| 释义 |
▪ I. silt, n.|sɪlt|
Also 5 cylt(e, 6 sylt, 9 silth.
[Of doubtful origin, but app. denoting a salty deposit: cf. Da. and Norw. sylt, Norw. and Sw. dial. sylta salt-marsh, sea beach; OLG. sulta (MLG. and LG. sulte, sülte, older Flem. sulte, Du. zult), OHG. sulza (MHG. sulze, G. sülze) salt-marsh, salt-pan, brine, all f. sult-, ablaut-variant of salt-: see salt n.1 and v.1 One or other grade of the same stem is also represented by OE. un(ᵹe)sylt unsalted, Du. zilt adj. salt.]
1. a. Fine sand, clay, or other soil, carried by moving or running water and deposited as a sediment on the bottom or beach; sometimes occurring as a stratum in soil.
αc1440Promp. Parv. 77 Cylte, soonde, glarea. 1523Skelton Garland Laurel 23 Thus stode I in the frytthy forest of Galtres, Ensowkid with sylt of the myry mose. 1610Holland Camden's Brit. i. 529 This Country which the Ocean hath laied to the land, by sands heaped and cast together, they it terme Silt. a1676Hale Prim. Orig. Man. (1677) 191 The great Changes that have been between the Sea and Lands..by casting up Silt and Sand. 1692Ray Disc. 45 The interjacent Fretum having been filled up by the Silt brought down by the River Nilus. a1707Patrick On Deut. xi. 11 Many times there followed, after the water was gone off, great sicknesses and diseases, by the smell of the silt which it had left behind. 1799View Agric. Lincoln 265 The stratum of silt in this neighbourhood is every where impregnated with salt. 1823Buckland Reliq. Diluv. 190 On the east coast of England there is also a considerable addition of silt and mud on some parts. 1863Kingsley Water-Bab. viii, Before Tom had stood there five minutes, he was buried in silt up to his ankles. 1878Huxley Physiogr. xvii. 280 When the Thames has overflowed its banks it has deposited silt on the neighbouring land.
fig.1870Lowell Among my Bks. Ser. i. (1873) 223 The perpetual silt of some one weakness. 1890Hall Caine Bondman iv, Such was the grey silt that came up to him that night from the deposits of his memory.
β1813Priest View Agric. Bucks. 23 These streams..are suffered to be filled with silth, rubbish, and all sorts of aquatic plants. 1839Civil Eng. & Arch. Jrnl. II. 99/1 There will be water undoubtedly, as the ground is sand and gravel, with silth below.
b. A bed or layer of this matter.
1881Rep. Geol. Expl. N.Z. 34 A dyke occurring close to the silts, which stretch from Tokatoka south past the Dwaroa river.
c. Soil. Sci. Applied spec. to particles whose sizes fall within a specified size range between those of sand and clay and to soils having a specified proportion of such particles (see quots.). Hence silt-grade; silt-size n. (adj.).
1873Amer. Jrnl. Sci. CVI. 288 It makes a material difference whether the grains of sand contained in a soil or clay are prevalently half a millimeter in diameter, or the tenth or twentieth part of that amount. Sand (or more properly silt) of the latter size is by no means impalpable. 1909A. G. McCall Physical Properties of Soils 88 Stir up the soil remaining in the centrifugal tube and allow to stand for about one minute, or until all particles larger than silt (0·05 [mm.]) have settled. 1920Silt grade [see siltstone]. 1958I. W. Cornwall Soils for Archaeologist xi. 125 Once the silt-grade is reached (below 0·06 mm.) a moderate wind is able to transport the grains..for long distances. 1967Gloss. Highway Engin. Terms (B.S.I.) 23 Silt. (1) A natural sediment of grading finer than sand consisting of granular products of rock weathering: it is gritty to the touch. (2) In soil analysis it comprises the fraction between 0·06 mm and 0·002 mm. 1968R. W. Fairbridge Encycl. Geomorphol. 675/1 Primary forms of lime include minute grains, incrustations on silt-size grain aggregates and snail shells. 1971Gloss. Soil Sci. Terms (Soil Sci. Soc. Amer.) 15/1 Silt, a soil separate consisting of particles between 0·05 and 0·002 mm in equivalent diameter. 1972[see sand n.2 1 h]. 1976L. F. Curtis et al. Soils in Brit. Isles i. 3 The mineral matter [of soil] includes particles of clay (less than 2 µm diameter), silt (2–50 µm diameter) and sand (50 µm–2 mm diameter).
†2. pl. Dregs, refuse, scum. Obs.—1
1635Heylin Sabbath ii. (1636) 107 The common prostitutes, such as received the silts of all the towne.
3. A silt-snapper (see 4).
App. an alteration of the earlier silk(-snapper).
