[en] Martian meteorites are the only samples available from the surface of Mars. Among them, olivine-phyric shergottites are basalts containing large zoned olivine crystals with highly magnesian cores (Fo 70–85) and rims richer in Fe (Fo 45–60). The Northwest Africa 1068 meteorite is one of the most primitive “enriched” shergottites (high initial 87Sr/86Sr and low initial ε143Nd). It contains olivine crystals as magnesian as Fo 77 and is a major source of information to constrain the composition of the parental melt, the composition and depth of the mantle source, and the cooling and crystallization history of one of the younger magmatic events on Mars (∼180 Ma). In this study, Fe-Mg isotope profiles analyzed in situ by femtosecond-laser ablation MC-ICP-MS are combined with compositional profiles of major and trace elements in olivine megacrysts. The cores of olivine megacrysts are enriched in light Fe isotopes (δ56FeIRMM-14 = −0.6 to −0.9‰) and heavy Mg isotopes (δ26MgDSM-3 = 0–0.2‰) relative to megacryst rims and to the bulk martian isotopic composition (δ56Fe = 0 ± 0.05‰, δ26Mg = −0.27 ± 0.04‰). The flat forsterite profiles of megacryst cores associated with anti-correlated fractionation of Fe-Mg isotopes indicate that these elements have been rehomogenized by diffusion at high temperature. We present a 1-D model of simultaneous diffusion and crystal growth that reproduces the observed element and isotope profiles. The simulation results suggest that the cooling rate during megacryst core crystallization was slow (43 ± 21 °C/year), and consistent with pooling in a deep crustal magma chamber. The megacryst rims then crystallized 1–2 orders of magnitude faster during magma transport toward the shallower site of final emplacement. Megacryst cores had a forsterite content 3.2 ± 1.5 mol% higher than their current composition and some were in equilibrium with the whole-rock composition of NWA 1068 (Fo 80 ± 1.5). NWA 1068 composition is thus close to a primary melt (i.e. in equilibrium with the mantle) from which other enriched shergottites derived.
Disciplines :
Earth sciences & physical geography
Author, co-author :
Collinet, Max; Massachusetts Institute of Technology - MIT > Department of Earth, Atmospheric, and Planetary Science
Charlier, Bernard ; Université de Liège > Département de géologie > Pétrologie, géochimie endogènes et pétrophysique
Namur, Olivier ; Université de Liège > Département de géologie > Pétrologie, géochimie endogènes et pétrophysique
Oeser, Martin
Médard, Etienne
Weyer, Stefan
Language :
English
Title :
Crystallization history of enriched shergottites from Fe and Mg isotope fractionation in olivine megacrysts
Publication date :
2017
Journal title :
Geochimica et Cosmochimica Acta
ISSN :
0016-7037
eISSN :
1872-9533
Publisher :
Pergamon Press - An Imprint of Elsevier Science, Oxford, United Kingdom
Anand, M., Russell, S.S., Blackhurst, R.L., Grady, M.M., Searching for signatures of life on Mars: an Fe-isotope perspective. Philos. Trans. Roy. Soc. B: Biol. Sci. 361 (2006), 1715–1720.
Aoudjehane, H.C., Avice, G., Barrat, J.-A., Boudouma, O., Chen, G., Duke, M.J.M., Franchi, I.A., Gattacceca, J., Grady, M.M., Greenwood, R.C., Herd, C.D.K., Hewins, R., Jambon, A., Marty, B., Rochette, P., Smith, C.L., Sautter, V., Verchovsky, A., Weber, P., Zanda, B., Tissint Martian Meteorite: a fresh look at the interior, surface, and atmosphere of mars. Science 338 (2012), 785–788.
Balta, J.B., Sanborn, M., McSween, H.Y., Wadhwa, M., Magmatic history and parental melt composition of olivine-phyric shergottite LAR 06319: Importance of magmatic degassing and olivine antecrysts in Martian magmatism. Meteorit. Planet. Sci., 2013, 1359–1382.
