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Fluorapatites from the Skaergaard intrusion, East Greenland

Published online by Cambridge University Press:  05 July 2018

G. M. Brown  and
A. Peckett
G. M. Brown
Affiliation:
Department of Geological Sciences, Durham University
A. Peckett
Affiliation:
Department of Geological Sciences, Durham University
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Summary

The compositions of apatite crystals from seven Skaergaard rocks were obtained by electron-probe microanalysis. These span the range of occurrence from the base to the top of the exposed zones of the layered series. Apatite occurs as an intercumulus phase in the lower zones, but becomes a cumulus phase at a structural height of 1850 m (c. 98 % crystallized), defining the base of Upper Zone b. All apatite analyses show a high F:Cl ratio. There is a slight but significant increase in F and decrease in Cl when the apatite becomes a cumulus phase, the F/Cl values changing from < 10 to > 30. Variations in F:Cl:OH are attributed to differential volatile migration from trapped intercumulus liquid sites. The apatite data provide new support for ferrodiorite-granophyre liquid immiscibility.

Type
Research Article
Information
Mineralogical Magazine , Volume 41 , Issue 318 , June 1977 , pp. 227 - 232
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1977

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References

Birks, (L. S.), 1972. Electron probe microanalysis (2nd edn.). New York, Wiley-Interscience.Google Scholar
Cruft, (E. F.), Ingamells, (C. O.), and Muysson, (J.), 1965. Chemical analysis and the stoichiometry of apatite. Geochim. Cosmochim. Acta, 29, 581-97.CrossRefGoogle Scholar
Henderson, (P.), 1968. The distribution of phosphorus in the early and middle stages of fractionation of some basic layered intrusions. Geochim. Cosmochim. Acta, 32, 897–911.CrossRefGoogle Scholar
Huang, (W. H.) and Johns, (W. D.), 1967. Simultaneous determination of fluorine and chlorine in silicate rocks by a rapid spectrophotometric method. Anal. Chim. Acta, 37, 508-15.CrossRefGoogle Scholar
McBirney, (A. R.), 1975. Differentiation of the Skaergaard intrusion. Nature, 253, 691–4.CrossRefGoogle Scholar
Paster, (T. P.), Schauwecker, (D. S.), and Haskin, (L. A.), 1974. The behaviour of some trace elements during solidification of the Skaergaard layered series. Geochim. Cosmochim. Acta, 38, 1549-77.CrossRefGoogle Scholar
Peck, (D. L.), Wright, (T. L.), and Moore, (J. G.), 1966. Crystallization of tholeiitic basalt in Alae lava lake, Hawaii. Bull. Volcanol. 29, 629–56.CrossRefGoogle Scholar
Puchelt, (H.) and Emmermann, (R.), 1976. Bearing of rare earth patterns of apatites from igneous and meta- morphic rocks. Earth Planet. Sci. Lett. 31, 279–86.CrossRefGoogle Scholar
Stormer, (J. C.) and Carmichael, (I. S. E.), 1971. Fluorine-hydroxyl exchange in apatite and biotite: a potential igneous geothermometer. Contrib. Mineral. Petrol. 31, 121–31.CrossRefGoogle Scholar
Sweatman, (T. R.) and Long, (J. V. P.), 1969. Quantitative electron-probe microanalysis of rock-forming minerals. J. Petrol. 10, 332-79.CrossRefGoogle Scholar
Wager, (L. R.), 1960. The major element variation of the layered series of the Skaergaard intrusion and a re-estimation of the average composition of the Hidden Layered Series and of the successive residual magmas. J. Petrol. 1, 364.98.CrossRefGoogle Scholar
Wager, (L. R.), and Brown, (G. M.), 1968. Layered Igneous Rocks. Edinburgh, Oliver and Boyd.Google Scholar
Wager, (L. R.) and Wadsworth, (W. J.), 1960. Types of igneous cumulates. J. Petrol. 1, 73–85.CrossRefGoogle Scholar