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Exsolution lamellae in a clinopyroxene megacryst aggregate from Cenozoic basalt, Leizhou Peninsula, South China: petrography and chemical evolution

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Abstract

Petrographic investigations and electron microprobe analyses have been performed on a rare aggregate of clinopyroxene megacrysts collected from Cenozoic basalts in Yinfengling, Leizhou Peninsula of South China. The aggregate, composed of several clinopyroxene megacrysts, shows abundant exsolution lamellae of garnet (Grt) and orthopyroxene (Opx), and granular texture. Cr- and Ti-poor spinels are also present in this sample. They occur predominantly as Sp–Opx–Grt clusters (Cr# = 0.025–0.034) at the interspace between different megacrysts, and subordinately as bleb-shaped (Cr# = 0.025–0.034) or thin-lamella crystals (Cr# = 0.006–0.021) in clinopyroxene. Three different assemblages of exsolution are identified, namely (1) Sp (high Cr/Al) and Opx; (2) Grt–Opx; (3) Sp (low Cr/Al) and Opx. In addition, some garnets were likely developed as response to breakdown of the high-Cr/Al Sp. The homogeneous compositions in all constituent minerals and the good agreement between calculated Cpx/Grt partition coefficients (K d’s) for trace elements and reference data strongly suggest a chemical equilibrium among coexisting minerals, probably attained by diffusion after the exsolution. Thermobarometric calculation based on exsolved assemblage yields a temperature of 900 ± 30°C and a pressure of 12 ± 2.2 kbar, corresponding to the present-day thermal gradient in the region. Much higher P–T estimates (T = 1,210 ± 30°C, P = 16.2 ± 3.5 kbar) are obtained for the reconstructed composition of cpx prior to exsolution. The contrast in thermal state before and after the exsolution might reflect the thermal evolution of the lithosphere beneath South China during the Cenozoic.

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References

  • Aoki K, Fujimaki H, Kitamura M (1980) Exsolved garnet-bearing pyroxene megacrysts from some south African kimberlites. Lithos 13:269–279

    Article  Google Scholar 

  • Becker H (1997) Petrological constraints on the cooling history of high-temperature garnet peridotite massifs in lower Austria. Contrib Mineral Petrol 128:272–286

    Article  Google Scholar 

  • Bertrand P, Mercier J-CC (1985) The mutual solubility of coexisting ortho- and clinopyroxene: toward an absolute geothermometer for natural system? Earth Planet Sci Lett 76:109–122

    Article  Google Scholar 

  • Brey GP, Köhler T (1990) Geothermobarometry in four-phase lherzolites: II. New thermobarometers, and practical assessment of existing thermobarometers. J Petrol 31:1353–1378

    Google Scholar 

  • Buseck PR, Nord GL, Veblen DR (1980) Subsolidus phenomena in pyroxenes. In: Prewitt CT (ed) Reviews in mineralogy, pyroxenesm. vol 7. Mineralogical Society of America, Washington, pp 117–211

    Google Scholar 

  • Clarke DB, Pe-Piper GG (1982) Multiply exsolved clinopyroxene megacrysts from the Frank Smith mine, Cape province, South Africa. Lithos 16:75–84

    Article  Google Scholar 

  • Desnoyers C (1975) Exsolutions d’amphibole, de grenat et de spinelle dans les pyroxenes de roches ultrabasiques: periodtites et pyroxenolites. Bull Soc Fr Min Cristal 98:65–77

    Google Scholar 

  • Ellis DJ, Green DH (1979) An experimental study of the effect of Ca upon garnet-clinopyroxene Fe-Mg exchange equilibria. Contrib Mineral Petrol 71:13–22

    Article  Google Scholar 

  • Fan WM, Menzies MA (1992) The composition of lithospheric mantle in rifting volcanism environment: geochemical evidence from Cenozoic basaltic rocks from Leiqiong area. In: Liu RX (ed) Geochronology and geochemistry of Cenozoic volcanic rocks in China. Seismic Press, Beijing, pp 320–329 (in Chinese)

  • Field SW, Haggerty SE (1994) Symplectites in upper mantle peridotites: development and implications for the growth of subsolidus garnet, pyroxene and spinel. Contrib Mineral Petrol 118:138–156

    Article  Google Scholar 

  • Green DH (1966) The origin of “eclogites” from Salt Lake crater, Hawaii. Earth Planet Sci Lett 1:414–420

    Article  Google Scholar 

  • Griffin WL, Wass SY, Hollis JD (1984) Ultramaffic xenoliths from Bullenmerri and Gnotuk maars, Victoria, Australia: petrology of a sub-continental crust-mantle transition. J Petrol 25:53–87

    Google Scholar 

  • Harte B, Gurney JJG (1975) Evolution of clinopyroxene and garnet in an eclogite nodule from the Roberts Victor kimberlite pipe, South Africa. Phys Chem Earth 9:367–387