Balta, J.B., Sanborn, M.E., Udry, A., Wadhwa, M., McSween, H.Y., Petrology and trace element geochemistry of Tissint, the newest shergottite fall. Meteorit. Planet. Sci. 50 (2015), 63–85.
Barrat, J.A., Jambon, A., Bohn, M., Gillet, P., Sautter, V., Gopel, C., Lesourd, M., Keller, F., Petrology and chemistry of the picritic shergottite North West Africa 1068 (NWA 1068). Geochim. Cosmochim. Acta 66 (2002), 3505–3518.
Basu Sarbadhikari, A., Day, J.M.D., Liu, Y., Rumble, D., Taylor, L.A., Petrogenesis of olivine-phyric shergottite Larkman Nunatak 06319: implications for enriched components in martian basalts. Geochim. Cosmochim. Acta 73 (2009), 2190–2214.
Basu Sarbadhikari, A., Goodrich, C.A., Liu, Y., Day, J.M.D., Taylor, L.A., Evidence for heterogeneous enriched shergottite mantle sources in Mars from olivine-hosted melt inclusions in Larkman Nunatak 06319. Geochim. Cosmochim. Acta 75 (2011), 6803–6820.
Bouvier, A., Blichert-Toft, J., Albarede, F., Martian meteorite chronology and the evolution of the interior of Mars. Earth Planet. Sci. Lett. 280 (2009), 285–295.
Buening, D.K., Buseck, P.R., Fe-Mg lattice diffusion in olivine. J. Geophys. Res. 78 (1973), 6852–6862.
Bunch, T.E., Irving, A.J., Wittke, J.H., Rumble, D. III, Korotev, R.L., Gellissen, M., Palme, H., Petrology and composition of Northwest Africa 2990; a new type of fine-grained, enriched, olivine-phyric shergottite. 40th Lunar and Planetary Science Conference, 2009 abstract 2274.
BVSP, Experimental Petrology of Basalts and Their Source Rocks. Basaltic Volcanism on the Terrestrial Planets. 1981, Pergamon Press Inc, New York, 1286.
Chakrabarti, R., Jacobsen, S.B., The isotopic composition of magnesium in the inner Solar System. Earth Planet. Sci. Lett. 293 (2010), 349–358.
Chakraborty, S., Farver, J.R., Yund, R.A., Rubie, D.C., Mg tracer diffusion in synthetic forsterite and San Carlos olivine as a function of P, T and fO2. Phys. Chem. Miner. 21 (1994), 489–500.
Collinet, M., Médard, E., Charlier, B., Vander Auwera, J., Grove, T.L., Melting of the primitive martian mantle at 0.5–2.2 GPa and the origin of basalts and alkaline rocks on Mars. Earth Planet. Sci. Lett. 427 (2015), 83–94.
Costa, F., Chakraborty, S., Decadal time gaps between mafic intrusion and silicic eruption obtained from chemical zoning patterns in olivine. Earth Planet. Sci. Lett. 227 (2004), 517–530.
Costa, F., Dungan, M., Short time scales of magmatic assimilation from diffusion modeling of multiple elements in olivine. Geology 33 (2005), 837–840.
Costa, F., Dohmen, R., Chakraborty, S., Time scales of magmatic processes from modeling the zoning patterns of crystals. Rev. Mineral. Geochem. 69 (2008), 545–594.
Dauphas, N., Roskosz, M., Alp, E.E., Neuville, D.R., Hu, M.Y., Sio, C.K., Tissot, F.L.H., Zhao, J., Tissandier, L., Médard, E., Cordier, C., Magma redox and structural controls on iron isotope variations in Earth's mantle and crust. Earth Planet. Sci. Lett. 398 (2014), 127–140.
Dauphas, N., Teng, F.-Z., Arndt, N.T., 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. Geochim. Cosmochim. Acta 74 (2010), 3274–3291.
de Maisonneuve, C.B., Costa, F., Huber, C., Vonlanthen, P., Bachmann, O., Dungan, M.A., How do olivines record magmatic events? Insights from major and trace element zoning. Contrib. Miner. Petrol. 171 (2016), 1–20.
