Contrasting Group I and Group II eclogite xenolith petrogenesis: Petrological, trace element and isotopic evidence from eclogite, garnet-websterite and alkremite xenoliths in the Kaalvallei Kimberlite, South Africa

Journal of Petrology

Volumn 46, Issue 10, 2005, Pages 2059-2090

  Viljoen, K S ^a,b   Schulze, D J ^c   Quadling, A G ^a  

^a De Beers Group   (South Africa)

^b UNIVERSITY OF THE WITWATERSRAND   (South Africa)

^c UNIVERSITY OF TORONTO   (Canada)

Author keywords

Diamonds; Eclogite xenoliths; Isotopic composition; REE; Trace elements

Indexed keywords

ECLOGITE; ISOTOPIC COMPOSITION; XENOLITH;

AFRICA; EASTERN HEMISPHERE; SOUTH AFRICA; SOUTHERN AFRICA; SUB-SAHARAN AFRICA; WORLD;

EID: 24944434739     PISSN: 00223530     EISSN: None     Source Type: Journal    
DOI: 10.1093/petrology/egi047     Document Type: Review

References (132)

1. Ahmed, Z. & Hall, A. (1984). Petrology and mineralisation of the Sakhakot-Qila ophiolite, Pakistan. In: Gass, T. G., Lippard, S. J. & Shelton, A. W. (eds) Ophiolites and Oceanic Lithosphere. Oxford: Blackwell, pp. 231-252.
2. Aulbach, S., Stachel, T., Viljoen, K. S., Brey, G. P. & Harris, J. W. (2002). Eclogitic and websteritic diamond sources beneath the Limpopo Belt - is slab melting the link? Contributions to Mineralogy and Petrology 143, 56-70.
3. Barth, M. G., Rudnick, R. L., Horn, I., McDonough, W. F., Spicuzza, M. J. Valley, J. W. & Haggerty, S. E. (2001). Geochemistry of xenolithic eclogites from West Africa, Part 1: A link between low MgO eclogites and Archean crust formation. Geochimica et Cosmochimica Acta 65, 1499-1527.
4. Barth, M. G., Rudnick, R. L., Horn, I., McDonough, W. F., Spicuzza, M.J., Valley, J. W. & Haggerty, S. E. (2002). Geochemistry of xenolithic eclogites from West Africa, Part 2: Origins of the high MgO eclogites. Geochimica et Cosmochimica Acta 66, 4325-4345.
5. Basaltic Volcanism Study Project (1981). Basaltic Volcanism on the Terrestrial Planets. New York: Pergamon Press, 1286 pp.
6. Beard, B. L., Fraracci, K. N., Taylor, L. A., Snyder, G. A., Clayton, R. A. Mayeda T. K. & Sobolev, N. V. (1996). Petrography and geochemistry of eclogites from the Mir kimberlite, Yakutia, Russia. Contributions to Mineralogy and Petrology 125, 293-310.
7. Bishop F. C., Smith, J. V. & Dawson, J. B. (1978). Na, K, P and Ti in garnet, pyroxene and olivine from peridotite and eclogite xenoliths from African kimberlites. Lithos 11, 155-173.
8. Blamart, D, Trumbull, R. B. & Chaussidon, M. (1993). Oxygen and boron isotopic composition of the Archaean Sinieni pluton: Implications for the occurrence of S-type granites in Swaziland. In: 16th Colloquium of African Geology. Extended Abstracts, Vol. 1, pp. 29-31.
9. Brey, G. & Kohler, T. (1990). Geobarometry in four-phase lherzolites II. New thermobarometers, and practical assessment of existing barometers. Journal of Petrology 31, 1353-1378.
10. Brey, G. P., Kohler, T. & Nickel, K. G. (1990). Geothermobarometry in four-phase lherzolites I. Experimental results from 10 to 60 kb. Journal of Petrology 31, 1313-1352.
11. Bundy, F. R. (1980). The P, T phase and reaction diagrams for elemental carbon. Journal of Geophysical Research 85, 6930-6936.
12. Caporuscio F.A. & Smyth J. R. (1990). Trace element crystal chemistry of mantle eclogites. Contributions to Mineralogy and Petrology 105, 550-561.
