Abstract:

Abstract:  We have performed partial melting experiments on a massive amphibolite sample under 1.5 GPa and 950 ℃ for 101 hours: the sample was collected from Archaean terrain in the northern margin of the North China craton. Experimental products consisted of Hb+Cpx+Gt+Gl and the melt is granodioritic in composition. Trace element compositions of melt and minerals were measured by LAICPMS to get the partition coefficients (Ds) between minerals and melt in the system. The Ds of amphibole, clinopyroxene and garnet are consistent with the previous studies under similar conditions, which indicates that the state of the starting material has little effect on the Ds between minerals and melt. The curve of Ds of REE versus ionic radius for each mineral is coincident with the lattice strain elastic moduli very well. On the whole, the Ds of LILE and LREE for amphibole, clinopyroxene and garnet are lower; the Ds of HREE are higher relatively; garnet is enriched in HREE intensively. Thus, the melt is enriched in LILE, LREE and depleted in HREE. Since there is no rutile in restites, the melt does not show negative Nb and Ta anomaly obviously. The major and trace element characteristics of melt are consistent with the Mesozoic adakitic rocks in the eastern North China craton, which approves the hypothesis that these rocks “could have been derived from the partial melting of ancient lower crust”.

Key words:

Key words: amphibolite; massive; partial melting; partition coefficients; granodioritic