Skip to main content
SpringerLink
Log in

Primary basalts and magma genesis

I. Skye, North-West Scotland

  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

Three Eocene lavas from Skye, NW Scotland, have been subjected to anhydrous experimental studies within their melting ranges at pressures up to 30 kb. Two of these, an olivine-phyric magnesian alkali basalt and a near-aphyric Mg-poor transitional basalt, appear to show four-phase points on their liquidi at high pressures which are thought to have genetic significance. From experimental and mineralogical evidence, the magnesian basalt is postulated to be a primary magma, erupted without significant compositional change from its genesis by slight partial melting of a relatively Fe-rich spinel lherzolite upper mantle at about 60 km depth. The liquid seems to have had a reaction relationship with Ca-poor pyroxene (pigeonite) in the residual lherzolite. Partial crystallization of batches of this magma, delayed during its ascent at depths of about 40 km, is thought to have given rise to the Mg-poor basaltic liquids. The third lava studied experimentally, a sparsely olivine-phyric hawaiite, does not have olivine on the liquidus in any part of its anhydrous P-T diagram and therefore cannot have been derived under anhydrous conditions from olivine-saturated sources. The mineralogy and chemistry of the lavas are used to support an hypothesis that the hawaiites are products of partial crystallization of pockets of basalt magma at depths approximating to the crust/ mantle boundary beneath Skye, with \(P_{{\text{H}}_{\text{2}} {\text{O}}}\) rising to sufficient values to make the residual liquids comparatively rich in normative feldspar. Finally, the genesis of all other Skye Eocene lavas is reviewed in the light of the new experimental data.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Anderson, F. W., Dunham, K. C.: The geology of Northern Skye. Mem. Geol. Surv. Gt. Britain (1966)

  • Beckinsale, R. D., Thompson, R. N., Durham, J. J.: Petrogenetic significance of initial 87Sr/ 86Sr ratios in the North Atlantic Tertiary Igneous Province in the light of Rb-Sr, K-Ar and 18O-abundance studies of the Sarqâta qáqâ Intrusive Complex, Ubekendt Ejland, West Greenland. J. Petrol. 15 (in press 1974)

  • Bence, A. E., Albee, A. L.: Empirical correction factors for the electron microanalysis of silicates and oxides. J. Geol. 76, 382–403 (1968)

    Google Scholar 

  • Biggar, G. M., O'Hara, M. J., Humphries, D. J., Peckett, A.: Maria lavas, mascons, layered complexes, achondrites and the lunar mantle. In: The moon S. K., Runcorn and H. C. Urey, Int. Astronomical Union Symp. 47, 129–164: D. Reidel Publishing Co. 1972

  • Biggar, G. M., O'Hara, M. J., Peckett, A., Humphries, D. J.: Lunar lavas and the achondrites: Petrogenesis of protohypersthene basalts in the maria lava lakes. Geochim. Cosmochim. Acta, Suppl. 2, 617–643 (1971)

    Google Scholar 

  • Boyd, F. R.: Quantitative electron-probe analysis of pyroxenes. Carnegie Inst. Wash. Year book 66, 327–330 (1968)

    Google Scholar 

  • Boyd, F. R., England, J. L.: Apparatus for phase equilibrium measurements at pressures of up to 50 kb and temperatures up to 1750° C. J. Geophys. Res. 65, 741–748 (1960)

    Google Scholar 

  • Bryan, W. B., Finger, L. W., Chayes, F.: Estimating proportions in petrographic mixing equations by least-squares approximation. Science 163, 926–927 (1969)

    Google Scholar 

  • Buddington, A. F., Lindley, D. H.: Iron-titanium oxide minerals and synthetic equivalents. J. Petrol. 5, 310–357 (1964)

    Google Scholar 

  • Bultitude, R. J., Green, D. H.: Experimental studies of crystal-liquid relationships at high pressures in olivine nephelinite and basanite compositions. J. Petrol. 12, 121–147 (1971)

