Sal (Cape Verde)

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Sal
Satellite image
Satellite image
Waters Atlantic Ocean
Archipelago Ilhas de Barlavento
Geographical location 16 ° 44 ′  N , 22 ° 56 ′  W Coordinates: 16 ° 44 ′  N , 22 ° 56 ′  W
Sal (Cape Verde) (Cape Verde)
Sal (Cape Verde)
length 30 km
width 12 km
surface 216 km²
Highest elevation Monte Grande
406  m
Residents 36,769 (February 28, 2017)
170 inhabitants / km²
main place Espargos
Map of the island
Map of the island

Sal (actually Portuguese: Ilha do Sal ; German: Island of Salt ) is one of the Cape Verde Islands in the Atlantic .

facts and figures

geography

With its 216 km², Sal is one of the smaller of the Cape Verde Islands, is located on the northeastern edge of the archipelago and is of ancient (approx. 50 million years) volcanic origin. The largely flat island with limestone plateaus and dune landscape is dominated by some witness mountains and weathered volcanic vents. In the north, lava rocky coasts and beaches predominate, while the south is characterized by kilometer-wide, fine sandy, light beaches, flat dunes and abandoned salt pans . Individual oases with wind-ruffled date palms such as Fontona were used in the past for horticulture and cattle breeding. In Pedra de Lume, there is a perfectly circular caldera , the bottom of which has sunk below sea level and which was used industrially as a salt works. Today it is used almost exclusively for tourist purposes, because the high salt concentration in the saline basins makes it possible to "swim" like in the Dead Sea.

geology

Geologically, Sal can be subdivided as follows (from young to old):

The "Old Eruptivkomplex" has 25.6 million years BP , the highest ever for age volcanic rocks of Cape Verde rendered ( Upper Oligocene ). It consists of submarine lava ( pillow lava and Hyaloklastiten of alkalibasaltischer composition. This submarine deposits were of a striking passage swarm variable chemistry intruded ( basalts to Trachyte ). Preferred transition directions are N 070, N 090 and N 160. Also intrusive consisting of Foidsyeniten ( nepheline syenites ), Gabbros and alkali pyroxenites ( Essexites ) are encountered. They often show a circular zonal structure and are interpreted as sub-volcanic magma chambers, which were formed from nepheline- normative magmas with separation of a pyroxenitic cumulus phase. In the eruptive complex, pelagic micrites are stored in more than 300 Meters of water have been deposited, thus proving a seamount stage for Sal. Subaeric volcanic rocks are also present in the eruptive complex (lava flows and veins of melanephelinite and phonolite ), but relatively insignificant in terms of volume.

After a phase of intense erosion, the Middle Miocene “main eruptive” formed, which occurs both submarine and subaeric and is characterized by a very high extraction rate. From 15.8 million years BP ( Langhium ), alkali olivin basalts formed and from 14.2 million years BP, olivine nephelinites formed . The main eruptives are in the southeast part of Sal. They are also penetrated by a gang swarm, which is however oriented differently with N 040.

The “Ponta-do-Altar-Baleia-Complex” above shows, like the main eruptiva , an alkali olivine basalt-olivine nephelinite sequence, which, however, is separated by 2 meter thick marine sediments ( calcarenites , conglomerates , siltites and claystones ). For the olivine nephelinite of the hanging wall, ages between 11.2 and 8.7 million years BP ( tortonium ) were determined. After the olivine nephelinite eruption, there was a drastic decline in volcanic production and erosion processes gained the upper hand: Lahar- like deposits formed, limes and calcarenites of marine origin and Upper Miocene age were also deposited.

With the "Serra-Negra-Eruptiva" a new phase of volcanic activity began at the end of the Miocene around 5.5 million years BP ( Messinian ). In it, submarine is gradually being replaced by subaeric volcanism. In contrast to the previous crevasse volcanism, the Serra-Negra-Eruptiva were extracted via vent centers. It formed Hypersthen -normative basalts .

After a rest period of 4.5 million years, the volcanic rocks of the "Monte Grande Pedra Lume Formation" - olivine nephelinites and olivine melilithites , which exist as lava flows and pyroclastic cones - formed in the early Pleistocene from 1.06 million years BP . A phreatomagmatic explosion blasted out the circular crater of Pedra Lume . The pyroclastic cones partly follow a north-east-south-west oriented belt. The volcanic activity lasted until the Middle Pleistocene (600,000 years BP).

