Abstract
The two main diamond associations are either of eclogitic or peridotitic mineralogy, exemplified by inclusions in diamond or rocks in which diamond has formed, notably xenoliths in kimberlites. Outside cratonic areas where kimberlites typically occur, diamonds have been recorded in alpine peridot-ites and gravels associated with them. Graphite pseudomorphs after di-amonds occur in the Beni Bousera peridotite massif (Kornprobst, 1969) within garnet pyroxenites or eclogites (Slodkevich, 1980b). They have cubic morphology and contain cpx inclusions of high pressure cubo-octahedral morphology similar to those in natural diamonds. They possess isotopically light δ13C values. The garnet pyroxenites have similar mineralogy to diamond bearing eclogite xenoliths and have a wide oxygen isotope variation (δ18O= 4.9 to 9.3%) – much greater than that of the associated peridotites.
They are believed to represent portions of hydrothermally altered sub-ducted oceanic lithosphere that resided at great depth (≫ diamond stability limit) before diapiric uprise and final cumulate segregation. The evolution of these rocks is compared with that of the sparsely diamondiferous alpine peridotites which probably have a simpler and shorter subduction history to relatively shallow depths.
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References
Akaogi, M. and Akimoto, S., 1977. Pyrope-garnet solid solution equilibria in the systems Mg4Si4O12 - Mg3Al2Si3O12 and Fe4Si4O12 - Fe3Al2Si3O12 at high pressures and temperatures., Phys. Planet. Earth Interiors, 15: 90–106.
Allegre, C.J. and Turcotte, D.L., 1986. Implications of a two component marble-cake mantle., Nature, London. 323: 123–126.
Bonini, W.E., Loomis, T.P. and Robertson, J.D., 1973. Gravity anomalies, ultramafic intrusions and the tectonics of the region around the Straits of Gibralter., J. Geophys. Res., 78: 1372–1382.
Boyd, F.R. and Gurney. J.J., 1986. Diamonds and the African lithsophere., Science, 232: 472–477.
Cocker, J.D., Griffin, B.J. and Muehlenbachs, K., 1982. Oxygen and carbon isotope evidence for seawater hydrothermal alteration of the Macquarie Island ophiolite., Earth Planet. Sci. Lett., 61: 112–122.
Coleman, R.G., 1977. Ophiolites. Springer-Verlag, New York, 229 pp.
Dawson, J.B., 1983. New developments in diamond geology., Naturwissenschaften, 70: 586–593.
Deines, P., 1980. The carbon isotopic composition of diamonds: relationship to diamond shape,color, occurrence and vapor composition., Geochim. Cosmochim. Acta, 44: 943–961.
Fang, Chingson and Bai Wenji, 1981. The discovery of Alpine-type diamond bearing ultrabasic intrusion in Xizang (Tibet)., Int. Geol Rev., 27: 455–457 (in Chinese).
Girardeau, J. and Mercier, J-C.C., 1988. Petrology and texture of the ultramafic rocks of theXigaze ophiolite (Tibet): constraints for mantle structure beneath slow-spreading ridge., Tectonophysics, 147: 33–58.
Gregory, R.G. and Taylor, H.P., 1981. An oxygen isotope profile in a section of Cretaceous oceanic crust, Samail ophiolite, Oman: evidence for δ180 buffering of oceans by deep (> 5 km) seawater hydrothermal alteration at mid ocean ridges., J. Geophys. Res., 86: 2737–2755.
Helmstaedt, H. and Doig, R., 1975. Eclogite nodules from kimberlite pipes of the Colorado Plateau - samples of subducted Franciscan-type oceanic lithosphere., Phys. Chem. Earth, 9: 95–111.
Jacques, A.L., Hall, A.E. et al., 1989. Composition of crystalline inclusions and C-isotopic composition of Argyle and Ellendale diamonds. In: Ross et al. (Eds), “Kimberlites and related rocks”, Vol.2., Geol. Soc. Aust, Spec. Pub., 14, Blackwell: pp. 966–990.
Javoy, M., 1980. 18O/16O and D/H ratios in high temperature peridotites., Colloq. Int. C.N.R.S. 272: 279–287.
Kaminskii, F.V., 1984. The diamond content of non-kimberlitic eruptive rocks. Izd-vo Nedra, Moscow. 171 pp (in Russian).