    Article  Google Scholar 

  • Harte B, Kirkley MB (1997) Partitioning of trace elements between clinopyroxene and garnet: data from mantle eclogites. Chem Geol 136:1–24

    Article  Google Scholar 

  • He LJ, Wang KL, Xion LP, Wang JY (2001) Heat flow and thermal history of the South China Sea. Phys Earth Planet Inter 126:211–220

    Article  Google Scholar 

  • Herzberg C (1978) Pyroxene geothermometry and geobarometry: experimental and thermodynamic evaluation of some subsolidus phases relations involving clinopyroxenes in the system CaO-MgO-Al2O3-SiO2. Geochim Cosmochim Acta 42:945–957

    Article  Google Scholar 

  • Ho KS, Chen JC, Juang WS (2000) Geochronology and geochemistry of late Cenozoic basalts from the Leiqiong area, souther China. J Asian Earth Sci 18:307–324

    Article  Google Scholar 

  • Jerde EA, Taylor LA, Crozaz G, Sobolev NV (1993) Exsolution of garnet within clinopyroxene of mantle eclogites: major and trace-element chemistry. Contrib Mineral Petrol 114:148–159

    Article  Google Scholar 

  • Johnson KTM (1994) Experimental cpx/and garnet/melt partitioning of REE and other trace elements at high pressures: petrogenetic implications. Mineral Mag 58A:454–455

    Article  Google Scholar 

  • Klemme S, O’Neill HStC (2000) The near-solidus transition from garnet lherzolite to spinel lherzolite. Contrib Mineral Petrol 138:237–248

    Article  Google Scholar 

  • Krogh EJ (1988) The garnet-clinopyroxene Fe-Mg geothermometer—a reinterpretation of existing experimental data. Contrib Mineral Petrol 99:44–48

    Article  Google Scholar 

  • Lappin MA, Dawson BD (1975) Two Roberts-Victor cumulate eclogites and their re-equilibration. Phys Chem Earth 9:351–365

    Article  Google Scholar 

  • Lin CY, Huang XL, Xu YG, Shi LB, Chen XD (2003) Thermal structure and rheology of upper mantle beneath Leizhou Peninsula, Guangdong Province, China. J Trop Oceanogr 22:49–62 (in Chinese with English abstract)

    Google Scholar 

  • Liu XC, Zhao ZR, Zha Y, Chen J, Liu XH (2003) Pyroxene exsolution in mafic granulites from the Grove Mountains, east Antarctiva: constraints on Pan-African metamorphic conditions. Eur J Mineral 15:55–65

    Article  Google Scholar 

  • McCallister RH (1978) The coarsening kinetics associated with exsolution in an iron-free clinopyroxene. Contrib Mineral Petrol 65:327–331

    Article  Google Scholar 

  • Mercier J-CC (1980) Single-pyroxene thermobarometry. Tectonophysics 70:1–37

    Article  Google Scholar 

  • Mercier J-CC, Nicolas A (1975) Textures and fabrics of upper-mantle peridotites as illustrated by xenoliths from basalts. J Petrol 16:454–487

    Google Scholar 

  • Nickel HG, Green DH (1985) Empirical geothermobarometry for garnet peridotites and implications for the nature of the lithosphere, kimberlites and diamonds. Earth Planet Sci Lett 73:158–170

    Article  Google Scholar 

  • Nimis P, Taylor WR (2000) Single clinopyroxene thermobarometry for garnet peridotites. Part I: calibration and testing of a Cr-in-Cpx barometer and an enstatite-in-Cpx thermometer. Contrib Mineral Petrol 139:541–554

    Article  Google Scholar 

  • Nimis P (1999) Clinopyroxene geobarometry of magmatic rocks. Part 2. Structural geobarometers for basic to acid, tholeiitic and mildly alkaline magmatic systems. Contrib Mineral Petrol 135:62–74

    Article  Google Scholar 

  • Qi Q, Taylor LA, Zhou XM (1995) Petrology and geochemistry of mantle peridotite xenoliths from SE China. J Petrol 36:55–79

    Google Scholar 

  • Reiche M, Bautsch H-J (1985) Electron microscopical study of garnet exsolution in orthopyroxene. Phys Chem Mineral 12:29–33

    Google Scholar 

  • Sautter V, Hart B (1988) Diffusion gradients in an eclogite xenolith from the Roberts Victor kimberlite pipe: 1. Mechanism and evolution of garnet exsolution in Al2O3-rich clinopyroxene. J Petrol 29:1325–1352

    Google Scholar 

  • Sautter V, Hart B (1990) Diffusion gradients in an eclogite xenolith from the Roberts Victor kimberlite pipe: (2) kinetics and implications for petrogenesis. Contrib Mineral Petrol 105:637–649

    Article  Google Scholar 

  • Schmickler B, Jacob DE, Foley SF (2004) Eclogite xenoliths from the Kuruman kimberlites, South Africa: geochemical fingerprinting of deep subduction and cumulate processes. Lithos 75:173–207

