MECHANISMS OF CONTINENTAL CRUST GENERATION THROUGH GEOLOGIC TIME AND ITS CHEMICAL COMPOSITION

The Earth formed approximately 4567 million years ago from the solar nebula. Although in theory planets should have similar compositions according to their formation time, they have experienced geochemical differentiation. In the case of Earth, this differentiation is manifested in its structure of core, mantle, and crust, resulting from the segregation of metallic iron and nickel from silicate material. This paper reviews the mechanisms of continental crust generation throughout geologic time, from the initial magma ocean to the establishment of plate tectonics. The geophysical and geochemical evidence of early differentiation, the record of Archean komatiites, the transition toward more evolved compositions in the Proterozoic, and the tectonic models proposed for the formation of granulites and anorthosites are analyzed. The integration of isotopic and trace element data allows reconstructing the compositional evolution of the crust and evaluating the role of processes such as subduction, mafic underplating, and crustal thickening in different geodynamic contexts. Recent studies on komatiite alteration and anorthosite complexes provide new constraints on Archean surface conditions and Proterozoic magmatic systems, reinforcing the operation of plate tectonic processes since at least 3.8 Ga.