Debaille, V., Yin, Q.Z., Brandon, A.D., Jacobsen, B., Martian mantle mineralogy investigated by the 176Lu–176Hf and 147Sm–143Nd systematics of shergottites. Earth Planet. Sci. Lett. 269 (2008), 186–199.
Dohmen, R., Becker, H.-W., Chakraborty, S., Fe–Mg diffusion in olivine I: experimental determination between 700 and 1200 °C as a function of composition, crystal orientation and oxygen fugacity. Phys. Chem. Miner. 34 (2007), 389–407.
Dohmen, R., Chakraborty, S., Fe–Mg diffusion in olivine II: point defect chemistry, change of diffusion mechanisms and a model for calculation of diffusion coefficients in natural olivine. Phys. Chem. Miner. 34 (2007), 409–430.
Dohmen, R., Ter heege, J.H., Becker, H.-W., Chakraborty, S., Fe-Mg interdiffusion in orthopyroxene. Am. Miner. 101 (2016), 2210–2221.
Filiberto, J., Chin, E., Day, J.M.D., Franchi, I.A., Greenwood, R.C., Gross, J., Penniston-Dorland, S.C., Schwenzer, S.P., Treiman, A.H., Geochemistry of intermediate olivine-phyric shergottite Northwest Africa 6234, with similarities to basaltic shergottite Northwest Africa 480 and olivine-phyric shergottite Northwest Africa 2990. Meteorit. Planet. Sci., 2012, 1256–1273.
Filiberto, J., Dasgupta, R., Fe2+-Mg partitioning between olivine and basaltic melts: Applications to genesis of olivine-phyric shergottites and conditions of melting in the Martian interior. Earth Planet. Sci. Lett. 304 (2011), 527–537.
Filiberto, J., Musselwhite, D.S., Gross, J., Burgess, K., Le, L., Treiman, A.H., Experimental petrology, crystallization history, and parental magma characteristics of olivine-phyric shergottite NWA 1068: Implications for the petrogenesis of “enriched” olivine-phyric shergottites. Meteorit. Planet. Sci. 45 (2010), 1258–1270.
Filiberto, J., Treiman, A.H., Le, L., Crystallization experiments on a Gusev Adirondack basalt composition. Meteorit. Planet. Sci. 43 (2008), 1137–1146.
Genova, A., Goossens, S., Lemoine, F.G., Mazarico, E., Neumann, G.A., Smith, D.E., Zuber, M.T., Seasonal and static gravity field of Mars from MGS, Mars Odyssey and MRO radio science. Icarus 272 (2016), 228–245.
Goodrich, C.A., Olivine-phyric martian basalts: a new type of shergottite. Meteorit. Planet. Sci. 37 (2002), B31–B34.
Goodrich, C.A., Petrogenesis of olivine-phyric shergottites Sayh Al Uhaymir 005 and elephant moraine A79001 lithology A. Geochim. Cosmochim. Acta 67 (2003), 3735–3772.
Gross, J., Treiman, A.H., Filiberto, J., Herd, C.D.K., Primitive olivine-phyric shergottite NWA 5789: Petrography, mineral chemistry, and cooling history imply a magma similar to Yamato-980459. Meteorit. Planet. Sci. 46 (2011), 116–133.
Gross, J., Filiberto, J., Herd, C.D.K., Daswani, M.M., Schwenzer, S.P., Treiman, A.H., Petrography, mineral chemistry, and crystallization history of olivine-phyric shergottite NWA 6234: A new melt composition. Meteorit. Planet. Sci., 2013 n/a-n/a.
Herd, C.D.K., The oxygen fugacity of olivine-phyric martian basalts and the components within the mantle and crust of Mars. Meteorit. Planet. Sci. 38 (2003), 1793–1805.
