Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-05T10:37:59.510Z Has data issue: false hasContentIssue false

Controls on the trace element composition of crustal melts

Published online by Cambridge University Press:  03 November 2011

F. Bea
Affiliation:
F. Bea, Department of Mineralogy and Petrology, Campus Fuentenueva,University of Granada, 18002 Granada, Spain

Abstract:

The behaviour of trace elements during partial melting depends primarily on their mode of occurrence. For elements occurring as trace constituents of major phases (e.g. Li, Rb, Cs, Eu, Sr, Ba, Ga, etc.), slow intracrystalline diffusion (D ≍ 10−16 cm2 s−1) at the temperature range of crustal anatexis causes all effective crystal-melt partition coefficients to have a value close to unity and impedes further melt-restite re-equilibration. Usually, therefore, the trace element composition of crustal melts simply depends on the mass balance between the proportion and composition of phases that melt and the proportion and composition of newly formed phases. The behaviour of trace elements occurring as essential structural components in accessory phases (e.g. P, La-Sm, Gd-Lu, Y, Th, U, Zr, Hf, etc.) depends on the solubility, solution kinetics, grain size and the textural position of accessory phases. In common crustal protoliths a significant mass fraction of monazite, zircon, xenotime, Th-orthosilicates, uraninite; etc.—but not apatite—is included within other major and accessory phases. During low melt fraction anatexis the amount of accessory phases available for the melt is not sufficient for saturation, thus producing leucosomes with concentrations of La-Sm, Gd-Lu, Y, Th, U and Zr lower than expected from solubility equations. Low concentrations of these elements may also occur if the melt is prevented from reaching equilibrium with the accessories due to fast segregation. However, the first mechanism seems more feasible as leucosomes that are undersaturated with respect to monazite and zircon are frequently saturated, even oversaturated, with respect to apatite.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1996

