Experimentally determined element distribution of fluids normalized to the starting materials of pelitic composition. The major and trace element compositions of the starting materials and the fluids produced at HP to UHP conditions are given in Additional file 2: Table S1. Blue-green curves denote aqueous solutions, where data at 2.2 GPa are after Spandler et al. (2007); data at 2.5 to 4.5 GPa and 600 and 700°C are after Hermann and Spandler (2008) for major elements and Table S1 in Additional file 2 for trace elements from the same experiments. Red-orange curves denote hydrous melts with data after Hermann and Rubatto (2009).