downthrow

/ˈdaʊnˌθroʊ/
noun
  1. In geology, the side of a fault that has moved downward relative to the other side.
    • The downthrow side of the fault is often where younger rock layers are found.
    • The downthrow of the fault created a visible cliff face.
    • Geologists mapped the downthrow to understand the region's earthquake history.
Antonyms