obˈduction
[ad. L. obductiōn-em, n. of action f. obdūcĕre: see obduce.]
† 1. The action of covering or enveloping. Obs.
In quot. 1609 repr. L. obductio of the Vulgate, tr. Gr. ἐπαγωγή of the LXX., variously explained in the versions.
| 1578 Banister Hist. Man i. 34 A strong Ligament within the ioynt..beside the outward obductions, and clothynges with Ligamentes. 1609 Bible (Douay) Ecclus. ii. 2 Make no hast in the time of obduction. 1623 Cockeram, Obduction, a couering. 1656 Blount Glossogr., Obduction, a covering or laying over. |
2. Geol. The movement of a lithospheric plate sideways and upwards over the margin of an adjacent plate.
| 1971 R. G. Coleman in Jrnl. Geophysical Res. LXXVI. 1216/2 According to Davies.., the ophiolites represent a slab of oceanic crust and mantle emplaced in Cretaceous or Eocene time by overthrusting (obduction) oceanic crust onto the continental crust. 1972 Rep. 24th Internat. Geol. Congr. iii. 409 The obduction zone is..an upthrust of the oceanic crust and mantle..mostly of a marginal sea (small ocean basin). 1972 Nature 31 Mar. 222/2 The Alpine orogeny culminated with the collision between the continental plates of Eurasia and Africa and was probably preceded by subduction or obduction of the Tethyan plate along the European continental margin. 1975 Ibid. 20 Feb. 615/2 Ophiolite emplacement is integrally associated with plate subduction, either by the accretion of oceanic crust on to the wall of the upper plate (in oceanic trenches) or by the bodily thrusting (obduction) of the oceanic crust on to a continental margin. |