The National Geographic Magazine, Vol. II., No. 2, May, 1890

The National Geographic Magazine, Vol. II., No. 2, May, 1890

Northern New Jersey is drained by several streams which rise in the Archean Highlands, flow southeastward across the central Triassic plain and reach the sea near the inland margin of the Cretaceous formation. What kinds of rivers are these? Such a question can hardly be answered until we have examined rivers in many parts of the world, gaining material for a general history of rivers by induction from as large as possible a variety of examples; and until we have deduced from our generalizations a series of critical features sufficient to serve for the detection of rivers of different kinds wherever found. Consequent rivers.Those that have in their birth, at the time of their original establishment on the country which they drain, selected courses in accordance with the constructional slopes of the surface; for example, the Red River of the North and such of its branches as flow on the even surface of the lacustrine plain of Lake Agassiz; the several streams that drain the broken lava blocks of Southern Oregon; certain streams and rivers of the Jura that drain the synclinal troughs of those mountains. Consequent streams may be divided into definite and indefinite groups. Definite consequent streams are those that follow well defined constructional channels, such as the axial line of a synclinal trough, or the lowest point of an anticlinal arch between two synclinal basins; they are defined in location as well as in direction. Indefinite consequent streams are those that flow down constructional slopes, such as the flanks of an anticline, but whose precise location depends on those minor inequalities of surface that we term accidental; they are defined in direction but not in location; and they are as a rule branches of definite consequent streams. ......Buy Now (To Read More)

Product details

Ebook Number: 51382
Author: Various
Release Date: Mar 6, 2016
Format: eBook
Language: English