13. Carswell, D. A. & Harley, S. L. (1990). Mineral barometry and thermometry. In: Carswell, D. A. (ed.) Eclogite Facies Rocks. London: Blackie, pp. 315-349.
14. Dawson, J. B. (1984). Contrasting types of upper-mantle metasomatism? In: Kornprobst, J. (ed.) KimberTites II: the Mantle and Crust-Mantle Relationships. Amsterdam: Elsevier, pp. 289-294.
15. Dawson J. B. & Carswell, D. A. (1990). High temperature and ultrahigh pressure eclogites. In: Carswell, D. A. (ed.) Eclogite Facies Rocks London: Blackie, pp. 315-349.
16. 18O variations in diamond and graphite eclogites from Orapa, Botswana, and the nitrogen content of their diamonds. Geochimica et Cosmochimica Acta 55, 515-524.
17. Deines P., Harris, J. W. & Gurney, J. J. (1993). Depth-related carbon isotope and nitrogen concentration variability in the mantle below the Orapa kimberlite, Botswana, Africa. Geochimica et Cosmochimica Acta 57, 2781-2796.
18. Egglington B. M. & Harmer R. E. (1991). GEODATE: A program for the processing and regression of isotope data using IBM-compatible microcomputers. CSIR Manual EMA-H9102. Pretoria: Division of Earth, Marine and Atmospheric Science and Technology, Geochronology Division, Council for Scientific and Industrial Research.
19. Ellis D. J. & 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, 13-22.
20. Erlank, A. J., Waters, F. G., Hawkesworth, C. J., Haggerty, S. E., Allsopp, H. L., Rickard, R. S. & Menzies, M. (1987). Evidence for mantle metasomatism in peridotite nodules from the Kimberley pipes, South Africa. In: Menzies, M. & Hawkesworth, C. J. (eds) Mantle Metasomatism. London: Academic Press, pp. 221-309.
21. Faure, G. (1986). Principles of Isotope Geology. New York: John Wiley.
22. Floyd, P. (1991). Oceanic islands and seamounts. In: Floyd, P. (ed.) Oceanic Basalts. London: Blackie, 190 pp.
23. Frey, F. A. (1980). The origin of pyroxenites from Salt Lake Crater, Oahu, Hawaii: Trace element evidence. American Journal of Science 280-A, 427-449.
24. Freyer, B. J., Jackson, S. E. & Longerich, H. P. (1995). The design, operation and role of the laser-ablation microprobe coupled with an inductively coupled plasma-mass spectrometer (LAM-ICP-MS) in the earth sciences. Canadian Mineralogist 33, 303-312.
25. Fung, A. T. & Haggerty, S. E. (1995). Petrography and mineral compositions of eclogites from the Koidu Kimberlite Complex, Sierra Leone. Journal of Geophysical Research 100, 20451-20473.
26. Garlick G. D., MacGregor, I. D. & Vogel, D. E. (1971). Oxygen isotope ratios in eclogites from kimberlite. Science 172, 1025-1027.
27. 2. American Mineralogist 69, 1025-1035.
28. Green D. H. & Sobolev, N. V. (1965). Coexisting garnets and ilmenites synthesised from pyrolite and olivine basanite and their significance for kimberlite assemblages. Contributions to Mineralogy and Petrology 50, 217-229.
29. Griffin, W. L., Doyle, B. J., Ryan, C. G., Pearson, N. J., O'Reilly, S. Y., Davies, R., Kivi, K., Van Achterberg, E. & Natapov, L. M. (1999). Layered mantle lithosphere in the Lac de Gras area, Slave craton: composition, structure and origin. Journal of Petrology 40, 705-727.
30. Grutter, H. S. & Quadling, K. E. (1999). Can sodium in garnet be used to monitor eclogitic diamond potential? In: Gurney, J. J., Gurney, J. L., Pascoe, M. D. & Richardson, S. H. (eds) Proceedings of the VIIth International Kimberlite Conference, Vol. 1. Cape Town: Red Roof Design, pp. 314-320.
31. Günther, D. & Hattendorf, B. (2001). Elemental fractionation in LA-ICP-MS. In: Sylvester, P. (ed.) Laser Ablation-ICPMS in the Earth Sciences. Principles and Applications. Mineralogical Association of Canada Short Course Series 29, 83-92.
