Skip to main content Accessibility help

Phase equilibria and mixed parageneses of metabasites in lowgrade metamorphism

  • J. G. Liou (a1), S. Maruyama (a1) and M. Cho (a1)


The system Na2O-CaO-MgO Al2O3-SiO2-H2O is proposed to model phase equilibria and mineral parageneses for low-temperature metamorphism of basaltic rocks. Univariant reactions marking the transitions between various sub-greenschist facies are identified and some have been experimentally determined. The introduction of Fe2O3 into the model system at fixed FeO/MgO ratio creates continuous reactions for facies boundaries and discontinuous reactions for invariant points of the model system. Both qualitative and quantitative effects on P-T displacement and phase compositions are discussed. The X Fe3+ isopleths for epidote were plotted to exemplify the transition from the zeolite through prehnite-pumpellyite to prehnite-actinolite facies. T-X Fe 3+ relations were established for continuous and discontinuous reactions relating such facies transitions. Because of the common occurrence of two or three Ca-Al hydrosilicates in low-grade metabasites, an isobaric Al-Ca-Fe3+ projection from chlorite may be used to illustrate mineral assemblages and compositions of the coexisting Ca-Al silicates in the presence of quartz, albite, and chlorite. Reported occurrences in several classic burial metamorphic terrains and ocean-floor metabasites in ophiolites are described. Only the composition of a mineral from a buffered assemblage can constrain the intensive properties for metamorphism; previously reported compositional trends for pumpellyite and epidote with increasing metamorphic grade are oversimplified.



Hide All
Apted, M., and Liou, J. G. (1983) Am. J. Sci. 283-A, 328-54.
Bird, D. K., Schiffman, P., Elders, W. A., and Williams, A. E. (1984) Econ. Geol. 79, 671-95.
Bishop, D. G. (1972) Geol. Soc. Am. Bull. 83, 3177-98.
Bowen, N. L. (1928) The evolution of the Igneous Rocks. Princeton Press, Princeton, New Jersey, 332 pp.
Carman, J. H., and Gilbert, M. C. (1983) Am. J. Sci. 283-A, 414-37.
Cho, M., Liou, J. G., and Maruyama, S. (in press) J. Petrol.
Coombs, D. S. (1960) 21st Int. Geol. Congr. Copenhagen, 13, 339-51.
Coombs, D. S., Ellis, A. J., Fyfe, W. S., and Taylor, A. M. (1959) Geochim. Cosmochim. Acta, 17, 53107.
Coombs, D. S., Kawachi, Y., Houghton, B. F., Hyden, G., Pringle, I. J., and Williams, J. G. (1977) Contrib. Mineral. Petrol. 63, 229-46.
Coombs, D. S., Nakamura, Y., and Vuagnat, M. (1976) J. Petrol. 17, 440-71.
Ernst, W. G. (1977) Rend. Soc. Ital. Mineral. Petrol. 33, 191-220.
Ernst, W. G. (1983) Geol. Soc. China, Mem. 5, 229-68.
Ernst, W. G. and Liou, J. G. (in press) Ofioliti.
Evarts, R. C., and Schiffman, P. (1983) Am. J. Sci. 283, 289-340.
Houghton, B. F. (1982) N.Z. J. Geol. Geophys. 25, 1-19.
Kawachi, Y. (1975) Ibid. 18, 401-41.
Kuniyoshi, S. and Liou, J. G. (1976a) Am. J. Sci. 276, 1096-119.
Kuniyoshi, S. and Liou, J. G. (1976b) J. Petrol. 17, 73-9.
Levi, B., Aguirre, L., and Nystrom, J. O. (1982) Contrib. Mineral. Petrol. 80, 49-58.
Liou, J. G. (1971a) J. Petrol. 12, 379411.
Liou, J. G. (1971b) Am. Mineral. 56, 507-31.
Liou, J. G. (1979) Ibid. 64, 1-14.
Liou, J. G. (1983) Geol. Soc. China Mere. 5, 47-66.
Liou, J. G. and Ernst, W. G. (1979) Contrib. Mineral. Petrol. 68, 335-48.
Liou, J. G., Kim, H. S., and Maruyama, S. (1983) J. Petrol. 24, 321-42.
Liou, J. G., Seki, Y., Guillemette, R., and Sakai, H. (1985) Chem. Geol. 49 (in press).
Maresch, W. V. (1977) Tectonophysics, 43, 109-25.
Marnyama, S., Liou, J. G., and Cho, M. (in press).
Suzuki, K., and Liou, J. G. (1983) J. Petrol. 24, 583-604.
Nakajima, T., Banno, S., and Suzuki, T. (1977) J. Petrol. 18, 263-84.
Nitsch, K. H. (1971) Contrib. Mineral. Petrol. 30, 240-60.
Presnall, D. C., Dixon, J. R., O'Donnell, T. H., and Dixon, S. A. (1979) J. Petrol. 20, 335.
Schiffman, P. (1978) Unpubl. Ph.D. thesis, Stanford Uni versity.
Schiffman, P., Elders, W. A., Williams, A. E., McDowell, S. D., and Bird, D. K. (1984) Geology, 12, 12-15.
Schiffman, P. and Liou, J. G. (1980) J. Petrol. 21, 441-74.
Seki, Y. (1961) J. Petrol. 2, 407-23.
Schiffman, P. and Liou, J. G. (1981) Geol. Soc. China, Mere. No. 4, 207-28.
Schiffman, P., Oki, Y., Matsuda, T., Mikami, K., and Okumura, K. (1969) J. Japan Ass. Mineral. 61, 175.
Smith, R. E., Perdrix, J. L., and Parks, T. C. (1982) J. Petrol. 23, 75102.
Thompson, A. B. (1976) Am. J. Sci. 276, 401-24.
Zen, E. -A. (1974) J. Petrol. 15, 197242.



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed