? oo Formation of Valleys. past h. 



o 



I was assured had been carried onwards during floods ; 

 yet we have seen in the lower parts of the valleys, that 

 the torrents have seldom removed all the sea-checked 

 shingle forming the terraces, and have had time since 

 the last elevation in mass only to cat in the under- 

 lying rocks, gorges, deep and narrow, but quite insigni- 

 ficant in dimensions compared with the entire width 

 and depth of the valleys. 



Along the shores of the Pacific, I never ceased 

 during my many and long excursions to feel astonished 

 at seeing every valley, ravine, and even little inequality 

 of surface, both in the hard granitic and soft tertiary 

 districts, retaining the exact outline, which they had 

 when the sea left their surfaces coated with organic 

 remains. When these remains shall have decayed, 

 there will be scarcely any difference in appearance be- 

 tween this line of coast-land and most other countries, 

 which we are accustomed to believe have assumed their 

 present features chiefly through the agency of the 

 weather and fresh-water streams. In the old granitic 

 districts, no doubt it would be rash to attribute all the 

 modifications of outline exclusivelv to the sea-action; 

 for who can say how often this lately submerged coast 

 may not previously have existed as land, worn by run- 

 ning streams and washed by rain ? This source of doubt, 

 however, does not apply to the districts superficially 

 formed of the modern tertiary deposits. The valleys 

 worn bv the sea. through the softer formations, both on 

 the Atlantic and Pacific sides of the continent, are 

 generally broad, winding, and flat-bottomed : the only 

 district of this nature now penetrated by arms of the 

 sea, is the Island of Chiloe. 



Finally, the conclusion at which I have arrived, 

 with respect to the relative powers of rain and sea water 

 on the land, is, that the latter is far the most efficient 



