Maio, Cape Verde
Maio is one of the nine inhabited Cape Verde islands in the Atlantic.
Maio is part of the Ilhas de Sotavento (English: " Leeward Islands "). It is located east of Santiago Island and southwest of Boa Vista. Dominated by a few weathered volcanic vents, on a Kalksockel seated desert island has an area of 269 km ² and 8,400 inhabitants. Population density: 31 inhabitants / km ². The highest point is Mount Penoso (436 m). Capital and port city is Vila do Maio.
Maio is with Sal geologically the oldest island of Kapverdenarchipels. Geomorphological she is very strong leveled mainly by Quaternary, marine abrasion. The hilly interior of the island is the largely escaped. The geological career Maios can be categorized as follows ( from young to old):
- Quaternary and Holocene sediments
- Pliocene abrasion and renewed volcanism
- The central intrusive complex
- Coruja lineup
- Carquiejo lineup
- Morro lineup - pelagic limestones
- Bathala lineup - oceanic crust
The up to 4,000 meters into the air upscale and thereby tilted foundation Maios consists of oceanic crust ( Bathala formation - tholeiitic pillow lava with NMORB composition Lavabrekzien, hyaloclastite and intercalated sediments with a Cretaceous minimum age of 113 ± 8 million years BP, ie at the end Aptian ) of bright, pelagic carbonate sediments of the Morro formation from the lower to upper Cretaceous ( Valanginian to Barremian ) is continuously superimposed. According to Muller, inter alia, has the oceanic crust beneath Maios an age of about 136 million years BP and therefore comes from the Valanginian. A similar age (early Valanginian ) is including Fourcade based on Calpionelliden and radiolarian the earliest, embedded in the uppermost basalts sediments assigned.
The 180 to 350 m thick sedimentary sequence of the Morro Formation in Maiolica facies ( with radiolarians, Aptychen and ammonites) then goes to the hanging wall towards an increasingly shallow nascent depositional environment over which Carquiejo lineup. The latter is a maximum of 90 meters thick and consists of heterogeneous shales, siltstones and limestones dünnbankigen from the Albian to Cenomanian time. The pelagic depositional environment was initially near the Kalzitkompensationstiefe, but deepened rapidly. Turbiditströme brought a continental and calcareous components.
With the start of the 300 meters thick Coruja formation occurred for the first time on pyroclastic tuff layers, sandstones and conglomerates on the pelagic limestones and refer to again onset of volcanism. The tuffs are associated with Ruditen and thus occupy a emergence of the island, to also recognize clasts plutonic origin. They also prove the existence of a magmatic episode before the start of the actual volcanic activity on the island. Maio is likely to have experienced at that time a significant uplift and erosion. The Coruja formation is poorly dated, but it has definitely a mittelmiozänes age.
After leveling of the sedimentary sequence of hyaloclastite and pillow lava ankaramitische the Neogene have then unconformably submarine after a long hiatus with a pronounced angular unconformity, placed over the sediment. They were followed on the surface ausgedrungene ankaramitische lava flows and Lavadeltas with the associated volcaniclastic sediments ( tuff ) and river sediments. The entire sequence 15 to 7 million years BP old, she was born in the Central and Upper Miocene ( Messinian to Langhium ).
In addition, it came in the Tortonian in the period 9-7 million years BP to tectonically induced constriction - the Mesozoic sediments were folded and this internally south overthrust with the formation of layer repetitions (Monte Branco - thrust ). The sediments were additionally already penetrated the beginning of the Tortonian before 11 million years BP of greater sills.
The foundation Maios surrounds in a partial ring with a steep dip to the outside plutonic intrusive bodies of the so-called central intrusive complex ( engl. Central Intrusive Complex or abbreviated CIC) - usually Essexite or pyroxenite, occasionally syenites, carbonatites and transition swarms. The intrusive bodies originate most likely from the Lower Miocene and probably between 20 and 18 million years BP age ( Burdigalian ). The dome-like force upon the intrusive complex of steeply dipping faults should be made only after completion of tectonic movements in the Tortonian.
After a further erosion phase to make wise formation of a Laterithorizontes in the Pliocene was a wide plateau with undersaturated in silica lavas, Olivinmelilithiten and Nepheliniten. At topographically higher parts of the eastern part of the island emerged from powerful, lavas and pyroclastics ankaramitische; they are drained to the east by the dissected from the Mesozoic strata valleys.
The last section in the geological development Maios is nichtvulkanischer nature. Unconformably deposited Quaternary beach deposits and other sediments as alluvial fan sediments and aeolian sands of the Holocene on the volcanic rocks, the Quaternary deposits partially covered all previous series. The beach deposits are still found up to a height of 70 meters above the sea level.
The name Maio (German: "MAY" ) is derived from the date of discovery on May 1, 1460 A little later semi-nomadic shepherds slaves were settled that produced by the Portuguese royal family beef cattle and hides, to supply the slave ships of Cidade Velha. . In the 16th century came to the livestock industry added the cultivation of cotton and part of the population was sedentary. Fine woven cloths ( panos de Santiago) were a valuable means of exchange in continental Africa and served principally buying up other slaves. After Santiago had lost its dominant position in the 17th century, the natural salt pans were expanded and free settlers followed. For protection from pirate attacks, and last but not least, to move the salt trade dominant Englishmen to tax payments to be able to set up the Portuguese crown in the main town of Vila do Maio ( until 1975 Porto Inglês ) a small fortress with a few cannons.
Like the other Cape Verde islands was repeatedly ravaged by Hungerkatastropen, which sometimes forced the free population to sell themselves as slaves to America and Maio. The decrease in salt production and increasing droughts in the early 20th century was followed by a sustained emigration movement. After independence in 1975, the survival had to be secured through job creation programs in road construction and reforestation. The inside largely vegetation-free island has a small but sustainable forest again and exporter of firewood and charcoal to Praia.
Economy and Tourism
The main economic activities are extensive livestock farming, fishing and crafts ( ceramics). Many families receive gifts from family members of Praia and from overseas.
With its miles of fine white sand beaches and wild romantic rocky coastline Maio has an impressive tourist potential, which is little used, as long as the transport of water sports equipment is difficult. The few visitors are looking forward to secluded beaches and wide walks and excursions into the interior of the island. One attraction is the reef João Valente.