| 释义 |
bioturbation, n. Oceanogr.|ˌbaɪəʊtɜːˈbeɪʃən|
[a. G. Bioturbation (R. Richter 1952, in Notizblatt des Hess. Landesamtes f. Bodenforschung zu Wiesbaden III. 68), f. L. turbātio, -ōnem disturbance: see bio-.]
The disturbance and mixing of sediment by the activity of living organisms; the disturbed state that results.
1967Senckenbergiana Lethaea XLVIII. 219 The sediment types, stratification fabrics, shells, and bioturbation fabrics are studied. 1976Nature 17 June 576/2 Complete bioturbation extending over several centimetres has been noticed at three horizons. 1978Ibid. 12 Jan. 124/1 Bioturbation of tephra layers mixes the tephra with other sediments and can reduce visible tephra layer thicknesses, dispersing tephra in the overlaying sediment. 1984A. C. & A. Duxbury Introd. World's Oceans xv. 487 Bottom photographs and cores show that the deep sediments are continually disturbed and reworked by sea cucumbers and worms in the process of extracting organic matter. This reworking of the sediment destroys layering and results in the uniform sediments that cover vast areas of the ocean floor. This process is called bioturbation.
Hence ˈbioturˌbated ppl. a., disturbed as a result of bioturbation; ˌbioturˈbational a., of or pertaining to bioturbation.
1969Jrnl. Sedimentary Petrol. XXXIX. 605/2 Almost all the muds are highly bioturbated. Ibid. 606/1 Bioturbational processes like..closing of burrows by compaction and the bringing of sediment to the surface where it is effectively redeposited. 1973Nature 30 Mar. 324/2 Even if deep sea meiobenthic communities are much sparser than their counterparts in shallower waters, their bioturbational effects..may well assume a far greater significance. 1984Science 25 May 873/1 Chondrites is a common trace fossil in..bioturbated sequences. |