Herd, C.D.K., Insights into the redox history of the NWA 1068/1110 martian basalt from mineral equilibria and vanadium oxybarometry. Am. Miner. 91 (2006), 1616–1627.
Huebner, J.S., Buffering techniques for hydrostatic systems at elevated pressures. Ulmer, G.C., (eds.) Research Techniques for High Pressure and High Temperature, 1971, Springer, Berlin Heidelberg, Berlin, Heidelberg, 123–177.
Jackson, S.E., LAMTRACE data reduction software for LA-ICP-MS. Sylvester, P., (eds.) Laser ablation-ICP-mass spectrometry in the Earth sciences: Current practices and outstanding issues. Mineralogical Association of Canada Short Course Series, 2008, 305–307.
Jambon, A., Isotopic fractionation: A kinetic model for crystals growing from magmatic melts. Geochim. Cosmochim. Acta 44 (1980), 1373–1380.
Jambon, A., Sautter, V., Barrat, J.A., Gattacceca, J., Rochette, P., Boudouma, O., Badia, D., Devouard, B., Northwest Africa 5790: Revisiting nakhlite petrogenesis. Geochim. Cosmochim. Acta 190 (2016), 191–212.
Jochum, K.P., Willbold, M., Raczek, I., Stoll, B., Herwig, K., Chemical characterisation of the USGS reference glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G, BCR-2G, BHVO-2G and BIR-1G Using EPMA, ID-TIMS, ID-ICP-MS and LA-ICP-MS. Geostand. Geoanal. Res. 29 (2005), 285–302.
Jones, J.H., Various aspects of the petrogenesis of the Martian shergottite meteorites. Meteorit. Planet. Sci. 50 (2015), 674–690.
Koizumi, E., Mikouchi, T., Monkawa, A., Miyamoto, M., Origin of olivine in megacrysts and the groundmass crystallization of the Dar al Gani 476 shergottite. Antarct. Meteor. Res. 17 (2004), 84–96.
Lazarov, M., Horn, I., Matrix and energy effects during in-situ determination of Cu isotope ratios by ultraviolet-femtosecond laser ablation multicollector inductively coupled plasma mass spectrometry. Spectrochim. Acta, Part B 111 (2015), 64–73.
Liu, Y., Baziotis, I.P., Asimow, P.D., Bodnar, R.J., Taylor, L.A., Mineral chemistry of the Tissint meteorite: Indications of two-stage crystallization in a closed system. Meteorit. Planet. Sci., 2016 n/a–n/a.
Longerich, H.P., Jackson, S.E., Gunther, D., Inter-laboratory note. Laser ablation inductively coupled plasma mass spectrometric transient signal data acquisition and analyte concentration calculation. J. Anal. At. Spectrom. 11 (1996), 899–904.
Longhi, J., Pan, V., The parent magmas of the SNC meteorites. Procedings of the 19th Lunar and Planetary Science Conference, 1989, 451–464.
Magna, T.H.Y., Teng, F.-Z., Mezger, K., 2017. Magnesium isotope systematics of SNC meteorites: evidence for crystal fractionation or surface process? 48th Lunar and Planetary Science Conference, abstract 1795.
Marsh, B.D., On the crystallinity, probability of occurrence, and rheology of lava and magma. Contrib. Miner. Petrol. 78 (1981), 85–98.
Marsh, B.D., Crystal size distribution (CSD) in rocks and the kinetics and dynamics of crystallization. Contrib. Miner. Petrol. 99 (1988), 277–291.
McSween, H.Y., Jarosewich, E., Petrogenesis of the Elephant Moraine A79001 meteorite: Multiple magma pulses on the shergottite parent body. Geochim. Cosmochim. Acta 47 (1983), 1501–1513.
Mikouchi, T., Miyamoto, M., Olivine cooling rate of the northwest Africa 1068 shergottite. 33th Lunar and Planetary Science Conference, 2002 abstract 1346.
Mikouchi, T., Miyamoto, M., McKay, G.A., Mineralogy and petrology of the Dar al Gani 476 martian meteorite: implications for its cooling history and relationship to other shergottites. Meteorit. Planet. Sci. 36 (2001), 531–548.
