Geology
The volcanic origin of Madeira Island ...
Macaronesia , a group of five archipelagos of volcanic origin located in the North Atlantic is composed of the Madeira Islands, Canary Islands, Cape Verde, and the Azores. The Archipelago of Madeira was created through a "Hot Spot". The island is only the top quarter of the entire volcanic system. The cliffs are covered by water from the surface to a depth of 4000 meters.
- Curral das Freiras
Madeira was formed in many volcanic phases which are why the crater is no longer found today. Remains found in some areas of the interior of the island such as pyroclastic rocks of basaltic material demonstrate the phases of eruption. In some locations in the high mountains surprising cliffs and volcanic domes are clearly visible as well as ex vent passages which unlike surrounding rocks have not eroded.
- Faial
The first phase of volcanic activity began about 18 million years ago was completed with the transition from the Miocene to Pliocene periods of the geologic timescale approximately 3 million years ago. This first phase was marked due to strong eruptions. In the second phase of volcanic activity, projected lava and pyroclastic sediments expanded, increasing the size of the island especially in the south, west and southeast, and at the tip. Two other phases formed the volcanic cliffs of the northern and southern shores, as well as the formation of basalts in Paul da Serra mainly because of a crack in Bica da Cana 550,000 years ago, where the last volcanic activity occurred. Pieces of charcoal were discovered in some stones and through the radiocarbon method it has been stipulated that this phase was over 6450 years ago.
- São Vicente Caves
The São Vicente Caves, presently a tourist attraction in Madeira, were formed during this last phase of volcanic activity. The caves were the result of an outbreak of lava that cooled and solidified on the surface creating a tubular cavity while lava continued to flow in high temperatures and speeds through these newly created underground “pipes” until the volcano no longer had lava to flow. Calcareous sediments that formed in Miocene reefs, are also in some parts of the island. In some areas snail shell fossils draw conclusions that the climate in Madeira during the Miocene period was much hotter than the weather today.
- Pico Areeiro
The rivers of Madeira Island tend to have a big gap. Numerous waterfalls lead directly to the sea. Pico Ruivo with its 1862 meters is the highest peak of the island and simultaneously one of the highest in Portugal. Madeira´s coast is steep and rocky.
Located in the western part of Camara de Lobos is the Cape Girão, which is the second highest in the World (Height: 580 m).