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
Mid-Continent Public Library North Independence, and Blue Springs South. The system has one of the nation’s largest Summer Reading Programs, which was completed by 106,846 patrons in fiscal 2009. It is known for its array of services, including more than 250 online learning tools and research databases with remote access, downloadable audiobooks, and Library-by-Mail for homebound patrons. Library branches offer self-checkout machines and self-service hold pick-ups, and LCD flat-panel monitors on every on-site public access computer. Most branches also offer free wi-fi access. The library system collaborates and partners with local foundations. On 21 June 2008, Mid-Continent Public Library inaugurated the Midwest Genealogy