Maakoore

Maakoore is a term used in Estonian geoscience to denote Earth's continental crust, the outer shell that forms the major landmasses of the planet. It is distinguished from the oceanic crust by its lighter, granitic composition, greater thickness, and longer geological history. The word maakoore literally translates to “land crust” and is used to describe the supracrustal rocks that underpin continents and continental margins.

In terms of composition and structure, maakoore is primarily granitic and granodioritic, with felsic rocks being common components. By contrast, oceanic crust is dominantly basaltic and more mafic. The thickness of maakoore varies widely, roughly from 25 to 70 kilometers, and it is typically thickest beneath stable continental interiors (cratons) and thinner along orogenic belts and margins. It rides on the denser mantle and forms part of the lithosphere, interacting with the underlying mantle beneath tectonic plates.

Geologically, maakoore evolves through processes of crust formation, differentiation, and accretion, with portions dating back billions of years. Its growth is influenced by plate tectonics, including subduction, collision, and continent-continent tectonics that build mountain belts and stabilize cratons. The maakoore's buoyancy and composition shape continental topography, seismic behavior, and long-term geochemical evolution of the planet.

The maakoore hosts most terrestrial mineral resources, groundwater systems, and soils essential for ecosystems and human use. It is studied using seismic imaging, gravity measurements, and radiometric dating to understand crustal formation, deformation, and the history of Earth’s continents.