The story of the universe. Volume 2 (of 4) : $b The earth : land and sea
History
The story of the universe. Volume 2 (of 4) : $b The earth : land and sea
Astronomy; Earth (Planet); Natural history
The second European deluge is supposed to have been the result of
the formation and upheaval of the Alps. It has filled with débris
and transported material the valleys of France, Germany, and Italy
over a circumference which has the Alps for its centre. The proofs
of a great convulsion at a comparatively recent geological date are
numerous. The Alps may be from eighty to one hundred miles across,
and the probabilities are that their existence is due, as Sir Charles
Lyell supposes, to a succession of unequal movements of upheaval and
subsidence; that the Alpine region had been exposed for countless
ages to the action of rain and rivers, and that the larger valleys
were of pre-glacial times, is highly probable. In the eastern part
of the chain some of the Primary fossiliferous rocks, as well as
Oolitic and Cretaceous rocks, and even Tertiary deposits, are
observable; but in the central Alps these disappear, and more recent
rocks, in some places even Eocene strata, graduate into metamorphic
rocks, in which Oolitic, Cretaceous, and Eocene strata have been
altered into granular marble, gneiss, and other metamorphic schists;
showing that eruptions continued after the deposit of the Middle
Eocene formations. Again, in the Swiss and Savoy Alps, Oolitic and
Cretaceous formations have been elevated to the height of 12,000
feet, and Eocene strata 10,000 feet above the level of the sea; while
in the Rothal, in the Bernese Alps, occurs a mass of gneiss 1,000
feet thick between two strata containing Oolitic fossils.
Besides these proofs of recent upheaval, we can trace effects of two
different kinds, resulting from the powerful action of masses of
water violently displaced by this gigantic upheaval. At first broad
tracks have been hollowed out by the diluvial waves, which have, at
these points, formed deep valleys. Afterward these valleys have been
filled up by materials derived from the mountain and transported
into the valley, these materials consisting of rounded pebbles,
argillaceous and sandy mud, generally calcareous and ferriferous.
This double effect is exhibited, with more or less distinctness, in
all the great valleys of the centre and south of France. The valley
of the Garonne is, in respect to these phenomena, classic ground, as
it were.
The small valleys, tributary to the principal valley, would appear to
have been excavated secondarily, partly out of diluvial deposits, and
their alluvium, essentially earthy, has been formed at the expense of
the Tertiary formation, and even of the diluvium itself. Among other
celebrated sites, the diluvial formation is largely developed in
Sicily. The ancient temple of the Parthenon at Athens is built on an
eminence formed of diluvial earth.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account