32. Gurney, J. J., Harris, J. W. & Rickard, R. S. (1984). Silicate and oxide inclusions in diamonds from the Orapa mine, Botswana. In: Kornprobst, J. (ed.) Kimberlites II: The Mantle and Crust-Mantle Relationships. Amsterdam: Elsevier, pp. 3-10.
33. Gurney, J. J. (1989). Diamonds. In: Ross, J. (ed.) Kimberlites and Related Rocks. Vol. 2. Their Mantle/Crust Setting, Diamonds and Diamond Exploration. Geological Society of Australia, Special Publications 14, 827-832.
34. Gurney, J. J., Moore, R. O., Otter, M. L., Kirkley, M. B., Hops, J. J. & McCandless, T. E. (1991a). Southern African kimberlites and their xenoliths. In: Kampunzu, A. B. & Lubala, R. T. (eds) Magmatism in Extensional Structural Settings - the Phanerozoic African Plate. Berlin: Springer, pp. 495-536.
35. Gurney, J. J. (1991b). The diamondiferous roots of our wandering continents. South African Journal of Geology 93, 424-437.
36. Harte, B. (1983). Mantle peridotites and processes - the kimberlite sample. In: Hawkesworth, C. J. & Norry, M. J. (eds) Continental Basalts and Mantle Xenoliths. Nantwich: Shiva, pp. 46-91.
37. Harte, B & Kirkley, M. B. (1997). Partitioning of trace elements between clinopyroxene and garnet: Data from mantle eclogites. Chemical Geology 136, 1-24.
38. Hatton, C. J. (1978). The geochemistry of xenoliths from the Roberts Victor mine. Ph.D. thesis, University of Cape Town.
39. Hatton, C. J. & Gurney, J. J. (1987). Roberts Victor eclogites and their relation to the mantle. In: Nixon, P. H. (ed.) Mantle Xenoliths. Chichester: John Wiley, pp. 453-463.
40. Heaman, L. M., Creaser, R. A. & Cookenboo, H. O. (2002). Extreme enrichment of high field strength elements in Jericho eclogite xenoliths: A cryptic record of Paleoproterozoic subduction, partial melting, and metasomatism beneath the Slave craton, Canada. Geology 30, 507-510.
41. Hills D. V. & Haggerty S. E. (1989). Petrochemistry of eclogites from the Koidu Kimberlite Complex, Sierra Leone. Contributions to Mineralogy and Petrology 103, 397-422.
42. Ireland T. R. Rudnick, R. L. & Spetsius, Z. (1994). Trace elements in diamond inclusions from eclogites reveal link to Archean granites. Earth and Planetary Science Letters 128, 199-213.
43. Irifune, T., Hibberson, W. O. & Ringwood, A. E. (1989). Eclogite-garnetite transformation at high pressure and its bearing on the occurrence of garnet inclusions in diamond. In: Ross, J. (ed.) Kimberlite and Related Rocks. Vol. 2. Their Mantle/Crust Setting, Diamonds and Diamond Exploration. Geological Society of Australia, Special Publications 14, 877-882.
44. Irving, A. J. (1980). Petrology and geochemistry of composite ultramafic xenoliths in alkalic basalts and implications for magmatic processes within the mantle. American Journal of Science 280-A, 389-426.
45. Ito, E. White, W. M. & Gopel, C. (1987). The O, Sr, Nd and Pb isotope geochemistry of MORB. Chemical Geology 62, 157-176.
46. Jackson, S. (2001). The application of Nd:YAg lasers in LA-ICP-MS. In: Sylvester, P. (ed.) Laser Ablation-ICPMS in the Earth Sciences. Principles and Applications. Mineralogical Association of Canada Short Course Series 29, 29-46.
47. Jacob, D. & Jagoutz, E. (1994). A diamond-graphite bearing eclogite xenolith from Roberts Victor (South Africa): Indications for petrogenesis from Pb, Nd and Sr isotopes. In: Meyer, H. O. A. & Leonardos, O. H. (eds) Proceedings of the 5th International Kimberlite Conference, Vol. 1. Companhia de Pesquisa de Recursos Minerais, Special Publication 1/A, 304-317.
