Generation of Earth’s Early Continents From a Relatively Cool Archean Mantle

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1029/2018GC008079. This is version 2 of this Preprint.

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Authors

Andrea Piccolo, Boris J. P. Kaus , Richard W. White, Richard M. Palin 

Abstract

Several lines of evidence suggest that the Archean (4.0–2.5 Ga) mantle was hotter than today’s potential temperature
(TP ) of 1350 ýC. However, the magnitude of such dierence is poorly constrained, with TP estimation spanning
from 1500 ýC to 1600 ýC during the Meso-Archean (3.2-2.8 Ga). Such dierences have major implications for the
interpreted mechanisms of continental crust generation on the early Earth, as their ecacy is highly sensitive to the
TP . Here, we integrate petrological modeling with thermo-mechanical simulations to understand the dynamics of
crust formation during Archean. Our results predict that partial melting of primitive oceanic crust produces felsic
melts with geochemical signatures matching those observed in Archean cratons from a mantle TP as low as 1450
ýC thanks to lithospheric-scale Rayleigh–Taylor-type instabilities. These simulations also infer the occurrence of
intraplate deformation events that allow an ecient transport of crustal material into the mantle, hydrating it.

DOI

https://doi.org/10.31223/X5T030

Subjects

Physical Sciences and Mathematics

Keywords

numerical modelling, Archean, PerpleX, Thermocalc

Dates

Published: 2021-06-18 01:52

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License

CC BY Attribution 4.0 International

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