262 Sir S. H. Hoivorth — Surface Geology of N. Europe. 



boulders The river banks at Sater, as at numbei'less 



places on the Dal Elf, consist of mounds of finely laminated sandy 

 loam." (Q.J.G.S., iii, 372.) Murchison goes on to describe the 

 sometimes finely laminated sands which are seen in following the 

 Dal Elf through tbe fertile tracts of Gustafsland (id., p. 373). I have 

 recently been spending some days in this same district, and have 

 been deeply impressed by the same facts, and notably as they occur 

 about Leksand and thence to Insjon. 



A third notable testimony to the marine origin of the asar is the 

 presence in several cases in their upper layers of marine molluscs 

 like those now living in the Baltic. At Upsala I collected 

 numerous specimens of Tellina BaltMca, Cardium ediile, Littorina 

 litorea, and Mytihis edulis. The last-named were much decayed and 

 reduced to fragments. They still I'etained their colour, which gave 

 a purple tinge to the clayey bed in which they lie. 



This kind of evidence is a very potent support to the view that 

 the asar are, in fact, of submarine origin, and witness, as so many 

 other facts in Scaudinavia do, a recent submergence of a large part 

 of the country. It is, nevertheless, clear that when we examine 

 other features of the asar we cannot attribute them to the ordinary 

 operations of the ocean, and I confess I cannot see in them, as some 

 others have done, a kind of sea-beaches or dunes. Their shape, their 

 internal structure, the alignment of the stones in them ; the fact that 

 they consist of a number of parallel ramparts ; the further fact that 

 their main trunks have a number of branches ; their occurrence at 

 all levels from 2,000 feet downwards ; their running up and down 

 hill and being distributed entirely independently of the contours of 

 the country ; their sometimes occurring athwart each other and 

 sometimes as cross pieces joining two separate asars ; the rounded 

 and elliptical forms they assume when their continuity is broken : 

 all these facts seem to be at issue with their having been beaches. 



On the other hand, the sea in its normal moods does not diversify 

 its actual bed with such ramparts as these. The sea in its 

 normal action is a great leveller and smoother of its beds into 

 soft and curving outlines, and does not lay down upon it a succession 

 of ramparts with steep sides and running for scores of miles in direct 

 lines. Nevertheless, it is from the operations of the sea, not in its 

 normal but in its abnormal moods, that the only explanation of the 

 asar which fits in with the facts is derivable, and has long ago 

 been derived. Playfair has a pregnant passage on this subject 

 written long ago. " Sandbanks," he says, " such as abound in the 

 German Ocean, to whatever they owe their origin, are certainly 

 modified, and their form determined, by the tides and currents. 

 Without the operation of these last, banks of loose sand and mud 

 could hardly preserve their form and remain intersected by many 

 narrow channels. The formation of the banks on the coast of 

 Holland, and even of the Dogger Bank itself, has been ascribed to 

 the meeting of tides, by which a state of tranquillity is produced 

 in the waters, and in consequence a more copious deposition of 

 their mud. Even the gieat Bank of Newfoundland seems to be 



