Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-24T18:29:31.208Z Has data issue: false hasContentIssue false

Garnet exsolution in garnet clinopyroxenite and clinopyroxenite xenoliths in early Cretaceous intrusions from the Xuzhou region, eastern China

Published online by Cambridge University Press:  05 July 2018

W. Xu
Affiliation:
College of Earth Sciences, Jilin University, Changchun 130061, China
X. Liu
Affiliation:
Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing 100081, China
Q. Wang
Affiliation:
College of Earth Sciences, Jilin University, Changchun 130061, China
J. Lin
Affiliation:
College of Earth Sciences, Jilin University, Changchun 130061, China
D. Wang
Affiliation:
College of Earth Sciences, Jilin University, Changchun 130061, China

Abstract

Exsolved garnet, sometimes associated with exsolved amphibole and zoisite, is abundant in aluminous clinopyroxene of garnet clinopyroxenite and clinopyroxenite xenoliths in the early Cretaceous dioriticmonzodioritic intrusions from the Xuzhou region, ∼100 km west of the Sulu ultrahigh-pressure (UHP) metamorphic terrane in eastern China. In addition to the mineral exsolutions, intergranular fine-grained garnet, zoisite, titanite, and sometimes amphibole are also present around the primary clinopyroxene grains. Clinopyroxene shows compositional gradients, with decreasing Al and increasing Si and Mg, adjacent to the garnet lamellae and intergranular garnet. In contrast, the exsolved and intergranular garnet is homogeneous in composition and typically more grossular-rich and pyrope- and almandinepoor than the coarse-grained primary garnet. The estimates of P and T for the precursor assemblage and garnet exsolution suggests a decrease of temperature from ∼950—1100ºC down to 620—780°C, and a nearly constant pressure from ∼15—20 kbar to 18 kbar, which are comparable with the metamorphic conditions of the associated eclogites. Therefore, garnet exsolution in garnet clinopyroxenite and clinopyroxenite xenoliths could be caused by high-pressure (HP) metamorphism. SHRIMP zircon U-Pb dating for the associated eclogite and gneiss xenoliths and Sm-Nd whole rock-garnet dating for the same eclogite demonstrate that parts of lower crust on the southeastern margin of the North China craton might be involved in the Triassic HP metamorphism due to the deep subduction of the Yangtze craton.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ames, L., Zhou, G. and Xiong, B. (1996) Geochronology and isotopic character of ultrahighpressure metamorphism with implications for collision of the Sino-Korean and Yangtze Cratons, central China. Tectonics, 15, 472489.CrossRefGoogle Scholar
Aoki, K.-I., Fujimaki, H. and Kitamura, M. (1980) Exsolved garnet-bearing megacrysts from some South African kimberlites. Lithos, 13, 269279.CrossRefGoogle Scholar
Carswell, D.A., Wilson, R.N. and Zhai, M. (1996) Ultrahigh pressure aluminous titanites in carbonatebearing eclogites at Shuanghe in Dabieshan, central China. Mineralogical Magazine, 60, 461471.CrossRefGoogle Scholar
Carswell, D.A., O’Brien, P.J., Wilson, R.N. and Zhai, M. (1997) Thermobarometry of phengite-bearing eclogites in the Dabie Mountains of central China. Journal of Metamorphic Geology, 15, 239252.CrossRefGoogle Scholar
Ellis, D.J. and Green, D.H. (1979) An experimental study of the effect of Ca upon garnet-clinopyroxene Fe-Mg exchange equilibria. Contributions to Mineralogy and Petrology, 71, 1322.CrossRefGoogle Scholar
Gasparik, T. (1984) Experimentally determined stability of clinopyroxenes + garnet + corundum in the system CaO–MgO–Al2O3–SiO2 . American Mineralogist, 69, 10251035.Google Scholar
