The creation of Fuerteventura

The creation of Fuerteventura

Fuerteventura – the “Oldie” amongst the Canary Islands.

The first steps in the creation of Fuerteventura have been made some 250 million years ago, however its rise above the water surface dates from about 23 million years ago, which makes it the oldest island of the Canaries. Here is its story with the then occurring general geologic and climate conditions on our planet. The duration of the geologic periods have been rounded to accommodate reading. At the end of each period you will get suggestions to visit remnants of the described locations and geologic events.
WARNING: Please do NOT collect any fossil, stone or whatever geologic / archaeological element from any site! Not only is it highly disrespectful to the history of Fuerteventura, but additionally, the penalties are horrendous, including imprisonment. If you find anything which seems to be of scientific value, leave it where you found it and call the local authorities: Tel.: 928 862 328 (Cabildo of Fuerteventura), Guardia Civil: 928 851 100 (SEPRONA), Environmental Agency: 928 852 106 (Agentes de Medio Ambiente) or the police (Policia Local) – please do NOT call the emergency number!

Nutshell Data Sheet Fuerteventura:
2nd largest island of the Canary Islands.
Surface: 1660km2 (Fuerteventura) + 15km2 (Lobos).
Longest distance: 100km.
Highest point: Pico de la Zarza (807m)
Climate: very dry (<100mm/Y.m2)

Base: one massive lava block, supporting Fuerteventura and Lanzarote, with a base on the Ocean floor, some 3000m below sea level.

What we can see today from Fuerteventura is merely a remnant of what it has been, millions of years ago. Due to the heavy erosion of Fuerteventura, we now are able to see the very deepest geological structures of the historic volcanic activity that created this wonderful island. The looks of the island today has been created by changes in climate, by changing sea levels and by a vertical movement of the island itself, due to weight loss caused by heavy erosion. Thanks to the lack of vegetation, this island shows its geologic history without any masking.
Basically, Fuerteventura has been created by two fundamentally different cycles: submarine volcanism and daylight volcanism + erosion. Both cycles result in different types of mineral.
Typical features of Fuerteventura are an omnipresent chalk crust (Caliche), dunes (Jables), collapsed slopes (Abanicos), a sediment layer in Costa Calma at 10m above sea level and another one in the peninsula Jandía at 65m above sea level. Both layers are testimonies of increased sea levels in the past.

250 – 200 Mya (Million years ago) – the Triassic Period.

Allmost all land on Earth was concentrated into a single super continent, called Pangea. In the middle of this period, the first cracks in this continent appeared, separating today’s New Jersey from Morocco. In between lies the location of a spot that later will form Fuerteventura. Slowly the landmass divides into two parts: Lausasia and Gondwana. This is also the time when the ancestors of the Dinosaurs appeared, together with the first true mammals and the first flying vertebrates.

The breaking up of the landmass into two separate parts results in the uplift of the ocean floor and in the start of a submarine outflow of lava that will create the
basaltic base complex of Fuerteventura and Lanzarote. This uplift and outflow of lava will continue for the coming 140 Million years. The Basal Complex is covered with a sediment layer of about 150m. You can see this old ocean floor on the west coast in Ajuy (Playa de los Muertos – Punta de la Laja – Playa de Jambio (N-Fue) and Puerto de la Peña – La Caleta de la Peña Vieja). You see the floor, covered with deep sea marine sediments and an overlay with marine lava, mixed with marine sediments (Ammonites). They are regarded as the oldest sediments and fossils of the Canary Islands. There are in total 5 layers, 4 of them from deep sea origin and one from Continental plate.

2. pangea 245

200 – 150 Mya – the Jurassic Period.
The North Atlantic Ocean was in the beginning still very narrow (500-1000km) and the South Atlantic Ocean still didn’t exist. Dinosaurs are dominating the scene on land and reptiles in the sea. The first birds – pterosaurs – and placentals appear. Conifers were the dominant land plants.

Further build up of the basal complex Fuerteventura – Lanzarote. This building up is combined with sedimentation of marine components which leads to chalky deposits and fossils (North of Puerto de la Peña) at Ajuy. Here you can see the ocean floor with an age of about 180Mya, which are regarded as the oldest minerals of Fuerteventura and the Canary Islands.

