Monocline
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.
Formation
Monoclines may be formed in several different ways (see diagram)
By differential compaction over an underlying structure, particularly a large fault at the edge of a basin due to the greater compactibility of the basin fill, the amplitude of the fold will die out gradually upwards.
By mild reactivation of an earlier extensional fault during a phase of inversion causing folding in the overlying sequence.
As a form of fault propagation fold during upward propagation of an extensional fault in basement into an overlying cover sequence.
As a form of fault propagation fold during upward propagation of a reverse fault in basement into an overlying cover sequence.
Examples
Waterpocket Fold in Capitol Reef National Park, Utah
Grandview-Phantom Monocline in Grand Canyon, Arizona
Lapstone monocline in the Blue Mountains (Australia)
