The Voyage Of The Beagle By Charles Darwin





































































 -   So that the Portillo, the loftiest line
in this part of the Cordillera, is not so old as the less - Page 494
The Voyage Of The Beagle By Charles Darwin - Page 494 of 776 - First - Home

Enter page number    Previous Next

Number of Words to Display Per Page: 250 500 1000

So That The Portillo, The Loftiest Line In This Part Of The Cordillera, Is Not So Old As The Less Lofty Line Of The Peuquenes.

Evidence derived from an inclined stream of lava at the eastern base of the Portillo, might be adduced to show, that it owes part of its great height to elevations of a still later date.

Looking to its earliest origin, the red granite seems to have been injected on an ancient pre-existing line of white granite and mica-slate. In most parts, perhaps in all parts, of the Cordillera, it may be concluded that each line has been formed by repeated upheavals and injections; and that the several parallel lines are of different ages. Only thus can we gain time, at all sufficient to explain the truly astonishing amount of denudation, which these great, though comparatively with most other ranges recent, mountains have suffered.

Finally, the shells in the Peuquenes or oldest ridge, prove, as before remarked, that it has been upraised 14,000 feet since a Secondary period, which in Europe we are accustomed to consider as far from ancient; but since these shells lived in a moderately deep sea, it can be shown that the area now occupied by the Cordillera, must have subsided several thousand feet - in northern Chile as much as 6000 feet - so as to have allowed that amount of submarine strata to have been heaped on the bed on which the shells lived. The proof is the same with that by which it was shown, that at a much later period, since the tertiary shells of Patagonia lived, there must have been there a subsidence of several hundred feet, as well as an ensuing elevation.

Enter page number   Previous Next
Page 494 of 776
Words from 132394 to 132680 of 208183


Previous 494 495 496 497 498 499 500 501 502 503 Next

More links: First 10 20 30 40 50 60 70 80 90 100
 110 120 130 140 150 160 170 180 190 200
 210 220 230 240 250 260 270 280 290 300
 310 320 330 340 350 360 370 380 390 400
 410 420 430 440 450 460 470 480 490 500
 510 520 530 540 550 560 570 580 590 600
 610 620 630 640 650 660 670 680 690 700
 710 720 730 740 750 760 770 Last

Display Words Per Page: 250 500 1000

 
Africa (29)
Asia (27)
Europe (59)
North America (58)
Oceania (24)
South America (8)
 

List of Travel Books RSS Feeds

Africa Travel Books RSS Feed

Asia Travel Books RSS Feed

Europe Travel Books RSS Feed

North America Travel Books RSS Feed

Oceania Travel Books RSS Feed

South America Travel Books RSS Feed

Copyright © 2005 - 2022 Travel Books Online