Gasparik, T. (1987) Orthopyroxene thermobarometry in simple and complex systems. Contributions to Mineralogy and Petrology, 71, 686693.Google Scholar
Gasparik, T. (2000) An internally consistent thermodynamic mode for the system CaO–MgO–Al2O3–SiO2 derived primarily from phase equilibrium data. Journal of Geology, 108, 103119.CrossRefGoogle Scholar
Graham, C.M. and Powell, R. (1984) A garnethornblende geothermometer and application to the Pelona schists, southern California. Journal of Metamorphic Geology, 2, 1322.CrossRefGoogle Scholar
Green, D.H. (1966) The origin of ‘eclogites’ from Salt Lake Crater, Hawaii. Earth and Planetary Science Letters, 1, 414420.CrossRefGoogle Scholar
Harte, B. and Gurney, J.J. (1975) Evolution of clinopyroxenes and garnet in an eclogite nodule from the Roberts Victor kimberlite pipe, South Africa. Physics and Chemistry of the Earth, 9, 367978.CrossRefGoogle Scholar
Hiramatsu, N. and Hirajima, T. (1995) Petrology of the Hujialin garnet clinopyroxenite in the Su-Lu ultrahigh-pressure province, eastern China. Island Arc, 4, 310323.CrossRefGoogle Scholar
Jerde, E.A., Taylor, L.A., Crozaz, G. and Sobolev, N.V. (1993) Exsolution of garnet within clinopyroxenes of mantle eclogites: major- and trace-element chemistry. Contributions to Mineralogy and Petrology, 114, 148159.CrossRefGoogle Scholar
Kretz, R. (1983) Symbols for rock-forming minerals. American Mineralogist, 68, 277279.Google Scholar
Krogh, E.J. (1988) The garnet-clinopyroxene Fe-Mg geothermometer – a reinterpretation of existing experimental data. Contributions to Mineralogy and Petrology, 99, 4448.CrossRefGoogle Scholar
Lappin, M.A. and Dawson, B.D. (1975) Two Roberts- Victor cumulate eclogites and their re-equilibration. Physics and Chemistry of the Earth, 9, 351365.CrossRefGoogle Scholar
Lappin, M.A. and Smith, D.C. (1978) Mantle-equilibrated orthopyroxene eclogite pods from the Basal Gneisses in the Selje district, western Norway. Journal of Petrology, 19, 530584.CrossRefGoogle Scholar
Leake, B.E., Woolley, A.R., Arps, C.E.S., Birch, W.D., Gilbert, M.C., Grice, J.D., Hawthorne, F.C., Kato, A., Kisch, H.J., Krivovichev, V.G., Linthout, K., Laird, J., Mandarino, J.A., Maresch, W.V., Nickel, E.H., Rock, N.M.S., Schumacher, J.C., Smith, D.C., Stephenson, N.C.N., Ungaretti, L., Whittaker, E.J.W. and Guo, Y. (1997) Nomenclature of amphiboles: report of the subcommittee on amphiboles of the International Mineralogical Association, Commission on New Minerals and Mineral Names. Mineralogical Magazine, 61, 295321.CrossRefGoogle Scholar
Li, S., Xiao, Y., Liu, D., Chen, Y., Ge, N., Zhang, Z., Sun, S.-S., Cong, B., Zhang, R., Hart, S.R. and Wang, S. (1993) Collision of the North China and Yangtze Blocks and formation of coesite-bearing eclogites: timing and processes. Chemical Geology, 109, 89111.CrossRefGoogle Scholar
Lovering, J.F. and White, A.J. (1969) Granulitic and eclogitic inclusions from basic pipes at Delegate, Australia. Contributions to Mineralogy and Petrology, 21, 952.CrossRefGoogle Scholar
Ma, C., Li, Z., Ehlers, C., Yang, K. and Wang, R. (1998) A post-collisional magmatic plumbing system: Mesozoic granitoid plutons from the Dabieshan high-pressure and ultrahigh-pressure metamorphic zone, east-central China. Lithos, 45, 431456.CrossRefGoogle Scholar
Powell, R. (1985) Regression diagnostics and robust regression geothermometer/ geobarometer calibration: the garnet-clinopyroxene geothermometer revisited. Journal of Metamorphic Geology, 3, 231243.CrossRefGoogle Scholar
Reiche, M. and Bautsch, H.-J. (1985) Electron microscopical study of garnet exsolution in orthopyroxene. Physics and Chemistry of Minerals, 12, 2933.Google Scholar