MEDIO Jurassic 2globes

150 – 66 Mya – the Cretaceous Period.
The break-up of the Pangea continent is completed, although the parts still were drifting towards their present day positions. Gondwana was split up into South America, Antarctica, Australia and Africa. The creation of the marine basal complex of Fuerteventura and Lanzarote is now almost coming to an end. This complex is now about 3.000m high and has about 2 times the surface of both islands as we know them today. The South Atlantic and Indian Oceans were formed. The geologically strong drifting of the continents lifted ocean floors and generated large undersea mountain chains so that the overall sea level raised substantially. At that time about one-third of the land, present today, was submerged. This drifting also generated a lot of stress in the earth’s crust with the result of intense volcanic activity. The first representatives of leafy trees and true grasses appear. Dinosaurs are at their maximum development and mammals were in a minor position. The end of this period is marked by a now generally accepted event of a meteorite or comet impact on the Yucatán Peninsula.

At Caleta Negra at the end of the Barranco de la Peña you can see a Clastic Mix of what was once a shallow lake, filled with sand and mud. At the end of the Barranco de la Peña Vieja and the South of Caleta Peña Vieja you can see another type of Clastic Mix. Pelagic Chalk deposits (from open-sea organisms) can be found in Caleta de la Peña Vieja and in the middle of Barranco de la Peña.

 

Early Cretaceous 120 Ma66 – 23 Mya – The Palaeogene Period.
The Atlantic Ocean continues to widen by a couple of centimetres per year, Africa moves up to the North to meet Europe and to form the Mediterranean Sea, India starts to collide with Asia and to form the beginning of the Himalaya. Mammals began to rapidly diversify and to proliferate, due to the opportunities left by the now mostly extinct Dinosaurs. Of these mammals some specialise in marine environment, some in airborne environment and some on land and in trees with the latter ones becoming primates. New grass species evolve due to optimal conditions. Ocean currents are modified by the continuing movement of the continents, leading to a reduction and finally a block of warm water currents towards the Poles. The first permanent Antarctic ice sheets appear and the global temperature drops by a couple of ºC.

The submarine volcanic activity that will create the bottom layers of daylight Fuerteventura starts in the beginning of this period and covers thick layers of marine sediments. This submarine activity causes breaches and generates Pillow lava that can be seen in Caleta de la Peña Vieja and Barranco del Tarajalito. Sediments there contain marine fossils. At the mouth of the Barranco de la Fuente Blanca you will be able to find fossils of reef organisms and plutonic lava – a proof of volcanic activity at daylight (30 Mya). There are also signs of huge collapses and immersions of volcanoes.

PALEOCEEN

23 – 5 Mya – The Miocene Period.
India continued its collision with Asia and the formation of the Himalaya. Africa collided further with Europe and the resulting uplift of mountains in the western Mediterranean (Pyreneans, Alps and Atlas) generated additional stress in the earth’s crust in this region. The Mediterranean Sea gets closed in on Gibraltar and the water starts to evaporate. Sea levels continue to fall due to subsequent ice ages and volcanic activity on Fuerteventura increases. Primates developed into apes which further diversified and about 100 species became widespread in Africa, Asia and Europe. At the end this period – about 8 Mya – the ancestors of hominids had split away from the ancestors of chimpanzees. In the seas kelp forests flourish. At the end of this period, the connection between the Atlantic Ocean and the Mediterranean basin gets re-established, resulting in the Zanclean Flood that filled up the Mediterranean basin and resulted in a sharp worldwide drop in sea level by 10m.

In the beginning of this period (20-13Mya) the central part of Fuerteventura emerges from the sea, followed later (17-14Mya) by the Southern part of the island and the Northern part (16-12Mya). It is believed that in this period, volcanoes of about 2.500m were formed, but then collapsed. Today we can see the silent witnesses of the historic increases in sea level that have formed these marine sediments and dunes along the west coast. Pillow lava can be seen at Barranco de Ajuy.

