Advertisement

Mineralogy and Petrology

, Volume 112, Supplement 2, pp 583–596 | Cite as

Cr-rich megacrysts of clinopyroxene and garnet from Lac de Gras kimberlites, Slave Craton, Canada – implications for the origin of clinopyroxene and garnet in cratonic lherzolites

  • Yannick BussweilerEmail author
  • D Graham Pearson
  • Thomas Stachel
  • Bruce A. Kjarsgaard
Original Paper

Abstract

Kimberlites from the Diavik and Ekati diamond mines in the Lac de Gras kimberlite field contain abundant large (>1 cm) clinopyroxene (Cr-diopside) and garnet (Cr-pyrope) crystals. We present the first extensive mineral chemical dataset for these megacrysts from Diavik and Ekati and compare their compositions to cratonic peridotites and megacrysts from the Slave and other cratons. The Diavik and Ekati Cr-diopside and Cr-pyrope megacrysts are interpreted to belong to the Cr-rich megacryst suite. Evidence for textural, compositional, and isotopic disequilibrium suggests that they constitute xenocrysts in their host kimberlites. Nevertheless, their formation may be linked to extensive kimberlite magmatism and accompanying mantle metasomatism preceding the eruption of their host kimberlites. It is proposed that the formation of megacrysts may be linked to failed kimberlites. In this scheme, the Cr-rich megacrysts are formed by progressive interaction of percolating melts with the surrounding depleted mantle (originally harzburgite). As these melts percolate outwards, they may contribute to the introduction of clinopyroxene and garnet into the depleted mantle, thereby forming lherzolite. This model hinges on the observation that lherzolitic clinopyroxenes and garnets at Lac de Gras have compositions that are strikingly similar to those of the Cr-rich megacrysts, in terms of major and trace elements, as well as Sr isotopes. As such, the Cr-rich megacrysts may have implications for the origin of clinopyroxene and garnet in cratonic lherzolites worldwide.

Keywords

Kimberlite Megacrysts Cr-rich Megacrysts Cratonic lherzolites 

Notes

Acknowledgements

This study forms part of Y.B.’s PhD funded through D.G.P’s Canada Excellence Research Chair. Yuri Kinakin and Gus Fomradas at Diavik Diamond Mine are thanked for access to drill core. Juanita Bellinger at Rio Tinto is thanked for sending concentrate samples. Y.B. is grateful for lab assistance from Andrew Locock (EPMA), Yan Luo (LA-ICP-MS), and Chiranjeeb Sarkar (TIMS). B.A.K. acknowledges support and funding from the Geological Survey of Canada, and EPMA lab assistance from Katherine Venance. We thank Maya Kopylova and an anonymous reviewer for detailed and constructive comments and Phil Janney for the efficient editorial handling. Y.B. is grateful for a University of Alberta Doctoral Recruitment Scholarship and a Society of Economic Geologists student research grant. At the University of Münster, Y.B. acknowledges support through a Marie Skłodowska-Curie Fellowship (Project ID 746518).

Supplementary material

710_2018_599_MOESM1_ESM.xlsx (18 kb)
ESM 1 (XLSX 18 kb)
710_2018_599_MOESM2_ESM.xlsx (48 kb)
ESM 2 (XLSX 48 kb)
710_2018_599_MOESM3_ESM.xlsx (42 kb)
ESM 3 (XLSX 42 kb)
710_2018_599_MOESM4_ESM.xlsx (41 kb)
ESM 4 (XLSX 41 kb)

