Skip to main content
Log in

Silica activity and P total in igneous rocks

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

Abstract

The variation of silica activity with temperature and pressure for a variety of silica buffers (mineral pairs) allows P total to be calculated for a wide range of igneous rocks. The method also depends on evaluating (∂ log a SiO 2/∂P)T and (Δ log a SiO 2/Δ T)p; the former is equivalent to the partial molar volume of silica in silicate liquids, while the latter is estimated from published experiments on natural melts. Results for calc-alkaline rhyolites with phenocrysts of quartz, olivine or orthopyroxene, and iron-titanium oxides, range from 3.45 to 9.58 kilobars; a pantellerite is intermediate at 7.53 kilobars. At 1327° C, the silicate inclusions in diamond equilibrated at 63.5 kilobars, and the kimberlite crystallisation path intersected the baddeleyite-zircon reaction at 55.7 kilobars. Two trachybasalts would equilibrate with their lherzolite xenoliths at 17.0 and 21.0 kilobars at surface quenching temperatures. Potassic lavas such as orendites and ugandites at 1300° C would be in equilibrium with mantle olivine-orthropyroxene at 35.1 and 69.0 kilobars respectively. Basalts and basaltic-andesites could equilibrate (at 1100° C) with quartz at between 24.9 and 26.8 kilobars; quartz can therefore be considered a possible high pressure “xenocryst” in lavas with low Sr87/Sr86 ratios. Andesites will equilibrate at 1300° C with the mantle at a depth of 75 kilometres; at greater depths andesite will have a basaltic precursor. In general, lavas with low silica activity will equilibrate at greater depths in the mantle than those with higher silica activities.

The Apollo 11 basalts contain minerals which suggest equilibration at 37 kilobars; the calculated quenching temperature is 1009° C, from which logf O 2 can be derived (−15.2) which in turn indicates approximately 0.10% Fe2O3 in these lavas.

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

Access this article

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

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Binns, R. A., Duggan, M. B., Wilkinson, J. F. G.: High-pressure megacrysts in alkaline lavas for north-eastern New South Wales. Am. J. Sci. 269, 132–168 (1970).

    Google Scholar 

  • Birch, F.: Density and composition of mantle and core. J. Geophys. Res. 69, 4377–4388 (1964).

    Google Scholar 

  • Bottinga, Y., Weill, D. F.: Densities of liquid silicate systems calculated from partial molar volumes of oxide components. Amer. J. Sci. 269, 169–182 (1970).

    Google Scholar 

  • Brown, F. H.: Volcanic petrology of Recent volcanic rocks in the Lake Rudolf region, Kenya. Unpublished Ph. D. thesis, University of California, Berkeley (1971).

    Google Scholar 

  • Brown, G. M.: Petrology, mineralogy and genesis of lunar crystalline igneous rocks. J. Geophys. Res. 75, 6480–6496 (1970).

    Google Scholar 

  • Buddington, A. F., Lindsley, D. H.: Iron-titanium oxide minerals and synthetic equivalents. J. Petrol. 5, 310–357 (1963).

    Google Scholar 

  • Burnham, C. W., Holloway, J. R., Davis, N. F.: Thermodynamic properties of water to 1000° C and 10,000 bars. Geol. Soc. Am. Spec. Paper 132 (1969).

  • Carmichael, I. S. E.: Natural liquids and the phonolitic minimum. Geol. J. 4, 55–60 (1964a).

    Google Scholar 

  • —: The petrology of Thingmuli, a Tertiary volcano in eastern Iceland. J. Petrol. 5, 435–460 (1964b).

    Google Scholar 

  • —: The iron-titanium oxides of salic volcanic rocks and their associated ferromagnesian silicates. Contr. Mineral. and Petrol. 14, 36–64 (1967 a).

    Google Scholar 

  • —: The mineralogy and petrology of the volcanic rocks from the Leucite Hills, Wyoming. Contr. Mineral. and Petrol. 15, 24–66 (1967 b).

    Google Scholar 

  • —: The mineralogy of Thingmuli, a Tertiary volcano in eastern Iceland. Am. Mineralogist 52, 1815–1841 (1967 c).

    Google Scholar 

  • —, Nicholls, J., Smith, A. L.: Silica activity in igneous rocks. Am. Mineralogist 55, 246–263 (1970).

    Google Scholar 

  • Combe, A. P., Holmes, A.: The kalsilite-bearing lavas of Kabirenge and Lyakauli, southwest Uganda. Trans. Roy. Soc. Edinburgh 41, 359–379 (1945).

    Google Scholar 

  • Dickinson, W. R.: Circum-Pacific andesite types. J. Geophys. Res. 73, 2261–2270 (1968).

    Google Scholar 

  • Eugster, H. P., Wones, D. R.: Stability relations of the ferruginous biotite, annite. J. Petrol. 3, 82–125 (1962).

    Google Scholar 

  • Ewart, A., Carmichael, I. S. E., Brown, F. H., Green, D. C.: Voluminous low temperature rhyolitic magmas in New Zealand. Contr. Mineral. and Petrol. (in press).

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

    Google Scholar 

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

    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 

  • Hamilton, D. L.: Nephelines as crystallization temperature indicators. J. Geol. 69, 321–329 (1961).

