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
Earth Platinum of each continent (showing political and physical features), maps of the oceans, (including shipwreck locations) and poles, as well as very detailed regional maps. The book also includes a double-page 6 feet x 9 feet layout of the world's flags. The atlas was printed in Italy and hand-bound in Hong Kong. Among its many spectacular images, "Earth Platinum" contains the world's largest image in a book, a photo of the Shanghai skyline. This image size is 272 gigapixels and made up of more than 12 thousand images tiled together. Published 20 February 2012, "Earth Platinum" follows publication of the "smaller"