Continent Europe and Asia together as a single continent, dubbed "Eurasia". In this model, the world is divided into six continents, with North America and South America considered separate continents. Geologists use the term "continent" in a different manner from geographers. In geology a continent is defined by continental crust: a platform of metamorphic and igneous rock, largely of granitic composition. Some geologists restrict the term 'continent' to portions of the crust built around stable Precambrian "shield", typically 1.5 to 3.8 billion years old, called a craton. The craton itself is an accretionary complex of ancient mobile belts (mountain belts) from
Middle-earth Middle-earth was part of his created world of Arda (which includes the Undying Lands of Aman and Eressëa, removed from the rest of the physical world), which itself was part of the wider creation he called Eä. Aman and Middle-earth are separated from each other by the Great Sea Belegaer (analogous to the Atlantic Ocean). The western continent, Aman, was the home of the Valar and the Elves called the Eldar. The eastern side of Middle-earth was washed by the Eastern Sea. Beyond this lay an uninhabited Eastern continent, but this does not figure in the stories. Most of the