Fluorphlogopite and fluortremolite in Adirondack marbles and calculated C-O-H-F fluid compositions

Chemical analyses are given for fluorphlogopite(2), fluortremolite(3) and norbergite from Grenville marbles near Balmat, New York. The high F contents correlate inversely with Fe solid solution, but do not affect the stable isotope fractionation of H. At 650 degrees C and 6 kbar, the estimated range of fugacities of eight C-O-H-F fluid components is: log fH (sub 2) O = 2.47 to 3.37, log fCO (sub 2) = 4.52 to 4.22, log fCH (sub 4) = 0.25 to 2.35, fCO = 2.07 to 1.92, log fH (sub 2) = 0.34 to 1.39, log fO (sub 2) = -18.01 to -18.31, log fHF = -1.27 to -0.37 and log fF (sub 2) = -34.19 to -33.43.