Sautter, V. and Harte, B. (1988) Diffusion gradients in an eclogite xenolith from the Roberts Victor kimberlite pipe: 1. Mechanism and evolution of garnet exsolution in Al2O3-rich clinopyroxenes. Journal of Petrology, 29, 13251352.Google Scholar
Sautter, V. and Harte, B. (1990) Diffusion gradients in an eclogite xenolith from the Roberts Victor kimberlite pipe: (2) Kinetics and implications for petrogenesis. Contributions to Mineralogy and Petrology, 105, 637649.CrossRefGoogle Scholar
Smith, D.C. (1988) A review of the peculiar mineralogy of the ‘Norwegian coesite-eclogite province,’ with crystal-chemical, petrological, geological, and geodynamical notes and an extensive bibliography. Pp. 1206 in: Eclogites and Eclogite-Facies Rocks (Smith, D.C., editor). Elsevier, Amsterdam, The Netherlands.Google Scholar
Smyth, J.R., McCormick, T.C. and Caporuscio, F.A. (1984) Petrology of a suite of eclogite inclusions from the Bobbejaan kimberlite, I: Two unusual corundum-bearing kyanite eclogites. Pp. 121132 in: Kimberlites II: The Mantle and Crust-Mantle Relationships (Kornprobst, J., editor). Elsevier, Amsterdam, The Netherlands.CrossRefGoogle Scholar
Smyth, J.R., Caporuscio, F.A. and McCormick, T.C. (1989) Mantle eclogites: evidence of igneous fractionation in the mantle. Earth and Planetary Science Letters, 93, 133141.CrossRefGoogle Scholar
Sobolev, V.S. and Sobolev, N.V. (1964) Xenoliths in kimberlites of northern Yakutia and the structure of the mantle. Doklady Akademeii Nauk SSSR, Series Geologi, 158, 2226.Google Scholar
Tsai, C.-H., Liou, J.G. and Ernst, W.G. (2000) Petrological characterization and tectonic significance of retrogressed garnet peridotites, Raobazhai area, North Dabie Complex, east-central China. Journal of Metamorphic Geology, 18, 181192.CrossRefGoogle Scholar
Wang, G., Jiang, B., Cao, D. and Zhou, H. (1998) On the Xuzhou-Suzhou arcuate duplex-imbricate fan thrust system. Acta Geologica Sinica, 72, 228236 (in Chinese with English abstract).Google Scholar
Webb, S.A.C. and Wood, B.J. (1986) Spinel-pyroxenegarnet relationships and their dependence on Cr/Al ratio. Contributions to Mineralogy and Petrology, 92, 471480.CrossRefGoogle Scholar
Xu, W., Wang, D., Liu, X., Lin, J. and Wang, Q. (2002) Discovery of eclogite inclusions and its geological significance in early Jurassic intrusive complex in Xuzhou-northern Anhui, eastern China. Chinese Science Bulletin, 47, 12121216.Google Scholar
Xu, W., Wang, Q., Liu, X., Wang, D. and Guo, L. (2004) Chronology and sources of Mesozoic intrusive complex in Xu-Huai region, Central China. Constraints from SHRIMP zircon U-Pb dating. Acta Geologica Sinica, 78, 96106.Google Scholar
Yang, J. (1991) Eclogite and Related Ultramafic Rocks in the Su-Lu Region, Eastern China. Geological Publishing House, Beijing, pp. 199 (in Chinese with English abstract).Google Scholar
Zhang, R.Y. and Liou, J.G. (1999) Exsolution lamellae in minerals from ultrahigh-pressure rocks. International Geology Review, 41, 981993.CrossRefGoogle Scholar
Zhang, R.Y., Liou, J.G. and Cong, B. (1994) Petrogenesis of garnet-bearing ultramafic rocks and associated eclogites in the Sulu ultrahigh-pressure metamorphic terrane, China. Journal of Metamorphic Geology, 12, 169186.CrossRefGoogle Scholar
Zhang, R.Y., Liou, J.G., Yang, J.S. and Yui, T.-F. (2000) Petrological constraints for dual origin of garnet peridotites from the Dabie-Sulu UHP terrains, eastern-central China. Journal of Metamorphic Geology, 18, 149166.CrossRefGoogle Scholar
Zhao, G., Wilde, S.A., Cawood, P.A. and Sun, M. (2001) Archean blocks and their boundaries in the North China craton: lithological, geochemical, structural and P-T path constraints and tectonic evolution. Precambrian Research, 107, 4573.CrossRefGoogle Scholar