References

  1. Araújo DP, Griffin WL, O’Reilly SY (2009) Mantle melts, metasomatism and diamond formation: insights from melt inclusions in xenoliths from Diavik, Slave Craton. Lithos 112:675–682CrossRefGoogle Scholar
  2. Armstrong JT (1988) Quantitative analysis of silicate and oxide minerals: comparison of Monte Carlo, ZAF and phi-rho-z procedures. Microbeam Anal 23:239–246Google Scholar
  3. Aulbach S, Griffin WL, Pearson NJ, O’Reilly SY, Doyle BJ (2007) Lithosphere formation in the central Slave Craton (Canada): plume subcretion or lithosphere accretion? Contrib Mineral Petrol 154:409–427CrossRefGoogle Scholar
  4. Aulbach S, Griffin WL, Pearson NJ, O’Reilly SY (2013) Nature and timing of metasomatism in the stratified mantle lithosphere beneath the central Slave craton (Canada). Chem Geol 352:153–169CrossRefGoogle Scholar
  5. Bell DR, Moore RO (2004) Deep chemical structure of the southern African mantle from kimberlite megacrysts. South African J Geol 107:59–80CrossRefGoogle Scholar
  6. Bell DR, Rossman GR (1992) The distribution of hydroxyl in garnets from the subcontinental mantle of southern Africa. Contrib Mineral Petrol 111:161–178CrossRefGoogle Scholar
  7. Bell DR, Rossman GR, Moore RO (2004) Abundance and partitioning of OH in a high-pressure magmatic system: megacrysts from the monastery kimberlite, South Africa. J Petrol 45:1539–1564CrossRefGoogle Scholar
  8. Boyd F, Dawson J, Smith J (1984) Granny smith diopside megacrysts from the kimberlites of the Kimberley area and Jagersfontein, South Africa. Geochim Cosmochim Acta 48:381–384CrossRefGoogle Scholar
  9. Brey GP, Bulatov VK, Girnis AV, Lahaye Y (2008) Experimental melting of carbonated peridotite at 6-10 GPa. J Petrol 49:797–821CrossRefGoogle Scholar
  10. Bussweiler Y, Stone RS, Pearson DG, Luth RW, Stachel T, Kjarsgaard BA, Menzies A (2016) The evolution of calcite-bearing kimberlites by melt-rock reaction: evidence from polymineralic inclusions within clinopyroxene and garnet megacrysts from Lac de Gras kimberlites, Canada. Contrib Mineral Petrol 171:65CrossRefGoogle Scholar
  11. Creaser RA, Grütter H, Carlson J, Crawford B (2004) Macrocrystal phlogopite Rb–Sr dates for the Ekati property kimberlites, Slave Province, Canada: evidence for multiple intrusive episodes in the Paleocene and Eocene. Lithos 76:399–414CrossRefGoogle Scholar
  12. Creighton S, Stachel T, Eichenberg D, Luth RW (2010) Oxidation state of the lithospheric mantle beneath Diavik diamond mine, central Slave craton, NWT, Canada. Contrib Mineral Petrol 159:645–657CrossRefGoogle Scholar
  13. Davies G, Spriggs A, Nixon P (2001) A non-cognate origin for the Gibeon kimberlite megacryst suite, Namibia: implications for the origin of Namibian kimberlites. J Petrol 42:159–172CrossRefGoogle Scholar
  14. de Bruin D (2005) Multiple compositional megacryst groups from the Uintjiesberg and Witberg kimberlites, South Africa. S Afr J Geol 108:233–246CrossRefGoogle Scholar
  15. Edgar AD, Arima M, Baldwin DK et al (1988) High-pressure-high-temperature melting experiments on a SiO2-poor aphanitic kimberlite from the Wesselton mine, Kimberley. South Africa Am Mineral 73:524–533Google Scholar
  16. Eggler DH, McCallum ME, Smith CB (1979) Megacryst assemblages in kimberlite from northern Colorado and southern Wyoming: petrology, geothermometry-barometry and areal distribution. Boyd Meyer 2:213–226Google Scholar
  17. Gaul O, Griffin W, O’Reilly S, Pearson N (2000) Mapping olivine composition in the lithospheric mantle. Earth Planet Sc Lett 182:223–235CrossRefGoogle Scholar
  18. Girnis AV, Brey GP, Ryabchikov ID (1995) Origin of group 1A kimberlites: fluid-saturated melting experiments at 45-55 kbar. Earth Planet Sc Lett 134:283–296CrossRefGoogle Scholar
