| 释义 |
▪ I. overfold, n. Geol.|ˈəʊvəfəʊld|
[f. over- 3, 6 + fold n., after Ger. überfaltung (Brögger Silurische Etagen).]
A fold of strata in which the axes of the component anticline and syncline have both been tilted or pushed over beyond the vertical, so that the strata involved in the middle third of the fold are turned upside down. (Also inclined, overturned, inverted, or reflexed fold.)
1883Lapworth in Geol. Mag. X. May 199 A sigmaplex or sigmoidal fold (Overfold of Brögger). Ibid. Aug. 340 In overfolds of vast extent the arch limb being nearer the surface is more rigid, the trough limb, being buried under more than double the burden, is more ductile. Ibid. 342 The various stages of rock deformation under lateral pressure (folds, overfolds, overfaults, and overthrusts). 1896Van Hise N. Amer. Pre-Cambrian Geol. (U.S. Geol. Surv.) 674 It has been long recognized that thrust faults are often related to overfolds... The overfolds may be broken along the reversed limbs, and the arch limbs be thrust over the trough limbs.
▪ II. overfold, v.|əʊvəˈfəʊld|
[over- 8, 3, 6.]
1. trans. To fold over, or so as to cover.
a1400–50Alexander 5463 Quen it was hewyn at his hest with heggis ouire-folden, Þan entirs in of his erles. c1420Pallad. on Husb. i. 523 A stondyng most be maad and ouer⁓folde And couered wel with shingil, tile, or broom. a1814Prophetess ii. ii. in New Brit. Theatre I. 192 Peace, Whose cheering plough o'erfolds the bloody track Of his [the God of War's] throne-shaking chariots.
2. Geol. Of folded strata: (In pass.) To be pushed over beyond the vertical, so as to overhang or overlie the strata on the other side of the axis: see overfold n.
1883Lapworth in Geol. Mag. X. Aug. 343 The causes and results of overfolding of rocks under tangential thrust. 1896Van Hise N. Amer. Pre-Cambrian Geol. (U.S. Geol. Surv.) 604 A fold is overturned or overfolded when the axial plane is inclined and the limbs have equal or unequal dips in the same direction at corresponding points. |