    Google Scholar 

  • Cawthorn, R. G., Curran, E. B., Arculus, R. J.: A petrogenetic model for the origin of the calc-alkaline suite of Grenada, Lesser Antilles. J. Petrol. 14, 327–337 (1973)

    Google Scholar 

  • Cawthorn, R. G., Ford, C. E., Biggar, G. M., Bravo, M. S., Clarke, D. B.: Determination of the liquid composition in experimental samples: discrepancies between microprobe analysis and other methods. Earth Planet. Sci. Lett. 21, 1–5 (1973)

    Google Scholar 

  • Chipman, D. W., Hays, J. F.: Partial melting in an anhydrous spinel lherzolite at 20 kb (abs). Trans. Am. Geophys. Union 53, 552 (1972)

    Google Scholar 

  • Cohen, L. H., Ito, K., Kennedy, G. C.: Melting and phase relations in an anhydrous basalt to 40 kilobars. Am. J. Sci. 265, 475–518 (1967)

    Google Scholar 

  • Cox, K. G., Jamieson, B. G.: The olivine-rich lavas of Nuanetsi: a study of polybaric magmatic evolution. J. Petrol. 14, in press (1974)

  • Dawson, J. B., Powell, D. G., Reid, A. M.: Ultrabasic xenoliths and lava from the Lashaine volcano, Northern Tanzania. J. Petrol. 11, 519–548 (1970)

    Google Scholar 

  • Dickey, J. S., Yoder, H. S., Jr.: Partitioning of chromium and aluminum between clino pyroxene and spinel. Carnegie Inst. Wash. Yearbook 71, 384–392 (1972)

    Google Scholar 

  • Finger, L. W., Hadidiacos, C. G.: Aspects of computer automation of an electron microprobe. Carnegie Inst. Wash. Yearbook 70, 269–275 (1971)

    Google Scholar 

  • Forbes, W. C., Flower, M. F. J.: Stability of titaniferous phlogopite. Earth Planet. Sci. Lett., in press (1974)

  • Green, D. H.: The origin of basaltic and nephelinitic magmas. Trans. Leicester Lit. and Phil. Soc. 64, 26–54 (1970)

    Google Scholar 

  • Green, D. H.: Experimental melting studies on a model upper mantle composition at high pressure under water-saturated and water-undersaturated conditions. Earth Planet. Sci. Lett. 19, 37–53 (1973)

    Google Scholar 

  • Green, D. H., Hibberson, W.: Experimental duplication of conditions of precipitation of high pressure phenocrysts in a basaltic magma. Phys. Earth Planet. Int. 3, 247–254 (1970)

    Google Scholar 

  • Green, D. H., Ringwood, A. E.: The genesis of basaltic magmas. Contr. Mineral. and Petrol. 15, 103–190 (1967)

    Google Scholar 

  • Green, D. H., Ringwood, A. E., Ware, N. G., Hibberson, W. O., Major, A., Kiss, E.: Experimental petrology and petrogenesis of Apollo 12 basalts. Geochim. Cosmochim. Acta, Suppl. 2, Proc. 2nd Lunar Sci. Conf. 1, 601–615 (1971)

    Google Scholar 

  • Green, T. H., Ringwood, A. E.: Genesis of the calc-alkaline igneous rock suite. Contr. Mineral. and Petrol. 18, 105–162 (1968)

    Google Scholar 

  • Hadidiacos, C. G.: Temperature controller for high-pressure apparatus. Carnegie Inst. Wash. Yearbook 71, 620–622 (1972)

    Google Scholar 

  • Holland, J. G., Brown, G. M.: Hebridean tholeiitic magmas: a geochemical study of the Ardnamurchan conesheets. Contr. Mineral. and Petrol. 37, 139–160 (1972)

    Google Scholar 

  • Irvine, T. N.: Chromian spinel as a petrogenetic indicator, Part 2, Petrologic applications. Canad. J. Earth Sci. 4, 71–103 (1967)

