Abstract
Crystal-melt relations at a water vapour pressure of 1 kilobar have been determined for planes at 3, 5, 7.5, and 10 weight per cent anorthite in the system NaAlSi3O8KAlSi3O8-CaAl2Si2O8-SiO2. The ratio of the silicate components in the liquids which are in univariant equilibrium with plagioclase, alkali feldspar, quartz and gas are Ab31∶Or28∶Q38∶An3 (weight per cent) at 730°±5–10° C, Ab21∶Or34∶Q40∶An5 at 745°±5–10° C and Ab10∶Or39∶ Q43.5∶An7.5 at 780°±10° C. The univariant curve on which the above compositions lieoriginates on the H2O-saturated Or-An-Q plane at a composition containing less than 10 weight per cent An and terminates within 1.5 weight per cent An of the H2O-saturated Or-Ab-Q plane. Experimental data for the synthetic system have been used to illustrate a discussion on the partial melting of metasediments and the possible significance of such a process with respect to the genesis of granitic rocks. Data taken from the literature (Winkler and v. Platen, 1960, 1961a) have been used to illustrate that the normative salic composition of a sediment has a strong influence on the composition of any melt which form when such a rock is subjected to high temperatures and pressures.
Similar content being viewed by others
References
Barth, T. F. W.: Température de formation de certains granites Préoambrians de Norvege méridionale. International Colloquium. Science de la Terre. Ann. école nat. supérieure, Nancy 119–129 (1955).
—: Aspects of the crystallization of quartzofeldspathic plutonic rocks. Tschermak's mineral. u. petrogr. Mitt. 11, 3–4, 209–223 (1965).
Bowen, N. L.: The melting phenomena of the plagioclase feldspars. Am. J. Sci. 35, 577–599 (1913).
—, and O. F. Tuttle: The system NaAlSi3O8-KAlSi3O8-H2O. J. Geol. 58, 489–511 (1950).
Butler, B. C. M.: Metamorphism and metasomatism of rocks of the Moine series by a dolerite plug in Glenmore, Ardnamurchan. Mineral. Mag. 32, 866–897 (1961).
Carmichael, I. S. E.: The feldspar phenocrysts of some Tertiary acid glasses. Geol. Mag. 99, 253–264 (1960).
— The crystallization of feldspar in volcanic acid liquids. Quart. J. Geol. Soc. London 119, 95–131 (1963).
Goranson, R. W.: The solubility of water in granite magmas. Am. J. Sci. 22, 481–502 (1931).
Hamilton, D. L.: The ternary feldspar solvus. Abst. I.M.A. meeting, Cambridge (1966).
-, and A. D. Edgar: The variation of the ¯201 reflection in plagioclases. Mineral. Mag. (in press 1969).
—, and C. M. B. Henderson: The preparation of silicate compositions by a gelling method. Mineral. Mag. 36, 832–838 (1968).
—, and W. S. Mackenzie: Nepheline solid solution in the system NaAlSiO4-KAlSiO4-SiO2. J. Petrology 1, 56–72 (1960).
Kempe, D. R. C.: A note on the 201 spacing of some lime-rich alkali feldspars from Kangerdlyssuang, East. Greenland. Mineral. Mag. 35, 704–714 (1966).
Kranck, E. H., and R. V. Oja: Experimental studies of anatexis. Int. Geol. Congr. XXI, Norden, pt. 16, 16–29 (1960).
Lindsley, D. H.: Melting relations of plagioclase at high pressures. Carnegie Inst. Wash. Yr. Book 65, 204 (1966).
Lundgren, L. W.: Muscovite reactions and partial melting in southeastern Connecticut. J. Petrology 7, 421–454 (1966).
Luth, W. C. The influence of pressure on the composition of eutectic liquids in the binary systems sanidine-silica and albite-silica. Carnegie Inst. Wash. Yr. Book 66, 480–484 (1967).
—, R. H. Jahns, and O. F. Tuttle: The granite system at 4 to 10 kilobars. J. Geophys. Research 64, 759–773 (1964).
Nockolds, S. R.: The granitic cotectic curve. Geol. Mag. 84, 19–28 (1947).
Orville, P. M.: Feldspar investigations. Cernegie Inst. Wash. Yr. Book 57, 206–209 (1957).
Perrin, R.: Granites, eutectiques ou metamorphiques? Discussion d'études recentes. Bull. soc. géol. France, Ser. 6, 7, 91–113 (1957).
