A calanque (, "inlet"; co, calanca, plural ''calanche'' or ''calanchi''; oc, calanca, plural ''calancas'') is a narrow, steep-walled inlet that is developed in limestone, dolomite, or other carbonate

strata 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 ei ...

and found along the Mediterranean coast. A calanque is a steep-sided valley formed within

karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

ic regions either by

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

erosion or the collapse of the roof of a cave that has been subsequently partially submerged by a rise in sea level.Bird, E.C.F., 2008, ''Coastal Geomorphology: An Introduction'', 2nd ed. John Wiley and Sons Ltd. West Sussex, England. Goudie, A., 2004, ''Encyclopedia of Geomorphology.'' Routledge. London, England. Monroe, W.H., 1970, ''A Glossary of Karst Terminology.'' Water-Supply Paper 1899-K. U.S. Geological Survey. Reston, Virginia.

Characteristics

Location

The best known examples of this formation can be found in the Massif des Calanques (''Massís dei calancas'' in Occitan, the traditional local language) in the Bouches-du-Rhône

department Department may refer to: * Departmentalization, division of a larger organization into parts with specific responsibility Government and military *Department (administrative division), a geographical and administrative division within a country, ...

Southern France Southern France, also known as the South of France or colloquially in French language, French as , is a defined geographical area consisting of the regions of France that border the Atlantic Ocean south of the Marais Poitevin,Louis Papy, ''Le midi ...

. The range extends for in length and in width along the coast between Marseille and Cassis, culminating in Mont Puget (). Similar calanques can also be found on the

French Riviera The French Riviera (known in French as the ; oc, Còsta d'Azur ; literal translation " Azure Coast") is the Mediterranean coastline of the southeast corner of France. There is no official boundary, but it is usually considered to extend fro ...

near the Massif de l'Esterel and on the island of

Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...

( Calanques de Piana). The highest points along the calanques are located at Mont Puget () and in the mountains of Marseilleveyre (). Similarities are seen between calanques and '' rias'', the river mouths formed along the coast of Brittany in Northern France. The limestone calanques of the Massif des Calanques lie within the recently created Calanques National Park (2012) and include the Calanque de Sormiou, Calanque de Morgiou, Calanque de Port-Miou and Calanque de Sugiton. There are additional calanques in the national park, further east along the coast, incised into Cap Canaille. These calanques formed in different rock strata, often in layers of cemented pebble

conglomerate Conglomerate or conglomeration may refer to: * Conglomerate (company) * Conglomerate (geology) * Conglomerate (mathematics) In popular culture: * The Conglomerate (American group), a production crew and musical group founded by Busta Rhymes ** Co ...

. Calanques are also present in the Italian Apennines, in locations such as the Accona Desert and in the ''Calanchi'' natural preserve of Atri.

Geology

Modern day calanques along the Mediterranean Sea are steep-sided valleys that the Holocene ( Flandrian) marine transgression partially submerged to form cliff-edged inlets. These valleys were either incised by rivers or created by cave collapse as karstic dry valleys when sea level was lower than at present. Along the coast of the Mediterranean Sea, some of the valleys, which were flooded to form calanques, might date back to the Messinian salinity crisis between 5.96 and 5.32 million years ago. During this period of time, the Mediterranean Sea became isolated from the Atlantic Ocean and its surface level dropped as much as below the level of the Atlantic Ocean.Krijgsman W., F.J. Hilgen, I. Raffi, F.J. Sierro, and D.S. Wilson, 1999, ''Chronology, causes and progression of the Messinian salinity crisis.'' Nature. v. 400, no. 6745, pp. 652-655.Ryan W.B.F., 1976, ''Quantitative evaluation of the depth of the Western Mediterranean before during and after the Last Miocene salinity crisis.'' Sedimentology. v. 23, no. 6, pp. 791-813. As a result, not only did evaporites accumulate on the abyssal plains of the Mediterranean Sea, but also rivers flowing into it deepened their valleys by hundreds of metres. The Rhône most notably cut a

canyon A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...

as deep as into Cretaceous carbonate strata near its confluence with its tributary the

Ardèche Ardèche (; oc, Ardecha; frp, Ardecha) is a department in the Auvergne-Rhône-Alpes region of Southeastern France. It is named after the river Ardèche and had a population of 328,278 as of 2019.Mocochain, L., P. Audra, G. Clauzon, O. Bellier, J.-Y. Bigot, O. Parize, and P. Monteil, 2009, ''The effect of river dynamics induced by the Messinian Salinity Crisis on karst landscape and caves: Example of the Lower Ardèche river (mid Rhône valley)'' Geomorphology, v. 106, no. 1-2, pp. 46-61. Also at this time, steep-walled, dry karstic valleys were formed by the collapse of caves that developed in limestone, dolomite, and other carbonate rocks in response to the greatly lowered sea level of the Mediterranean Sea.Audra, P., L. Mocochain, H. Camus, E. Gilli, G. Clauzon, and J.-Y. Bigot, 2004, ''The effect of the Messinian Deep Stage on karst development around the Mediterranean Sea. Examples from Southern France.'' Geodinamica Acta. v. 17, no. 6, pp. 27–38. Later, during the Pleistocene, these valleys were further enlarged and modified by fluvial, karst, and other processes during

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene in ...

drops of sea level within the range. During these periods of interglacial low sea level, additional steep-sided valleys, which were later flooded to create calanques, along the Mediterranean coastline were formed by fluvial and karst processes.Collina-Girard, J., 1996
''Prehistory and coastal karst area: Cosquer Cave and the “Calanques” of Marseille.''
Karstologia. v. 27, pp. 27-40. Today, they can be seen as deep, narrow valleys that are partly submerged by the sea and are made up of limestone or granite.