48. Jacob, D., Jagoutz, E., Lowry, D., Mattey, D. & Kudrjavtseva, G. (1994). Diamondiferous eclogites from Siberia: Remnants of Archean oceanic crust. Geochimica et Cosmochimica Acta 58, 5191-5207.
49. Jacob, D., Jagoutz, E., Lowry, D. & Zinngrebe, E. (1998). Comment on 'The origins of Yakutian eclogite xenoliths' by G. A. Snyder, L. A. Taylor, G. Crozaz, A. N. Halliday, B. L. Beard, V. N. Sobolev and N. V. Sobolev. Journal of Petrology 39, 1527-1533.
50. Jacob D. E. & Foley S. F. (1999). Evidence for Archean crust with low field strength element signature from diamondiferous eclogite xenoliths. Lithos 48, 317-336.
51. Jacob, D. E., Schmickler, B. & Schulze, D. J. (2003). Trace element geochemistry of coesite-bearing eclogites from the Roberts Victor kimberlite, Kaapvaal craton. Lithos 71, 337-351.
52. Jacob, D. E. (2004). Nature and origin of eclogite xenoliths from kimberlites. Lithos 77, 295-316.
53. Jagoutz, E., Carlson, R. W. & Lugmair, G. W. (1980). Equilibrated Nd-unequilibrated Sr isotopes in mantle xenoliths. Nature 286 708-710.
54. Jagoutz, E., Dawson, J. B., Hoernes, S., Spettel, B. & Wanke, H. (1984). Anorthositic oceanic crust in the Archaean Earth. In: Proceedings of the 15th Lunar and Planetary Science Conference. Journal of Geophysical Research, Supplement 90, 395-396.
55. Jerde, E. A., Taylor, L. A., Crozaz, G., Sobolev, N. V. & Sobolev, V. N. (1993a). Diamondiferous eclogites from Yakutia, Siberia: Evidence for a diversity of protoliths. Contributions to Mineralogy and Petrology 114, 189-202.
56. Jerde, E. A., Taylor, L. A., Crozaz, G. & Sobolev, N. V. (1993). Exsolution of garnet within clinopyroxene of mantle eclogites: Major- and trace-element chemistry. Contributions to Mineralogy and Petrology 114, 148-159.
57. Kelemen, P. B., Hart, S. R. & Bernstein, S. (1998). Silica enrichment in the continental upper mantle via melt/rock reaction. Earth and Planetary Science Letters 164, 387-406.
58. Kennedy, C. S. & Kennedy, G. C. (1976). The equilibrium boundary between graphite and diamond. Journal of Geophysical Research 81, 2467-2470.
59. Kesson, S. E. & Ringwood, A. E. (1989). Slab-mantle interactions 2. The formation of diamonds. Chemical Geology 78, 97-118.
60. Kiviets, G. B., Gurney, J. J., Richardson, S. H., Harris, C., Milledge, H. J. & Taylor, W. R. (1995). A detailed study of a suite of diamondiferous eclogite xenoliths from the Kaalvallei kimberlite, South Africa. In: Extended Abstracts of the Sixth International Kimberlite Conference. Novosibirsk: Russian Academy of Sciences, United Institute of Geology, Geophysics and Mineralogy, pp. 279-281.
61. Kiviets, G. B. (2000). A detailed geochemical investigation of diamond-bearing eclogite xenoliths from the Kaalvallei kimberlite, South Africa. M.Sc. thesis, University of Cape Town.
62. Krogh, E. J. (1988). The garnet-clinopyroxene Fe-Mg geothermometer - a reinterpretation of existing experimental data. Contributions to Mineralogy and Petrology 99, 8-44.
63. Kyser, T. K. (1986). Stable isotope variations in the mantle. In: Valley, J. W. (ed.) Stable Isotopes in High Temperature Geologic Processess. Mineralogical Society of America, Reviews in Mineralogy 16, 141-164.
64. MacGregor, I. D. & Carter, J. L. (1970). The chemistry of clinopyroxenes and garnets of eclogite and peridotite xenoliths from the Roberts Victor mine, South Africa. Physics of the Earth and Planetary Interiors 3, 391-397.
65. MacGregor, I. D. & Manton, W. I. (1986). Roberts Victor eclogites: ancient oceanic crust. Journal of Geophysical Research 91, 14063-14079.