    Article  Google Scholar 

  • Sen G, Jones RE (1988) Exsolved silicate and oxide phases from clinopyroxenes in a single Hawaiian xenolith: implications for oxidation state of the Hawaiian upper mantle. Geology 16:69–72

    Article  Google Scholar 

  • Sun S-s, McDonough WF (1989) Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In: Saunders AD, Norry MJ (eds) Magmatism in the Ocean Basins. Geological Society, London, pp 313–345

    Google Scholar 

  • Walter M, Katsura T, Kubo A, Shinmei T, Nishikawa O, Ito E, Lesher C, Funakoshi K (2002) Spinel-garnet lherzolite transition in system CaO-MgO-Al2O3-SiO2 revisited: an in situ X-ray study. Geochim Cosmochim Acta 66:2109–2121

    Article  Google Scholar 

  • Weinbruch S, Styrsa V, Müller WF (2003) Exsolution and coarsening in iron-free clinopyroxene during isothermal annealing. Geochim Cosmochim Acta 67:5071–5082

    Article  Google Scholar 

  • Wells PRA (1977) Pyroxene thermometry in simple and complex systems. Contrib Mineral Petrol 62:129–139

    Article  Google Scholar 

  • Wood BJ (1974) Solubility of alumina in orthopyroxene coexisting with garnet. Contrib Mineral Petrol 46:1–15

    Article  Google Scholar 

  • Xu WL, Liu XC, Wang QH, Lin JQ, Wang DY (2004) Garnet exsolution in garnet clinopyroxenite and clinopyroxenite xenoliths in early Cretaceous intrusions from the Xuzhou region, eastern China. Mineral Mag 68:443–453

    Article  Google Scholar 

  • Xu XS, O’Reilly SY, Zhou XM, Griffin WL (1996) A xenolith-derived geotherm and the crust-mantle boundary at Qilin, southeastern China. Lithos 38:41–62

    Article  Google Scholar 

  • Xu YF, Zhu ZH, Wen Q, Wen G, Pu ZH (1999) Clay mineral, chemical characteristics and environmental record of the multi-stage laterite at Yingfengling section, Leizhou Peninsula. Geochimica 28:281–288 (in Chinese with English abstract)

    Google Scholar 

  • Xu YG, Sun M, Yan W, Liu Y, Huang XL, Chen XM (2002) Xenolith evidence for polybaric melting and stratification of the upper mantle beneath South China. J Asian Earth Sci 20:937–954

    Article  Google Scholar 

  • Yu JH, O’Reilly SY, Griffin WL, Xu X, Zhang M, Zhou X (2003) The thermal state and composition of the lithospheric mantle beneath the Leizhou Penisula South China. J Volcanol Geotherm Res 122:165–189

    Article  Google Scholar 

  • Zack T, Foley SF, Jenner GA (1997) A consistent partition coefficient set for clinopyroxene, amphibole and garnet from laser ablation microprobe analysis of garnet pyroxenites from Kakanui, New Zealand. Neues Jahrb Mineral Abhirchen 172:23–41

    Google Scholar 

  • Zhang RY, Liou JG (2003) Clinopyroxenite from the Sulu ultrahigh-pressure terrane, eastern China: origin and evolution of garnet exsolution in clinopyroxene. Am Mineral 88:1591–1600

    Google Scholar 

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Acknowledgments

We gratefully acknowledge the constructive comments of L. Taylor, S. Tappe, and an anonymous reviewer, which helped improve the manuscript. Dr. Y.S. Liu is thanked for his kind help during the LA-ICP-MS analyses and Dr. X.C. Liu for helpful discussions on the initial draft. The financial supports from the China National Science Foundation (40421303, 40202009, 40673038, and 49925308) and the Chinese Academy of Sciences (KZCX2-101, KZCX2-209, the Bairen Project) are gratefully acknowledged. This represents part of a collaborative research program of the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences and the Department of Geosciences, National Taiwan University.

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Authors and Affiliations

  1. Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, People’s Republic of China

    Xiao-Long Huang & Yi-Gang Xu

  2. Department of Geosciences, National Taiwan University, Taipei 106, Taiwan

    Ching-Hua Lo

  3. State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing, 210093, People’s Republic of China

    Ru-Cheng Wang

  4. Institute of Geology, China Seismological Bureau, Beijing, 100029, People’s Republic of China

    Chuan-Yong Lin

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  1. Xiao-Long Huang
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Correspondence to Yi-Gang Xu.

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Communicated by J. Hoefs.

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Huang, XL., Xu, YG., Lo, CH. et al. Exsolution lamellae in a clinopyroxene megacryst aggregate from Cenozoic basalt, Leizhou Peninsula, South China: petrography and chemical evolution. Contrib Mineral Petrol 154, 691–705 (2007). https://doi.org/10.1007/s00410-007-0218-4

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