Miyamoto, M., Mikouchi, T., Satake, W., Koizumi, E., Kaiden, H., The cooling rate of several olivine-phyric shergottites on the basis of Fe-Mg zoning in olivine. 41st Lunar and Planetary Science Conference, 2010 abstract 1143.
Monders, A.G., Medard, E., Grove, T.L., Phase equilibrium investigations of the Adirondack class basalts from the Gusev plains, Gusev crater, Mars. Meteorit. Planet. Sci. 42 (2007), 131–148.
Moser, D.E., Chamberlain, K.R., Tait, K.T., Schmitt, A.K., Darling, J.R., Barker, I.R., Hyde, B.C., Solving the Martian meteorite age conundrum using micro-baddeleyite and launch-generated zircon. Nature 499 (2013), 454–457.
Musselwhite, D.S., Dalton, H.A., Kiefer, W.S., Treiman, A.H., Experimental petrology of the basaltic shergottite Yamato-980459: Implications for the thermal structure of the Martian mantle. Meteorit. Planet. Sci. 41 (2006), 1271–1290.
Norman, M.D., Yaxley, G.M., Bennett, V.C., Brandon, A.D., Magnesium isotopic composition of olivine from the Earth, Mars, Moon, and pallasite parent body. Geophys. Res. Lett., 33, 2006, L15202.
O'Neill, H.S.C., Quartz-fayalite-iron and quartz-fayalite-magnetite equilibria and the free energy of formation of fayalite (Fe2SiO4) and magnetite (Fe3O4). Am. Miner. 72 (1987), 67–75.
Oeser, M., Weyer, S., Horn, I., Schuth, S., High-precision Fe and Mg isotope ratios of silicate reference glasses determined in situ by femtosecond LA-MC-ICP-MS and by solution nebulisation MC-ICP-MS. Geostand. Geoanal. Res. 38 (2014), 311–328.
Oeser, M., Dohmen, R., Horn, I., Schuth, S., Weyer, S., Processes and time scales of magmatic evolution as revealed by Fe–Mg chemical and isotopic zoning in natural olivines. Geochim. Cosmochim. Acta 154 (2015), 130–150.
Peslier, A.H., Hnatyshin, D., Herd, C.D.K., Walton, E.L., Brandon, A.D., Lapen, T.J., Shafer, J.T., Crystallization, melt inclusion, and redox history of a Martian meteorite: Olivine-phyric shergottite Larkman Nunatak 06319. Geochim. Cosmochim. Acta 74 (2010), 4543–4576.
Peters, T.J., Simon, J.I., Jones, J.H., Usui, T., Moriwaki, R., Economos, R.C., Schmitt, A.K., McKeegan, K.D., Tracking the source of the enriched martian meteorites in olivine-hosted melt inclusions of two depleted shergottites, Yamato 980459 and Tissint. Earth Planet. Sci. Lett. 418 (2015), 91–102.
Poitrasson, F., Freydier, R., Heavy iron isotope composition of granites determined by high resolution MC-ICP-MS. Chem. Geol. 222 (2005), 132–147.
Poitrasson, F., Halliday, A.N., Lee, D.-C., Levasseur, S., Teutsch, N., Iron isotope differences between Earth, Moon, Mars and Vesta as possible records of contrasted accretion mechanisms. Earth Planet. Sci. Lett. 223 (2004), 253–266.
Rapp, J.F., Draper, D.S., Mercer, C.M., Anhydrous liquid line of descent of Yamato-980459 and evolution of Martian parental magmas. Meteorit. Planet. Sci., 2013, 1780–1799.
Richter, F., Chaussidon, M., Mendybaev, R., Kite, E., Reassessing the cooling rate and geologic setting of Martian meteorites MIL 03346 and NWA 817. Geochim. Cosmochim. Acta 182 (2016), 1–23.