66. Mattey D., Lowry, D. & MacPherson, C. (1994a). Oxygen isotopic composition of mantle peridotite. Earth and Planetary Science Letters 128, 231-241.
67. Mattey, D. P., Lowry, D., MacPherson, C. G. & Chazot, G. (1994). Oxygen isotope composition of mantle minerals by laser fluorination analysis: Homogeneity in peridotites, heterogeneity in eclogites. Mineralogical Magazine 58A, 573-574.
68. Mazzone, P. & Haggerty, S. E. (1989a). Corganites and corgaspinites: Two new types of aluminous assemblages from the Jagersfontein pipe. In: Ross, J. (ed.) Kimberlites and Related Rocks. Vol. 2. Their Mantle/Crust Setting, Diamonds and Diamond Exploration. Geological Society of Australia, Special Publications 14, 795-808.
69. Mazzone, P. & Haggerty, S. E. (1989b). Peraluminous xenoliths in kimberlite: Metamorphosed restites produced by partial melting of pelites. Geochimica et Cosmochimica Acta 53, 1551-1561.
70. McCandless, T. E. & Gurney, J. J. (1989). Sodium in garnet and potassium in clinopyroxene: Criteria for classifying mantle eclogites. In: Ross, J. (ed.) Kimberlites and Related Rocks. Vol. 2. Their Mantle/Crust Setting, Diamonds and Diamond Exploration. Geological Society of Australia, Special Publications 14, 827-832.
71. McDonough, W. F. & Sun, S.-S. (1995). The composition of the Earth. Chemical Geology 120, 223-253.
72. Menzies, M. A. & Hawkesworth, C. J. (1987). Mantle Metasomatism. London: Academic Press.
73. Meyer, H. O. A. (1987). Inclusions in diamond. In: Nixon, P. H. (ed.) Mantle Xenoliths. Chichester: Wiley, pp. 501-522.
74. Moukadiri, A. & Kornprobst, J. (1984). Garnet and/or spinel bearing pyroxenites in alkali basalts near Azrou (middle Atlas, Morocco): Mantle derived alumina-rich xenoliths related to the 'ariegite-grospydite' trend. In: Kornprobst, J. (ed.) Kimberlites II: the Mantle and Crust-Mantle Relationships. Amsterdam: Elsevier, pp. 179-190.
75. Neal, C. R. & Taylor, L. A. (1990). Comment on 'Mantle eclogites: evidence of igneous fractionation in the mantle' by J. R. Smith, F. A. Caporuscio and T. C. McCormick. Earth and Planetary Science Letters 101, 112-119.
76. Neal, C. R., Taylor, L. A., Davidson, J. P., Holden, P., Halliday, A. N. Nixon, P. H., Paces, J. B., Clayton, R. N. & Mayeda, T. K. (1990). Eclogites with oceanic crustal and mantle signatures from the Bellsbank kimberlite, South Africa. Part 2. Sr, Nd and O isotope geochemistry. Earth and Planetary Science Letters 99, 362-379.
77. Noble, S. R., Lightfoot, P. C. & Scharer, U. (1989). A new method for single-filament isotopic analysis of Nd using in situ reduction. Chemical Geology 79, 15-19.
78. Norman, M. D., Pearson, N. J., Sharma, A. & Griffin, W. L. (1996). Quantitative analysis of trace elements in geological materials by laser ablation ICP-MS: Instrumental operating conditions and calibration of NIST glasses. Geostandards Newsletter 20, 247-261.
79. Norman, M. D. (1998). Melting and metasomatism in the continental lithosphere: Laser ablation ICPMS analysis of minerals in spinel lherzolites from eastern Australia. Contributions to Mineralogy and Petrology 130, 240-255.
80. Nowell, G. M., Pearson, D. G., Jacob, D. J., Spetsius, Z. V., Nixon, P. H. & Haggerty, S. E. (2003). The origin of alkremites and related rocks: Lu-Hf, Rb-Sr and Sm-Nd isotope study. In: Extended Abstracts, Seventh International Kimberlite Conference. Cape Town: University of Cape Town, Abstract FLA_0271.
