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I.—On Denudation now in Progress 1

Published online by Cambridge University Press:  01 May 2009

Archibald Geikie
Affiliation:
Director of the Geological Survey of Scotland.

Extract

The extent to which a country suffers denudation at the present time is to be measured by the amount of mineral matter removed from its surface and carried into the sea. An attentive examination of this subject is calculated to throw some light on the vexed question of the origin of valleys and also on the value of geological time. Of the mineral substances received by the sea from the land, one portion, and by far the larger, is brought down by streams, the other is washed of by the waves of the sea itself.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1868

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Footnotes

1

Abstract of part of a paper read before the Geological Society was of Glasgow on 26th March, and which will appear in a forthcoming part of the Transactions of that Society.

References

page 249 note 2 Tylor, , Phil. Mag., 4th series, v. 260 (1853). My attention was first called to this very obvious and instructive method of representing the results of denudation by some remarks of Mr. Croll in the Phil. Mag. for February, 1867. Mr. Tylor's earlier publication was afterwards pointed out to me by Professor Ramsay. Mr. Croll, following up the line of argument suggested in his former paper, has gone into further detail upon this subject in a memoir published in the Phil. Mag. for this month (May), which will be of essential service to geology.Google Scholar

page 250 note 1 These fractions represent the amount of solid rock removed from the drainagebasins, allowing 1·9 as the specific gravity of the silt, and 2·5 as that of average rock.

page 250 note 2 Repot on the physics and Hydraulics of the Mississippi River. 1861.Google Scholar

page 250 note 3 Appendix C to Second Report of Tidal Harbour Commission, 1847, p. 603.Google Scholar

page 251 note 1 Asie Centrale, tome i. 168.Google Scholar

page 254 note 1 The action of meteoric agents and of the sea is independent of subterranean movements, and must go on whether a land is upheaved or depressed. These movements will in some cases favour subaerial denudation, in others marine denudation, as shewn in the paper of which the above is an abstract. But in taking a generalized view of the subject their influenee may be disregarded.