The first are those which commonly
form the alpine countries, consisting of various schisti, of quartzy
stone, and granites. The second, again, are the whinstone or basaltic
hills scattered up and down the low country, and evidently posterior to
the strata of that country, which they break, elevate, and displace.
Thus there are in this country, as well as every where else, three
things to be distinguished; first, the alpine or elevated country;
secondly, the flat or low country; and, thirdly, that which has been of
posterior formation to the strata which it traverses, in whatever shape
or quality; whether as a mountain, or only as a vein; whether as a
basaltes, a porphyry, or a granite, or only as a metal, a siliceous
substance, or a spar.
Those three things which are here distinguished do not differ with
regard to the chemical character of their substances; for, in each of
these, every different substance is to be found, more or less; and it
is not in being composed of materials peculiar to itself, that makes an
alpine country be distinguished from a flat country; it is chiefly in
the changes which the strata of the alpine country have been made to
undergo, posterior to their original collection, that the rocks of the
alpine country differ from those of the flat country.
Pages:
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553