Richter, F.M., Liang, Y., Davis, A.M., Isotope fractionation by diffusion in molten oxides. Geochim. Cosmochim. Acta 63 (1999), 2853–2861.
Richter, F.M., Davis, A.M., DePaolo, D.J., Watson, E.B., Isotope fractionation by chemical diffusion between molten basalt and rhyolite. Geochim. Cosmochim. Acta 67 (2003), 3905–3923.
Schmidt, M.E., McCoy, T.J., The evolution of a heterogeneous Martian mantle: Clues from K, P, Ti, Cr, and Ni variations in Gusev basalts and shergottite meteorites. Earth Planet. Sci. Lett. 296 (2010), 67–77.
Shafer, J.T., Brandon, A.D., Lapen, T.J., Righter, M., Peslier, A.H., Beard, B.L., Trace element systematics and (super 147) Sm/ (super 143) Nd and (super 176) Lu/ (super 176) Hf ages of Larkman Nunatak 06319; closed system fractional crystallization of an enriched shergottite magma. Geochim. Cosmochim. Acta 74 (2010), 7307–7328.
Shea, T., Lynn, K.J., Garcia, M.O., Cracking the olivine zoning code: Distinguishing between crystal growth and diffusion. Geology 43 (2015), 935–938.
Shearer, C.K., McKay, G., Papike, J.J., Karner, J.M., Valence state partitioning of vanadium between olivine-liquid: Estimates of the oxygen fugacity of Y980459 and application to other olivine-phyric martian basalts. Am. Miner. 91 (2006), 1657–1663.
Shearer, C.K., Burger, P.V., Papike, J.J., Borg, L.E., Irving, A.J., Herd, C., Petrogenetic linkages among Martian basalts: Implications based on trace element chemistry of olivine. Meteorit. Planet. Sci. 43 (2008), 1241–1258.
Shearer, C.K., Aaron, P.M., Burger, P.V., Guan, Y., Bell, A.S., Papike, J.J., Petrogenetic linkages among fO2, isotopic enrichments-depletions and crystallization history in Martian basalts. Evidence from the distribution of phosphorus in olivine megacrysts. Geochim. Cosmochim. Acta 120 (2013), 17–38.
Shih, C.-Y., Nyquist, L.E., Wiesmann, H., Barrat, J.A., 2003. Age and Petrogenesis of Picritic Shergottite NWA1068: Sm-Nd and Rb-Sr Isotopic Studies. 34th Lunar and Planetary Science Conference, abstract 1439.
Shirai, N., Ebihara, M., Chemical characteristics of a Martian meteorite, Yamato 980459. Antarct. Meteorite Res. 17 (2004), 55–67.
Sio, C.K.I., Dauphas, N., Thermal and crystallization histories of magmatic bodies by Monte Carlo inversion of Mg-Fe isotopic profiles in olivine. Geology, 2016, 10.1130/G38056.1.
Sio, C.K.I., Dauphas, N., Teng, F.-Z., Chaussidon, M., Helz, R.T., Roskosz, M., Discerning crystal growth from diffusion profiles in zoned olivine by in situ Mg–Fe isotopic analyses. Geochim. Cosmochim. Acta 123 (2013), 302–321.
Sossi, P.A., Nebel, O., Anand, M., Poitrasson, F., On the iron isotope composition of Mars and volatile depletion in the terrestrial planets. Earth Planet. Sci. Lett. 449 (2016), 360–371.
Steinhoefel, G., Horn, I., von Blanckenburg, F., Matrix-independent Fe isotope ratio determination in silicates using UV femtosecond laser ablation. Chem. Geol. 268 (2009), 67–73.
Sugawara, T., Empirical relationships between temperature, pressure, and MgO content in olivine and pyroxene saturated liquid. J. Geophys. Res.: Solid Earth 105 (2000), 8457–8472.
Taylor, G.J., The bulk composition of Mars. Chem. Erde 73 (2013), 401–420.
Teng, F.-Z., Dauphas, N., Helz, R.T., Gao, S., Huang, S., Diffusion-driven magnesium and iron isotope fractionation in Hawaiian olivine. Earth Planet. Sci. Lett. 308 (2011), 317–324.
