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The deep continental crust has a larger Mg isotopic variation than previously thought

  • Zhao-Feng Zhang EMAIL logo
Published/Copyright: February 18, 2016
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Abstract

Magnesium isotope compositions of the bulk continental crust is a key to understand Mg isotope behaviors during crustal processes, and is the prerequisite to study mantle-crust material exchange/reaction by Mg isotopes. However, thus far, little is known about Mg isotopic compositions of the middle and lower continental crust. In the article by Yang et al. in this issue entitled “Magnesium isotopic composition of the deep continental crust,” the authors present high-precision Mg isotopic analyses of high-grade metamorphic terrane samples and granulite xenoliths from China, which represent the middle and lower continental crust, respectively. Large Mg isotopic variation is observed in the deep continental crust, reflecting the combination of several processes, such as continental weathering, involvement of supracrustal materials, and fluid metasomatism. In addition, this article also provides an average Mg isotope composition of the bulk continental crust, which is crucial to future applications of Mg isotopes.

References cited

Bourdon, B., Tipper, E.T., Fitoussi, C., and Stracke, A. (2010) Chondritic Mg isotope composition of the Earth. Geochimica et Cosmochimica Acta, 74, 5069–5083.10.1016/j.gca.2010.06.008Search in Google Scholar

Dauphas, N., Teng, F.-Z., and Arndt, N.T. (2010) Magnesium and iron isotopes in 2.7 Ga Alexo komatiites: Mantle signatures, no evidence for Soret diffusion, and identification of diffusive transport in zoned olivine. Geochimica et Cosmochimica Acta, 74, 3274–3291.10.1016/j.gca.2010.02.031Search in Google Scholar

Foster, G., von Strandmann, P, and Rae, J. (2010) Boron and magnesium isotopic composition of seawater. Geochemistry, Geophysics, Geosystems, 11(8), Q08015.10.1029/2010GC003201Search in Google Scholar

Handler, M.R., Baker, J.A., Schiller, M., Bennett, V.C., and Yaxley, G.M. (2009) Magnesium stable isotope composition of Earth’s upper mantle. Earth and Planetary Science Letters, 282, 306–313.10.1016/j.epsl.2009.03.031Search in Google Scholar

Huang, K.-J., Teng, F.-Z., Wei, G.-J., Ma, J.-L., and Bao, Z.-Y. (2012) Adsorption- and desorption-controlled magnesium isotope fractionation during extreme weathering of basalt in Hainan Island, China. Earth and Planetary Science Letters, 359-360, 73–83.10.1016/j.epsl.2012.10.007Search in Google Scholar

Huang, K.-J., Teng, F.-Z., Elsenouy, A., Li, W.-Y, and Bao, Z.-Y. (2013) Magnesium isotopic variations in loess: Origins and implications. Earth and Planetary Science Letters, 374, 60–70.10.1016/j.epsl.2013.05.010Search in Google Scholar

Li, W. Y., Teng, F.Z., Ke, S., Rudnick, R.L., Gao, S., Wu, F.Y., and Chappell, B.W. (2010) Heterogeneous magnesium isotopic composition of the upper continental crust. Geochimica et Cosmochimica Acta, 74, 6867–6884.10.1016/j.gca.2010.08.030Search in Google Scholar

Ling, M.-X., Sedaghatpour, F., Teng, F.-Z., Hays, PD., Strauss, J., and Sun, W. (2011) Homogeneous magnesium isotopic composition of seawater: an excellent geostandard for Mg isotope analysis. Rapid Communications in Mass Spectrometry, 25, 2828–2836.10.1002/rcm.5172Search in Google Scholar PubMed

Liu, S.-A., Teng, F.-Z., He, Y., Ke, S., and Li, S. (2010) Investigation of magnesium isotope fractionation during granite differentiation: Implication for Mg isotopic composition of the continental crust. Earth and Planetary Science Letters, 297, 646–654.10.1016/j.epsl.2010.07.019Search in Google Scholar

Liu, X.-M., Teng, F.-Z., Rudnick, R.L., McDonough, W.F., and Cummings, M.L. (2014) Massive magnesium depletion and isotope fractionation in weathered basalts. Geochimica et Cosmochimica Acta, 135, 336–349.10.1016/j.gca.2014.03.028Search in Google Scholar