  19. Giuliani A, Kamenetsky VS, Kendrick MA, Phillips D, Wyatt BA, Maas R (2013) Oxide, sulphide and carbonate minerals in a mantle polymict breccia: Metasomatism by proto-kimberlite magmas, and relationship to the kimberlite megacrystic suite. Chem Geol 353:4–18CrossRefGoogle Scholar
  20. Giuliani A, Phillips D, Kamenetsky VS, Kendrick MA, Wyatt BA, Goemann K, Hutchinson G (2014) Petrogenesis of mantle polymict breccias: insights into mantle processes coeval with kimberlite magmatism. J Petrol 55:831–858CrossRefGoogle Scholar
  21. Giuliani A, Phillips D, Kamenetsky VS, Goemann K (2016) Constraints on kimberlite ascent mechanisms revealed by phlogopite compositions in kimberlites and mantle xenoliths. Lithos 240–243:189–201CrossRefGoogle Scholar
  22. Grégoire M, Bell DR, Le Roex AP (2003) Garnet lherzolites from the Kaapvaal Craton (South Africa): trace element evidence for a metasomatic history. J Petrol 44:629–657CrossRefGoogle Scholar
  23. Griffin W, Doyle B, Ryan C (1999) Layered mantle lithosphere in the Lac de Gras area, Slave craton: composition, structure and origin. J Petrol 40:705–727CrossRefGoogle Scholar
  24. Grütter HS (2009) Pyroxene xenocryst geotherms: techniques and application. Lithos 112:1167–1178CrossRefGoogle Scholar
  25. Grütter HS, Gurney JJ, Menzies AH, Winter F (2004) An updated classification scheme for mantle-derived garnet, for use by diamond explorers. Lithos 77:841–857CrossRefGoogle Scholar
  26. Günther M, Jagoutz E (1994) Isotopic disequilibria (Sm/Nd, Rb/Sr) between minerals of coarse grained, low temperature garnet peridotites from Kimberley floors, southern Africa. In: Meyer HOA, Leonardos OH (eds) Proc. 5 th Int. kimberlite Conf. I. Companhia de Pesquisa de Recursos Minerais spec Publ 1A. Brasilia, pp 354–365Google Scholar
  27. Harte B (1983) Mantle peridotites and processes - the kimberlite sample. In: Hawkesworth CJ, Norry MJ (eds) Continental basalt and mantle xenoliths. Shiva, Nantwich, pp 46–91Google Scholar
  28. Harte B, Hunter RH, Kinny PD (1993) Melt geometry, movement and crystallization, in relation to mantle dykes, veins and metasomatism. Philos Trans R Soc Lond A 342:1–21CrossRefGoogle Scholar
  29. Heaman LM, Kjarsgaard BA, Creaser RA (2003) The timing of kimberlite magmatism in North America: implications for global kimberlite genesis and diamond exploration. Lithos 71:153–184CrossRefGoogle Scholar
  30. Höfer HE, Lazarov M, Brey GP, Woodland AB (2009) Oxygen fugacity of the metasomatizing melt in a polymict peridotite from Kimberley. Lithos 112:1150–1154CrossRefGoogle Scholar
  31. Hops JJ, Gurney JJ, Harte B (1992) The jagersfontein Cr-poor megacryst suite — towards a model for megacryst petrogenesis. J Volcanol Geotherm Res 50:143–160CrossRefGoogle Scholar
  32. Hunter RH, Taylor LA (1984) Magma-mixing in the low velocity zone: kimberlitic megacrysts from Fayette County, Pennsylvania. Am Mineral 69:16–29Google Scholar
  33. Kargin AV, Sazonova LV, Nosova AA, Lebedeva NM, Tretyachenko VV, Abersteiner A (2017) Cr-rich clinopyroxene megacrysts from the Grib kimberlite, Arkhangelsk province, Russia: relation to clinopyroxene–phlogopite xenoliths and evidence for mantle metasomatism by kimberlite melts. Lithos 292-293:34–48CrossRefGoogle Scholar
  34. Keshav S, Corgne A, Gudfinnsson GH, Bizimis M, McDonough WF, Fei Y (2005) Kimberlite petrogenesis: insights from clinopyroxene-melt partitioning experiments at 6 GPa in the CaO-MgO-Al2O3-SiO2-CO2 system. Geochim Cosmochim Acta 69:2829–2845CrossRefGoogle Scholar
  35. Kopylova MG, Nowell GM, Pearson DG, Markovic G (2009) Crystallization of megacrysts from protokimberlitic fluids: geochemical evidence from high-Cr megacrysts in the Jericho kimberlite. Lithos 112:284–295CrossRefGoogle Scholar
