24 Anniversary Address of the 



must have been arranged in beds which sloped away from 

 their parent rocks of the Alps; yet after sinking successively 

 to enormous depths, they have been brought up again, so 

 as to dip towards the older rocks, as if they passed under 

 them. 



The first part of this grand subsidence of the sea-bottom 

 was doubtless analogous to that now in progress on part of 

 the coast of Greenland. But if the adjoining land partici- 

 pated in the same downward movement, it is difficult to con- 

 ceive how it escaped being submerged, or how it could con- 

 tinue to retain its size and altitude so as to continue to be 

 the source of such an inexhaustible supply of pebbles. We 

 can scarcely avoid speculating on a contemporaneous slow 

 upheaval of the mountains. There may have been an ascend- 

 ing movement in one region, and a descending one in a con- 

 tiguous parallel zone of country, as the northern part of 

 Scandinavia is now rising while the southern portion in 

 Scania is sinking, or at least has sunk within the historical 

 period. Perhaps the not uncommon occurrence, of deep sea 

 in the immediate vicinity of bold coasts and mountain-chains, 

 may be connected with extensive lines of fault, parallel to 

 the shores, on the opposite sides of which vertical move- 

 ments may be taking place in contrary directions, or one 

 side may be motionless, while the other is subsiding. In no 

 other way does it seem possible to account for the proximity, 

 throughout a long series of ages, of high land, and of a sea- 

 bottom always going down so gradually as to remain for a 

 long time the receptacle of annual tributes of rolled pebbles, 

 and acquiring in the end a thickness of 5000 and 8000 feet. 

 In regard to faults which have shifted rocks several thousand 

 feet in a vertical direction, it is often too hastily assumed 

 that they must have been produced suddenly ; whereas the 

 reverse is indicated by the fact that the walls of such faults 

 are rubbed, polished, and striated, as if they had been sub- 

 jected to friction long continued, or many times repeated. 

 The mass moreover of fragmentary matter usually included 

 between the opposite walls of such rents is partly reduced to 

 fine clay or dust, and partly filled with stone which have been 

 supei*ficially scored in various directions. 