Kornprobst, J., 1966. A propos des péridotites du massif des Beni Bousera (Rif Septentrional, Maroc)., Bull. Soc. Fr. Minéral. Cristallog., 89: 399–404.
Kornprobst, J., 1969. Le massif ultrabasique des Beni Bouchera (Rif Interne, Maroc)., Contrib. Mineral. Petrol., 23: 283–322.
Kornprobst, J., 1974. Contribution a l’etude petrographique et structurale de la zone interne du Rif (Maroc Septentrional)., Notes. Serv. Geol. Maroc. T251: 256 pp.
Kornprobst, J., Piboule, M. and Roux, L., 1982. Corundum bearing garnet pyroxenites at Beni Bousera (Morocco): An exceptionally Al-rich clinopyroxene from grospydites associated with ultramafic rocks., Terra Cognita, 2: 257–259.
Kornprobst, J. and Vielzeuf, D., 1984. Transcurrent crustal thinning: a mechanism for the uplift of deep continental crust/upper mantle associations. In: J. Kornporbst (ed) “Kimberlites II: The Mantle and Crust-Mantle Relations”, Elsevier, Amsterdam, pp.347–355.
Kornprobst, J., Piboule, M., Roden, M. and Tabit, A., 1990. Corundum-bearing garnet clinopyroxenites at Beni Bousera (Morocco): original plagioclase-rich gabbros recrystallized at depth within the mantle?, J. Petrol., 31: 717–745.
Kramers, J.D., 1979. Lead, uranium, strontium, potassium and rubidium in inclusion-bearing diamonds and mantle derived xenoliths from Southern Africa. Earth Planet. Sci. Lett., 42: 58–70.
Kyser, T.K., 1986. Stable isotope variations in the mantle. In: J.W. Valley, H.P. Taylor and J.R. O’Neil (eds), “Stable Isotopes in High Temperature Geological Processes”, Reviews in Mineralogy., Vol.16. Min. Soc. Am., pp.141–164.
Kyser, T.K., O’Neil, J.R. and Carmichael, I.S.E., 1981. Oxygen isotope thermometry of basic lavas and mantle nodules., Contrib. Mineral. Petrol., 77: 11–23.
Loubet, M.. and Allègre, C.J., 1982. Trace elements in orogenic lherzolites reveal the complex history of the upper mantle., Nature, 298: 809–814.
MacGregor, I.D. and Manton, W.I., 1986. Roberts Victor eclogites: an ancient oceanic crust., J. Geophys. Research., 91: 14063–14079.
McCulloch, M.T., Gregory, R.T., Wasserburg, G.J. and Taylor, H.P., 1980. A neodymium, strontium and oxygen isotopic study of the Cretaceous Samail ophiolite and implications for the petrogenesis and seawater-hydrothermal alteration of oceanic crust., Earth Planet. Sci. Lett., 46: 201–211.
Meyer, H.O.A., 1982. Mineral inclusions in natural diamond. International Geological Proceedings: Gemological Institute of America, Los Angeles, pp. 447–465.
Moore, R.O. and Gurney, J.J., 1985. Pyroxene solid solution in garnets included in diamond., Nature, London, 318: 533–555.
Nixon, P.H., Davies, G.R., Slodkevich, V.V. and Bergman, S.C., 1986. Graphite pseudo-morphs after diamond in the eclogite-peridotite massif of Beni Bousera, Morocco, and a review of anomalous diamond occurrences., Fourth Internat. Kimberlite Conf., Perth, W. Australia, extend. abstr.: pp. 412–414.
Pallister, J.S. and Knight, R.J., 1981. Rare-earth element geochemistry of the Samail ophiolite near Ibra, Oman., J. Geophys. Res., 86: 2673–2697.
Pearson, D.G. 1989. The petrogenesis of pyroxenites containing octahedral graphite and associated mafic and ultramafic rocks of the Beni Bousera peridotite massif, N. Morocco., Ph.D. thesis, Dept. Earth Sci., Univ. Leeds, 413 pp.
Pearson, D.G., Davies, G.R., Nixon, P.H. and Milledge, H.J., 1989a. Graphitized diamonds from a peridoite massif in Morocco and implications for anomalous diamond occurrences., Nature, London. 338: 60–62.
