Geologists have uncovered a mechanism for the emergence of the modern Earth’s crust and continents from a protocrust that existed billions of years ago. According to an article published in the journal Nature Communications, the discovery debunks popular hypotheses of the geological evolution of the Earth, which provided for both external impact and the emergence of tectonic plates before the continents themselves
Adverts
It is known that most of the Earth’s crust, which emerged during the Archean eon from 4 to 2.5 billion years ago, was an association of three rock types – tonalite, trondhjemite and granodiorite (TTG). However, scientists have been unable to explain what they arose from because so many geological processes took place between the initial melting and final crystallisation.
The new work analysed data from all samples ever studied from Archean craton fragments found around the world. Cratons are large remnants of the basement of ancient continental crust that have not undergone significant change since the Archaean.
