downthrow

A downthrow can create a new valley between two rock layers.

Definition

1. Noun (Geology):
   • A downward displacement of rock strata: "downthrow" refers to the side of a geological fault that has moved downward relative to the other side. It is the opposite of "upthrow."

Usage Examples

• Noun:
  • The downthrow of the fault was clearly visible in the cliff face. (The side of the fault that had sunk downward was exposed.)
  • Geologists measured the displacement of the downthrow to understand the earthquake's impact. (They calculated how far the rock had moved downward.)

Advanced Usage

• "downthrow side": the specific block of rock that has moved downward in a fault.

  • The downthrow side of the fault contained older sedimentary layers. (The sunken block held older rock formations.)

• "downthrow fault": a fault where the relative movement is downward on one side.

  • The mine was located on the downthrow fault, making excavation more challenging. (The fault's downward movement affected mining conditions.)

Variants and Related Words

• Downthrown (adj): having moved downward in a geological fault.

  • The downthrown block was buried under newer deposits. (The rock that had sunk was covered by younger material.)

• Throw (n): the vertical displacement of rock along a fault (includes both downthrow and upthrow).

  • The total throw of the fault was 50 meters. (The vertical distance between the two sides was 50 meters.)

Synonyms

• Subsidence: the gradual sinking of land or rock.
• Sag: a downward bend or depression in rock layers.

Related Idioms

• "on the downthrow": in geology, referring to the side of a fault that has sunk.
  • The oil reservoir was found on the downthrow of the fault. (The oil was trapped in the sunken rock block.)

Phrasal Verbs

• Throw down (related, though not a direct phrasal verb for "downthrow"): to cause to fall or drop.
  • The earthquake threw down the rock face. (The quake caused the rock to collapse downward.)