Personal Narrative Of Travels To The Equinoctial Regions Of America During The Years 1799-1804 - Volume 3 - By Alexander Von Humboldt And Aime Bonpland.
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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. Considerations on the
aspect of a country are independent of those which indicate the nature
of the soil, the heterogeneity of matter, the superposition of rocks
and the direction and inclination of strata.
In taking a general view of the geological constitution of a chain of
mountains, we may distinguish five elements of direction too often
confounded in works of geognosy and physical geography. These elements
are: -
1. The longitudinal axis of the whole chain.
2. The line that divides the waters (divortia aquarum).
3. The line of ridges or elevation passing along the maxima of height.
4.
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