    Google Scholar 

  • Hatherton, T., Dickinson, W. R.: The relationship between andesitic volcanism and seismicity in Indonesia, the Lesser Antilles and other island arcs. J. Geophys. Res. 74, 5301–5310 (1969).

    Google Scholar 

  • Kelley, K. K.: High-temperature heat-content, heat-capacity, and entropy data for the elements and inorganic compounds. U.S. Bur. Mines Bull. 584 (1960).

  • - Heats and free-energies of formation of anhydrous silicates. U.S. Bur. Mines Rept. Invest. 5901 (1962).

  • Kennedy, G. C., Nordlie, B. E.: The genesis of diamond deposits. Econ. Geol. 63, 495–503 (1968).

    Google Scholar 

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

    Google Scholar 

  • Lipman, P. W., Prostka, H. J., Christiansen, R. L.: Cenozoic volcanism and plate-tectonic evolution of the western United States. Part I: Early and Middle Cenozoic. Trans. Roy. Soc. (London) (in press).

  • Lowder, G. G.: The volcanoes and caldera of Talasea, New Britain: Mineralogy. Contr. Mineral. and Petrol. 26, 324–340 (1970).

    Google Scholar 

  • —, Carmichael, I. S. E.: The volcanoes and caldera of Talasea, New Britain: Geology and petrology. Bull. Geol. Soc. Am. 81, 17–38 (1970).

    Google Scholar 

  • MacGregor, I. D.: An hypothesis for the origin of kimberlite. Mineral. Soc. Amer. Spec. Pap. 3, 51–62 (1970).

    Google Scholar 

  • Meyer, H. O. A.: Inclusions in diamonds. Ann. Rept. Carnegie Inst. Washington Yr. Book 68, 315–320 (1970).

    Google Scholar 

  • —, Boyd, F. R.: Mineral inclusions in diamonds. Ann. Rept. Carnegie Inst. Wash. Yr. Book 67, 130–135 (1969).

    Google Scholar 

  • Nixon, P. H., Knorring, O. von, Rooke, J. M.: Kimberlites and associated inclusions of Basutoland: a mineralogical and geochemical study. Am. Mineralogist 48, 1090–1132 (1963).

    Google Scholar 

  • Pankratz, L.: High temperature heat contents and entropies of dehydrated analcite, kaliophilite and leucite. U.S. Bur. Mines, Rept. Invest. 7201 (1968).

  • Peterman, Z. E., Carmichael, I. S. E., Smith, A. L.: Sr87/Sr86 ratios of Quaternary lavas of the Cascade range, northern California. Bull. Geol. Soc. Am. 81, 311–318 (1970a).

    Google Scholar 

  • —, Lowder, G. G., Carmichael, I. S. E.: Sr87/Sr86 ratios of the Talasea series, New Britain, Territory of New Guinea. Bull. Geol. Soc. Amer. 81, 39–40 (1970b).

    Google Scholar 

  • Robie, R. A., Waldbaum, D. R.: Thermodynamic properties of minerals and related substances at 298.15° K (25.0° C) and one atmosphere (1.013 bars) pressure and higher temperatures. U.S. Geol. Surv. Bull. 1259 (1968).

  • Simpkin, T., Smith, J. V.: Minor element distribution in olivine. Geol. Soc. Am. Spec. Paper 203 (1966).

  • Smith, A. L.: Sphene, perovskite and co-existing Fe-Ti oxide minerals. Am. Mineralogist 55, 264–269 (1970).

    Google Scholar 

  • —, Carmichael, I. S. E.: Quaternary lavas from the Southern Cascades, western U.S.A. Contr. Mineral. and Petrol. 19, 212–238 (1968).

    Google Scholar 

  • —: Quaternary trachybasalts from southern California. Am. Mineralogist 54, 909–923 (1969).

    Google Scholar 

  • Tuttle, O. F., Bowen, N. L.: Origin of granite in the light of experimental studies in the system NaAlSi3O8-KAlSi3O8-SiO2-H2O. Geol. Soc. Am. Mem. 74 (1958).

  • White, R. W.: Ultramafic inclusions in basaltic rocks from Hawaii. Contr. Mineral. and Petrol. 12, 245–314 (1966).

    Google Scholar 

  • Williams, R. J.: Reaction constants in the system FeO-MgO-SiO2-O2 at 1 atm. between 900° and 1300/dg C: Experimental results. Am. J. Sci. 270, 334–360 (1971 a).

    Google Scholar 

  • —: Equilibrium temperatures, pressures, and oxygen fugacities of the equilibrated chondrites. Geochim. et Cosmochim. Acta 85, 407–411 (1971 b).

    Google Scholar 

  • Wones, D. R., Gilbert, M. C.: The fayalite-magnetite-quartz assemblage between 600° C and 800° C. Am. J. Sci. 267-A, 480–488 (1969).

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Nicholls, J., Carmichael, I.S.E. & Stormer, J.C. Silica activity and P total in igneous rocks. Contr. Mineral. and Petrol. 33, 1–20 (1971). https://doi.org/10.1007/BF00373791

Download citation

  • Received:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00373791

Keywords

Navigation