A monocline is a type of fold in rock layers where the strata are inclined in one direction, creating a step-like structure. Monoclines are often associated with faulting and are important in understanding structural geology, the formation of basins, and the tectonic history of an area.
Source Stewart, J. H., Poole, F. G., & Wilson, R. F. (1972). “Stratigraphy and Origin of the Chinle Formation and Related Upper Triassic Strata in the Colorado Plateau Region.” USGS Professional Paper 690.