Contributions to Mineralogy and Petrology

, Volume 111, Issue 1, pp 37–52 | Cite as

Carbonate metasomatism in the lithospheric mantle: peridotitic xenoliths from a melilititic district of the Sahara basin

  • J. M. Dautria
  • C. Dupuy
  • D. Takherist
  • J. Dostal
Article
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Abstract

The petrological and geochemical study of harzburgitic and dunitic xenoliths from the melilititic district of In Teria (Algerian Sahara) shows that the lighospheric mantle of this region has been affected by a multi-stage metasomatism. The first metasomatic event is related to the injection of alkali silicated (basaltic or kimberlitic) melt and was responsible for the crystallization of phlogopite at depths ranging between 80 and 100 km and the crystallization of amphibole at about 60 km. During this first event, carbonate probably precipitated in the garnet stability field. In a second stage, the spinal peridotites suffered strong mineral changes resulting in an extensive formation of high-Cr endiopside and leading to conversion of harzburgite and dunite into lherzolite and wehrlite. These changes are associated with an enrichment in the most incompatible trace elements including light REE (rare-earth elements), Ta, Th and variable values of ratios such as Th/La and Ta/La. This second event is atributed to the injection (under conditions of decarbonatation and release of CO2) of a carbonatitic melt resulting from incipient melting of the garnet peridotites, which were previously carbonated. This interpretation is corroborated by the calculation of a diffusion-percolation model which reproduces well the observed distribution of incompatible trace elements in the spinel peridotites. Given the proposed sequence of events, it appears that most of the specificities of the In Teria xenoliths can be explained by the successive geochemical modifications induced within the lithospheric mantle during reheating.

Keywords

Crystallization Silicated Mineral Resource Lithospheric Mantle Extensive Formation 
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References

