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The significance of the melting interval of basaltic magmas at various pressures

Published online by Cambridge University Press:  01 May 2009

S. Maaløe
S. Maaløe
Affiliation:
Institute of General GeologyØstervoldgade 5 1350, Copenhagen K, Denmark
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Summary

The melting intervals of basaltic magmas are investigated in detail at various pressures, as the size of the interval has an important bearing on the genesis of igneous rocks. Tholeiitic magmas do not have a more pronounced four phase proximity at low pressures than at higher ones. This result seems to oppose the generally accepted low pressure character of these magmas; but as there is a general decrease in melting intervals with increasing pressure, the four phase proximity is nevertheless sustained. The melting intervals of alkaline rocks decrease rapidly with increasing pressure. Small variations in the temperature may therefore generate large variations in the composition of the liquids developed at high pressures.

Type
Articles
Information
Geological Magazine , Volume 110 , Issue 2 , March 1973 , pp. 103 - 112
Copyright
Copyright © Cambridge University Press 1973

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References

Biggar, G. M. 1972. Polyhedra representing solid solution ranges in four component systems. Prog. exp. Petrology 2, 121–2.Google Scholar
Bultitude, R. J. & Green, D. H. 1971. Experimental study of crystal-liquid relationships at high pressures in olivine nephelinite and basanite compositions. J. Petrology 12, 121–48.CrossRefGoogle Scholar
Clark, S. P. Jr. 1966. Handbook of physical constants. Mem. geol. Soc. Amer. 97.Google Scholar
Cohen, L. H., Ito, K. & Kennedy, G. C. 1967. Melting and phase relations in an anhydrous basalt to 40 kilobars. Am. J. Sci. 265, 475–518.CrossRefGoogle Scholar
Green, D. H. & Ringwood, A. E. 1967. The genesis of basaltic magmas. Contr. Mineral. and Petrol. 15, 103–90.CrossRefGoogle Scholar
Green, D. H. & Ringwood, A. E. 1968. Genesis of the calc-alkaline rock suite. Contr. Mineral, and Petrol. 18, 105–62.CrossRefGoogle Scholar
Ito, K. & Kennedy, G. C. 1968. Melting and phase relations in the plane tholeiite-Iherzolite-nepheline basanite to 40 kilobars with geological implications. Contr. Mineral, and Petrol. 19, 177–211.CrossRefGoogle Scholar
Kern, R. & Weisbrod, A. 1967. Thermodynamics for Geologists. 304p. Freeman, Cooper & Co. San Francisco.Google Scholar
Kushiro, I., Shimizu, N., Nakamura, Y. & Akimoto, S. 1972. Compositions of coexisting liquid and solid phases formed upon melting of natural garnet and spinel Iherzolites at high pressures: A preliminary report. Earth Planet. Sci, Letters 14, 19–25.CrossRefGoogle Scholar
Lewis, G. N. & Randall, M. 1961. Thermodynamics. 723 pp. McGraw-Hill Book Co., New York.Google Scholar
O'Hara, M. J. 1965. Primary magmas and the origin of basalts. Scott. J. Geol. 1, 19–40.CrossRefGoogle Scholar
O'Hara, M. J. 1968. The bearing of phase equilibria studies in synthetic and natural systems on the origin and evolution of basic and ultrabasic rocks. Earth Sci. Rev. 4, 69–133.CrossRefGoogle Scholar
Robie, R. A. & Waldbaum, D. R. 1968. Thermodynamic properties of minerals and related substances at 298.15°K (25.0°C) and one atmosphere (1,013 bars) pressure and at higher temperatures. Bull. geol. Surv. U.S. 1259, 1–256.Google Scholar
Tilley, C. E., Yoder, H. S. & Schairer, J. F. 1965. Melting relations of volcanic tholeiite and alkali rock series. Yb. Carnegie Instn Wash. 63, 69–82.Google Scholar
Tilley, C. E., Yoder, H. S. & Schairer, J. F. 1966. Melting relations of volcanic rock series. Yb. Carnegie Instn. Wash. 65, 260–9.Google Scholar
Yoder, H. S. & Tilley, C. E. 1962. Origin of basalt magmas: An experimental study of natural and synthetic rock systems. J. Petrology 3, 342–523.CrossRefGoogle Scholar