Geochemistry of high-pressure to ultrahigh-pressure granitic melts produced by decompressional melting of deeply subducted continental crust in the Sulu orogen, east-central China

•Granitic rocks from the Yangkou region record crustal anatexis at HP to UHP conditions.•These rocks are derived from partial melting of the underlying granitic gneisses.•The pressure effect on melt composition reflects the key role of accessory minerals during anatexis.•The Nd-Hf isotope variation is due to dissolution of apatite and garnet into anatectic melt.