Metamorphism and melting of picritic crust in the early Earth
Karen Ziaja, Stephen F Foley, Richard W White, Stephan Buhre
Lithos | ELSEVIER | Published : 2014
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..View full abstract
The research was funded by the Geocycles Research Centre of the University of Mainz. We thank two anonymous reviewers for their comments and suggestions.