TIERRA del FUEGO (FIRE LAND in Spanish) consists of a main island, ISLA GRANDE de TIERRA del FUEGO, often called simply TIERRA FUEGO or ISLA GRANDE, with an area of 48,100 sq.km, and a group of smaller islands. The main island is split between 2 countries : 38.47% of the total area, belongs to Argentina, while 61.43% of the total area, belongs to Chile. The archipelago is divided by an east-west channel, the BEAGLE CHANNEL, immediately south of the main island. The largest islands, south of the Beagle Channel are HOSTE & NAVARINO.
The geology of the archipelago is characterized by the effects of the ANDEAN OROGENY and the repeated PLEISTOCENE GLACIATIONS. The geology of the island can be divided into large east-west oriented units. The south-western islands of the archipelago, included CAPE HORN, are part of the PATAGONIAN BATHOLITH, while CORDILLERA DARWIN and the area around Beagle Channel form the principal cordillera hosting the highest mountains. The Magallanes “fold and thrust belt” extends north of ALMIRANTAZKO FJORD & FAGNANO Lake, and north of this lies the Magallanes foreland —- an old sedimentary basin that hosts “hydrocarbon reserves.” ORTHOGNEISS dated at 525 million years, is known to underlie some of the oil wells in northern Tierra del Fuego.
The Magallanes-Fagnano Fault, a “dextral strike slip” fault crosses the southern part of the main island from west to east. It is an active “seismic fault”, located inside and parallel to the Fuegian “fold and thrust belt”, an dmarks the boundary between a southern belt of Paleozoic meta sediments and a northern Mesozoic belt of sedimentary sequences. Fagnano Lake occupies a “glacier-carved depression” in a pull-apart basin that has developed along the Megallanes-Fagnano Fault Zone.
Only 30% of the island have forests which are classified as Magallanic Sub-polar. The northeast is made up of steppe and cool semi-desert. Canelo or Winter’s Bark and several kinds of fruits grow in open spaces in these forests, such as beech, strawberry and calafate, which have long been gathered by both Native Americans and residents of European descent. These fruits are “unique in the world” for having developed in a climate with such cold summers. Winds are so strong that trees, in wind-exposed areas, grow into “twisted shapes” inspiring people to call them “flag trees”.
Among the most notable animals are austral parakeets, sea gulls, foxes, guanacos, condors, king penguins, owls and fire-crown hummingbirds. North Americans beavers, introduced in the 1940s, have proliferated and caused considerable damage to the island’s forests. The governments have established a wide-reaching program to trap and kill beavers in Tierra del Fuego.
The archipelago also boasts of some of the finest trout fishing in the world. Sea-run brown trout often exceed 9kg, particularly in rivers. Sightings of southern right whales have increased in recent years, as well as some others such as blue whales, southern fins and southern minks. Beagle Channel is a prominent area to watch rare endemic dolphins, and the less-studied pygmy right whales. There are also South American sea lions, South American fur seals and gigantic southern elephant seals.
Today, the main economic activities are fishing, natural gas and oil extraction, sheep-farming and eco-tourism. Tourism is gaining in importance, as it attracts numerous upmarket visitors. Much of the tourism is based on claims of “southernmost things” : for example, both USHUAIA & PUERTO WILLIAMS claim to be the “southernmost city in the world”. On the Argentine side of Tierra del Fuego, the government has promoted the establishment of several electronic companies. Energy production is a crucial economic activity. During the 2005-2010 period, petroleum and natural gas extraction contributed to 20% of the region’s economic output.