Definition

Noun: A specific type of geological fault, or fracture in the Earth's crust, where compressional forces cause one block of rock (the hanging wall) to move up and over an adjacent block (the footwall). The fault plane, the surface along which the movement occurs, is typically at a low angle.

Usage

This term is used in geology and earth sciences to describe a structural feature resulting from tectonic compression. * Seismic data revealed a major overthrust fault beneath the mountain range. * The presence of an overthrust fault can create traps for hydrocarbons like oil and gas.

Advanced Usage

• Thrust fault vs. Overthrust fault: While often used interchangeably in general contexts, "overthrust fault" can specifically imply a very large-scale thrust fault with significant horizontal displacement (many kilometers). The term emphasizes the "overthrusting" action.
  • The regional geology is dominated by a series of overthrust faults that have transported older rocks over younger ones.

Variants and Related Words

• Thrust fault (n): A more general term for a low-angle reverse fault caused by compression. An overthrust fault is a type of thrust fault.
• Reverse fault (n): A fault where the hanging wall moves up relative to the footwall. Thrust and overthrust faults are specific types of reverse faults with low-angle planes.
• Overthrust (n): Can be used as a shorter noun form synonymous with "overthrust fault."
  • The valley is bounded by a major overthrust.

Synonyms

• Thrust fault
• Overthrust (as a noun)

Antonyms

• Normal fault: A geological fault where the hanging wall moves down relative to the footwall, typically caused by extensional forces.

Noun

1. a geological fault in which the upper side appears to have been pushed upward by compression