When geologists first explored the Falkland Islands, 250 miles off the coast of southern Argentina, they found rock strata that did not correlate with those found on the mainland. Composed of igneous, metamorphic and volcanic rocks ranging from the Precambrian to the Jurassic, the two primary islands and their archipelago of numerous islets, were noted to possess a geological structure very similar to that found in South Africa. The solution to that mystery remained elusive until the theory of plate tectonics was proposed in the 1960s and has since been confirmed by field work.
As Pangea began to break up, some 200 million years ago, the Falkland microplate rifted from the southeast coast of South Africa and was pushed westward by rotation of the Antarctic Plate; since Africa, Antarctica and South America were still in close formation (as components of Gondwana), the Farallon microplate moved off with South America as the Atlantic Ocean opened during the Jurassic, some 150 million years ago. Indeed, dikes of Jurassic basalt are found on the islands and the Falkland Plateau, on which the islands rest, is Jurassic in age; like the Florida Platform, the Falkland Plateau switched continents as the Atlantic rifted the Americas from Africa.
Today, the Falkland Islands, high points on the Falkland Plateau, sit near the edge of the Continental Shelf; though lying at a subpolar latitude, the islands benefit from the Brazil Current, which yields a more Temperate climate. Known for its fabulous diversity of marine mammals and sea birds (including five species of penguin), the Falklands are devoid of native amphibians, reptiles and terrestrial mammals. The Falkland wolf, now extinct, once roamed the islands, having likely wandered in from the mainland when sea levels fell during the Pleistocene.