Platen, H. v.: Experimental anatexis and genesis of migmatites. In: Controls of metamorphism, ed. by W. S. Pitcher and G. W. Flinn. Edinburgh and London: Aliver & Boyd 1965.
Roy, R.: Aids in hydrothermal experimentation: II. Methods of making mixtures for both “dry” and “wet” phase equilibrium studies. J. Am. Ceram. Soc. 39, 145–146 (1956).
Schairer, J. F., and N. L. Bowen: System CaAl2Si2O8-SiO2. Bull. soc. géol. Finlande 20, 71 (1947).
Seki, Y., and G. C. Kennedy: Muscovite and its melting relations in the system KAlSi3O8H2O. Geochim. et Cosmochim. Acta 29, 1077–1083 (1965).
Shaw, H. R.: The four-phase curve sanidine-quartz-liquid-gas between 500 and 4000 bars. Am. Mineralogist 48, 883–896 (1963).
Stewart, D. B.: The system CaAl2Si2O8-SiO2-H2O. Carnegie Inst. Washington, Yr. Book 56, 214–216 (1956).
— Four phase curve in the system CaAl2Si2O8-SiO2-H2O between 1 and 10 kilobars. Schweiz. mineral. petrogr. Mitt. 47 (1), 35–59 (1967).
Tuttle, O. F.: Two pressure vessels for silicate-water studies. Bull. Geol. Soc. Am. 60, 1727–1729 (1949).
-, and N. L. Bowen: Origin of granite in the light of experimental studies in the system NaAlSi3O8-KAlSi3O8-SiO2H2O. Geol. Soc. Amer. Mem. 74 (1958).
Vaughan, D. E. W.: The crystallization ranges of the Spruce Pine and Harding pegmatites. M. Sc. Thesis, Penn. State University, Dept. of Geochemistry (1963).
Washington, H. S.: Chemical analyses of igneous rocks. Prof. Pap. U.S. Geol. Surv. 99 (1917).
Waters, A. C.: Volcanic rocks and the tectonic cycle. Geol. Soc. Am. Spec. Paper 62, Crust of the earth (ed. Poldervaart), 703–722 (1955).
Weill, D. F., and A. H. Kudo: Initial melting in alkali feldspat-plagioclase-quartz systems. Geol. Mag. 104, 325–337 (1968).
White, A. J. R.: Genesis of migmates from the Palmer region of South Australia. Chem. Geology 1, 165–200 (1966).
Winkler, H. G.: Experimentelle Gesteinsmetamorphose. I. Hydrothermale Metamorphose Karbonatfreier Tone. Geochim. et Cosmochim. Acta 13, 42–69 (1957).
— Petrogenesis of metamorphic rocks. Berlin-Heidelberg-New York: Springer 1965.
Winkler, H. G., u. H. v. Platen: Experimentelle Gestemsmetamorphose. II. Bildung von anatektischen granitischen Schmelzen bei der Metamorphose von NaCl-führenden kalkfreien Tonen. Geochim. et Cosmochim. Aota 15, 91–111 (1958).
— — Experimentelle Gesteinsmetamorphose. III. Anatektische Ultrametamorphose kalkhaltiger Tone. Geochim. et Cosmochim. Acta 18, 295–316 (1960).
— — Experimentelle Gesteinsmetamorphose. IV. Geochim. et Cosmochim. Acta 24, 48–69 (1961a).
— — Experimentelle Gestemsmetamorphose. V. Geochim. et Cosmochim. Acte 24, 250–259 (1961b).
Wyllie, P. J., and O. F. Tuttle: Melting in the earth's crust. Proceedings of 21st Inter. Geol. Congr., Copenhagen. pt. 18, 227–235 (1960).
— — Hydrothermal melting of shales. Geol. Mag. 93, 56–66 (1961).
Yoder, H. S., Jr.: System Ab-An-Q-H2O at 5 kb. Carnegie Inst. Wash. Yr. Book 66, 477–478 (1967).
— D. B. Stewart, and J. R. Smith: Ternary feldspars. Carnegie Inst. Wash. Yr. Book 56, 206–214 (1956).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
James, R.S., Hamilton, D.L. Phase relations in the system NaAlSi3O8-KAlSi3O8-CaAl2Si2O8-SiO2 at 1 kilobar water vapour pressure. Contr. Mineral. and Petrol. 21, 111–141 (1969). https://doi.org/10.1007/BF00403341
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00403341