Geochemical differentiation during partial melting of metasedimentary rocks: an example from the northern Sierra de Comechingones, Argentina

OTAMENDI JUAN E

Calafate Santa Cruz

Congreso; XV Congreso Geológico Argentino; 2002

Partial meltingexperiments showed that supracrustal sedimentary rocks yield felsic melts overtemperatures (759 – 900 ºC) typical of high-grade metamorphism. Thispetrogenetic process rendes to separate the bulk metasedimentary protolith intotwo rocks of constrasting mineralogical and geochemical compositions. These arethe felsic melt and the residual material. This led to many workers to assertthat the petrological mechanism is central in provoking the chemicaldifferentiation across a vertical profile of the contienental crust. However,the generalization of this hypotheses might now be regarded as premature or, atleast, incomplete.