Geography & Geology

  • 63


Sri Lanka is an Island located in the Indian Ocean. Ancient Greek geographers called it ‘Taprobane’. Arabs referred to it as ‘Serendib’. Later European mapmakers called it ‘Ceylon’, a name still used occasionally for trade purposes. It officially became Sri Lanka in 1972. ‘Teardrop’ shaped island of Sri Lanka has a total area of 65,610 km², with 64,740 km² of land and 870 km² of water. The coastline is 1,340 km (830 miles) long. The main island of Sri Lanka has an area of 65,268 km². It is the Twenty-Fifth largest island in the world by area. Dozens of offshore islands account for the remaining 342 km² area. The largest offshore island, Mannar Island, leads to Adam's Bridge.

Sri Lanka is located about 645km from the North Equator. It is separated from the Indian subcontinent by the Gulf of Mannar and the Palk Strait. At one point it was completely passable, but Adam's Bridge broke apart in the late 15th century when a cyclone hit the region. Today, after reconstruction, the bridge is (30 km long and ranges from 3 - 30ft. (1 - 10m) deep in some areas.

Sri Lanka's climate includes tropical monsoons: the northeast monsoon (December to March), and the southwest monsoon (June to October). Its terrain is mostly low, a flat to rolling plain, with mountains in the south-central interior. The highest point is Pidurutalagala at 2,524.13 m (8,281.3 ft.). Natural resources include limestone, graphite, mineral sands, gems, phosphates, clay, and hydropower.


Sri Lanka is part of a Precambrian craton, some two billion years old metamorphic rocks. Such rocks were originally sedimentary rocks but were transformed by a long series of crust movements, subsidence, high pressure and temperature inside the earth. This craton is a part of the supercontinent Gondwanaland and was connected with the craton of the Indian subcontinent until it collided with the Asian plate and formed the Himalaya some 45 Million years ago. After this collision, the small piece which is the base of Sri Lanka was separating from the Indian plate. This separation caused earthquakes and volcanism which created some volcanic rocks on the island.

The geologic history of the island results in a huge amount of metamorphic rocks, but also a small amount of volcanic and sedimentary rocks. The metamorphic rocks are rich in mineral deposits, including iron ore, zinc, manganese, molybdenum, nickel, cobalt, arsene, wolfram, tellurium, and gold. There are numerous precious gems found on the island too, rubies, sapphires, topaz, and spinel. Unfortunately, the history of the country did not result in the development of show mines so far, although it is a popular tourist destination.

There are only very few natural caves of limestone in isolated spots. Most common are erosional caves in all kinds of rocks, created by erosional forces of the tropic climate. However, they are always of limited depth, more or less overhanging cliff faces and abris. Nevertheless, they were used over the centuries as hermit's homes and to build temples or Buddha statues inside.  There are several cave temples in the country.