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Ultra-high pressure aluminous titanites in carbonate-bearing eclogites at Shuanghe in Dabieshan, central China

Published online by Cambridge University Press:  05 July 2018

D. A. Carswell ,
R. N. Wilson  and
M. Zhai
D. A. Carswell
Affiliation:
Department of Earth Sciences, University of Sheffield, Sheffield S3 7HF, UK
R. N. Wilson
Affiliation:
Department of Geology, University of Leicester, Leicester LE1 7RH, UK
M. Zhai
Affiliation:
Institute of Geology, Academia Sinica, P.O. Box 634, Beijing 100029, China
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Abstract

Petrographic features and compositions of titanites in eclogites within the ultra-high pressure metamorphic terrane in central Dabieshan are documented and phase equilibria and thermobarometric implications discussed. Carbonate-bearing eclogite pods in marble at Shuanghe contain primary metamorphic aluminous titanites, with up to 39 mol.% Ca(Al,Fe3+)FSiO4 component. These titanites formed as part of a coesite-bearing eclogite assemblage and thus provide the first direct petrographic evidence that AlFTi−1O−1 substitution extends the stability of titanite, relative to rutile plus carbonate, to pressures within the coesite stability field. However, it is emphasised that A1 and F contents of such titanites do not provide a simple thermobarometric index of P—T conditions but are constrained by the activity of fluorine, relative to CO2, in metamorphic fluids — as signalled by observations of zoning features in these titanites.

These ultra-high pressure titanites show unusual breakdown features developed under more H2O-rich amphibolite-facies conditions during exhumation of these rocks. In some samples aluminous titanites have been replaced by ilmenite plus amphibole symplectites, in others by symplectitic intergrowths of secondary, lower Al and F, titanite plus plagioclase. Most other coesite-bearing eclogite samples in the central Dabieshan terrane contain peak assemblage rutile often partly replaced by grain clusters of secondary titanites with customary low Al and F contents.

Keywords

ultra-high pressure metamorphismtitaniteseclogitesDabieshan, China
Type
Mineralogy
Information
Mineralogical Magazine , Volume 60 , Issue 400 , June 1996 , pp. 461 - 471
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1996

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References

Berman, R.G. (1988) Irvternally-consistent thermodynamic data for minerals in the system Na2O-K2O- CaO-MgO-FeO-Fe2O3-Al2O3-SiO2-TiO2-H2O- CO2. J. Petrol., 29, 445–522.CrossRefGoogle Scholar
Carswell, D.A., Wilson, R.N., Cong, B., Zhai, M. and Zhao, Z. (1993) Areal extent of the ultra-high pressure metamorphism of eclogites and gneisses in Dabieshan, central China. Terra Abstracts (Terra Nova 5), No. 4, 5.Google Scholar
Cong, B., Zhai, M., Carswell, D.A., Wilson, R.N., Qingchen, W., Zhai, Z. and Windley, B.F. (1995) Petrogenesis of ultrahigh-pressure rocks and their country rocks at Shuanghe in Dabieshan, central China. Eur. J. Mineral, 1, 119—38.Google Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1992) An Introduction to the Rock-forming Minerals. 2nd Ed. Longman.Google Scholar
Droop, G.T.R., Lombardo, B. and Pognante, U. (1990) Formation and distribution of eclogite facies rocks in the Alps. In Eclogite Facies Rocks (Carswell, D.A., ed.), Blackie, Glasgow, 225—59.CrossRefGoogle Scholar
Enami, M., Suzuki, K., Liou, J.G. and Bird, D.K. (1993) Al-Fe3+ and F-OH substitutions in titanite and constraints on their P-T dependence. Eur. J. Mineral. , 5, 219–31.CrossRefGoogle Scholar
Franz, G. and Spear, F.S. (1983) High pressure metamorphism of siliceous dolomites from the central Tauern Window, Austria. Amer. J. Sci., 283A, 396–413.Google Scholar
Franz, G. and Spear, F.S. (1985) Aluminous titanite (sphene) from the eclogite zone, south-central Tauern Window, Austria. Chem. GeoL, 50, 33–46.CrossRefGoogle Scholar
Frank, W., Hock, V. and Miller, C. (1987) Metamorphic and tectonic history of the central Tauern Window. In Geodynamics of the Eastern Alps (Rugel, H.W. and Faupl, P., eds.), Deuticke, Vienna, 34—54.Google Scholar
Hirajima, T., Zhang, R., Li, J. and Cong, B, (1992) Petrology of the nyboite-bearing eclogite in the Donghai area, Jiangsu province, eastern China. Mineral. Mag., 56, 37–46.CrossRefGoogle Scholar
Manning, C.E. and Bohlen, S.R. (1991) The reaction titanite + kyanite = anorthite + rutile and titanite- rutile barometry in eclogites. Contrib. Mineral. Petrol., 109, 1–9.CrossRefGoogle Scholar
Mottana, A., Carswell, D.A., Chopin, C. and Oberhansli, R. (1990) Eclogite facies mineral parageneses. In Eclogite Facies Rocks (Carswell, D.A., ed.), Blackie, Glasgow, 14—52.Google Scholar
Oberti, R., Smith, D.C., Rossi, G. and Caucia, F. (1991) The crystal-chemistry of high-aluminium titanites. Eur. J. Mineral., 3, 777–92.CrossRefGoogle Scholar
Smith, D.C. (1977) Aluminium bearing sphene in eclogites from SunnmGre (Norway). Geolognytt, 10, 32–3.Google Scholar
Smith, D.C. (1981) The pressure and temperature dependence of Al-solubility in sphene in the system Ti-Al-Ca-Si-O-F. Progr. Experim. Petrol. N.E.R.C. Publication Series D-18, 193—7.Google Scholar
Smith, D.C. (1988) A review of the peculiar mineralogy of the ‘Norwegian coesite-eclogite province’, with crystal-chemical, petrological, geochemical and geodynamical notes and an extensive bibliography. In: Eclogites and Eclogite-Facies Rocks (Smith, D.C., ed.), Elsevier, 1—206.Google Scholar
Spear, F.S. and Franz, G. (1986) P-T evolution of metasediments from the Eclogite Zone, south-central Tauern window, Austria. Lithos, 19, 219–34.CrossRefGoogle Scholar
Sobolev, N.V. and Shatsky, V.S. (1990) Diamond inclusions in garnets from metamorphic rocks: a new environment for diamond formation. Nature, 343, 742–6.CrossRefGoogle Scholar
Wang, X. and Liou, J.G. (1993) Ultra-high-pressure metamorphism of carbonate rocks in the Dabie Mountains, central China. J. metam. GeoL, 11, 75-88.CrossRefGoogle Scholar