| 释义 |
Silurian, a. and n.1|sɪˈljʊərɪən, saɪ-|
[f. L. Silur-es, an ancient British tribe which inhabited the south-eastern part of Wales.]
1. Of or belonging to the ancient Silures, or to the district inhabited by them.
1708J. Philips Cyder ii. 89 To the utmost Bounds of this Wide Universe, Silurian Cyder borne shall please all Tasts. 1740Somerville Hobbinol iii. 97 Others apart, in the cool Shade retir'd, Silurian Cyder quaff. 1757Dyer Fleece i. 492 If your sheep are of Silurian breed. 1839Murchison Silurian Syst. p. xxxi, We have no precise definition of the geographical limits of the Silurian kingdom. 1908Outlook 14 Nov. 656/1 The hero who is sometimes called a ‘British’, and sometimes a ‘Silurian’ chief.
2. a. Geol. Orig., the name given to the system or series of Palæozoic rocks lying immediately below the Devonian or Old Red Sandstone; of or belonging to this formation, or to the period when it was deposited. Now, the name is restricted to a system of Lower Palæozoic rocks underlying the Devonian and overlying the Ordovician, so corresponding to the Upper Silurian as originally defined.
As orig. defined by Murchison the Silurian included what was subsequently called the Ordovician, and this use continued for a time after the introduction of the Ordovician in 1879.
1835Murchison in Philos. Mag. July 48, I venture to suggest that..the term ‘Silurian System’ should be adopted as expressive of the deposits which lie between the old red sandstone and the slaty rocks of Wales. 1842Miller O.R. Sandst. xiii. (ed. 2) 275 The animal organisms of the newer Silurian strata form essentially different groups from those of the Lower Old Red Sandstone. 1851Richardson Geol. viii. (1855) 208 The seas of the silurian and oolitic periods. 1876Nature XIV. 557/2 The classification of the Silurian, Devonian, and Permo-Triassic (Poikilitic) formations. 1879C. Lapworth in Geol. Mag. VI. 3 The Lyell-Hicks division of Cambrian and Lower Silurian are as rightly entitled to the rank of separate systems as the true or Upper Silurian itself. Ibid. 9 The general restriction of the title Silurian to the strata that are comprehended between the line marking the base of the Lower Llandovery, and that denoting the commencement of the brackish or fresh-water conditions of the typical Old Red Sandstone, appears..inevitable. Ibid. 15 The ideas of the extreme party which claims all the Lower Palæozoics for the Silurian are fated soon to become wholly extinct. 1902A. J. Jukes-Browne Student's Handbk. Stratigr. Geol. vii. 64 Murchison supposed that Sedgwick's Cambrian lay entirely below his Silurian, but when the fossils were collected and described, it was found that the Upper Cambrian was equivalent to the Lower Silurian... Group after group of Sedgwick's Cambrian was gradually absorbed into it [sc. the Lower Silurian], till the Lower Silurian came to include the whole of the rocks (below the Upper Silurian) in which any fossils had been found. 1903A. Geikie Text-Bk. Geol. (ed. 4) II. 934 Murchison's ‘Lower Silurian’ has by many writers been replaced by ‘Ordovician’, and his ‘Upper Silurian’ is in a similar manner being ousted by some other term... I shall continue to employ Murchison's terminology. 1912Q. Jrnl. Geol. Soc. LXVIII. 332 In fixing the boundary between the Ordovician and the Silurian the peculiar characters and mode of weathering of the Lower Birkhill rocks have been found useful. 1931Gregory & Barrett Gen. Stratigr. v. 77 The Silurian is now usually restricted to the strata between the Ordovician and Devonian. 1955[see Gotlandian, Gothlandian a.]. 1964Rep. Internat. Geol. Congr. XXI Sess., 1960 XXVIII. 254 The Commission transmits to the Congress the following proposals on the terminology of the Silurian and Ordovician... 1) Two systems are to be recognized between the Cambrian and Devonian systems. 2) The name of the lower shall be Ordovician. 3) The name of the upper shall be Silurian. 1971Jrnl. Geol. Soc. CXXVII. 106 When the standard classification of the correlation charts is considered in relationship to local successions the Silurian of the British Isles is found to be something of a monument to stratigraphical chaos.
b. As n. in pl. Silurian strata.
1842Penny Cycl. XXII. 13/2 Upper Silurians,..Lower Silurians. 1855J. Phillips Man. Geol. 89 It [sc. gneiss] may be regarded as older than the silurians of that region. 1862Chambers's Encycl. III. 541/1 The clay-slates of the Lower Silurians.
c. transf., loosely designating a primitive age or period in the remote past.
1875‘Mark Twain’ in Atlantic Monthly Aug. 193/2 In the Old Oölitic Silurian Period, just a million years ago next November. 1962E. Snow Red China Today (1963) xvi. 116 When I last saw Mao..China was weak, disunited and bankrupt. Since then China's Silurian age had ended. ‘China has stood up,’ as Mao proclaimed.
3. Also with lower-case initial.
a. Of, pertaining to, or designating a paper showing two or more contrasting colours on its surface; usu. applied to stationery of a blue-grey appearance. Also, of the colour itself.
1892J. Heywood Wholesale Catal. Stationery & Stationers' Sundries 22 Scotch Tinted Writings... Silurian—5 8. 1930W. de la Mare On the Edge 28 The drawer beneath contained only envelopes and letter paper—Montrésor, in large pale-blue letters on a ‘Silurian’ background. 1937E. J. Labarre Dict. Paper 153/1 Granite paper, also termed French grey, Ingres, Silurian grey, Mottled, Ingrain, is paper which clearly shows two or more contrasting colours of pulp on its surface. 1964M. Clive Day of Reckoning viii. 73 Their correspondents wrote on double sheets of grey ‘silurian’ paper which looked hairy but was slippery.
b. As n., paper or stationery of this type.
1942H. A. Maddox Dict. Stationery (ed. 2) 100 Silurian, a tinted writing paper formerly much in favour for note and envelopes. Characterised by a blue-grey mottled colour which gave rise to the occasional term, French Granite. 1954Paper Terminol. (Spalding & Hodge) 54 Silurian, coloured paper, usually a writing or cover, produced by introducing into the coloured pulp, fibres dyed a deeper shade. 1960D. Holman-Hunt My Grandmothers & I i. 24, I..sucked the pen and began to scratch at the grey silurian. |