  36. Kostrovitsky SI, Malkovets VG, Verichev EM, Garanin VK, Suvorova LV (2004) Megacrysts from the Grib kimberlite pipe (Arkhangelsk Province, Russia). Lithos 77:511–523CrossRefGoogle Scholar
  37. Krogh EJ (1988) The garnet-clinopyroxene Fe-Mg geothermometer - a reinterpretation of existing experimental data. Contrib Mineral Petrol 99:44–48CrossRefGoogle Scholar
  38. Kusky T (1989) Accretion of the Archean Slave province. Geology 17:63–67CrossRefGoogle Scholar
  39. Lawless PJ, Gurney JJ, Dawson JB (1979) Polymict peridotites from the Bultfontein and de Beers Mines, Kimberly, South Africa. In: Boyd FR, Meyer HOA (eds) The mantle sample: inclusions in kimberlites and other volcanics. Amer Geophys Union Spec Publ, pp 144–155Google Scholar
  40. Lockhart G, Grütter H, Carlson J (2004) Temporal, geomagnetic and related attributes of kimberlite magmatism at Ekati, Northwest Territories, Canada. Lithos 77:665–682CrossRefGoogle Scholar
  41. Malarkey J, Pearson DG, Kjarsgaard BA, Davidson JP, Nowell GM, Ottley CJ, Stammer J (2010) From source to crust: tracing magmatic evolution in a kimberlite and a melilitite using microsample geochemistry. Earth Planet Sc Lett 299:80–90CrossRefGoogle Scholar
  42. Mather K (2012) A xenolith-based lithospheric transect of the Slave Craton, NWT, Canada. In: Durham universityGoogle Scholar
  43. McDonough WF, Sun SS (1995) The composition of the Earth. Chem Geol 120:223–253Google Scholar
  44. Menzies A, Westerlund K, Grütter H, Gurney J, Carlson J, Fung A, Nowicki T (2004) Peridotitic mantle xenoliths from kimberlites on the Ekati Diamond Mine property, N.W.T., Canada: major element compositions and implications for the lithosphere beneath the central Slave craton. Lithos 77:395–412CrossRefGoogle Scholar
  45. Mitchell RH (1995) Kimberlites, orangeites, and related rocks. Plenum Press, New York, 410 ppCrossRefGoogle Scholar
  46. Mitchell RH (1986) Kimberlites: mineralogy, geochemistry and petrology. Plenum Press, New York, 442 ppCrossRefGoogle Scholar
  47. Mitchell RH (1977) Geochemistry of magnesian ilmenites from kimberlites in South Africa and Lesotho. Lithos 10:29–37CrossRefGoogle Scholar
  48. Mofokeng SW (1998) A comparison of the nickel and the conventional geothermometers with respect to the Jagersfontein and the Matsoku kimberlite peridotite xenolits. University of Cape TownGoogle Scholar
  49. Moore A, Belousova E (2005) Crystallization of Cr-poor and Cr-rich megacryst suites from the host kimberlite magma: implications for mantle structure and the generation of kimberlite magmas. Contrib Mineral Petrol 149:462–481CrossRefGoogle Scholar
  50. Moss S, Russell JK, Andrews GDM (2008) Progressive infilling of a kimberlite pipe at Diavik, Northwest Territories, Canada: insights from volcanic facies architecture, textures, and granulometry. J Volcanol Geotherm Res 174:103–116CrossRefGoogle Scholar
  51. 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 139:541–554CrossRefGoogle Scholar
  52. Nixon PH, Boyd FR (1973) The discrete nodule association in kimberlites from northern Lesotho. In: Lesotho kimberlites. Maseru, Lesotho Natl Dev Corp. Cape and Transvaal Printers, South. Africa:67–75Google Scholar
  53. Nowell GM, Pearson DG, Bell DR et al (2004) Hf isotope systematics of kimberlites and their megacrysts: new constraints on their source regions. J Petrol 45:1583–1612CrossRefGoogle Scholar
  54. Nowicki T, Crawford B, Dyck D, Carlson J, McElroy R, Oshust P, Helmstaedt H (2004) The geology of kimberlite pipes of the Ekati property, Northwest Territories, Canada. Lithos 76:1–27CrossRefGoogle Scholar