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

Bea, F. 1991. Geochemical modelling of low melt-fraction anatexis in a peraluminous system: the Peña Negra Complex (central Spain). GEOCHIM COSMOCHIM ACTA 55, 1859–74.CrossRefGoogle Scholar
Bea, F. 1996. Residence of REE, Y, Th and W in granites and crustal protoliths; implications for the chemistry of crustal melts. J PETROL 37(3), in press.CrossRefGoogle Scholar
Bea, F.&Corretgé, L. G. 1986. Petrography, geochemistry, and differentiation models of lamprophyres from Sierra de Gredos, central Spain. HERCYNICA 2, 115.Google Scholar
Bea, F.&Pereira, M. D. 1990. Estudio petrológico del Complejo Anatéctico de la Peña Negra, Batolito de Avila. REV SOC GEOL ESPANA 3, 87104.Google Scholar
Bea, F..Pereira, M. D.&Stroh, A. 1994. Mineral/leucosome traceelement partitioning in a peraluminous migmatite (a laser ablation-ICP-MS study). CHEM GEOL 117, 291312.CrossRefGoogle Scholar
Brabander, D. J.&Giletti, B. J. 1995. Strontium diffusion kinetics in amphiboles and significance to thermal history determinations. GEOCHIM COSMOCHIM ACTA 59, 2223–38.CrossRefGoogle Scholar
Brady, J. B. 1995. Diffusion data for silicate minerals, glasses, and liquids. In Ahrens, T. J. (ed.) Mineral physics & crystallography. A handbook of physical constants, 269–90. Washington: AGU.Google Scholar
Brown, M. Y., Averkin, A., McLellan, E. L.&Sawyer, E. W. 1995. Melt segregation in migmatites. J GEOPHYS RES SOLID EARTH 100, 15 655–79.CrossRefGoogle Scholar
Burton, J. A., Prim, R. C.&Slichter, W. P. 1953. The distribution of solute from crystals grown from the melt. Part 1: theoretical. J CHEM PHYS 21, 1987–99.CrossRefGoogle Scholar
Carrington, D. P.&Watt, G. R. 1995. A geochemical and experimental study of the role of K-feldspar during water-undersaturated melting of metapelites. CHEM GEOL 122, 5976.CrossRefGoogle Scholar
Cherniak, D. J. 1995. Sr and Sm diffusion in titanite. CHEM GEOL 125, 219–32.CrossRefGoogle Scholar
Cherniak, D. J.&Ryerson, F. J. 1993. A study of strontium diffusion in apatite using Rutherford backscattering spectroscopy and ion implantation. GEOCHIM COSMOCHIM ACTA 57, 4653–62.CrossRefGoogle Scholar
Cherniak, D. J.&Watson, E. B. 1992. A study of strontium diffusion in K-feldspar using Rutherford backscattering spectroscopy. EARTH PLANET SCI LETT 113, 411–25.CrossRefGoogle Scholar
Cherniak, D. J.&Watson, E. B. 1994. A study of strontium diffusion in plagioclase using Rutherford backscattering spectroscopy. GEOCHIM COSMOCHIM ACTA 58, 5179–90.CrossRefGoogle Scholar
Cherniak, D. J., Lanford, W. A.&Ryerson, F. J. 1991. Lead diffusion in apatite and zircon using ion implantation and Rutherford backscattering techniques. GEOCHIM COSMOCHIM ACTA 55, 1663–73.CrossRefGoogle Scholar
Crank, J. 1975. The mathematics of diffusion, 2th edn. Oxford: Oxford Science Publications.Google Scholar
Dabrio, C. J., Esteban, M.&Martín, J. M. 1981. The coral reef of Nijar, Messinian (Uppermost Miocene), Almeria Province S. E. Spain. J SEDIMENT PETROL 51, 521–39.Google Scholar
Dougan, T. W. 1981. Melting reactions and trace element relationships in selected specimens of migmatitic pelites from New Hampshire and Maine. CONTRIB MINER PETROL 78, 337–44.CrossRefGoogle Scholar
Giletti, B. J. 1991. Rb and Sr diffusion in alkali feldspars, with implications for cooling histories of rocks. GEOCHIM COSMOCHIM ACTA 55, 1331–43.CrossRefGoogle Scholar
Harris, N. B., Gravestock, W. P.&Inger, S. 1992. Ion-microprobe determinations of trace-element concentration in garnets from anatectic assemblages. CHEM GEOL 100, 41–9.CrossRefGoogle Scholar
Hart, S. R.&Allègre, C. J. 1980. Trace-element constraints of magma genesis. In Hargraves, R. B. (ed.) Physics of magmatic processes, 121–59. Princeton: Princeton University Press.CrossRefGoogle Scholar
Henderson, P. 1982. Inorganic geochemistry: Oxford: Pergamon Press.Google Scholar
Henderson, P.&Williams, C. T. 1979. Variations in trace element partition (crystal/magma) as a function of crystal growth rate. In Ahrens, L. H. (ed.) Origin and distribution of the elements, 191–8. Oxford: Pergamon Press.Google Scholar
Hodges, K. V.&Bowring, S. A. 1995. 40Ar/39Ar thermochronology of isotopycally zoned micas: insights from the southwestern USA Proterozoic orogen. GEOCHIM COSMOCHIM ACTA 59, 3205–20.CrossRefGoogle Scholar
Hofman, A. W.&Hart, S. R. 1978. An assessment of local and regional isotopic equilibrium in the mantle. EARTH PLANET SCI LETT 38, 4462.CrossRefGoogle Scholar
Montel, J. 1986. Experimental determination of the solubility of Ce-monazite in SiO2-Al2O3-K2O-Na2O melts at 800⋘C, 2 kb, under H2O-saturated conditions. GEOLOGY 14, 659–62.2.0.CO;2>CrossRefGoogle Scholar
