Destructive plate margin magmatism: Geochemistry and melt generation

Abstract

Subduction related magmas are characterised by distinctive minor and trace element ratios which are widely attributed to the introduction of a hydrous component from the subducted crust. In general, high LIL HFSE ratios are best developed in low HFSE rocks, and the variation in LILE is less than that in HFSE. Moreover, the size of the contributions from subducted material estimated on the basis of minor and trace element variations are consistently greater than those inferred from radiogenic isotopes. The Nd isotope ratios of island arc rocks are lower than those of N-MORB, and there is a broad negative correlation between 143Nd 144Nd and 208Pb* 206Pb* consistent with a small contribution ..