PHOSPHORUS ZONING FROM SECONDARY OLIVINE IN MANTLE XENOLITH FROM MIDDLE ATLAS MOUNTAINS (MOROCCO, AFRICA): IMPLICATIONS FOR CRYSTAL GROWTH KINETICS

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Published: Jul 28, 2016
DOI: https://doi.org/10.12681/bgsg.11933
Keywords:
melt vein boundary layer enrichment Tafraoute maar
K. Mavrogonatos
S. Flemetakis
A. Papoutsa
S. Klemme
J. Berndt
G. Economou
A. Pantazidis
I. Baziotis
P.D. Asimow
Abstract

Mantle xenolith samples in contact with basalt flows were collected from the Tafraoute maar in Morocco. Discrete melt veins are present in one xenolith sample, crosscutting primary layering and foliation. We used both optical microscopy and electron microprobe analysis to characterize the glasses and minerals in the melt veins. The melt veins consist of glass and crystals of olivine, clinopyroxene, plagioclase, spinel and apatite. The olivine in the melt veins is quite distinct from the same mineral within the matrix due to its characteristic P-enriched rims (up to 0.3 wt.%). Correlations between Al and P, as well as experimentally determined partition coefficient for P, point towards non-equilibrium partitioning during rapid crystal growth at the end of crystallization.

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  • Petrology and Mineralogy
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References
Baziotis, I., Asimow, P.D., Ntaflos, T., Boyce, J.W., McCubbin, F.M., Koroneos, A., Perugini, D.,
Flude, S., Storey, M., Liu, Y.S., Klemme, S., Berndt, J. and Stolper, E.M., 2016. Phosphorus
zoning as a recorder of crystal growth kinetics: application to secondary olivine and pyroxene
in mantle xenoliths from Cima Volcanic Field, Journal of Petrology, Under Review.
Boesenberg, J.S. and Hewins, R.H., 2010. An experimental investigation into the metastable
formation of phosphoran olivine and pyroxene, Geochimica et Cosmochimica Acta, 74,
-1941.
El Azzouzi, M., Bernard-Griffiths, J., Bellon, H., Maury, R.C., Piqué, A., Fourcade, S., Cotten, J.
and Hernandez, J., 1999. Evolution des sources du volcanisme marocain au cours du Néogène,
C. R. Acad. Sci. Paris, 329, 95-102.
El Azzouzi, M., Maury, R.C., Bellon, H., Youbi, N., Cotten, J. and Kharbouch, F., 2010. Petrology
and K-Ar chronology of the Neogene-Quaternary Middle Atlas basaltic province, Morocco,
Bull. Soc. Géol. Fr., 181, 243-257.
El Messbahi, H., Bodinier, J.L., Vauchez, A., Dautria, J.M., Ouali, H. and Garrido, C.J., 2015. Short
wavelength lateral variability of lithospheric mantle beneath the Middle Atlas (Morocco) as
recorded by mantle xenoliths, Tectonophysics, 650, 34-52.
Gomez, F., Allmendinger, R., Barazangi, M., Er-Raji, A. and Dahmani, M., 1998. Crustal shortening
and vertical strain partitioning in the Middle Atlas Mountains of Morocco, Tectonics, 17,
-533.
Grant, T.B. and Kohn, S.C., 2013. Phosphorus partitioning between olivine and melt: An
experimental study in the system Mg2SiO4-Ca2Al2Si2O9-NaAlSi3O8-Mg3(PO4)2, American
Mineralogist, 98, 1860-1869.
Harte, B., 1977. Rock nomenclature with particular relation to deformation and recrystallization
textures in olivine-bearing xenoliths, The Journal of Geology, 85, 279-288.
Jambon, A., Lussiez, P., Clocchiatti, R., Weisz, J. and Hernandez, J., 1992. Olivine growth rates in
a tholeiitic basalt: An experimental study of melt inclusions in plagioclase, Chemical
Geology, 96(3), 277-287.
Lenaz, D., Youbi, N., De Min, A., Boumehdi, M.A. and Abbou, M.B., 2014. Low intra-crystalline
closure temperatures of Cr-bearing spinels from the mantle xenoliths of the Middle Atlas
Neogene-Quaternary Volcanic Field (Morocco): Mineralogical evidence of a cooler mantle
beneath the West African Craton, American Mineralogist, 99(2-3), 267-275.
Mallmann, G., O'Neill, H.C.St. and Klemme, S., 2009. Heterogeneous distribution of phosphorus in
olivine from otherwise well-equilibrated spinel peridotite xenoliths and its implications for
the mantle geochemistry of lithium, Contributions to Mineralogy and Petrology, 158, 485-
Milman-Barris, M.S., Beckett, J.R., Baker, M.B., Hofmann, A.E., Morgan, Z., Crowley, M.R.,
Vielzeuf, D. and Stolper, E., 2008. Zoning of phosphorus in igneous olivines, Contributions
to Mineralogy and Petrology, 155, 739-765.
Reitano, R., Smith, P.M. and Aziz, M.J., 1994. Solute trapping of group III, IV, and V elements in
silicon by an aperiodic stepwise growth mechanism, Journal of Applied Physics, 76(3), 1518-
Toplis, M.J. and Carroll, M.R., 1995. An experimental study of the influence of oxygen fugacity on
Fe-Ti oxide stability, phase relations, and mineral-melt equilibria in ferro-basaltic systems,
Journal of Petrology, 36, 1137-1170.
Watson, E.B., Cherniak, D.J. and Holycross, M.E., 2015. Diffusion of phosphorus in olivine and
molten basalt, American Mineralogist, 100, 2053-2065.
Welsch, B., Hammer, J. and Hellebrand, E., 2014. Phosphorus zoning reveals dendritic architecture
of olivine, Geology, 42, 867-870.
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