| 释义 |
oolite Min. and Geol.|ˈəʊəlaɪt|
[a. F. oölithe (Dict. Acad. 1762), mod.L. oölitēs, f. Gr. ᾠόν egg + λίθος stone: see -lite.]
1. Min. A concretionary limestone composed of small rounded granules, like the roe of a fish, each consisting of carbonate of lime around a grain of sand as a nucleus; roe-stone. In later usage restricted to that of the geological formation in 2.
[1785Hutton in Trans. R. Soc. Edin. I. (1788) 252 Among these, are different species of oolites marble.] 1802–3tr. Pallas's Trav. (1812) I. 425 Which consists of shelly fragments and small grained oolites. 1807Aikin Dict. II. 45 Oölite..occurs in mass and is without lustre. 1833Lyell Princ. Geol. III. 215 A white oolite. 1884W. J. Loftie in Pall Mall Gaz. 18 Aug. 1/2 The railways did not yet bring oolite from the hills of Bath.
2. Geol. The name of an important series of fossiliferous rocks of the character described in sense 1, lying between the Chalk, or the Wealden, and the Lias; sometimes applied to the whole series of limestones, sandstones, and clays, to which these belong; now usually included, with the Lias, in the Jurassic system.
The series is generally subdivided in England into the Upper or Portland Oolite, the Middle, Great, or Oxford Oolite, and the Lower or Bath Oolite.
1816W. Smith Strata Ident. 30 Distinguished from the under Oolite. 1822Conybeare & Phillips Outl. Geol. ii. ii. §1. 119 The interval between the chalk and oolites. 1842Miller O.R. Sandst. xi. (ed. 2) 253 We find..the Great Oolite uptilted against it [the gneiss] on the eastern coast of Sutherland. 1862Smiles Engineers III. 315 It consisted of shale of the lower oolite. 1878Huxley Physiogr. 36.
3. attrib. Pertaining to or consisting of oolite; oolitic.
1813Bakewell Introd. Geol. (1815) 357 The coal formation..rises from under the oolite lime-stone. 1816W. Smith Strata Ident. 27 The covering of the upper Oolite rock. 1851Richardson Geol. i. 9 The geological site of the locality, which is about the middle of the oolite formation. 1854Ronalds & Richardson Chem. Technol. (ed. 2) I. 32 The limestones of the oolite group which constitute the Jura.
4. = oolith.
1851H. T. De la Beche Geol. Observer viii. 123 The little grains termed oolites, formed of concentric coatings of calcareous matter. 1907E. H. Adye Mod. Lithology xii. 60 The oolites..formed in shallow waters are cemented together by calcareous material. 1955E. E. Wahlstrom Petrographic Mineral. x. 335 Most oolites in clastic rocks contain a nucleus of organic matter, a fragment of shell, or a more or less rounded silicate or carbonate particle. 1961J. H. Johnson Limestone-Building Algae 256 Algal pisolites are composed of more or less spherical masses ranging in sizes from that of a large oolite to spherules having a diameter as much as an inch across. |