Munksgaard, N. C. 1984. High ∆18O and possible pre-eruptional Rb-Sr isochrons in cordierite-bearing Neogene volcanics from SE Spain. CONTRIB MINER PETROL 87, 351–8.CrossRefGoogle Scholar
Nicholls, I. A.&Harris, K. L. 1980. Experimental rare earth element partition coefficients for garnet, clinopyroxene and amphibole coexisting with andesitic and basaltic liquids. GEOCHIM COSMOCHIM ACTA 44, 287308.CrossRefGoogle Scholar
Pereira, M. D.&Bea, F. 1994. Cordierite-producing reactions at the Peña Negra complex, Avila batholith, central Spain: the key role of cordierite in low-pressure anatexis. CAN MINERAL 32, 763–80.Google Scholar
Pereira, M. D., Ronkin, Y.&Bea, F. 1992. Dataciones Rb/Sr en el Complejo Anatéctico de la Peña Negra (Batolito de Avila, España Central): evidencias de magmatismo pre-hercínico. REV SOC GEOL ESPANA 5, 129–34.Google Scholar
Pichavant, M., Montel, J. M.&Richard, L. R. 1992. Apatite solubility in peraluminous liquids: experimental data and an extension of the Harrison-Watson model. GEOCHIM COSMOCHIM ACTA 56, 3855–61.CrossRefGoogle Scholar
Rapp, R. P.&Watson, E. B. 1986. Monazite solubility and dissolution kinetics: implications for the thorium and light rare earth chemistry of felsic magmas. CONTRIB MINER PETROL 94, 304–16.CrossRefGoogle Scholar
Reid, M. R. 1990. Ionprobe investigation of rare earth elements distribution and partial melting of metasedimentary granulites. In Vielzeuf, D.&Vidal, P. (eds) Granulites and crustal evolution, 506–22. Amsterdam: Kluwer Academic.Google Scholar
Sawyer, E. W. 1991. Disequilibrium melting and the rate of meltresiduum separation during migmatization of mafic rocks from the Grenville Front, Quebec. J PETROL 32, 701–38.CrossRefGoogle Scholar
Shaw, D. M. 1970. Trace element fractionation during anatexis. GEOCHIM COSMOCHIM ACTA 34, 237–43.CrossRefGoogle Scholar
Shaw, D. M. 1978. Trace element behaviour during anatexis in the presence of a fluid phase. GEOCHIM COSMOCHIM ACTA 42, 933–43.CrossRefGoogle Scholar
Shaw, D. M. 1979. Trace element melting models. In Ahrens, L. H. (ed.) Origin and distribution of elements, 577–86. Oxford: Pergamon Press.Google Scholar
Sisson, T. W.&Bacon, C. R. 1992. Garnet/high silica rhyolite trace element partition coefficients measured by ion microprobe. GEOCHIM COSMOCHIM ACTA 56, 2133–6.CrossRefGoogle Scholar
Smith, V. G., Tiller, W. A.&Rutter, J. W. 1955. A mathematical analysis of solute redistribution during solidification. CAN J PHYS 33, 723–45.CrossRefGoogle Scholar
Sneeringer, M., Hart, S. R.&Shimizu, N. 1984. Strontium and samarium diffusion in diopside. GEOCHIM COSMOCHIM ACTA 48, 1589–608.CrossRefGoogle Scholar
Watson, E. B.&Harrison, T. M. 1983. Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types. EARTH PLANET SCI LETT 64, 295304.CrossRefGoogle Scholar
Watson, E. B.&Harrison, T. M. 1984. Accessory minerals and the geochemical evolution of crustal magmatic systems: a summary and prospectus of experimental approaches. PHYS EARTH PLANET INTER 35, 1930.CrossRefGoogle Scholar
Watson, E. B., Harrison, T. M.&Ryerson, F. J. 1985. Diffusion of Sm, Sr, and Pb in fluorapatite. GEOCHIM COSMOCHIM ACTA 49, 1813–23.CrossRefGoogle Scholar
Watson, E. B., Vicenzi, E. P.&Rapp, R. P. 1989. Inclusion/host relations involving accessory minerals in high-grade metamorphic and anatectic rocks. CONTRIB MINERAL PETROL 101, 220–31.CrossRefGoogle Scholar
Watt, G. R.&Harley, S. L. 1993. Accessory phase controls on the geochemistry of crustal melts and restites produced during waterundersaturated partial melting. CONTRIB MINERAL PETROL 114, 550–6.CrossRefGoogle Scholar
Weber, C, Barbey, P., Cuney, M.&Martin, H. 1985. Trace element behavior during migmatization. Evidence for a complex meltresiduum-fuid interaction in the St. Malo migmatitic dome (France). CONTRIB MINERAL PETROL 90, 5262.CrossRefGoogle Scholar
Wolf, M. B.&London, D. 1994. Apatite dissolution into peraluminous haplogranitic melts: an experimental study of solubilities and mechanisms. GEOCHIM COSMOCHIM ACTA 58, 4127–46.CrossRefGoogle Scholar
Wolf, M. B.&London, D. 1995. Incongruent dissolution of REEand Sr-rich apatite in peraluminous granitic liquids: differential apatite, monazite, and xenotime solubilities during anatexis. AM MINERAL 80, 765–75.CrossRefGoogle Scholar
Yund, R. A., Quigley, J.&Tullis, J. 1989. The effect of dislocations on bulk diffusion in feldspars during metamorphism. J METAMORPH GEOL 7, 337–41.CrossRefGoogle Scholar
Zeck, H. P. 1970. An erupted migmatite from Cerro del Hoyazo, SE Spain. CONTRIB MINERAL PETROL 26, 225–46.CrossRefGoogle Scholar