Did Earth’s first continents form in subduction zones?
Me and Alan Hastie think so!
Why? Read in detail here in Journal of Petrology doi.org/10.1093/petr...
The take home: Melting @ < 60km ➡️ No rutile ➡️ no Nb anomaly ➡️ no continental crust signature.
Rutile + garnet only stable at ≥60 km.
doi.org
Subduction Origin of the Nb Anomaly in Earth’s Oldest Continents
Abstract. Earth is unique in the solar system in having plate tectonics, which controls the growth of life-sustaining continents and the habitability of ou