1863Jamaica Notes in Intellect. Obs. III. 194 The mode of fishing for deep-water Silts is very effective. 1883Fish. Exhib. Catal. (ed. 4) 170 The principal salt-water fishes are..Silts,..King-fish, Barracouta and many others.
4. attrib. and Comb., as silt-land, silt-trap; silt-bearing adj.; silt-bucket, grass, -ground (see quots.); silt loam, a soil composed at least half of silt; silt-snapper, a Jamaican fish (cf. 3); siltstone Petrol. (see quot. 1920).
1884Manch. Exam. 3 May 4/7 A silt-bearing river like the Mersey.
1884Health Exhib. Catal. 57/1 Silt-buckets for preventing the choking of drains.
1889J. H. Maiden Useful Plants 104 Paspalum distichum,..‘Sea-side Millet’, ‘Water Couch’, ‘Silt Grass’.
1863Jamaica Notes in Intellect. Obs. III. 194 [A canoe] on its way to the Silt-ground at two hundred fathoms depth.
1927Daily Express 11 July 11/3 Both fenland and silt-land in these counties boast rich alluvial soil. 1963Times 1 Feb. 13/6 Being essentially a study of the silt lands that border the Wash, it did not attempt to deal in detail with the equally interesting Roman occupation of the southern part of the region.
1917Mosier & Gustafson Soil Physics & Management x. 138 The silt loam soils cover extensive areas in the middle west of the United States and owe their origin to loess. 1957H. B. Vanderford Managing Southern Soils iv. 93 Surface soils which have medium to coarse textures (sandy loams, silt loams, and clay loams) are suitable for cultivation and relatively easy to keep in good tilth.
1863Jamaica Notes in Intellect. Obs. III. 194 The deep-water Silt-Snappers include some five different species, all similar in colour.
1920A. Holmes Nomencl. Petrol. 211 Siltstone, a very fine-grained sandstone, the particles of which are predominantly of silt grade. 1946L. D. Stamp Britain's Struct. & Scenery xii. 116 The lower Carboniferous deposits in the Central Lowlands of Scotland are sandstones, shales, cementstones and siltstones with only occasional bands of limestones. 1977A. Hallam Planet Earth 264 The graptolites..are often common in offshore black shales and siltstones.
1946F. D. Davison Dusty viii. 84 They..were going to clear out the silt-trap of one of the tanks. 1966E. Palmer Plains of Camdeboo xviii. 301 Dams, water-troughs, silt traps.
▪ II. silt, v.
[f. the n.]
1. a. intr. Of a channel, river-bed, etc.: To become filled or choked up with silt or sediment. Also fig.
1799View Agric. Lincoln 16 [The well] runs equally every year, and in all seasons,..but it is apt to silt up. 1830Lyell Princ. Geol. I. 304 There is naturally a tendency in all estuaries to silt up partially. 1840Evid. Hull Docks Com. 79 The harbour is silting up at the east point. 1873G. C. Davies Mountain & Mere v. 28 As the years rolled on, the water subsided, the hollows silted up. 1955Times 10 June 7/3 [The] streets of London silt up with the swelling torrent of motor traffic.
b. To flow or drift in after the manner of silt. Also transf. to pass gradually away.
1863H. Kingsley A. Elliott I. 33 If the wreck of the Mary Anne was moved, the sand would silt in again. 1892Clark Russell List, ye Landsmen iii, It seemed to me that the electric mass was silting away north, and that there would come a clear sky in the south presently.
2. trans.
a. Of silt: To fill, block, or choke up (a channel, the bed of a river or the sea, etc.) by gradual accumulation. Also rarely without up. Chiefly in pa. pple.
a1825Forby Voc. E. Anglia 301 Silt-up, to obstruct..by a large accumulation of sand. 1832Lyell Princ. Geol. II. 275 The deposits which within the historical period have silted up some of our estuaries. 1865Esquiros Cornwall 158 The sands with which the mouth of the Exe is silted. 1875J. Croll Climate & T. xxix. 469 That the tendency of the sea filling this valley is to silt it up rather than to deepen it.
transf.a1853Robertson Lect. i. (1858) 43 The sand of the desert daily silting up the temples. 1860Maury Phys. Geog. Sea x. §481 The whole Atlantic ocean would..be finally silted up with salt.
fig.1855Bailey Mystic 59 While Time's last sands silt up the streams of soul.
b. To cover up or over with silt.
1830Herschel Study Nat. Phil. ii. vi. (1851) 145 To leave his shell in the mud where it becomes silted over and imbedded. 1878Huxley Physiogr. 224 If, by the overflow of a river, the plant should become silted up in mud.
Hence ˈsilted ppl. a.: also with up.
1890Clacton News 25 Jan. 2/4 The silted matter from the ditch is generally required to make up the bank. 1960Archaeologia Cambrensis CIX. 56 The excavations..revealed a massive stone platform built partly on the peat filling of a silted-up cistern. |