| 释义 |
scabland U.S. Physical Geogr.|ˈskæblænd|
[f. scab n. + land n.]
Flat, elevated land consisting of igneous rock with a patchy covering of poor, thin soil and little vegetation, and deeply scarred by channels of glacial or fluvioglacial origin; spec. that forming part of the Columbia Plateau, Washington State, U.S.A. Freq. pl.
1923J. H. Bretz in Bull. Geol. Soc. Amer. XXXIV. 577 The ‘Scablands’ are lowlands among the groups of ‘Palouse Hills’, plane in a general way, but diversified by a multiplicity of irregular and commonly anastomosing channels and rock-basins eroded in basalt, and containing meadows, swamps, and lakes... The local name refers to the absence of soil over much of these tracts, the basalt outcropping in ledges and over considerable level areas. 1923― in Jrnl. Geol. XXXI. 617 The terms ‘scabland’ and ‘scabrock’ are used in the Pacific Northwest to describe areas where denudation has removed or prevented the accumulation of a mantle of soil, and the underlying rock is exposed or covered largely with its own coarse, angular débris. Ibid. 620 The channeled scablands are the erosive record of large, high-gradient, glacier-born streams. 1943Science 10 Sept. 229/1 The rock basins of the scablands are found in the wider channels particularly, and rock basins are an almost universal feature of glaciated regions. It is the channels with their included low mesas which are the unique feature of the scablands. 1956C. Relander Drummers & Dreamers 235 The River People were virtually forgotten in their deep desolation of sagebrush, basaltic cliffs, raw umber hills and scabland. 1966N.Z. Jrnl. Geol. & Geophysics IX. 130 (heading) Antarctic scablands. 1976C. L. Matsch N. Amer. & Great Ice Age vi. 74 At peak stage Lake Missoula had a surface area of about 7,500 km2 and contained an estimated 2,000 km3 of water. All this water is thought to have discharged westward in a matter of a few days... This great flood moved boulders with diameters greater than 10 m and scoured a system of coulees across the Columbia Plateau. This great tract of flood-eroded topography is called the channeled scablands. |