Skip to main content Accessibility help
×
Home

Terminology of postcumulus processes and products in the Rhum layered intrusion

  • W. J. Wadsworth (a1)

Abstract

The terminology of cumulates is discussed with particular reference to postcumulus processes as exemplified by the Rhum layered intrusion. The history of the terms orthocumulate, adcumulate, heteradcumulate and harrisitic cumulate is reviewed, and some modifications to the classification scheme proposed by Irvine (1982) are suggested. Possible mechanisms of adcumulus growth are considered and, on balance, the Rhum evidence confirms the view that postcumulus cementation occurred at a relatively early stage, while the intercumulus melt was in effective contact with the main body of magma.

Copyright

References

Hide All
Brown, G. M. 1956. The layered ultrabasic rocks of Rhum, Inner Hebrides. Philosophical Transactions of the Royal Society B240, 153.
Butcher, A. R. 1985. Channelled metasomatism in Rhum layered cumulates – evidence from late-stage veins. Geological Magazine 122, 503–18.
Butcher, A. R., Young, I. M. & Faithfull, J. W. 1985. Finger structures in the Rhum Complex. Geological Magazine 122, 491502.
Donaldson, C. H. 1974. Olivine crystal types in harrisitic rocks of the Rhum pluton and in Archaean spinifex rocks. Bulletin of the Geological Society of America 85, 1721–6.
Donaldson, C. H. 1982. Origin of some of the Rhum harrisite by segregation of intercumulus liquid. Mineralogical Magazine 45, 201–9.
Dunham, A. C. & Wadsworth, W. J. 1978. Cryptic variation in the Rhum layered intrusion. Mineralogical Magazine 42, 347–56.
Hess, G. B. 1972. Heat and mass transport during crystallization of the Stillwater igneous complex. Memoir of the Geological Society of America 132, 503–20.
Hess, H. H. 1939. Extreme fractional crystallisation of a basaltic magma: the Stillwater igneous complex. Transactions of the American Geophysical Union, Reports and Papers, Volcanology 3, 430–2.
Hess, H. H. 1960. Stillwater Igneous Complex, Montana: a quantitative mineralogical study. Memoir of the Geological Society of America 80, 1230.
Huppert, H. E. & Sparks, R. S. J. 1980. The fluid dynamics of a basaltic magma chamber replenished by influx of hot, dense ultrabasic magma. Contributions to Mineralogy and Petrology 75, 279–89.
Irvine, T. N. 1980 a. Magmatic infiltration metasomatism, double-diffusive fractional crystallisation, and adcu-mulus growth in the Muskox intrusion and other layered intrusions. In Physics of Magmatic Processes (ed. Hargraves, R. B.), pp. 325–83. Princeton, N.J.: Princeton University Press.
Irvine, T. N. 1980 b. Magmatic density currents and cumulus processes. American Journal of Science 280A, 158.
Irvine, T. N. 1982. Terminology for layered intrusions. Journal of Petrology 23, 127–62.
Jackson, E. D. 1967. Ultramafic cumulates in the Stillwater, Great Dyke and Bushveld intrusions. In Ultramafic and Related Rocks (ed. Wyllie, P. J.), pp. 30–8. New York: John Wiley & Sons, Inc.
Korzhinskii, D. S. 1965. The theory of systems with perfectly mobile components and processes of mineral formation. American Journal of Science 263, 193205.
McBirney, A. R. & Noyes, R. M. 1979. Crystallisation and layering of the Skaergaard intrusion. Journal of Petrology 20, 487544.
Morse, S. A. 1979. Kiglapait geochemistry. II: Petrography. Journal of Petrology 20, 591624.
Morse, S. A. 1980. Basalts and Phase Diagrams. New York: Springer-Verlag. 493 pp.
Tait, S. R., Huppert, H. E. & Sparks, R. S. J. 1984. The role of compositional convection in the formation of adcumulate rocks. Lithos 17, 139–46.
Wadsworth, W. J. 1961. The ultrabasic rocks of south-west Rhum. Philosophical Transactions of the Royal Society B244, 2164.
Wadsworth, W. J., Dunham, A. C. & Almohandis, A. A. 1982. Cryptic variation in the Kapalagulu intrusion, western Tanzania. Mineralogical Magazine 45, 227–36.
Wager, L. R. 1963. The mechanism of adcumulus growth in the layered series of the Skaergaard intrusion. Special Papers of the Mineralogical Society of America 1, 119.
Wager, L. R. & Brown, G. M. 1968. Layered Igneous Rocks. Edinburgh: Oliver and Boyd Ltd. 588 pp.
Wager, L. R., Brown, G. M. & Wadsworth, W. J. 1960. Types of igneous cumulates. Journal of Petrology 1, 7385.
Wager, L. R. & Deer, W. A. 1939. Geological investigations in East Greenland, Part III. The petrology of the Skaergaard intrusion, Kangerdlugssuak, East Greenland. Meddelelser om Grønland 105, 1352.

Terminology of postcumulus processes and products in the Rhum layered intrusion

  • W. J. Wadsworth (a1)

Metrics

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