Recipient,
approaches so near the banks of the basin or the ridge of partition
that the ridge partly crosses it.
The distribution of the inequalities of the surface of the globe does
not present any strongly marked limits between the mountainous country
and the low regions, or geologic basins. Even where real chains of
mountains rise like rocky dykes issuing from a crevice, spurs more or
less considerable, seem to indicate a lateral upheaving. While I admit
the difficulty of properly defining the groups of mountains and the
basins or continuous plains, I have attempted to calculate their
surfaces according to the statements contained in the preceding
sheets.
TABLE OF AREAS FOR SOUTH AMERICA.
COLUMN 1 : GEOGRAPHICAL LOCATION.
COLUMN 2 : AREA IN SQUARE MARINE LEAGUES.
1. MOUNTAINOUS PART:
Andes : 58,900.
Littoral Chain of Venezuela : 1,900.
Sierra Nevada de Merida : 200.
Group of the Parime : 25,800.
System of the Brazil mountains : 27,600.
TOTAL : 114,400.
2. PLAINS:
Llanos of the Lower Orinoco, the Meta, : 29,000.
and the Guaviare
Plains of the Amazon : 260,400.
Pampas of Rio de la Plata and Patagonia : 135,200.
Plains between the eastern chain of the
Andes of Cundinamarca and the chain of Choco : 12,300.
Plains of the shore on the west of the Andes : 20,000.
TOTAL : 456,900.
The whole surface of South America contains 571,300 square leagues (20
to a degree), and the proportion of the mountainous country to the
region of the plains is as 1 to 3.9. The latter region, on the east of
the Andes, comprises more than 424,600 square leagues, half of which
consists of savannahs; that is to say, it is covered with gramina.
SECTION 2.
GENERAL PARTITION OF GROUND.
DIRECTION AND INCLINATION OF THE STRATA.
RELATIVE HEIGHT OF THE FORMATIONS ABOVE THE LEVEL OF THE OCEAN.
In the preceding section we have examined the inequalities of the
surface of the soil, that is to say, the general structure of the
mountains and the form of the basins rising between those variously
grouped mountains. These mountains are sometimes longitudinal, running
in narrow bands or chains, similar to the veins that preserve their
directions at great distances, as the Andes, the littoral chain of
Venezuela, the Serra do Mar of Brazil, and the Alleghenies of the
United States. Sometimes they are in masses with irregular forms, in
which upheavings seem to have taken place as on a labyrinth of
crevices or a heap of veins, as for example in the Sierra Parime and
the Serra dos Vertentes. These modes of formation are linked with a
geognostic hypothesis, which has at least the recommendation of being
founded on facts observed in remote times, and which strongly
characterize the chains and groups of mountains.
