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
Australia (continent) overseas, with top countries being Italy, Lebanon, Vietnam and Iraq, among others. Melbourne is also fairly multicultural, having the largest Greek-speaking population outside of Europe, and the second largest Asian population in Australia after Sydney. Australia is the only first world country in the Australian-New Guinea continent, although the economy of Australia is by far the largest and most dominant economy in the region and one of the largest in the world. Australia's per-capita GDP is higher than that of the UK, Canada, Germany, and France in terms of purchasing power parity. The Australian Securities Exchange in Sydney is the