Hostname: page-component-848d4c4894-p2v8j Total loading time: 0.001 Render date: 2024-05-18T03:24:41.643Z Has data issue: false hasContentIssue false
  • English
  • Français

Thermal structure of crystallizing magma with two-phase Convection

Published online by Cambridge University Press:  01 May 2009

Stearns A. Morse
Stearns A. Morse
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, UK and Department of Geology and Geography, University of Massachusetts, Amherst, MA 01003, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

Two-phase packets of crystals plus liquid form rapidly at a magma contact having a high thermal contrast with its surroundings. The packets can detach from an upper contact and settle rapidly with respect to crystal settling or turbulent stirring velocities. They carry crystals and supercooling downward and act as heat sinks for crystallization of floor cumulates. Evolution of picritic magma toward neutral buoyancy and overturn into overlying basalt magma proceeds most efficiently with two-phase convection. Sinking of hot bronzite-laden liquid into cooler anorthositic liquid destroys the liquid stratification within a day or so. Two-phase convection rarely yields crystal mush thicknesses suitable for compaction of cumulates, which occurs only for a narrow window of cooling rates. Two-phase convection leads to cool, thin boundary layers above and below hot interior magma and may tend to prevent or control turbulence. The critical timing and scale of two-phase layer detachment need further study.

