mechanical agency by which the chaotic arrangement 

 of enormous blocks apparently in situ has been produced, and further 



DECADE IV. ^VOL. IT. — ^^NO. IX. 26 



