Scapolites from a rutile-phlogopite-scapolite rock associated with the apatite-phlogopite-enstatite veins at the old Ødegardens Verk, Bamble, South Norway appear to be the most Cl-rich variety hitherto reported. Besides Cl ( 3.74-3.91 wt%, 0.92-0.94 atoms per formula unit), SO3 (0.57-0.81 wt%) and Br (328 ppm) are present. Together with the results of Mora and Valley ( 1989), the Ødegårdens Verk scapolites indicate a revision of the solid solution line between the Cl-free and Cl-rich end members in the Al-Cl diagram. Together the scapolites detine a solid solution line between approximately Si7.2Al4.8Cl0 and Si8.3Al3.7Cl1 This is explained by coupling the scapolite substitution CaAl·CaCO3 = NaSi·NaCl to the Al= Si substitution.
Dick J. Ueftink*,Timo G. Nijland & Cees Maijer, Department of Geochemistry, University of Utrecht, PO Box 80.021, 3508 TA Utrecht, The Netherlands.
* Present address: Mineralogical Museum, Faculty of Mining and Petroleum Engineering, Delfi University of Technology, PO Box 5028, 2600 GA Delft, The Netherlands.