'Cuesta' is a
geological term, used to describe the ridges formed by gently tilted hard
rock layers. Every cuesta has a steep slope, where the rock layers are exposed on their edges, called an
escarpment or, if more severe, a
cliff. Usually an
erosion-resistant rock layer also has a more gentle slope on the other side of the ridge called a '
dip slope'. The term derives from the
Spanish word for 'slope'.
Two well-known cuestas in western
New York and southern
Ontario are the
Niagara escarpment and the
Onondaga escarpment, where the
dip is about 40 feet per mile to the south. The escarpment edge faces north and, in its most populated section, runs roughly parallel to the southern
Lake Ontario shoreline.
The
Gulf Coastal Plain of
Texas is punctuated by a series of cuestas that parallel the coast. The cuestas have gentle slopes gulf-ward to the southeast and steeper northwest-facing escarpments. The Reynosa Plateau is the most coast-ward cuesta, which sees surface expression with the Bordes-Oakville escarpment, on the northwest side and a low ridge on the eastern boundary, called the Reynosa cuesta, where the deposits dip below later
Pliocene-
Pleistocene deposits of the Willis and Lissie Formation.
Cuestas have less dramatic expression in the
United Kingdom, with two notable examples being the northwest-facing escarpment of the
Jurassic chalk White Horse Hills and the similarly-aligned escarpment of the
Cotswolds. In continental Europe, the
Swabian Alb offers particularly good views of cuestas in
Jurassic rock. In
France, the term for a cuesta is the same as for a coastline: "côte". Notable French cuestas are the wine-growing regions of
Côte d'Or and
Côtes du Rhône.
See also
★
Escarpment
★
Dip slope
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Strike and dip
★
Hogback
External links
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Escarpment geology