Premium
Mg‐metasomatism of metagranitoids from the Alps: genesis and possible tectonic scenarios
Author(s) -
Ferrando Simona
Publication year - 2012
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2012.01078.x
Subject(s) - metasomatism , geology , tectonics , ultramafic rock , diachronous , geochemistry , subduction , rift , continental collision , mantle (geology) , continental crust , earth science , paleontology
Terra Nova, 24, 423–436, 2012 Abstract Mg‐metasomatic rocks (e.g. whiteschists, leucophyllites) derived from post‐Variscan granitoids are common in the Alps. Previously reported field, petrological, geochemical and fluid inclusion data are combined to trace the genetic processes and the associated tectonic scenarios. Many common features can be recognised in all of the continental Mg‐metasomatic rocks, indicating that the genetic process is likely common in the entire range of the Alps. This process assumes highly channelised fluids – derived from ultramafic rocks previously interacting with seawater – that infiltrated the continental crust along strain zones and produced chromatographic fractionation of major and trace elements. Three tectonic scenarios, involving distinct mantle sources, are proposed: rift‐related ocean‐continent transition, continental subduction and continent–continent collision. All these data suggest that the Mg‐metasomatism was diachronous and occurred at different structural levels during the Alpine history.