underthrust

[ uhn-der-thruhst ]
/ ˈʌn dərˌθrʌst /

noun Geology.

a thrust fault in which the footwall moved and the hanging wall did not (opposed to overthrust).

Origin of underthrust

First recorded in 1890–95; under- + thrust

British Dictionary definitions for underthrust

underthrust
/ (ˈʌndəˌθrʌst) /

noun

geology a reverse fault in which the rocks on the lower surface of a fault plane have moved under the relatively static rocks on the upper surface Compare overthrust