repeatedly injected, after intervals sufficiently long to allow the
upper parts or wedges to cool and become solid;--for if the strata had
been thrown into their present highly inclined, vertical, and even
inverted positions, by a single blow, the very bowels of the earth
would have gushed out; and instead of beholding abrupt mountain-axes of
rock solidified under great pressure, deluges of lava would have flowed
out at innumerable points on every line of elevation. [2]
[1] M. Arago in L'Institut, 1839, p. 337. See also Miers's Chile, vol.
i. p. 392; also Lyell's Principles of Geology, chap. xv., book ii.
[2] For a full account of the volcanic phenomena which accompanied the
earthquake of the 20th, and for the conclusions deducible from them, I
must refer to Volume V. of the Geological Transactions.
CHAPTER XV
PASSAGE OF THE CORDILLERA
Valparaiso--Portillo Pass--Sagacity of Mules--Mountain-torrents--Mines,
how discovered--Proofs of the gradual Elevation of the
Cordillera--Effect of Snow on Rocks--Geological Structure of the two
main Ranges, their distinct Origin and Upheaval--Great Subsidence--Red
Snow--Winds--Pinnacles of Snow--Dry and clear
Atmosphere--Electricity--Pampas--Zoology of the opposite Side of the
Andes--Locusts--Great Bugs--Mendoza--Uspallata Pass--Silicified Trees
buried as they grew--Incas Bridge--Badness of the Passes
exaggerated--Cumbre--Casuchas--Valparaiso.
MARCH 7th, 1835.--We stayed three days at Concepcion, and then sailed
for Valparaiso. The wind being northerly, we only reached the mouth of
the harbour of Concepcion before it was dark. Being very near the
land, and a fog coming on, the anchor was dropped. Presently a large
American whaler appeared alongside of us; and we heard the Yankee
swearing at his men to keep quiet, whilst he listened for the breakers.
Captain Fitz Roy hailed him, in a loud clear voice, to anchor where he
then was. The poor man must have thought the voice came from the
295