  1. Bailey DK (1987) Mantle metasomatism: perspective and prospect. In: Fitton JG, Upton BGJ (eds) Alkaline igneous rocks. Geol Soc Spec Publ 30, pp 1–13Google Scholar
  2. Bergman SC, Foland KA, Spera J (1981) On the origin of an amphibole-rich vein in a peridotite inclusion from the Lunar Crater volcanic field, Nevada, USA. Earth Planet Sci Lett 56:342–361Google Scholar
  3. Bertrand P, Mercier JCC (1986) The mutual solubility of coexisting ortho- and clinopyroxene: toward an absolute geothermometer for the natural systems? Earth Planet Sci Lett 79:109–122Google Scholar
  4. Bodinier JL, Dupuy C, Dostal J (1988) Geochemistry and petrogenesis of Eastern Pyrenean peridotites. Geochim Cosmochim Acta 52:2893–2907Google Scholar
  5. Bodinier JL, Vasseur G, Vernières J, Dupuy C, Fabriès J (1990) Mechanism of mantle metasomatism: gcochemical evidence from the Lherz orogenic periodotite. J Petrol 31:597–628Google Scholar
  6. Bodinier JL, Menzies MA, Thirlwall MF (1991) Continental to oceanic mantle transition-REE and Sr−Nd isotopic geochemistry of the Lanzo lherzolite massif. J Petrol Spec. Lherzolites Iss.: 191–210Google Scholar
  7. Bossieres G, Megartsi M (1982) Pétrologie des nodules de pyroxénolites associés à la rushayite d'In Téria (NE d'Illizi, ex Fort-Polignac), Algérie. Bull Mineral 105:89–98Google Scholar
  8. Brey G, Green DH (1976) Solubility of CO2 in olivine melilitite at high pressures and role of CO2 in the earth's upper mantle. Contrib Mineral Petrol 55:217–230Google Scholar
  9. Brey GP, Köhler T (1990) Geothermobarometry in four-phase lherzolites II: new thermobarometers, and practical assessment of existing thermobarometers. J Petrol 31:1353–1378Google Scholar
  10. Brey G, Brice WR, Ellis DJ, Green DH, Harris KL, Ryabchikov ID (1983) Pyroxene-carbonate reactions in the upper mantle. Earth Planet Sci 62:63–74Google Scholar
  11. Chen CY, Frey FA, Garcia MO (1990) Evolution of the alkalic lavas at Halcakala volcano, East Maui, Hawaii: major, trace elements and isotopic constraints. Contrib Mineral Petrol 105:197–218Google Scholar
  12. Dautria JM, Liotard JM, Cabanes N, Girod M, Briqueu L (1987) Amphibole-rich xenoliths and host alkali basalts: petrogenetic constraints and implications on the recent evolution of the upper mantle beneath Ahaggar (Central Sahara, Southern Algeria). Contrib Mineral Petrol 95:133–144Google Scholar
  13. Eggler DH (1987) Solubility of major and trace elements in mantle metasomatic fluids: experimental constraints. In: Menzies MA, Hawkesworth CJ (eds) Mantle metasomatism. Academic Press, London, pp 21–41Google Scholar
  14. Eggler DH, McCallum ME, Smith CB (1979) Megacryst assemblages in kimberlite from Northern Colorado and Southern Wyoming: petrology, geothermometry-barometry and a real distribution. In: Boyd FR, Meyer HOA (eds) Kimberlites, diatremes and diamonds; their geology, petrology and chemistry. Proc Int Kimberlite Conf 2, vol 2 Am Geophys Union, Washington, D.C., pp 330–338Google Scholar
  15. Ehrenberg SN (1982) Petrogenesis of garnet lherzolite and megacrystalline nodules from the Thumb, Navajo Volcanic Field. J Petrol 23:507–547Google Scholar
  16. Falloon TJ, Green DH (1990) Solidus of carbonated fertile peridotite under fluid-staturated conditions. Geology 18:195–199Google Scholar
  17. Francis DM (1976) The origin of amphibole in lherzolite xenoliths from Nunivak Island, Alaska. J Petrol 17 (3): 357–379Google Scholar
  18. Frey FA, Green DH (1974) The mineralogy, geochemistry and origin of lherzolitic inclusions in Victorian basanites. Geochim Cosmochim Acta 38:1023–1059Google Scholar
  19. Frey FA, Green DH, Roy SD (1978) Integrated models of basalt petrogenesis: a study of quartz tholeiites to olivine melilitites from Southeastern Australia utilizing geochemical and experimental petrological data. J Petrol 19:463–515Google Scholar
  20. Green DH, Ringwood AE (1967) The stability fields of aluminous pyroxene peridotite and garnet peridotite and their relevance in upper mantle structure. Earth Planet Sci Lett 3:151–160Google Scholar
  21. Green DH, Wallace ME (1988) Mantle metasomatism by ephemeral carbonatite melts. Nature 336:459–462Google Scholar
  22. Gurney JJ, Harte B (1980) Chemical variations in upper mantle nodules from southern African kimberlites. Philos Trans R Soc London A297:273–293Google Scholar
  23. Hamilton DL, Bedson P, Esson J (1989) The behaviour of trace elements in the evolution of carbonatites. In: Bell K (ed) Carbonatites: genesis and evolution. Unwyn Hyman, London, pp 405–427Google Scholar
  24. Harte B (1983) Mantle peridotites and processes — the kimberlite samples. In: Hawkesworth CJ, Norry MJ (eds) Continental basalts and mantle xenoliths. Shiva Publishing Ltd., Nantwich, Cheshire, UK, pp 46–91Google Scholar
  25. Irving AJ (1980) Petrology and geochemistry of composite ultramafic xenoliths in alkalic basalts and implications for magmatic processes within the mantle. Am J Sci 280-A:389–426Google Scholar
  26. Lesquer A, Beltrao JF, De Abreu FAM (1984) Proterozoic links between Northeastern Brazil and West Africa: a plate tectonic model based on gravity data. Tectonophysics 110:9–26Google Scholar
  27. Lesquer A, Takherist D, Dautria JM, Hadiouche O (1990) Geophysical and petrological evidence for the presence of an “anomalous” upper mantle beneath the Sahara Basins (Algeria). Earth Planet Sci Lett 96:407–418Google Scholar
