Origin of continental crust on early Earth

Area of Science:

• Geosciences
• Early Earth geology
• Tectonic realms

Background:

• Continental crust's origin is linked to tectonic realms on early Earth.
• Inferring major element composition of crustal rocks solely from trace elements in zircon is questionable.
• The Hadean eon likely featured non-plate tectonics for mafic crust generation.

Purpose of the Study:

• To investigate the role of tectonic realms in early continental crust formation.
• To address the limitations of using zircon trace elements for inferring crustal composition.
• To understand the transition from mafic to felsic crust during Earth's early history.

Main Methods:

• Analysis of zircon trace element compositions.
• Geochemical modeling of crustal evolution.
• Comparative study of Hadean and Archean tectonic regimes.

Main Results:

• Trace element analysis of zircon alone is insufficient for determining major element composition of crustal rocks.
• Non-plate tectonics likely dominated mafic crust formation during the Hadean eon.
• Plate tectonics was essential for transforming Hadean mafic crust into Archean felsic crust.

Conclusions:

• Tectonic realm evolution is critical for understanding early continental crust origin.
• A shift from non-plate to plate tectonics marked a significant change in crustal composition.
• The transformation to felsic crust in the Archean was driven by plate tectonic processes.