Pearson, D.G., Davies, G.R., Nixon, P.H., 1989b. Graphite-bearing pyroxenites from Morocco: evidence of recycled oceanic lithosphere and the origin of E-type diamonds. Extended abstracts: Workshop on Diamonds 28th Internat., Geol. Cong. Washington, 83–86.
Pearson, D.G., Davies, G.R., Nixon, P.H., Greenwood, P.B. and Mattey, D.P., 1991. Oxygen isotope evidence for the origin of pyroxenites in the Beni Bousera peridotite massif, N. Morocco: derivation from subducted oceanic lithosphere. Earth and Planetary Sci. Lett., 102: 289–301.
Pearson, D.G., Davies, G.R., Nixon, P.H. and Mattey, D.P., 1991. A carbon isotope study of diamond facies pyroxenites and associated rocks from the Beni Bousera peridotite, N. Morocco. In Menzies, M.A., Dupuy, C. and Nicoles, A. (eds), “Orogenic Lherzolites and Mantle Processes”, Spec. Pub., J. Pet. (in press).
Reuber, I., Michard, A., Chalcouan, A., Juteau, T. and Jermoumi, B., 1982. Structure and emplacement of the Alpine type peridoites from Beni Bousera. Rif Morocco: a polyphase tectonic interpretation., Tectonophysics., 82: 231–251.
Richardson, S.H., Gurney, J.J., Erlank A.J. and Harris, J.W., 1984. Origin of diamonds in old enriched mantle., Nature, London, 310: 198–201.
Ringwood, A.E., 1977. Synthesis of pyrope-knorringite solid solution series., Earth Planet. Sci. Lett., 36: 443–448.
Ringwood, A.E., 1989. Constitution and evolution of the mantle. In: Ross, et al. (eds), “Kimber-lites and Related Rocks”, Vol.2, Geol. Soc. Aust. Spec. Pub. 14, Blackwell: 457–485.
Robinson, D.N., Gurney, J.J. and Shee, S.R., 1984. Diamond eclogite and graphite eclogite xenoliths from Orapa Botswana. In: J. Kornprobst (ed), “Kimberlites II, The Mantle and Crust-Mantle Relations”, Elsevier: Amsterdam., pp. 11–24.
Schulze, D.J., 1986. Calcium anomalies in the mantle and a subducted metaserpentinite origin for diamonds., Nature, 319: 483–485.
Sharp, W.E., 1974. A plate tectonic origin for diamond-bearing kimberlites., Earth Planet. Sci. Lett., 21: 351–354.
Shilo, L.A., Kaminskii, F.V., Palandzhyan, S.M. et al., 1981. First diamond finds in alpine-type ultramafic rocks of northeastern USSR., Doklady Akad. Nauk SSSR, 241: 179–182.
Slodkevich, V.V., 1980a. Polycrystalline aggregates of octandral graphite. Doklady, Akad.Nauk SSSR, 253: 194–196.
Slodkevich, V.V., 1980b. Graphite pseudomorphs after diamond., Internat. Geol. Rev. 25, No.5.
Slodkevich, V.V. and Lobkov, V.A., 1983. Isotopic composition of graphite from the maficultramafic pluton at Beni Bousera, Morocco (in Russian)., Doklady Akad. Nauk SSSR, 272: 698–701.
Sobolev, N.V. and Lavrent’ev, Ju.G., 1971. Isomorphic sodium admixture in garnets formed at high pressures. Contrib. Mineral. Petrol. 31: 1–12.
Sobolev, N.V., Galimov, E.M., Ivanovskaya, I.N. and Yefimova, E.S., 1979. Isotopic composition of carbon of diamonds containing crystalline inclusions. (in Russian)., Doklady Akad. Nauk SSSR, 249: 1217–1220.
Thayer, T.P., 1960. Some critical differences between alpine-type and stratiform peridotitegabbro complexes., Internat. Geol. Congr. 21st Sess. Copenhagen. 13: 247–259.
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Nixon, P.H., Pearson, D.G., Davies, G.R. (1991). Diamonds: the Oceanic Lithosphere connection with Special Reference to Beni Bousera, North Morocco. In: Peters, T., Nicolas, A., Coleman, R.G. (eds) Ophiolite Genesis and Evolution of the Oceanic Lithosphere. Petrology and Structural Geology, vol 5. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-3358-6_15
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DOI: https://doi.org/10.1007/978-94-011-3358-6_15
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