ABOUT OCEANS AND VOLCANOES
In the beginning, about 10 million years ago, large amounts of molten lava successively surged from the centre of the earth in South-West of the Indian Ocean creating the plateau of the Mascarenes. One of the emerging parts was a small island which, after numerous transformations of its physical structure by weathering and repeated eruptions will become the Island of Mauritius.
The relief of the Island of Mauritius is very peculiar. It is made up of three distinctive structures shaped by successive volcanic eruptions.
The Central Plateau1. A large central plateau representing about 50% of the total area and corresponding to the remnants of two superimposed caldeiras the first one at about 200 metres and the top one at about 700 metres. The Central Plateau is fringed with peaks culminating at not more than 900 metres above sea level. The positioning of this plateau with respect to the prevailing winds has determined the amount and distribution of rainfall precipitation over the whole island; hence, heavily influencing the fauna and flora of the various parts of the island.The south–west fringe is the important massif of the Rivière Noire Range extending South into the Savanne Range. The highest peak: The Piton de la Rivière Noire culminates at 872 metres.
The Montagne du Rempart limits the plateau on the west. The north-west limits of the plateau have some quite high peaks with Le Pouce (812 metres) and the Pieter Both (823 metres) from the Moka range. The south-east is fringed with a string of hills from Mahébourg and Vieux Grand-Port, projecting towards the east.
Trou aux cerfs crater in Curepipe
Rempart Mountain - Black River
The coastal plains2- The coastal plains have become one of the major natural resources for the economic development of the country. Wider in the north, it forms a belt of fertile soil composed mainly of successive strata of decomposed lava. The white beaches are composed of coral particles from the reefs which form a natural barrier protecting the beaches from the heavy waves of the Indian Ocean. The beaches are washed by the calm waters of lagoons enclosed between the reefs and the beach. Two of the very large lagoons have proved to be naturally safe havens for ships: The Mahébourg lagoon has sheltered the South East Port for quite some time until Port-Louis, also a large lagoon, was preferred because it was not exposed to the prevailing winds.
3. The northern plains including the flat northern part of the island and the islets Coin de Mire, Flat Island, Gabriel Island, Round Island and Ile aux Serpents lying in a NNE-SSW direction were formed by volcanic activity and erosion. These islands formed part of the plains at the time when the sea level was lower by about 100 metres. They are now separated from the main island by the sea. The decomposition of successive layers of lava produced a very fertile soil in that region of the main island. In fact, the only natural resources of this country have long been fertile soil and sandy beaches.