A monocline (or, rarely, a monoform) is a step-like fold in rock

strata In geology and related fields, a stratum (: strata) is a layer of Rock (geology), rock or sediment characterized by certain Lithology, lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by v ...

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 Inversion or inversions may refer to: Arts * ''Inversion'' (artwork), a 2005 temporary sculpture in Houston, Texas * Inversion (music), a term with various meanings in music theory and musical set theory * ''Inversions'' (novel) by Iain M. Bank ...

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 geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic f ...

in basement into an overlying cover sequence.

Examples

Waterpocket Fold The Waterpocket Fold is a geologic landform that extends from southern Wayne through Garfield and ending in northern Kane counties of southern Utah, United States.''Utah Atlas & Gazeteer,'' DeLorme, 9th ed., 2014, pp. 44, 52, 60–1 The ge ...

Capitol Reef National Park Capitol Reef National Park is a List of national parks of the United States, national park of the United States in south-central Utah. The park is approximately long on its northsouth axis and just wide on average. The park was established in ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

Comb Ridge Comb Ridge () is a linear north to south-trending monocline nearly 80 miles long in Southeastern Utah and Northeastern Arizona. Its northern end merges with the Abajo Mountains some eleven miles west of Blanding, Utah, Blanding. It extends essen ...

in southern

* Grandview-Phantom Monocline in

Grand Canyon The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is long, up to wide and attains a depth of over a mile (). The canyon and adjacent rim are contained within Grand Canyon Nati ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

Grand Hogback The Grand Hogback is a , curving, spine-like ridge in Western Colorado that extends from near McClure Pass in Pitkin County, Colorado, Pitkin County through Garfield County, Colorado, Garfield County and then to near Meeker, Colorado, Meeker in R ...

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

Lebombo Mountains The Lebombo Mountains, also called Lubombo Mountains, Rivombo Mountains (), are an , narrow range of mountains in Southern Africa. They stretch from Hluhluwe in KwaZulu-Natal in the south to Punda Maria in the Limpopo Province in South Africa ...

in Southern Africa * Lapstone Monocline in the

Blue Mountains (Australia) The Blue Mountains ( Gundungurra/Dharug: Colomatta or Gulumada) are a mountainous region and a mountain range located in New South Wales, Australia. The region is considered to be part of the western outskirts of the Greater Sydney area. ...

* Beaumaris Monocline in

Victoria (Australia) Victoria, commonly abbreviated as Vic, is a States and territories of Australia, state in southeastern Australia. It is the second-smallest state (after Tasmania), with a land area of ; the second-most-populated state (after New South Wales), ...

Purbeck Monocline The Purbeck Monocline is a geological fold in southern England. The term 'fold' is used in geology when one or more originally flat sedimentary strata surfaces are bent or curved as a result of plastic (i.e. permanent) deformation. A monocline i ...

on the

Isle of Purbeck The Isle of Purbeck is a peninsula in Dorset, England. It is bordered by water on three sides: the English Channel to the south and east, where steep cliffs fall to the sea; and by the marshy lands of the River Frome, Dorset, River Frome and Poo ...

, Dorset, England * Fore-Sudetic Monocline, Poland * Sindh Monocline,

Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...

* Torres Flexure, southern

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

References

{{Structural geology Structural geology Deformation (mechanics)

Formation

Examples

See also

References