Ecosystem

left, Calanques at Vezzano sul Crostolo, Italian Apennines The calanques have a particular ecosystem, as soil is almost non-existent there, and the limestone cliffs instead contain numerous cracks into which the roots of plants are anchored. Nevertheless, the biota is diverse, with over 900 plant species, including a number of endemics like the Marseille Tragacanth and Sabline de Marseille: members of the Papilionaceae family, which can only be found in the hills of Marseille. In places where cliffs are less vertical, the vegetation is a classic Mediterranean

maquis Maquis may refer to: Resistance groups * Maquis (World War II), predominantly rural guerrilla bands of the French Resistance * Spanish Maquis, guerrillas who fought against Francoist Spain in the aftermath of the Spanish Civil War * The network ...

, typically consisting of densely growing evergreen

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s such as sage,

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...

and myrtle. It is similar to heath in many aspects, but with taller shrubs, typically high as opposed to for heath. Like elsewhere on the Mediterranean coast, the Calanques' climate is arid, with moisture during much of the year coming only from the evaporation of the sea. This dry habitat associated with salt spray conditions the subsistence of adapted vegetation. The Calanques shelter

rabbit Rabbits, also known as bunnies or bunny rabbits, are small mammals in the family Leporidae (which also contains the hares) of the order Lagomorpha (which also contains the pikas). ''Oryctolagus cuniculus'' includes the European rabbit speci ...

fox Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail (or ''brush''). Twelv ...

es, large crows and

Bonelli's eagle The Bonelli's eagle (''Aquila fasciata'') is a large bird of prey. The common name of the bird commemorates the Italian ornithologist and collector Franco Andrea Bonelli. Bonelli is credited with gathering the type specimen, most likely from an ...

s, as well as many

reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates (lizards and snakes) and rhynchocephalians ( ...

s and wild boars.

Tourism

The calanques between Marseille and Cassis are popular amongst tourists and locals alike, offering several vantage points (such as the Corniche des Crêtes and Cap Canaille) allowing spectacular

panorama A panorama (formed from Greek πᾶν "all" + ὅραμα "view") is any wide-angle view or representation of a physical space, whether in painting, drawing, photography, film, seismic images, or 3D modeling. The word was originally coined in ...

s. A great number of hikers frequent the area, following numerous pre-marked trails. The cliffs are also used as training spots for rock climbers. However, this excessive use has posed problems of potential damage to this delicate microhabitat. Most of the calanques are also closed to the public during the summer (typically July through September) due to the risks of forest fire that often happen during the dry season. The best time to visit calanques is probably March through May, when temperatures are cool and, unlike autumn and winter, rain is rare. As no fresh water sources are available in the calanques, visitors are advised to carry large supplies of water, especially during the summer heat, to prevent dehydration. Boat tours are also available starting either from Marseille, Cassis or La Ciotat, which can provide for some spectacular sightseeing. In April 2012, most of the calanques were declared a national park due to their uniqueness.

Cosquer Cave

The Cosquer Cave is an underwater

grotto A grotto is a natural or artificial cave used by humans in both modern times and antiquity, and historically or prehistorically. Naturally occurring grottoes are often small caves near water that are usually flooded or often flooded at high ti ...

in the Calanque de Morgiou, underwater, that was once inhabited during the

Paleolithic The Paleolithic or Palaeolithic (), also called the Old Stone Age (from Greek: παλαιός ''palaios'', "old" and λίθος ''lithos'', "stone"), is a period in human prehistory that is distinguished by the original development of stone too ...

when the sea level was much lower than today. Its walls are covered with paintings and engravings dating back to between 27,000 and 19,000 BC and depict many terrestrial animals such as

bison Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised. Of the two surviving species, the American bison, ''B. bison'', found only in North Ame ...

, ibex, and horses as well as sea animals like seals and auks.Collina-Girard, J., 2004
''La transgression finiglaciaire, l’archéologie et les textes (exemples de la grotte Cosquer et du mythe de l’Atlantide)
Human records of recent geological evolution in the Mediterranean Basin-historical and archaeological evidence.

CIESM The Mediterranean Science Commission, or CIESM, (French language, French: ''Commission Internationale pour l'Exploration Scientifique de la Méditerranée'') unites 24 Member States, hundreds of marine Institutes, and thousands of marine researc ...

Workshop Monographs. no. 24, page 63-70.

References

External links

* Cassis Tourist Office's web site
Calanques de cassis

Calanques photo at maps.google.com
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