Cratons

A craton is a stable and ancient part of the continental lithosphere that has remained relatively undeformed for a very long time, typically since the late Precambrian or earlier. Cratons form the cores of continents and consist of both the continental crust and the underlying thick, cold lithospheric mantle. Their stability is reflected in low heat flow, thick lithospheric roots, and high seismic velocities.

Geologically, cratons are characterized by a rigid and buoyant lithosphere that can endure tectonic stresses for billions of years. They are often described as comprising two surface expressions: shields, where ancient basement rocks are exposed, and platforms, where those rocks are concealed beneath younger sedimentary layers. Around cratons, mobile belts and orogenic zones record past collisions and mountain-building events that encircle the stable core.

Cratons occur on most continental landmasses and are among the oldest parts of the Earth’s crust. They range in age from Archean to Proterozoic and serve as the long-term nuclei around which continents have grown. Notable examples include the Canadian Shield, the West African and Kalahari Cratons in Africa, the Baltic and Siberian Cratons in Eurasia, the Australian Craton, and parts of the Indian shield.

Significance and resource potential accompany cratons. Their long-term stability and thick, chemically distinct mantle roots influence geodynamics and petrology, and cratonic regions host major mineral deposits such as gold, diamonds, and basemetal ores. Cratons remain central to studies of continental evolution and crust-mantle interactions.