Monocline

block diagram of a monocline
The Grandview-Phantom Monocline in the Grand Canyon, Arizona
Monocline at Colorado National Monument
Monocline formed at tip of small thrust fault, Brims Ness, Caithness, Scotland

A monocline (or, rarely, a monoform) is a step-like fold in rock strata consisting of a zone of steeper dip within an otherwise horizontal or gently dipping sequence.