Type
Articles
Information
Geological Magazine , Volume 123 , Issue 3 , May 1986 , pp. 205 - 214
Copyright
Copyright © Cambridge University Press 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arndt, N. T. 1985. Layering in komatiite flows. Terra Cognita, 5, 211.Google Scholar
Belkin, H. E. 1983. Petrofabric analysis of selected rocks from the Kiglapait layered intrusion, Labrador. Geological Society of America Abstracts with Programs 15, 525.Google Scholar
Berg, J. H. 1980. Snowflake troctolite in the Hettasch intrusion: evidence for magma mixing and supercooling in a plutonic environment. Contributions to Mineralogy and Petrology 72, 339–51.CrossRefGoogle Scholar
Berg, J. H., Briegel, J. S. & Pencak, M. S. 1984. The nature and role of olivine-rich rocks in the anorthositic Nain complex, Labrador. Geological Society of America Abstracts with Programs 16, 443.Google Scholar
Brandeis, G., Jaupart, C. & Allègre, C. J. 1984. Nucleation, crystal growth, and the thermal regime of cooling magma. Journal of Geophysical Research 89, 10161–77.CrossRefGoogle Scholar
Cox, K. G. 1985. Crystal settling is a major differentiation process. Terra Cognita 5, 210.Google Scholar
Cranmer, D., Salomaa, R., Yinnon, H. & Uhlmann, D. R. 1980. Nucleation barrier in anorthite. Lunar and Planetary Science XI, 177–9, Houston: Lunar and Planetary Institute.Google Scholar
Doelter, C. 1905. Physikalisch-chemische Mineralogie. Leipzig; J. A. Barth.Google Scholar
Donaldson, C. H. 1979. An experimental investigation of the delay in nucleation of olivine in mafic magmas. Contributions to Mineralogy and Petrology 69, 21–32.CrossRefGoogle Scholar
Goldsmith, J. R. 1953. A ‘simplexity principle’ and its relation to ‘ease’ of crystallization. Journal of Geology 61, 439–51.CrossRefGoogle Scholar
Grout, F. F. 1918. Two phase convection in igneous magmas. Journal of Geology 26, 481–99.CrossRefGoogle Scholar
Grout, F. F. 1928. Anorthosites and granites as differentiates of a diabase sill at Pigeon Point, Minnesota. Geological Society of America Bulletin 39, 555–78.CrossRefGoogle Scholar
Grove, T. L. 1978. Kinetic effects on the liquid line of descent in basalts. Geological Society of America Abstracts with Programs 10, 413.Google Scholar
Hawkes, D. D. 1967. Order of abundant crystal nucleation in a natural magma. Geological Magazine 104, 473–86.CrossRefGoogle Scholar
Herbert, F., Drake, M. J., Sonett, C. P. & Wiskerchen, M. J. 1977. Some constraints on the thermal history of the lunar magma ocean. Proceedings of the Lunar Science Conference (8th), 573–82.Google Scholar
Hess, H. H. 1956. Discussion. American Journal of Science 254, 446–51.Google Scholar
Hess, H. H. 1960. Stillwater igneous complex, Montana, a quantitative mineralogical study. Geological Society of America Memoir 80, 230 pp.Google Scholar
Huppert, H. E. & Sparks, R. S. J. 1980. The fluid dynamics of a basaltic magma chamber replenished by an influx of hot, dense ultrabasic magma. Contributions to Mineralogy and Petrology 75, 279–89.CrossRefGoogle Scholar
Irvine, T. N. 1970. Heat transfer during solidification of layered intrusions. I. Sheets and sills. Canadian Journal of Earth Sciences 7, 1031–61.CrossRefGoogle Scholar
Irvine, T. N., Keith, D. W. & Todd, S. G. 1983. The J-M platinum-palladium reef of the Stillwater Complex, Montana. I. Origin by double-diffusive convective magma mixing and implications for the Bushveld Complex. Economic Geology 78, 1287–334.CrossRefGoogle Scholar
Jackson, E. D. 1961. Primary textures and mineral associations in the ultramafic zone of the Stillwater complex, Montana. United States Geological Survey Professional Paper 358, 106 pp.Google Scholar
Jaupart, C., Brandeis, G. & Allègre, C. J. 1984. Stagnantlayers at the bottom of convecting magma chambers. Nature 308, 535–8.CrossRefGoogle Scholar
Kirkpatrick, R. J. 1983. Theory of nucleation in silicate melts. American Mineralogist 68, 66–77.Google Scholar
Loper, D. E. 1985. A simple model of whole-mantle convection. Journal of Geophysical Research 90, 1809–36.CrossRefGoogle Scholar
MaalØe, Sven 1978. The origin of rhythmic layering. Mineralogical Magazine 42, 337–45.CrossRefGoogle Scholar
McBirney, A. R. & Noyes, R. M. 1979. Crystallization and layering of the Skaergaard intrusion. Journal of Petrology 20, 487–554.CrossRefGoogle Scholar
Morse, S. A. 1969. The Kiglapait layered intrusion, Labrador. Geological Society of America Memoir 112, 146 pp.Google Scholar
Morse, S. A. 1979 a. Kiglapait geochemistry. I. systematics, sampling, and density. Journal of Petrology 20, 555–90.CrossRefGoogle Scholar
Morse, S. A. 1979 b. Kiglapait geochemistry. II. Petrography. Journal of Petrology 20, 591–624.CrossRefGoogle Scholar
Morse, S. A. 1982. Adcumulus growth of anorthosite at the base of the lunar crust. Journal of Geophysical Research 87, A10–A18.CrossRefGoogle Scholar
Morse, S. A. (in press) Convection in aid of adcumulus growth. Journal of Petrology.Google Scholar
Reynolds, D. L. 1947. The granite controversy. Geological Magazine 84, 209–23.CrossRefGoogle Scholar
Sparks, R. S. J., Huppert, H. E., Kerr, R. C., McKenzie, D. P. & Tait, S. R. 1985. Postcumulus processes in layered intrusions. Geological Magazine 122, 555–68.CrossRefGoogle Scholar
Wager, L. R. 1959. Differing powers of nucleation as a factor producing diversity in layered intrusions. Geological Magazine 96, 75–80.CrossRefGoogle Scholar
Wager, L. R. 1963. The mechanism of adcumulus growth in the layered series of the Skaergaard intrusion. Mineralogical Society of America Special Paper 1, 1–9.Google Scholar
Walker, D., Hager, B. H., & Hays, J. F. 1980. Mass and heat transport in a lunar magma ocean by sinking blobs. Lunar and Planetary Science XI, 1196–8. Houston: Lunar and Planetary Institute.Google Scholar
Walker, D., Jurewicz, S. & Watson, E. B. 1985. Experimental observation of an isothermal transition from orthocumulus to adcumulus texture (Abs). EOS Transactions of the American Geophysical Union 66, 362.Google Scholar
Walker, D. & Kiefer, W. S. 1985. Xenolith digestion in large magma bodies. Journal of Geophysical Research 90, C585–C590.CrossRefGoogle Scholar
Wiebe, R. A. 1974. Coexisting intermediate and basic magmas, Ingonish, Cape Breton Island. Journal of Geology 82, 74–87.CrossRefGoogle Scholar
Wiebe, R. A. 1980. Commingling of contrasted magmas in the plutonic environment: examples from the Nain anorthositic complex. Journal of Geology 88, 197–209.CrossRefGoogle Scholar
Wiebe, R. A. 1983. The Newark Island layered intrusion. In The Nain anorthosite project, Labrador: Field Report 1981 (ed. Morse, S. A.). Contribution 40, Department of Geology & Geography, University of Massachusetts, Amherst, Massachusetts, 65–74.Google Scholar