    Google Scholar 

  • Johannes, W., Bell, P. M., Mao, H. K., Boettcher, A. L., Chipman, D. W., Hays, J. F., Newton, R. C., Seifert, F.: An interlaboratory comparison of piston-cylinder pressure calibration using the albite breakdown reaction. Contr. Mineral. and Petrol. 32, 24–38 (1971)

    Google Scholar 

  • Kuno, H.: Mafic and ultramafic nodules in basaltic rocks of Hawaii. Geol. Soc. Am. Mem. 115, 189–234 (1969)

    Google Scholar 

  • Kuno, H., Aoki, K. I.: Chemistry of ultramafic nodules and their bearing on the origin of basaltic magmas. Phys. Earth Planet. Int. 3, 273–301 (1970)

    Google Scholar 

  • Kushiro, I.: Compositions of magmas formed by partial zone melting of the earth's upper mantle. J. Geophys. Res. 73, 619–634 (1968)

    Google Scholar 

  • Kushiro, I.: The system forsterite-diopside-silica with and without water at high pressures. Am. J. Sci. 267-A, 269–294 (1969)

    Google Scholar 

  • Kushiro, I.: Melting experiment on Apollo 14 high-alumina basalt. Carnegie Inst. Wash.Yearbook 71, 472–474 (1972a)

    Google Scholar 

  • Kushiro, I.: Partial melting of synthetic and natural peridotites at high pressures. Carnegie Inst. Wash. Yearbook 71, 357–362 (1972b)

    Google Scholar 

  • Kushiro, I.: Origin of some magmas in oceanic and circum-oceanic regions. Tectonophys. 17, 211–222 (1973)

    Google Scholar 

  • Kushiro, I., Shimizu, N., Nakamura, Y., Akimoto, S.: Compositions of coexisting liquid and solid phases formed upon melting of natural garnet and spinel lherzolites at high pressures: a preliminary report. Earth Planet. Sci. Lett. 14, 19–25 (1972)

    Google Scholar 

  • Kushior, I., Thompson, R. N.: Origin of some abyssal tholeiites from the Mid-Atlantic Ridge. Carnegie Inst. Wash. Yearbook 71, 403–406 (1972)

    Google Scholar 

  • Modreski, P. J.: The melting of phlogopite in the presence of enstatite, aluminous enstatite, diopside, spinel, corundum and pyrope. Carnegie Inst. Wash. Yearbook 71, 392–396 (1972)

    Google Scholar 

  • Nicholls, I. A., Ringwood, A. E.: Effect of water on olivine stability in tholeiites and the production of silica-saturated magmas in the island arc environment. J. Geol. 81, 285–300 (1973)

    Google Scholar 

  • O'Hara, M. J.: Primary magmas and the origin of basalts. Scot. J. Geol. 1, 19–40 (1965)

    Google Scholar 

  • O'Hara, M. J.: Mineral parageneses in ultrabasic rocks. In: Wyllie, P. J., ed., Ultramafic and related rocks, p. 393–403. New York: Wiley 1967

    Google Scholar 

  • O'Hara, M. J.: 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 (1968)

    Google Scholar 

  • O'Hara, M. J.: Upper mantle composition inferred from laboratory experiments and observation of volcanic products. Phys. Earth Planet. Int. 3, 236–245 (1970)

    Google Scholar 

  • O'Hara, M. J., Biggar, G. M.: A point of phase equilibria interpretation in connection with lavas from the Apollo 12 site. Earth Planet. Sci. Lett. 16, 388–390 (1972)

    Google Scholar 

  • O'Hara, M. J., Yoder, H. S., Jr.: Formation and fractionation of basic magmas at high pressures. Scot. J. Geol. 3, 67–117 (1967)

    Google Scholar 

  • Presnall, D. C., Brenner, N. L., O'Donnell, T. H.: Drift of Pt/Pt1ORh and W3Re/W25Re thermocouples in single stage piston-cylinder apparatus. Am. Min. 58, 771–777 (1973)