81. O'Reilly, S. Y. & Griffin, W. L. (1995). Trace-element partitioning between garnet and clinopyroxene in mantle-derived pyroxenites and eclogites: P-T-X controls. Chemical Geology 121, 105-130.
82. Ongley, J. S., Basu, A. R. & Kyser, T. K. (1987). Oxygen isotopes in coexisting garnets, clinopyroxenes and phlogopites from Roberts Victor eclogites: Implications for petrogenesis and mantle metasomatism. Earth and Planetary Science Letters 83, 80-84.
83. Pearce, N. J. G., Perkins, W. T., Wesgate, J. A., Gorton, M. P., Jackson, S. E., Neal, C. R. & Chenery, S. P. (1997). A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostandards Newsletter 21 115-144.
84. Pearson, D. G., Shirey, S. B., Carlson, R. W. & Taylor, L. A. (1992). Os isotopic constraints on the petrogenesis of eclogite xenoliths. EOS Transactions, American Geophysical Union, Spring Meeting Supplement 73(14), 376.
85. Pearson, D. G., Snyder, G. A., Shirey, S. B., Taylor, L. A., Carlson, R. W. & Sobolev, N. V. (1995). Archean Re-Os age for Siberian eclogites and constraints on Archean tectonics. Nature 374, 711-713.
86. Pearson, N. J., Griffin, W. L., Doyle, B. J., O'Reilly, S. E., Van Achterberg, E. & Kivi, K. (1999). Xenoliths from the Lac de Gras area, Slave craton, Canada. In: Gurney, J. J., Gurney, J. L., Pascoe, M. D. & Richardson, S. H. (eds) Proceedings of the VIIth International Kimberlite Conference, Vol. 2. Cape Town: Red Roof Design, pp. 644-658.
87. Plank, T. & Langmuir, C. H. (1998). The chemical composition of subducting sediment and its consequences for the crust and mantle. Chemical Geology 145, 325-394.
88. Pollack, H. N. & Chapman, D. S. (1977). On the regional variation of heat flow, geotherms and lithospheric thickness. Tectonophysics 38, 279-296.
89. Powell, R. (1985). Regression diagnostics and robust regression in geothermometer/geobarometer calibration: The garnet-clinopyroxene geothermometer revisited. Journal of Metamorphic Petrology 3 231-243.
90. Pyle, J. M. & Haggerty, S. E. (1998). Eclogites and the metasomatism of eclogites from the Jagersfontein kimberlite: Punctuated transport and implications for alkali magmatism. Geochimica et Cosmochimica Acta 61, 1207-1231.
91. Rapp, R. P., Watson, E. B. & Miller, C. F. (1991). Partial melting of amphibolite/eclogite and the origins of Archaean trondhjemites and tonalites. Precambrian Research 51, 1-25.
92. Rapp, R. P., Shimizu, N. & Norman, M. D. (2003). Growth of early continental crust by partial melting of eclogite. Nature 425 605-609.
93. 144Nd, a natural tracer: An application to oceanic basalts. Earth and Planetary Science Letters 31, 269-278.
94. Richardson, S. H., Erlank, A. J. & Hart, S. R. (1985). Kimberlite-borne garnet peridotite xenoliths from old enriched subcontinental lithosphere. Earth and Planetary Science Letters 75, 116-128.
95. Richardson, S. H. (1986). Latter-day origin of diamonds of eclogitic paragenesis. Nature 322, 623-626.
96. Richardson, S. H., Erlank, A. J., Harris, J. W. & Hart, S. R. (1990). Eclogitic diamonds of Proterozoic age from Cretaceous kimberlites. Nature 346, 54-56.
97. Rickwood, P. C., Gurney, J. J. & White-Cooper, D. R. (1969). The nature and occurrence of eclogite xenoliths in the kimberlites of Southern Africa. Geological Society of South Africa Special Publication 2, 371-394.
98. Ringwood, A. E. (1975). Composition and Petrology of the Earth's Mantle. New York: McGraw Hill, 618 pp.
99. Robinson, D. N., Gurney, J. J. & Shee, S. R. (1984). Diamond eclogite and graphite eclogite xenoliths from Orapa, Botswana. In: Kornprobst, J. (ed.) Kimberlites II: The Mantle and Crust-Mantle Relationships. Amsterdam: Elsevier, pp. 11-24.