Pogge von Strandmann, PA.E., James, R.H., van Calsteren, P, Gislason, S.R., and Burton, K.W. (2008) Lithium, magnesium and uranium isotope behaviour in the estuarine environment of basaltic islands. Earth and Planetary Science Letters, 274, 462–471.10.1016/j.epsl.2008.07.041Search in Google Scholar

Pogge von Strandmann, PA.E., Elliott, T., Marschall, H.R., Coath, C., Lai, Y.-J., Jeffcoate, A.B., and Ionov, D.A. (2011) Variations of Li and Mg isotope ratios in bulk chondrites and mantle xenoliths. Geochimica et Cosmochimica Acta, 75, 5247–5268.10.1016/j.gca.2011.06.026Search in Google Scholar

Shen, B., Jacobsen, B., Lee, C.T.A., Yin, Q.Z., and Morton, D.M. (2009) The Mg isotopic systematics of granitoids in continental arcs and implications for the role of chemical weathering in crust formation. Proceedings of the National Academy of Sciences, 106, 20,652-20,657.10.1073/pnas.0910663106Search in Google Scholar PubMed PubMed Central

Teng, F.Z., Wadhwa, M., and Helz, R.T. (2007) Investigation of magnesium isotope fractionation during basalt differentiation: Implications for a chondritic composition of the terrestrial mantle. Earth and Planetary Science Letters, 261, 84–92.10.1016/j.epsl.2007.06.004Search in Google Scholar

Teng, F.-Z., Li, W.-Y., Ke, S., Marty, B., Dauphas, N., Huang, S., Wu, F.-Y., and Pourmand, A. (2010a) Magnesium isotopic composition of the Earth and chondrites. Geochimica et Cosmochimica Acta, 74, 4150—4166.10.1016/j.gca.2010.04.019Search in Google Scholar

Teng, F.Z., Li, W. Y., Rudnick, R.L., and Gardner, L.R. (2010b) Contrasting lithium and magnesium isotope fractionation during continental weathering. Earth and Planetary Science Letters, 300, 63–71.10.1016/j.epsl.2010.09.036Search in Google Scholar

Teng, F. Z., Yang, W., Rudnick, R.L., and Hu, Y. (2013) Heterogeneous magnesium isotopic composition of the lower continental crust: A xenolith perspective. Geochemistry, Geophysics, Geosystems, 14, 3844–3856.10.1002/ggge.20238Search in Google Scholar

Tipper, E.T., Galy, A., Gaillardet, J., Bickle, M.J., Elderfield, H., and Carder, E.A. (2006) The magnesium isotope budget of the modern ocean: Constraints from riverine magnesium isotope ratios. Earth and Planetary Science Letters, 250, 241–253.10.1016/j.epsl.2006.07.037Search in Google Scholar

Tipper, E.T., Gaillardet, J., Louvat, P., Capmas, F., and White, A.F. (2010) Mg isotope constraints on soil pore-fluid chemistry: Evidence from Santa Cruz, California. Geochimica et Cosmochimica Acta, 74, 3883–3896.10.1016/j.gca.2010.04.021Search in Google Scholar

Xiao, Y., Teng, F.-Z., Zhang, H.-F., and Yang, W. (2013) Large magnesium isotope fractionation in peridotite xenoliths from eastern North China craton: Product of melt-rock interaction. Geochimica et Cosmochimica Acta, 115, 241–261.10.1016/j.gca.2013.04.011Search in Google Scholar

Yang, W., Teng, F.-Z., and Zhang, H.-F. (2009) Chondritic magnesium isotopic composition of the terrestrial mantle: A case study of peridotite xenoliths from the North China craton. Earth and Planetary Science Letters, 288, 475–482.10.1016/j.epsl.2009.10.009Search in Google Scholar

Yang, W., Teng, F.Z., Li, W. Y., Liu, S.-A., Ke, S., Liu, Y.S., Zhang, H.F., and Gao, S. (2016) Magnesium isotopic composition of the deep continental crust. American Mineralogist, 101, 243–252.10.2138/am-2016-5275Search in Google Scholar

  1. Manuscript handled by Keith Putirka.

Received: 2015-6-30
Accepted: 2015-7-10
Published Online: 2016-2-18
Published in Print: 2016-2-1

© 2016 by Walter de Gruyter Berlin/Boston

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