1. Mitchell, J. G., Geochim. Cosmochim. Acta, 32, 781 (1968).
2. Dunham, K. C., Fitch, J. F., Ineson, P. R., Miller, J. A., and Mitchell, J. G., Proc. Roy. Soc. A, 307, 251 (1968).
3. Fitch, F. J., Miller, J. A., and Mitchell, J. G., Data for Orogenic Studies, 1 (edit. by Spencer, A.) (Geological Society, London, 1969, in the press).