100. Rollinson, H. (1997). Eclogite xenoliths in west African kimberlites as residues from Archaean granitoid crust formation. Nature 389 173-176.
101. Rudnick, R. L. & Taylor, S. R. (1986). Geochemical constraints on the origin of Archaean tonalitic-trondhjemitic rocks and implications for lower crustal compositions. In: Dawson, J. B. Carswell, D. A., Hall, J. & Wedepohl, K. H. (eds) The Nature of the Lower Continental Crust. Geological Society, London, Special Publications 24, 179-191.
102. Rudnick, R. L. (1995). Making continental crust. Nature 378, 571-578.
103. Rudnick, R. L., Barth, M., Horn, I. & McDonough, W. F. (2000). Rutile-bearing refractory eclogites: The missing link between continents and depleted mantle. Science 287, 278-281.
104. Schulze, D. J. & Helmstaedt, H. (1988). Coesite-sanidine eclogites from kimberlite: Products of mantle fractionation or subduction? Journal of Geology 96, 435-443.
105. Schulze, D. J. (1989). Ultramafic nodules from the Kaalvallei kimberlite, OFS, South Africa: Evidence for thermal perturbation of lithosphere during megacryst formation. In: 28th International Geological Congress, Washington, DC, Extended Abstracts, Vol. 3, pp. 57-58.
106. Schulze, D. J., Valley, J. W. & Spicuzza, M. J. (2000). Coesite eclogites from the Roberts Victor kimberlite, South Africa. Lithos 54, 23-32.
107. Schmickler, B. Jacob, D. E. & Foley, S. F. (2004). Eclogite xenoliths from the Kuruman kimberlites, South Africa: Geochemical fingerprinting of deep subduction and cumulate processes. Lithos 75, 173-207.
108. Shee, S. R. (1978). The mineral chemistry of xenoliths from the Orapa kimberlite pipe, Botswana. M.Sc. thesis, University of Cape Town.
109. Shee, S. R. & Gurney, J. J. (1979). The mineralogy of xenoliths from Orapa, Botswana In: Boyd, F. R. & Meyer, H. O. A. (eds) The Mantle Sample: Inclusions in Kimberlites and Related Rocks. Washington, DC: American Geophysical Union, pp. 37-49.
110. Shervais, J. W., Taylor, L. A., Lugmair, G. W., Clayton, R. N., Mayeda, T. K. & Korotev, R. L. (1988). Early Proterozoic oceanic crust and the evolution of subcontinental mantle: Eclogites and related rocks from southern Africa. Geological Society of America Bulletin 100, 411-423.
111. Skinner, E. M. W. (1989). Contrasting Group I and Group II kimberlite petrology: Towards a genetic model for kimberlites. In: Ross, J. (ed.) Kimberlites and Related Rocks. Vol. 1. Their Composition, Occurrence, Origin and Emplacement. Geological Society of Australia, Special Publications 14, 528-544.
112. Smith, C. B. (1983). Pb, Sr and Nd isotopic evidence for sources of southern African Cretaceous kimberlites. Nature 304, 51-54.
113. Smyth, J. R. & Caporuscio, F. A. (1984). Petrology of a suite of eclogite inclusions from the Bobbejaan kimberlite. II. Primary phase compositions and origin. In: KornpTobst, J. (ed.) Kimberlites II: the Mantle and Crust-Mantle Relationships. Amsterdam: Elsevier, pp. 121-131.
114. Smyth, J. R., Caporuscio, F. A. & McCormick, T. C. (1989). Mantle eclogites: Evidence of igneous fractionation in the mantle. Earth and Planetary Science Letters 93, 133-141.
115. Smyth, J. R., Caporuscio, F. A. & McCormick, T. C. (1990). Reply to comment of CE R. Neal and L. A. Taylor on: Mantle eclogites: evidence of igneous fractionation in the mantle. Earth and Planetary Science Letters 101, 120-124.
116. Snyder, G. A., Jerde, E. A., Taylor, L. A., Halliday, A. N., Sobolev, V. N. & Sobolev, N. V. (1993). Nd and Sr isotopes from diamondiferous eclogites, Udachnaya kimberlite pipe, Yakutia, Siberia: Evidence of differentiation in the early Earth. Earth and Planetary Science Letters 118, 91-100.
