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.
Reference: 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.