monoclinen

A monocline, sometimes referred to as monoclinen, is a geological structure in which a single, step-like bend occurs in otherwise horizontal rock layers. The fold is characterized by a hinge line that runs roughly parallel to the surface, creating one steeper dipping limb and a comparatively flatter or less steep other side.

Monoclines typically form adjacent to faults or along the edge of a basement block. They can result from the tilting or uplift of a crustal block, or from the draping of overlying sediments over such a block. They may also arise from differential compaction of sediment.

In cross-section, the feature appears as a flat layer that abruptly shifts to a steeper dip, producing a step in the strata rather than the arch or trough characteristic of anticlines or synclines. The monocline is usually localized, with the surrounding rock sequence remaining relatively undeformed.

Geologists study monoclines to understand tectonic histories and basin geometry. They can influence surface drainage patterns, mineral and hydrocarbon traps, and groundwater flow by creating zones of differential dip. Recognizing monoclines helps distinguish localized structures from larger-scale folds and informs structural and sedimentary analyses.

Notable examples include the Front Range monocline in Colorado and the Wasatch monocline in Utah, which form part of larger tectonic settings associated with basement faults and regional uplift during orogenic episodes. See also anticline, syncline, and fault.