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Ilmenite exsolution in olivine from the serpentinite body at Zöblitz, Saxonian Erzgebirge – microstructural evidence using EBSD

Published online by Cambridge University Press:  05 July 2018

H.-J. Massonne  and
R. D. Neuser
H.-J. Massonne*
Affiliation:
Institut für Mineralogie und Kristallchemie, Universität Stuttgart, Azenbergstr. 18, D-70174 Stuttgart, Germany
R. D. Neuser
Affiliation:
Institut für Geologie, Mineralogie und Geophysik, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
*
*E-mail: [email protected]
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Abstract

In the large serpentinite body at Zöblitz, which is part of the Gneiss-Eclogite Unit of the Saxonian Erzgebirge, ilmenite rods have been detected in olivine. Although these rods are ≤1 μm wide, they can be unequivocally identified as ilmenite using electron backscatter diffraction. We also applied this method to prove that ilmenite is topotactically intergrown with the olivine host ([100]ol ‖ [001]ilm). This relation was found previously, e.g. for ilmenite exsolved from olivine of garnet peridotite from Alpe Arami, Swiss Alps. The degree of this exsolution phenomenon in the Alpe Arami rocks was taken as an indication of the original formation of a Ti-bearing mineral at depths of ∽300 km. As in the olivines of the serpentinite from Zöblitz, the density of the ilmenite rods is significantly less than in the rock from Alpe Arami. We think that our observation is compatible with previous P-T estimates of close to 4 GPa and 1000–1100°C for the ultramafic bodies in the central Saxonian Erzgebirge.

Keywords

olivineilmeniteexsolutionultrahigh pressure metamorphismgarnet peridotiteSaxonian ErzgebirgeGermanyelectron backscatter diffraction (EBSD)
Type
Research Article
Information
Mineralogical Magazine , Volume 69 , Issue 2 , April 2005 , pp. 119 - 124
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2005

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References

Bozhilov, K.N., Green, H.W. II and Dobrzhinetskaya, L. (1999) Clinoenstatite in Alpe Arami peridotite: Additional evidence of very high pressure. Science, 284, 128–132.CrossRefGoogle ScholarPubMed
Dobrzhinetskaya, L., Bozhilov, K.N. and Green, H.W. II (2000) The solubility of TiO2 in olivine: implications for the mantle wedge environment. Chemical Geology, 163, 325–338.CrossRefGoogle Scholar
Dobrzhinetskaya, L.F., Schweinehage, R., Massonne, H.-J. and Green, H.W. II (2002) Silica precipitates in omphacite from eclogite at Alpe Arami, Switzerland: evidence of deep subduction. Journal of Metamorphic Geology, 20, 481–492.CrossRefGoogle Scholar
Evans, B.W. and Trommsdorff, V. (1978) Petrogenesis of garnet lherzolite, Cima di Gagnone, Lepontine Alps. Earth and Planetary Science Letters, 40, 333–348.CrossRefGoogle Scholar
Green, H.W. II, Dobrzhinetskaya, L., Riggs, E.M. and Jin, Z.-M. (1997a) Alpe Arami: a peridotite massif from the mantle transition zone? Tectonophysics, 279, 1–21.CrossRefGoogle Scholar
Green, H.W. II, Dobrzhinetskaya, L. and Bozhilov, K. (19976) Response to “Determining the origin of ultrahigh-pressure lherzolites” by Hacker et al. Science, 278, 704–707.Google Scholar
Hacker, B.R., Sharp, T., Zhang, R.Y., Liou, J.G. and Hervig, R.L. (1997) Determining the origin of ultrahigh-pressure lherzolites. Science, 278, 702–704.CrossRefGoogle Scholar
Kröner, A. and Willner, A.P. (1998) Time of formation and peak of Variscan HP-HT metamorphism of quartz-feldspar rocks in the central Erzgebirge, Saxony, Germany. Contributions to Mineralogy and Petrology, 132, 1–20.Google Scholar
Massonne, H.-J. (2001) First find of coesite in the ultrahigh-pressure metamorphic region of the Central Erzgebirge, Germany. European Journal of Mineralogy, 13, 565–570.CrossRefGoogle Scholar
Massonne, H.-J. (2003) A comparison of the evolution of diamondiferous quartz-rich rocks from the Saxonian Erzgebirge and the Kokchetav Massif: are so-called diamondiferous gneisses magmatic rocks? Earth and Planetary Science Letters, 216, 345–362.CrossRefGoogle Scholar
Massonne, H.-J. and Bautsch, H.-J. (2004) Ultrahigh and high pressure rocks of Saxony. Field Trip Guide Books, 32nd International Geological Congress, Florence, Italy, Volume 2, B21, 36 pp.Google Scholar
Massonne, H.-J. and Grosch, U. (1995) P-T evolution of Palaeozoic garnet peridotites from the Saxonian Erzgebirge and the Åheim region, Norway. 6th International Kimberlite Conference, Novosibirsk, Volume of extended abstracts, pp. 353-355.Google Scholar
Massonne, H.-J., Nasdala, L. and Kennedy, A. (2001) U-Th-Pb dating of zircons and monazites from diamondiferous gneisses of the Saxonian Erzgebirge — Implications for their UHP/HP evolution. 6th International Eclogite Conference Niihama, Japan, Abstract Volume, p. 88.Google Scholar
Risold, A.-C, Trommsdorf, V. and Grobéty, B. (2003) Morphology of oriented ilmenite inclusions in olivine from garnet peridotites (Central Alps, Switzerland). European Journal of Mineralogy, 15, 289–294.CrossRefGoogle Scholar
Schmädicke, E. and Evans, B.W. (1997) Garnet-bearing ultramafic rocks from the Erzgebirge, and their relation to other settings in the Bohemian Massif. Contributions to Mineralogy and Petrology, 127, 57–74.Google Scholar
Tinker, D. (2001): Solubility of TiO2 in olivine from 1 to 8 GPa. EOS Transactions American Geophysical Union, 82, Fall Meeting Supplement, Abstract F1393.Google Scholar
Trommsdorff, V., Risold, A.C., Reusser, E., Conolly, J. and Ulmer, P. (2001) Titanian clinohumite: ilmenite rod inclusions and phase relations, central Alps. UHPM workshop 2001 Fluid/Slab/Mantle Interactions and Ultrahigh-P Minerals, Waseda University, Japan, Abstract Volume, pp. 84-85.Google Scholar
Van Roermund, H.L.M., Drury, M.R., Barnhoorn, A. and De Ronde, A.A. (2000) Super-silicic garnet microstructures from an orogenic garnet peridotite, evidence for an ultra-deep (>6 GPa) origin. Journal of Metamorphic Geology, 18, 135–147.CrossRefGoogle Scholar
Willner, A.P., Rötzler, K. and Maresch, W.V. (1997) Pressure-temperature and fluid evolution of quartzo-feldspathic metamorphic rocks with a relic high-pressure, granulite-facies history from the Central Erzgebirge (Saxony, Germany). Journal of Petrology, 38, 307–336.CrossRefGoogle Scholar
Zhang, R, Liou, J.G., Yang, J.S. and Ye, K. (2003) Ultrahigh-pressure metamorphism in the forbidden zone: the Xugou garnet peridotite, Sulu terrane, eastern China. Journal of Metamorphic Geology, 21, 539–550.CrossRefGoogle Scholar