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Clinopyroxenes of the gabbro cumulates of the Kap Edvard Holm complex, east Greenland

Published online by Cambridge University Press:  14 March 2018

W. A. Deer
Affiliation:
Department of Mineralogy and Petrology, Cambridge
D. Abbott
Affiliation:
Department of Mineralogy and Petrology, Cambridge

Summary

The major part of the Kap Edvard Holm complex consists of two series of conspicuously banded gabbroic rocks. The primary minerals of both lower and upper layered series show a progressive change in composition, from higher to lower temperature phases, with increasing height in the complex. Minor fluctuations in the differentiation of the two series occur but the division of the layered rocks into the lower and upper series is based on abrupt and major changes in the compositions of the pyroxenes, olivine and plagioclase. This break is correlated with the injection of a large volume of undifferentiated magma which occurred after much of the lower layered series had consolidated, and from which the rocks of the upper layered series were formed. Twelve pyroxenes, five from the lower and seven from the upper layered series have been analysed; the relationships between their optical properties and chemical composition, and between the cell parameters and composition are considered. The crystallization trend of the pyroxenes is compared with that of the Skaergaard calcium-rich pyroxenes; it is suggested that the restricted enrichment in iron shown by the Kap Edvard Holm pyroxenes may be related to the higher water-vapour pressures which prevailed during much of the period of crystallization.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1965

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References

Boyd, (F.R.) and Schairer, (J.F.), 1962. Carnegie Inst. Washington, Ann. gep. Dir. Geophys. Lab., 1961-62, p. 68.Google Scholar
Brown, (G.M.), 1956. Phil. Trans. Roy. Sot., ser B, vol. 240, p. 1.Google Scholar
Brown, (G.M.), 1957. Min. Mag., vol. 31, p. 5.1.Google Scholar
Rown, (G.M.), 1960. Amer. Min., vol. 45, p. 15.Google Scholar
Brown, (G.M.), and Vincent, (E.A.), 1963. Journ. Petr., vol. 4, p. 175.CrossRefGoogle Scholar
Carmichael, (I.S.E.), 1960. Journ. Petr., vol. 1, p. 309.Google Scholar
Carmichael, (I.S.E.), 1963. Min. Mag., vol. 33, p. 394.Google Scholar
Hess, (H.H.), 1949. Amer. Min., vol. 34, p. 621.Google Scholar
Hess, (H.H.), 1960. Geol. Soc. Amer., Memoir 80.Google Scholar
Hori, (F.), 1954. Scientific Papers, College General Education, Univ. Tokyo, vol. 4. p. 71.Google Scholar
Muir, (I.D.), 1951. Min. Mag., vol. 29, p. 690.Google Scholar
Murray, (R.J.), 1954. Geol. Mag., vol. 91, p. 17.CrossRefGoogle Scholar
Schairer, (J.F.), and Yoder, (H.S.), 1962. Carnegie Inst. Washington, Ann. Rep. Dir. Geophys. Lab., 195162, p. 75.Google Scholar
Segnit, (E. n.), 1953. Min. Mag., rot. 30, p. 218.CrossRefGoogle Scholar
Turner, (F.J.), 1947. Amer. Min., vol. 32, p. 389.Google Scholar
Wager, (L.R.), 1934. Meddel. om Gronlend, vol. 105, no. 2.Google Scholar
Wager, (L.R.), 1965. Min. Mag., this vol., p. 487.CrossRefGoogle Scholar
Wager, (L.R.), Brown, (G.M.) and Wadsworth, (W.J.), 1960. Journ. Petr., vol. 1, p. 73.CrossRefGoogle Scholar
Brown, (G.M.) and Deer, (W.A.), 1938. Geol. Mag., vol. 75, p. 39.Google Scholar
Brown, (G.M.) 1939. Meddel. om Gronland, vol. 105, No. 4.Google Scholar
Wilkinson, (J. F. G.), 1956. Amer. Min., vol. 41, p. 721.Google Scholar
Wilkinson, (J. F. G.), 1957. Geol. Mag., vol. 94, p. 123.CrossRefGoogle Scholar
Yoder, (H.S.) and SakasA (Th. G.), 1957. Amer. Min., vol. 42, p. 475.Google Scholar
Zvetkov, (A.I.), 1945. Mere. Soc. gusse Min., vol. 74, p. 215.Google Scholar