Journal article

Metamorphism and melting of picritic crust in the early Earth

Karen Ziaja, Stephen F Foley, Richard W White, Stephan Buhre

Lithos | ELSEVIER | Published : 2014

Abstract

Partial melting experiments with models of Archean oceanic crust (MAOC; with 11, 13 and 15. wt.% MgO) are used to investigate the role of metamorphism and melting of primary picritic compositions in the formation of TTG-like melts and continental crust on the early Earth. The approach investigates the possibility that the average early crust composition was comparatively MgO-rich and evolved to lower magnesium content during the secular cooling of the Earth. High-pressure partial melting experiments indicate a transition of melt compositions from aluminous basaltic melts in MAOC 15 to predominantly tonalitic melts in MAOC 11 and higher melting temperatures with increasing magnesium in the bu..

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University of Melbourne Researchers