In the end of the Quaternary period there was intensive "marine abrasion" on Sal from around 1 million years of BP, which left 17 terrace levels and surf platforms behind. The highest level reaches 100 meters.

history

The uninhabited at that time the island was amended by on behalf of the December 3, 1460 Henry the Navigator traveling Genoese captain Antonio da Noli discovered and named "Llana" (flat island) repossessed.

After the island was initially populated with shepherd slaves for extensive cattle breeding , free settlers followed in the 17th century to extract salt. In 1838 a large saltworks was built in Santa Maria, which was followed in the 19th century by the much more productive saltworks in the crater of Pedra Lume . The main destinations for salt exports were the English and Belgian colonies in Africa and Latin America.

Salt production and extensive animal husbandry only fed a marginal population, which grew only slightly after the opening of a tuna factory in 1930.

Saline in the crater of Pedra Lume

administration

The island belongs to the northern group of the Cape Verde Islands, the Ilhas de Barlavento . The capital of the island is Espargos , and Santa Maria has grown significantly due to the construction of numerous tourist buildings.

Administratively, Sal is divided into a district of the same name ( concelho ) with only one community ( freguesia ) called Nossa Senhora das Dores .

Economy and Transport

In 1939 the Axis powers secured the flight route from southern Europe to Latin America by building a military airfield on Sal through the Italian Mussolini regime . After the Second World War, it was completed as a civil airport in 1949. Since independence (1975) it bears the name of the national hero as Aeroporto Internacional Amílcar Cabral ( IATA code SID, ICAO code GVAC). The international airport near the island's capital Espargos has contributed significantly to the development of the island and the settlement of a growing population. The standard of living on Sal far exceeds the national average.

In May 1963, African heads of state agreed at the founding meeting of the Organization for African Unity in Addis Ababa to support the liberation movements ( All-Africa Charter ). All African states were called upon to sever their diplomatic and economic ties with the colonial power Portugal and South Africa because of its apartheid policy . Some African states have imposed an overflight embargo on South African commercial aircraft. Only the Cape Verde Islands, which belonged to the Portuguese sphere of influence until 1975, allowed stopovers in Europe and North America on Sal. After independence this was continued due to urgently needed foreign exchange income. The embargo also extended to shipping in African ports. In response to this restriction, the South African government decided to provide 3.8 million rand for the expansion of the airport on the island .

Sal is one of the driest places on earth with 350 days of sunshine a year and very constant, strong north-east wind. Thanks to wide, fine sandy beaches and shallow water areas, Sal has been a popular area for surfers, divers and bathers since the 1990s.

The main tourist resort is Santa Maria in the south of the island, the administrative center is Espargos. A motorway-like, paved expressway connects Espargos and the airport with Santa Maria at the south end of the island. Both taxis and shared taxis (Aluguers) operate here , which dominate overland traffic on all islands.

  • Beach at Santa Maria

  • Buracona

  • landscape

  • lighthouse

  • Children on the island of Sal

Nélson Marcos at Betis Sevilla (2009)

Sons and daughters of the island

Web links

Commons : Sal (Cape Verde)  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b Instituto Nacional de Estatística de Cabo Verde (INECV): Projeções demográficas da população por concelho e faixa etária, 2010-2030 , February 28, 2017, accessed on September 9, 2019.
  2. ↑ Torres, PC et al .: Petrology and Geochemistry of lavas from Sal Island: Implications for the variability of the Cape Verde magmatism . In: Comunicações Geológicas . tape 97 , 2010, p. 35-62 .
  3. ↑ Torres, PC et al .: Enquadramento geocronológico pelo método K / Ar das principais sequências vulcano-estratigráficas da Ilha do Sal - Cabo Verde . In: Garcia de Orta, Ser. Geol. Band 18 , no. 1–2 , 2002, pp. 9-13 .
  4. ↑ Caldeira, R. & Silva, LC: Intra-volcanic layered intrusions in Sal island (Cape Verde Archipelago): insights into an ocean island root zone . In: Geochim. Cosmochim. Acta . tape 72 , no. 12 Sup. 1, A129, 2008.
  5. ↑ Holm, PM et al.: An 40Ar-39Ar study of the Cape Verde hot spot: Temporal evolution in a semistationary plate environment . In: J. Geophys. Research . 113, B08201, 2008, doi : 10.1029 / 2007JB005339 .
  6. ↑ Ramalho, R. et al .: Tracers of uplift and subsidence in the Cape Verde archipelago . In: J. Geol. Soc. London . tape 167 , 2010, p. 519-538 .
  7. ^ SAIRR : A Survey of Race Relations in South Africa 1963. Johannesburg 1964, pp. 327-328.