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
Karain semi-continent semi-continent has four distinct watersheds, the largest of which makes up the entire core of the semi-continent itself. The center of the semi-continent is a massive valley running roughly south to north, and bordered on three sides by mountain chains. Runoff from the mountains flows downhill until it meets Lake M-pulo. To the south, the Karain watershed is bordered by the alpine Islandia Mountains, and meltwater from these provides most of the water to the valley. In the west, the Ono and Matclorn Rivers flow south and east out of the mountains over the Sobo steppes, which eventually merge into