  55. Padgham WA (1992) Mineral deposits in the Archean Slave Structural Province; lithological and tectonic setting. Precambrian Res 58:1–24CrossRefGoogle Scholar
  56. Paton C, Hellstrom J, Paul B, Woodhead J, Hergt J (2011) Iolite: freeware for the visualisation and processing of mass spectrometric data. J Anal At Spectrom 26:2508–2518CrossRefGoogle Scholar
  57. Paton C, Woodhead JD, Hergt JM, et al (2007) Strontium isotope analysis of kimberlitic groundmass perovskite via LA-MC-ICP-MS. Geostand Geoanal Res 31:321–330Google Scholar
  58. Pearson DG, Irivine GJ, Carlson RW et al (2002) The development of lithospheric keels beneath the earliest continents: time constraints using PGE and Re-Os isotope systematics. Geol Soc Spec Publ 199:65–90CrossRefGoogle Scholar
  59. Pivin M, Féménias O, Demaiffe D (2009) Metasomatic mantle origin for Mbuji-Mayi and Kundelungu garnet and clinopyroxene megacrysts (Democratic Republic of Congo). Lithos 112:951–960CrossRefGoogle Scholar
  60. Sarkar C, Heaman LM, Pearson DG (2015) Duration and periodicity of kimberlite volcanic activity in the Lac de Gras kimberlite field, Canada and some recommendations for kimberlite geochronology. Lithos 218–219:155–166CrossRefGoogle Scholar
  61. Schulze D (1985) Evidence for primary kimberlitic liquids in megacrysts from kimberlites in Kentucky, USA. J Geol 93:75–79CrossRefGoogle Scholar
  62. Schulze DJ (1997) The significance of eclogite and Cr-poor megacryst Garnets in diamond exploration. Explor Min Geol 6:349–366Google Scholar
  63. Shimizu N, Pokhilenko NP, Boyd FR, Pearson DG (1997) Geochemical characteristics of mantle xenoliths from Udachnaya kimberlite pipe. Geol Geofiz:194–205Google Scholar
  64. Shu Q, Pearson DG, Kjarsgaard BA, Read G (2017) 50 Myr kimberlite magmatism in the Fort à la Corne field, Sask craton, recorded by zircon megacrysts. 11th International Kimberlite Conference, Extended Abstract 4462Google Scholar
  65. Simon NSC, Irvine GJ, Davies GR et al (2003) The origin of garnet and clinopyroxene in “depleted” Kaapvaal peridotites. Lithos 71:289–322CrossRefGoogle Scholar
  66. Sokol AG, Kruk AN (2015) Conditions of kimberlite magma generation: experimental constraints. Russ Geol Geophys 56:245–259CrossRefGoogle Scholar
  67. Stachel T, Viljoen KS, Brey G, Harris JW (1998) Metasomatic processes in lherzolitic and harzburgitic domains of diamondiferous lithospheric mantle: REE in garnets from xenoliths and inclusions in diamonds. Earth Planet Sc Lett 159:1–12CrossRefGoogle Scholar
  68. Tappe S, Graham Pearson D, Kjarsgaard BA et al (2013) Mantle transition zone input to kimberlite magmatism near a subduction zone: origin of anomalous Nd-Hf isotope systematics at Lac de Gras, Canada. Earth Planet Sc Lett 371–372:235–251CrossRefGoogle Scholar
  69. Ubide T, Galé C, Larrea P et al (2014) Antecrysts and their effect on rock compositions: the Cretaceous lamprophyre suite in the Catalonian Coastal Ranges (NE Spain). Lithos 206–207:214–233CrossRefGoogle Scholar
  70. van Achterbergh E, Griffin WL, Ryan CG, O'Reilly SY, Pearson NJ, Kivi K, Doyle BJ (2004) Melt inclusions from the deep Slave lithosphere: implications for the origin and evolution of mantle-derived carbonatite and kimberlite. Lithos 76:461–474CrossRefGoogle Scholar
  71. van Achterbergh E, Griffin WL, Ryan CG, O'Reilly SY, Pearson NJ, Kivi K, Doyle BJ (2002) Subduction signature for quenched carbonatites from the deep lithosphere. Geology 30:743–746CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of Earth and Atmospheric SciencesUniversity of AlbertaEdmontonCanada
  2. 2.Institute for MineralogyUniversity of MünsterMünsterGermany
  3. 3.Geological Survey of CanadaOttawaCanada

Personalised recommendations