    Google Scholar 

  • Ridley, W. I.: The petrology of some volcanic rocks from the British Tertiary Province: The islands of Rhum, Eigg, Canna and Muck. Contr. Mineral. and Petrol. 32, 251–266 (1971)

    Google Scholar 

  • Ridley, W. I.: Zoned spinels in some British Tertiary basalts (abs). Trans. Am. Geophys. Union 53, 548 (1972)

    Google Scholar 

  • Ringwood, A. E., Green, D. H.: Crystallization of plagioclase in lunar basalts and its significance. Earth Planet. Sci. Litt. 14, 14–18 (1972)

    Google Scholar 

  • Roeder, P. L., Emslie, R. F.: Olivine—liquid equilibrium. Contr. Mineral. and Petrol. 29, 275–289 (1970)

    Google Scholar 

  • Thompson, R. N.: Evidence for a chemical discontinuity near the basalt—“andesite” transition in many anorogenic volcanic suites. Nature 236, 106–110 (1972a)

    Google Scholar 

  • Thompson, R. N.: The 1-atmosphere melting patterns of some basaltic volcanic series. Am. J. Sci. 272, 901–932 (1972b)

    Google Scholar 

  • Thompson, R. N.: Melting behavior of two Snake River lavas at pressures up to 35 kb. Carnegie Inst. Wash. Yearbook 71, 406–410 (1972c)

    Google Scholar 

  • Thompson, R. N.: Titanian chromite and chromian titanomagnetite from a Snake River Plain basalt, a terrestrial analogue to lunar spinels. Am. Mineralogist 58, 826–830 (1973)

    Google Scholar 

  • Thompson, R. N.: Some high pressure pyroxenes. Mineral. Mag. 40, in press (1974)

  • Thompson, R. N., Esson, J., Dunham, A. C.: Major element chemical variation in the Eocene lavas of the Isle of Skye, Scotland. J. Petrol. 13, 219–253 (1972)

    Google Scholar 

  • Thompson, R. N., Kushiro, I.: The oxygen fugacity within graphite capsules in pistoncylinder appartur at high pressures. Carnegie Inst. Wash. Yearbook 71, 615–616 (1972)

    Google Scholar 

  • Tilley, C. E., Muir, I. D.: The Hebridean Plateau Magma Type. Trans. Edinburgh Geol. Soc. 19, 208–215 (1962)

    Google Scholar 

  • Tilley, C. E., Yoder, H. S., Jr., Schairer, J. F.: Melting relations of volcanic tholeiite and alkali rock series. Carnegie Inst. Wash. Yearbook 64, 69–82 (1965)

    Google Scholar 

  • Wright, T. L.: Chemistry of Kilauea and Mauna Loa lava in space and time. U.S. Geol. Surv. Profess. Papers 735, 40 p. (1971)

  • Wright, T. L., Doherty, P. C.: A linear programming and least squares computer method for solving petrologic mixing problems. Bull. Geol. Soc. Am. 81, 1995–2008 (1970)

    Google Scholar 

  • Wright, T. L., Fiske, R. S.: Origin of the differentiated and hybrid lavas of Kilauea Volcano, Hawaii. J. Petrol. 12, 1–65 (1971)

    Google Scholar 

  • Yoder, H. S., Jr.: Calcalkaline andesites: experimental data bearing on the origin of their assumed characteristics. In: McBirney, A. R., ed., Proceedings of the Andesite Conference. Oregon Dept. Geol. Mineral Ind. Bull. 65, 77–89 (1969)

  • Yoder, H. S., Tilley, C. E.: Origin of basalt magmas: an experimental study of natural and synthetic rock systems. J. Petrol. 3, 342–532 (1962)

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Geology, Imperial College of Science and Technology, London, England

    R. N. Thompson

Authors
  1. R. N. Thompson
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Thompson, R.N. Primary basalts and magma genesis. Contr. Mineral. and Petrol. 45, 317–341 (1974). https://doi.org/10.1007/BF00371750

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00371750

Keywords

Search

Navigation