  28. Lloyd FE (1987) Characterization of mantle metasomatic fluids in spinel lherzolites and alkali clinopyroxenites from the West Eifel and south West Uganda. In: Menzies MA, Hawkesworth CJ (eds) Mantle metasomatism. Academic Press, London, pp 91–123Google Scholar
  29. Megartsi M (1972) Etude des structures circulaires du Nord-Est d'Illizi (ex Fort-Polignac) Sahara nord-oriental. Thèse 3ème Cycle. Université d'AlgerGoogle Scholar
  30. Menzies MA (1983) Mantle ultramafic xenoliths in alkaline magmas: evidence for mantle heterogeneity modified by magmatic activity. In: Hawkesworth CJ, Norry MJ (eds) Continental basalts and mantle xenoliths. Shiva Publishing Ltd., Nantwich, Cheshire, UK, pp 92–110Google Scholar
  31. Menzies MA, Hawkesworth (eds) (1987) Mantle Metasomatism. Academic Press, LondonGoogle Scholar
  32. Menzies MA, Wass SY (1983) CO2 and LREE-rich mantle below Eastern Australia: a REE and isotopic study of alkaline magmas and apatite-rich mantle xenoliths from the Southern Highlands Province, Australia. Earth Planet Sci Lett 65:287–302Google Scholar
  33. Mitchell RH (1989) Kimberlites: mineralogy, geochemistry, and petrology. Plenum Press, New YorkGoogle Scholar
  34. Navon O, Stolper E (1987) Geochemical consequence of melt percolation: the upper mantle chromatographic column. J Geol 95:285–305Google Scholar
  35. Nelson DR, Chivas AR, Chapell BW, McCulloch MT (1988) Geochemical and isotopic systematics in carbonatites and implications for the evaluation of ocean-island sources. Geochim Cosmochim Acta 52:1–17Google Scholar
  36. Nickel KG, Green DH (1985) Empirical geothermobarometry for garnet peridotites and implications for the nature of the lithosphere, kimberlites and diamonds. Earth Planet Sci Lett 73:158–170Google Scholar
  37. Nixon PH (ed) (1987a) Mantle xenoliths. John Wiley and sons, Chichester, UKGoogle Scholar
  38. Nixon PH (1987b) Kimberlitic xenoliths and their cratonic setting. In: Nixon PH (ed) Mantle xenoliths. John Wiley and sons, Chichester, UK, pp 215–239Google Scholar
  39. O'Reilly SY, Griffin W (1988) Mantle metasomatism beneath Victoria, Australia: I, metasomatic processes in Cr-diopside lherzolites. Geochim Cosmochim Acta 52:433–447Google Scholar
  40. Padovani ER, Carter JL (1977) Non equilibrium partial fusion due to decompression and thermal effects in crustal xenoliths. In: Dick HGJ (ed) Magma genesis. Oreg Dep Geol Miner Ind Bull, 96, pp 43–57Google Scholar
  41. Peterson TD (1989) Peralkaline nephelinites: II, low pressure fractionation and the hypersodic lavas of Oldonyo Lengai. Contrib Mineral Petrol 102:336–346Google Scholar
  42. Reid JB, Geoffrey AW (1978) Oceanic mantle beneath the Southern Rio Grande Rift. Earth Planet Sci Lett 41:302–316Google Scholar
  43. Ryabehykov ID, Schreyer W, Abraham K (1982) Compositions of aqueous fluids in equilibrium with pyroxenes and olivines at mantle pressures and temperatures. Contrib Mineral Petrol 79:80–84Google Scholar
  44. Savoyant L, Persin F, Dupuy C (1984) Determination des Terres Rares dans certaines roches basiques et ultrabasiques. Geostand Newlett 8:159–161Google Scholar
  45. Spera FJ (1984) Carbon dioxide in igneous petrogenesis III: role of volatiles in the ascent of alkaline magma with special reference to xenolith-bearing mafic lavas. Contrib Mineral Petrol 88:217–232Google Scholar
  46. Spera FJ (1987) Dynamics of translithospheric migration of metasomatic fluid and alkaline magma. In: Menzies MA, Hawkesworth CJ (eds) Mantle metasomatism. Academic Press, London, pp 1–18Google Scholar
  47. Stolz AJ, Davies GR (1988) Chemical and isotopic evidence from spinel lherzolite xenoliths for episodic metasomatism of the upper mantle beneath Southeast Australia. J Petrol (Spec Lithos Issue): 303–330Google Scholar
  48. Stosch HG, Seck HA (1980) Geochemistry and mineralogy of two spinel peridotite suites from Dreiser Weiher, West Germany. Geochim Cosmochim Acta 44:457–470Google Scholar
  49. Sun SS, McDonough WF (1989) Chemical and isotopic systematics of oceanic basalts: implication for mantle composition and processes. In: Saunders AD, Norry MJ (eds) Magmatism in Ocean Basins. Geol Soc London Spec Publ 42:313–345Google Scholar
  50. Takherist D, Lesquer A (1989) Misc en évidence d'importantes variations régionales du flux de chaleur en Algérie. Can J Earth Sci 26:615–626Google Scholar
  51. Vasseur G, Vernières J, Bodinier JL (1991) Modelling of element transfer between mantle melt and heterogranular peridotite matrix. J Petrol Spec. Lherzolites Iss.: 41–54Google Scholar
  52. Velde D, Yoder HS (1976) The chemical composition of the melilite-bearing eruptive rocks. Carnegie Inst Washington Yearb 75:574–580Google Scholar
  53. Wallace ME, Green DH (1988) Mantle metasomatism by ephemeral carbonatite melts. Nature 336:459–462Google Scholar
  54. Wells PRA (1977) Pyroxene thermometry in simple and complex systems. Contrib Mineral Petrol 62:129–139Google Scholar
  55. Wyllie PJ (1989) Origin of carbonatites: evidence from phase equilibrium studies. In: Bell K (ed) Carbonatites, genesis and evolution. Unwyn Hyman, London, pp 500–540Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • J. M. Dautria
    • 1
  • C. Dupuy
    • 1
  • D. Takherist
    • 2
  • J. Dostal
    • 3
  1. 1.Centre Géologique et GéophysiqueC.N.R.S., U.S.T.L.Montpellier Cedex 5France
  2. 2.SonatrachAlgerAlgérie
  3. 3.Department of GeologySaint Mary's UniversityHalifaxCanada

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