Insights into Collisional Magmatism from Isotopic Fingerprints of Melting Reactions
Kurt M. Knesel,1*
Jon P. Davidson2
Piston-cylinder experiments in the granite system demonstrate
that a variety of isotopically distinct melts can arise from progressive melting of a single source. The relation between the isotopic composition of Sr and the stoichiometry of the observed melting reactions suggests that isotopic signatures of anatectic magmas
can be used to infer melting reactions in natural systems. Our results
also indicate that distinct episodes of dehydration and fluid-fluxed
melting of a single, metapelitic source region may have contributed to
the bimodal geochemistry of crustally derived leucogranites of the
Himalayan orogen.
1 Department of Earth Sciences, University of
Queensland, Brisbane, Qld 4072, Australia.
2 Department of Earth Sciences, University of
Durham, Durham, DH1 3LE, UK.
*
To whom correspondence should be addressed. E-mail:
k.knesel{at}earth.uq.edu.au