Teng, F.-Z., Li, W.-Y., Ke, S., Yang, W., Liu, S.-A., Sedaghatpour, F., Wang, S.-J., Huang, K.-J., Hu, Y., Ling, M.-X., Xiao, Y., Liu, X.-M., Li, X.-W., Gu, H.-O., Sio, C.K., Wallace, D.A., Su, B.-X., Zhao, L., Chamberlin, J., Harrington, M., Brewer, A., Magnesium isotopic compositions of international geological reference materials. Geostand. Geoanal. Res. 39 (2015), 329–339.
Toplis, M.J., The thermodynamics of iron and magnesium partitioning between olivine and liquid: criteria for assessing and predicting equilibrium in natural and experimental systems. Contrib. Miner. Petrol. 149 (2005), 22–39.
Usui, T., Sanborn, M., Wadhwa, M., McSween, H.Y., Petrology and trace element geochemistry of Robert Massif 04261 and 04262 meteorites, the first examples of geochemically enriched lherzolitic shergottites. Geochim. Cosmochim. Acta 74 (2010), 7283–7306.
Van Orman, J.A., Krawczynski, M.J., Theoretical constraints on the isotope effect for diffusion in minerals. Geochim. Cosmochim. Acta 164 (2015), 365–381.
Vance, J.A., On synneusis. Contrib. Miner. Petrol. 24 (1969), 7–29.
Wadhwa, M., Lentz, R.C.F., McSween, H.Y., Crozaz, G., A petrologic and trace element study of Dar al Gani 476 and Dar al Gani 489: Twin meteorites with affinities to basaltic and lherzolitic shergottites. Meteorit. Planet. Sci. 36 (2001), 195–208.
Wang, K., Moynier, F., Dauphas, N., Barrat, J.-A., Craddock, P., Sio, C.K., Iron isotope fractionation in planetary crusts. Geochim. Cosmochim. Acta 89 (2012), 31–45.
Watson, E.B., Surface enrichment and trace-element uptake during crystal growth. Geochim. Cosmochim. Acta 60 (1996), 5013–5020.
Watson, E.B., Müller, T., Non-equilibrium isotopic and elemental fractionation during diffusion-controlled crystal growth under static and dynamic conditions. Chem. Geol. 267 (2009), 111–124.
Welsch, B., Hammer, J., Hellebrand, E., Phosphorus zoning reveals dendritic architecture of olivine. Geology, 2014, 10.1130/G35691.1.
Weyer, S., Anbar, A.D., Brey, G.P., Münker, C., Mezger, K., Woodland, A.B., Iron isotope fractionation during planetary differentiation. Earth Planet. Sci. Lett. 240 (2005), 251–264.
Weyer, S., Schwieters, J.B., High precision Fe isotope measurements with high mass resolution MC-ICPMS. Int. J. Mass Spectrom. 226 (2003), 355–368.
Weyer, S., Seitz, H.M., Coupled lithium- and iron isotope fractionation during magmatic differentiation. Chem. Geol. 294–295 (2012), 42–50.
Wiechert, U., Halliday, A.N., Non-chondritic magnesium and the origins of the inner terrestrial planets. Earth Planet. Sci. Lett. 256 (2007), 360–371.
Wilson, L., Head, J.W., Ascent and eruption of basaltic magma on the Earth and Moon. J. Geophys. Res.: Solid Earth 86 (1981), 2971–3001.
Zhang, Y., Ni, H., Chen, Y., Diffusion data in silicate melts. Rev. Mineral. Geochem. 72 (2010), 311–408.
Zipfel, J., Scherer, P., Spettel, B., Dreibus, G., Schultz, L., Petrology and chemistry of the new shergottite Dar al Gani 476. Meteorit. Planet. Sci. 35 (2000), 95–106.
Zuber, M.T., The crust and mantle of Mars. Nature 412 (2001), 220–227.