117. Snyder, G. A., Taylor, L. A., Jerde, E. A., Clayton, R. N., Mayeda, T. K., Deines, P. Rossman, G. R. & Sobolev, N. V. (1995). Archean mantle heterogeneity and the origin of diamondiferous eclogites, Siberia: evidence from stable isotopes and hydroxyl in garnet. American Mineralogist 80, 799-809.
118. Snyder, G. A., Taylor, L. A., Crozaz, G., Halliday, A. N., Beard, B. L., Sobolev, V. N. & Sobolev, N. V. (1997). The origins of Yakutian eclogite xenoliths. Journal of Petrology 38, 85-113.
119. Snyder, G. A., Taylor, L. A., Beard, B. L., Sobolev, V. N. & Sobolev, N. V. (1998). Reply to a comment by D Jacob et al., on 'The origins of Yakutian eclogite xenoliths'. Journal of Petrology 39, 1535-1543.
120. Snow, J. E., Hart, S. R. & Dick, H. J. B. (1993). Orphan strontium-87 in abyssal peridotites: Daddy was a granite. Science 262, 1861-1863.
121. Sobolev N. V. & Lavrent'yev Y. G. (1971). Isomorphic sodium admixture in garnets formed at high pressures. Contributions to Mineralogy and Petrology 31, 1-12.
122. Sobolev, V. N., Taylor, L. A., Snyder, G. A., Jerde, E. A., Neal, C. R. & Sobolev, N. V. (1999). Quantifying the effects of metasomatism in mantle xenoliths: Constraints from secondary chemistry and mineralogy in Udachnaya eclogites, Yakutia. International Geology Review 41 391-416.
123. Stiefenhofer, J. (1989). Petrography, mineralogy and geochemistry of the Kaalvallei kimberlite pipe, Orange Free State. B.Sc. Hons. thesis, Rhodes University, Grahamstown, South Africa.
124. Taylor L. A. & Neal, C. R. (1989). Eclogites with oceanic crustal and mantle signatures from the Bellsbank kimberlite, South Africa. Part 1. Mineralogy, petrography and whole rock chemistry. Journal of Geology 97, 551-567.
125. Taylor, L. A. Eckert, J. O., Neal, C. R. & Crozaz, G. (1991). Crustal signatures in mantle eclogites: REE patterns of clinopyroxene and garnet by SIMS and INAA. In: Extended Abstracts of the 5th International Kimberlite Conference. Companhia de Pesquisa de Recursos Minerais, Special Publication 2/91, 410-413.
126. Taylor, L. A., Snyder, G. A., Crozaz, G., Sobolev, V. N., Yefimova, E. S. & Sobolev N. V. (1996). Eclogitic inclusions in diamonds: Evidence of complex mantle processes over time. Earth and Planetary Science Letters 142, 535-551.
127. Taylor, L. A., Milledge, H. J., Bulanova, G. P., Snyder, G. A. & Keller, R. A. (1998). Metasomatic eclogitic diamond growth: Evidence from multiple diamond inclusions. International Geology Review 40 663-676.
128. Taylor, L. A., Snyder, G. A., Keller, R., Remley, D. A., Anand, M., Wiesli, R., Valley, J. & Sobolev, N. V. (2003). Petrogenesis of Group A eclogites and websterites: Evidence from the Obnazhennaya kimberlite, Yakutia. Contributions to Mineralogy and Petrology 145, 424-443.
129. 3 with silicate minerals, and their relevance to oxygen isotope analysis. Chemical Geology 86, 83-88.
130. Viljoen, K. S. (1994). The petrology and geochemistry of a suite of mantle-derived eclogite xenoliths from the Kaalvallei kimberlite, South Africa. Ph.D. thesis, University of the Witwatersrand, Johannesburg.
131. Viljoen, K. S. (1995). Graphite- and diamond-bearing eclogite xenoliths from the Bellsbank kimberlites, Northern Cape, South Africa. Contributions to Mineralogy and Petrology 121, 414-423.
132. Viljoen, K. S., Smith, C. B. & Sharp, Z. D. (1996). Stable and radiogenic isotope study of eclogite xenoliths from the Orapa kimberlite, Botswana. Chemical Geology 131, 235-255.