| 释义 |
overˈsteepened, ppl. a. Physical Geogr.
[over- 22.]
Steepened further; esp. (of a valley) having a greater steepness than running water would have caused owing to the predominantly downward erosive action of a glacier. So overˈsteepening vbl. n.
1900W. M. Davis in Proc. Boston Soc. Nat. Hist. XXIX. 308 In the same way, the waterfalls from the hanging valleys, the showering waste that forms the falls, and the landslides from the basal cliffs, all show that the banks of the glacial channel—the lower walls of the existing valleys—are too steep; and they may be therefore called ‘oversteepened’. 1922Bull. U.S. Geol. Survey No. 730. 13 In the Black Canyon..the broad floor of the valley and the steep cliffs that rise precipitously 2,000 feet at its side suggest oversteepening of the walls by ice. 1942O. D. von Engeln Geomorphol. xix. 462 That side of a valley reach against which the glacier current impinges is regularly oversteepened. 1964Amer. Jrnl. Sci. CCLXII. 783 Over the bar itself the steepened profile increases velocity and tends to erode the obstruction. This enhancement of erosion in the over-steepened reach and deposition in the flat area will..tend to eliminate the original bar. 1970R. J. Small Study of Landforms iv. 131 Each stream profile displays several apparent knick-points or oversteepened sections coincident with the gorges. |