radiolarian, a. and n.
(ˌreɪdɪəˈlɛərɪən)
[f. prec. + -an.]
A. adj. a. Zool. Of or pertaining to the Radiolaria. b. Geol. radiolarian chert, a cryptocrystalline type of radiolarite; loosely = radiolarite; radiolarian earth, unconsolidated siliceous rock formed from the remains of radiolaria; radiolarian ooze, a siliceous marine sediment rich in the remains of the tests of radiolarians.
| 1876 [see ooze n.2 2 b]. 1877 Thomson Voy. Challenger I. 231 It was found to contain so large a proportion of the tests of radiolarians, that Mr. Murray proposed for it the name ‘radiolarian⁓ooze’. 1889 J. W. Gregory in Q. Jrnl. Geol. Soc. Nov. 646 The Radiolarian deposits include a somewhat variable series of marls. 1890 Geol. Mag. VII. 144 (heading) Radiolarian chert in the Ballantrae series. 1911 [see ophiolitic a.]. 1913 Hatch & Rastall Petrology of Sedimentary Rocks i. iv. 143 One of the most notable instances of the abundant presence of this division of the Protozoa is afforded by the so-called Radiolarian earths of Barbados. Ibid. ii. iii. 233 An interesting example of the metamorphism of a nearly pure siliceous rock is found in the Galloway district, where certain radiolarian cherts of Arenig age are altered by the Loch Doon granite. 1926 W. H. Twenhofel Treat. Sedimentation v. 377 Radiolarian ooze is confined to the Pacific and Indian oceans. 1944 A. Holmes Princ. Physical Geol. xv. 317 The siliceous remains persist to greater depths, some of them down to 5,000 fathoms, the average for radiolarian ooze being about 3,000. 1953 Caribbean Q. III. iii. 179 Barbados..has a foundation of rocks... On top of this is a layer of deep sea deposit (radiolarian earth) and on top of this a slab of white limestone. 1971 B. W. Sparks Rocks & Relief ix. 306 Certain beds of radiolarian chert..are sufficiently resistant to form series of hog-back ridges across both outcrops. 1971 [see ooze n.2 2 b]. 1975 Fox & Heezen in Nairn & Stehli Ocean Basins & Margins III. x. 430 Piston cores obtained from the base of one escarpment recovered Early Eocene radiolarian ooze. |
B. n. One of the Radiolaria.
| 1877 Thomson Voy. Challenger I. iii. 186 They brought back..many large radiolarians. 1879 tr. Semper's Anim. Life 74 These yellow or sometimes green cells occur in many fresh-water Radiolarians. |