Contribution
The Start of an Ephemeral Stream
Wertz, Jacques B.
Zeitschrift für Geomorphologie Volume 14 Issue 1 (1970), p. 96 - 102
7 références bibliographiques
publié: Apr 24, 1970
ArtNo. ESP022001401004, Prix: 29.00 €
Abstract
Nowhere, it seems, is the start of an ephemeral stream as spectacularly exhibited as in some parts of the California desert. From a uniformly flat surface without an apparent break in the topography, a ravine suddenly opens up, increasing in depth into a canyon-like gash. This abrupt change is further emphasized by the relative narrowness of the channel, and the wanderer who happens to follow the valley may be quite at a loss, at places, to get out, as the walls may be very steep and almost vertical. Nowhere is the start of the ephemeral stream more interesting to observe because the conspicuous desert varnish, this shiny, dark brown coating of pebbles that characterize the flat, undissected portions of the peripediment, adds a tangible clue as to the origin of a new valley.
Kurzfassung
Tief eingeschnittene Rinnen scheinen sich sehr plötzlich zu bilden. Veränderungen in der Vegetation und im Wüstenlack spiegeln einiges über den Vorgang zu Beginn der Rinnenbildung wider.
Résumé
De profonds ravins semblent apparaître de façon plutôt soudaine. Il est possible de déceler le début du creusement de tels nouveaux chenaux dans des modifications de la couverture végétale et la répartition de vernis désertique.