| 释义 |
▪ I. boulder, bowlder, n.1|ˈbəʊldə(r)|
Also dial. boother, bowder.
[Shortened f. boulder-stone.]
1. A water-worn rounded stone, varying in size, but properly larger than a pebble, used frequently for paving and building purposes; a cobble.
1617Markham Caval. i. 57 Paued with pibble boulder, or some other kind of small stone. 1811Pinkerton Petral. I. 265 Brown clay slate, in bowlders, found in the bed of the Alecnundra. 1837Carlyle Fr. Rev. I. v. ix. 256 The Bastille..sinks day by day..its ashlars and boulders tumbling down continually. 1871Tyndall Fragm. Science (ed. 6) I. vi. 209 Fastened the sail at the top, and loaded it with boulders at the bottom.
2. spec. Geol. A large weather-worn mass or block of stone, frequently carried by natural forces to a greater or less distance from the parent rock, and generally lying on the surface of the ground, or in superficial deposits; an erratic block.
1813Bakewell Introd. Geol. (1815) 73 Some of the vertical beds of rock covering the granite contain..boulders. 1830Lyell Princ. Geol. I. 369 Enormous rounded boulders..of trachyte and basalt. 1859Darwin Orig. Spec. xii. 335 Erratic boulders have..been noticed on the Rocky Mountains.
fig.1858Hawthorne Fr. & It. Jrnls. (1872) I. 14 The first Napoleon..a great boulder in history.
3. transf. A lump or mass of some material; spec. in Mining, a large detached piece of ore found away from the regular lode. Also attrib. in the sense of ‘big, lumpy’.
1861Sala Tw. round Clock 173 Its boulders of whitening, and its turpentine-infected bundles of firewood. 1862Dana Man. Geol. 537 Boulders of Native Copper have been found. 1882Pall Mall G. 31 May 4/1 The birds will have..all of the seed; the boulder clods will never cover it.
4. Comb.: boulder-strewed, boulder-strewn adjs.; boulder-belt, a belt of boulders deposited by a glacier on melting; boulder-clay, a clayey deposit belonging to the ice-age, and containing boulders, etc.; boulder-drift = boulder-formation; boulder-flat, a tract of country strewed with boulders; boulder-formation, a formation or deposit consisting of mud, clay, etc., in which boulders are embedded; boulder-head, a kind of sea-wall; boulder-pavement, a bed of boulders naturally arranged; boulder-paving, paving made of boulders; boulder-period, the geological epoch in which boulder-formations were being produced, the Ice Age or Glacial Period; boulder-train, boulders deposited by the melting of a glacier; boulder-walls (see quot.).
1894J. Geikie Gt. Ice Age (ed. 3) 742 In some instances these *boulder-belts are all the marginal morainic representatives that can be detected over considerable tracts.
1859H. Miller Sketch-Bk. Pop. Geol. i. 30 The *boulder-clay exhibits certain unique appearences. 1878Huxley Physiogr. xvii. 282 An icy sea, from which the boulder clay and glacial gravels were deposited. 1884Dawson in Handbk. Canada 324 Stratified sands and gravels overlying the boulder-clay.
1876Page Adv. Text-bk. Geol. xix. 355 The *boulder-drift is a bold and clearly-defined formation.
1884J. Colborne With H. Pasha 44 The road across this *boulder-flat consisted of numerous pathways running side by side.
1845Darwin Voy. Nat. ix. (1873) 180 Fragments of primitive rocks derived from the surrounding *boulder-formation were very numerous.
1894J. Geikie Gt. Ice Age (ed. 3) 523 Here and there ‘*boulder-pavements’ occur.
1845Darwin Voy. Nat. viii. 174 The ice-transporting *boulder-period.
1897Outing (U.S.) XXIX. 339/2 A wearisome tramp over the *boulder-strewed mountain side. 1897Daily News 5 May 3/1 Arta Hill, bleak and boulder strewn.
1899Westm. Gaz. 11 Dec. 8/1 The precipitous *boulder-strewn heights.
1967Oceanogr. & Marine Biol. V. 135 *Boulder trains between drumlins along the New England coast are effective means of such protection.
1738Chambers Cycl., *Boulder-walls, a kind of walls built of round flints or pebbles, laid in a strong mortar.
▪ II. ˈboulder, bolder, n.2
The bulrush (Scirpus lacustris); ‘the rush used for bottoming chairs’.
1847–78Halliwell, Bolder. 1884G. C. Davies Norfolk Broads iii. 24 The weeds and boulders (or clumps of flags).
▪ III. boulder, v.|ˈbəʊldə(r)|
[f. boulder n.1]
To make into boulders. (Perh. only in pa. pple.)
1839Murchison Silur. Syst. i. xxxix. 540 They may have been carried down by streams to the shores, and have been long bowldered there. |