020 Miocene 3globes

5 – 2,5 Mya – The Pliocene Period.
South and North America joined, blocking warm sea water currents to the Atlantic Ocean and resulting in a cooling of the Atlantic. However, the overall global temperature is about 3ºC higher than today and the sea level is about 25m higher. The Mediterranean Sea is now completely formed. All continents have almost moved to their present location. The climate – although very unstable due to glacial and interglacial periods – is generally similar to what we experience today and the modern vegetation starts to develop and proliferate. Sea levels change dramatically and oceans are sometimes very warm which leads to the presence of tropical molluscs on the shores of Fuerteventura, then a lot higher than today (Playas Levantadas). There is evidence of sea turtles having laid their eggs on certain ancient beaches. Appearance of the first hominids, the Australopithecines. The island Lobos is forming.

Due to the higher sea level (+10-20m), the shore line was a lot higher up and you can see remnants of this – rock formations with chalky intermediate layers – in Playa del Algibe de la Cueva, Playa del Valle, and Barranco Leon, the latter located at 2km south of Barranco de los Molinos. In the Barranco de los Molinos they found fossils of turtle eggs. Old dunes can be visited in the Isthmo de la Pared (Agua Tres Piedras).

DESECACION CUENCA MEDITERRANEO

2,5 Mya – 12.000 Ya (Years ago) – The Pleistocene Period.
The continents didn’t move a lot in this little time span. This period is marked by regularly repeating ice ages (glacials). At their maximum, 30% of the Earth’s surface was covered with ice of some 1.500 – 3.000m thickness. This huge amount of water, transformed into ice, caused overall sea levels to drop about 100m or more. On the other hand the progression of the ice cap till Central Europe initiated a lot of stress to all living organisms, including the human species like the Neanderthals, which became extinct in this period. Humans evolved in their present form during the Pleistocene. The last glacial was about 12.000 years ago and recent scientific data suggests that the next glacial is to begin in about 3.000 years.

In these ice age periods, Fuerteventura and Lanzarote were one long island, both connected through the Plains of La Bocaina, similar like peninsula Jandía and Fuerteventura are now connected. Fuerteventura and Lobos were forming one unit and had another companion island in the South-West: Bajon de Amanay. It is during these regular significant drops in sea level that the marine sediments, based on chalk, become exposed to the heavy weathering forces, leading to the golden beaches we see today. Additionally, due to the arid climate at that time, groundwater evaporates and transforms the chalky deposits into a solid crust (Caliche). At the end of this period the climate softens and gets more humid, allowing flowers to prosper and bees and wasps to proliferate. Heavy N-E winds carry sediments and dust from later Corralejo to the hills of what is now Lajares, forming impressive accumulations of dust and sand in which wasps build their nests.

This omnipresent crust will become much later a source of income to the inhabitants in the 17th-19th Century. You can look for the wasp nests around Lajares (Barranco de la Costilla, Barranco de los Encantados and El Quemado) and in Isthmo de la Pared, Pozo Negro and Cofete. They are 30.000-10.000 years old. The sand accumulations show layers with inclusions that testify mild or heavy rains. Other witnesses of the warmer climate of the last interglacial are the remnants of the mollusc Strombus bubonius, which can be found along the shore in the precincts of Jandía (Matas Blancas) and La Oliva (North Shore). Sea level was again higher than now.

Pleistocene moll NL 550x275

12.000 Ya – now – The Holocene Period.
Tectonic movements are small (1km in 10.000 years), but the actual interglacial resulted in a raise of sea level of about 35m at the beginning of this period. The areas above 40º North which were once covered by thick ice sheet and now are freed, are re-bouncing slowly till today and lifted already by as much as 180m. The ancient marine sediments are blown all over the island. In the 10th – 14th centuries we experience a warmer period (Medieval Warm Period) and in the 14th to the 19th century a cooler period (Little Ice Age). Both have a significant influence on the development of Fuerteventura.
The sea level in this period is similar to the one of today. The form of the island is the same, but the vegetation is supposed to be a lot different, compared to now. Arrival of humans and domestic animals like goats have altered the local vegetation significantly and in a very short time. At that time, goats were dropped onto uninhabited islands to secure human survival in case of distress. Due to lack of predators, they multiplied exponentially. This phenomenon, the arid climate in this period and the use of wood for fire, construction and tools decimated the once abundant flora of Fuerteventura.

 

To view the described locations on the map of Fuerteventura, please go to: Fuerteventura-hiking.com

 

Michel

Sources: “Patrimonio Natural de la isla de Fuerteventura” – Octavio Rodríguez Delgado; Wikipedia.