20 



ELEVATION OF COASTS. 



Fig. 3. Temple of Serapis. 



sea to a height of about six- 

 teen feet above the pavement. 

 Marine animals then establish- 

 ed themselves on a portion of 

 the submerged columns, and 

 mollusks of the genus Pholas 

 excavated innumerable holes 

 in the same way as they do 

 rocKS now covered by the sea ; 

 but in the present day the state 

 of things is not the same, the 

 pavement of the temple is again 

 dry, and the traces of the pho- 

 lades we have just mentioned 

 are at a considerable height 

 above the level of the sea (fig. 

 3). Now, these changes in the 

 relative levels of the coast of 

 Puzzuoli, and the neighbour- 

 ing sea, cannot be attributed 

 to an alternate sinking and rise 

 of the waters, because move- 



ments of this sort must have been accompanied by fearful inun- 

 dations along the shores of the Mediterranean, and we cannot ex- 

 plain this phenomenon except by supposing that the coast itself, 

 after sinking, was again gradually raised up. 



34. At the present time Scandinavia and Chile exhibit an 

 analogous phenomenon. On the coasts of Sweden, for example, 

 we see certain rocks, which were formerly submerged, now above 

 water, and that the steep shore is gradually rising more and more 

 above the level of the sea. For a long time it was observed that 

 the sea abandoned certain parts of the coast, and that the depth of 

 water decreased in several ports of this region ; but these changes 

 of level have been ascertained in a more exact manner ; more than 

 a century since, marks were made on different rocks on a line with 

 the surface of the water, to serve as points of comparison, and on 

 examining them from year to year, il was found that these marks 

 were successively higher and higher above the level of the sea. 

 In the gulf of Bothnia, this rise appeared to be four feet in a 

 century, but at other places less, and at some points on the coasts 

 of the Baltic, it was nothing, which proves that the change of level 

 does not depend on the subsidence of the sea. 



We shall recur to the subject of stratification and the various 

 causes which influence it, after we have studied the characters o r 

 the various formations. 



34. What other instances Drove the slow movement of strata 



