Personal Narrative Of Travels To The Equinoctial Regions Of America During The Years 1799-1804 - Volume 1 - By Alexander Von Humboldt And Aime Bonpland.
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The Parasite Monocotyledons Take
Between The Tropics The Place Of The Moss And Lichens Of Our
Northern Zone.
As we advanced, the forms and grouping of the rocks
reminded us of Switzerland and the Tyrol.
The heliconia, costus,
maranta, and other plants of the family of the balisiers (Canna
indica), which near the coasts vegetate only in damp and low
places, flourish in the American Alps at considerable height. Thus,
by a singular similitude, in the torrid zone, under the influence
of an atmosphere continually loaded with vapours the mountain
vegetation presents the same features as the vegetation of the
marshes in the north of Europe on soil moistened by melting snow.*
(* Wahlenberg, de Vegetatione Helvetiae et summi Septentrionis
pages 47, 59.)
Before we leave the plains of Cumana, and the breccia, or
calcareous sandstone, which constitutes the soil of the seaside, we
will describe the different strata of which this very recent
formation is composed, as we observed it on the back of the hills
that surround the castle of San Antonio.
This breccia, or calcareous sandstone, is a local and partial
formation, peculiar to the peninsula of Araya, the coasts of
Cumana, and Caracas. We again found it at Cabo Blanco, to the west
of the port of Guayra, where it contains, besides broken shells and
madrepores, fragments, often angular, of quartz and gneiss. This
circumstance assimilates the breccia to that recent sandstone
called by the German mineralogists nagelfluhe, which covers so
great a part of Switzerland to the height of a thousand toises,
without presenting any trace of marine productions. Near Cumana the
formation of the calcareous breccia contains: - first, a compact
whitish grey limestone, the strata of which, sometimes horizontal,
sometimes irregularly inclined, are from five to six inches thick;
some beds are almost unmixed with petrifactions, but in the
greatest part the cardites, the turbinites, the ostracites, and
shells of small dimension, are found so closely connected, that the
calcareous matter forms only a cement, by which the grains of
quartz and the organized bodies are united: second, a calcareous
sandstone, in which the grains of sand are much more frequent than
the petrified shells; other strata form a sandstone entirely free
from organic fragments, yielding but a small effervescence with
acids, and enclosing not lamellae of mica, but nodules of compact
brown iron-ore: third, beds of indurated clay containing selenite
and lamellar gypsum.
The breccia, or agglomerate of the sea-coast, just described, has a
white tint, and it lies immediately on the calcareous formation of
Cumanacoa, which is of a bluish grey. These two rocks form a
contrast no less striking than the molasse (bur-stone) of the Pays
de Vaud, with the calcareous limestone of the Jura. It must be
observed, that, by contact of the two formations lying upon each
other, the beds of the limestone of Cumanacoa, which I consider as
an Alpine limestone, are always largely mixed with clay and marl.
Lying, like the mica-slate of Araya, north-east and south-west,
they are inclined, near Punta Delgada, under an angle of 60
degrees to south-east.
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