A homoclinal ridge or strike ridge is a

hill A hill is a landform that extends above the surrounding terrain. It often has a distinct summit, and is usually applied to peaks which are above elevation compared to the relative landmass, though not as prominent as Mountain, mountains. Hills ...

ridge A ridge is a long, narrow, elevated geomorphologic landform, structural feature, or a combination of both separated from the surrounding terrain by steep sides. The sides of a ridge slope away from a narrow top, the crest or ridgecrest, wi ...

with a moderate, generally between 10° and 30°, sloping backslope. Its backslope is a '' dip slope,'' that conforms with the dip of a resistant

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

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 ...

, called '' caprock.'' On the other side of the other slope, which is its frontslope, of a homoclinal ridge is a steeper or even cliff-like frontslope ( escarpment) that is formed by the outcrop of the caprock. The escarpment cuts through the dipping strata that comprises the homoclinal ridge. Cotton, C.A. (1952) ''Geomorphology An Introduction to the Study of Landforms.'' John Wiley and Sons, New York. 505 pp.Simonett, SD (1968) ''Cuesta.'' In RW Fairbridge, ed., pp. 233, ''The Encyclopedia of Geomorphology'' (Encyclopedia of Earth Sciences, Volume III), Reinhold, New York, 1296 pp. Huggett, JR (2011) ''Fundamentals of Geomorphology,'' 3rd ed., Routledge, New York. 516 pp. Twidale, C.R. and E.M. Campbell (1993) ''Australian Landforms: Structure, Process and Time.'' Gleneagles Publishing, Adelaide, South Australia, Australia. 568 pp. Hogback ridges in Colorado

Homoclinal ridges are the expression of regional outcrops of moderately dipping

, typically

sedimentary Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...

strata, that consist of alternating beds of hard, well-lithified strata, i.e.

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

and

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

and weak or loosely cemented strata, i.e.

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

, mudstone, and

marl Marl is an earthy material rich in carbonate minerals, Clay minerals, clays, and silt. When Lithification, hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. M ...

. The surface of hard, erosion-resistant rock strata forms the caprock of the backslope (dip-slope) of the homoclinal ridges from which erosion has preferentially stripped any weaker strata. The opposite slope, its frontslope, that forms the front of a homoclinal ridge consists of an escarpment that cuts across the

bedding Bedding, also called bedclothes or bed linen, is the materials laid above the mattress of a bed for hygiene, warmth, protection of the mattress, and decorative effect. Bedding is the removable and washable portion of a human sleeping environment ...

of the strata comprising it. Because of the moderately dipping nature of the strata that forms a homoclinal ridge, a significant shift in horizontal location will take place the landscape is lowered by

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

.Thornbury, W. D., 1954, ''Principles of Geomorphology'' New York, John Wiley & Sons, 618 pp. Because the slope of a homoclinal ridge dips in the same direction as the sedimentary strata underlying it, the dip angle of this bedding (Ө) can be calculated by v/h= tan(Ө) where v is equal to the vertical distance and h is equal to the horizontal distance perpendicular to the strike of the beds.Easterbrook, DJ (1999) ''Surface Processes and Landforms'', 2nd ed. Prentice-Hall, Inc, Upper Saddle River, New Jersey.

Cuesta A cuesta () is a hill or ridge with a gentle slope on one side, and a steep slope on the other. In geology, the term is more specifically applied to a ridge where a harder sedimentary rock overlies a softer layer, the whole being tilted somew ...

s, homoclinal ridges, and hogbacks comprise a sequence of landforms that form a gradational continuum. These landform differ only on the steepness of their backslopes and relative differences in the inclination of their backslopes and frontslopes. These differences depends upon whether the dip of the strata from which they have been eroded are either nearly vertical, moderately dipping, or gently dipping. In general, homoclinal ridges, or strike ridges, are associated with strata that dip between 10° and 30°. The symmetrical ridges that characterize hogbacks develop where the strata dip very steeply at 40° or more. Because they are gradational in nature, the exact angle of the backslope used to define these landforms is arbitrary and can vary in the scientific literature.Fairbridge, RW (1968) ''Hogback and Flatiron.'' In RW Fairbridge, ed., pp. 524-525, ''The Encyclopedia of Geomorphology'' (Encyclopedia of Earth Sciences, Volume III), Reinhold, New York, 1296 pp.

References

{{reflist Geomorphology Structural geology Slope landforms Erosion landforms Ridges