Some specific features of genesis of microdiamonds of octahedral and cubic habit from kimberlites of the Udachnaya pipe (Yakutia) inferred from carbon isotopes and main impurity defects

Russian Geology and Geophysics - Tập 48 Số 3 - Trang 299-304 - 2007
V. N. Reutsky1, D. A. Zedgenizov1
1Institute of Geology and Mineralogy, Siberian Branch of the RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia

Tóm tắt

Abstract Microdiamonds (crystals smaller than 1 mm) of octahedral and cubic habit from Udachnaya kimberlite pipe (Yakutia) have been compared in order to distinguish genetic features inferred from carbon isotopic composition and impurity defects. Microdiamonds of cubic habit from the Udachnaya kimberlite pipe have a fibrous internal structure and a high content of nitrogen impurity (400–3000 ppm). Octahedral microdiamonds from the same deposit are distinguished by a low nitrogen content of 0 to 500 ppm and zoning structure. The isotopic composition of carbon (δ13C is –4.7‰ for octahedra and –4.5‰ for cuboids) suggests a common source of carbon for these morphologic groups. The studied characteristics can be due to crystallization of octahedra from carbon dissolved in the melt, and cuboids, under the conditions of the hampered diffusion of carbon.

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Tài liệu tham khảo

Bartoshinsky, 1991, Crystal morphology of diamond [in Russian], Naukova Dumka, Kiev

Boyd, 1994, Modelling the growth of natural diamonds, Chem. Geol., 116, 29, 10.1016/0009-2541(94)90156-2

Bulanova, 1993, Nature diamond: genetic aspects [in Russian], Nauka, Novosibirsk

Cartigny, 2001, Diamond genesis, mantle fractionations and mantle nitrogen content: a study of (δ13C–N concentrations in diamonds, Earth Planet. Sci. Lett., 185, 85, 10.1016/S0012-821X(00)00357-5

Chernov, 1971, Theory of stability of faceted forms of crystals, Kristallografiya, 16, 842

De, 2001, Chemical heterogeneity in carbonado, an enigmatic polycrystalline diamond, Earth Planet. Sci. Lett., 185, 315, 10.1016/S0012-821X(00)00369-1

Dubinina, 1997, A kinetic model of isotopic exchange in dissolution-precipitation processes, Geochim. Cosmochim. Acta, 61, 2265, 10.1016/S0016-7037(97)00076-8

Galimov, 1984, Variations of diamond isotopic composition and their relationship with diamond formation conditions, Geokhimiya, 8, 1091

Harris, 1975, A classification scheme for diamonds and comprehensive study of South African diamond characteristics, Phys. Chem. Earth, 9, 765, 10.1016/0079-1946(75)90050-6

Kinny, 1999, Carbon isotopic analysis of microdiamonds, in: Proceedings of 7th Int, Kimb. Conf., V. 1. Cape Town, 429

Lemarchand, 2004, Rate-controlled calcium isotope fractionation in synthetic calcite, Geochim. Cosmochim. Acta, 68, 4665, 10.1016/j.gca.2004.05.029

Maruoka, 2004, Isotopic composition of carbon in diamonds of diamondites: Record of mass fractionation in the upper mantle, Geochim. Cosmochim. Acta, 68, 1635, 10.1016/j.gca.2003.10.007

Nepsha, 1990, Diamond coolers in electronic devices, in: Diamond in electronics [in Russian], Energoatomizdat, 140

Orlov, 1973, Diamond mineralogy [in Russian], Nauka, Moscow

Reutsky, 1999, Isotopic composition of carbon of polycrystal aggregations of chromite-bearing diamonds from Mir kimberlite pipe (Yakutia), Geokhimiya, 11, 1191

Reutsky, 2001, Isotopic composition of carbon of diamond microcrystals from Udachnaya pipe (Yakutia), in: Crystal genesis and mineralogy: Proc. of International Conf. [in Russian], St., 318

Snyder, 1995, Archean mantle heterogeneity and the origin of diamondiferous eclogites, Siberia: evidence from stable isotopes and hydroxyl in garnet, Amer. Miner., 80, 799, 10.2138/am-1995-7-816

Sobolev, 1979, Carbon isotopic composition of diamond with crystal inclusions, Dokl. AN SSSR, 249, 1217

Sunagawa, 1984, Morphology of natural and synthetic diamond crystals, in: Materials Science of Earth’s Interior, Tokyo, TERRA PUB, 303

Taylor, 1989, The role of reduced C-O-H fluids in mantle partial melting, in: Kimberlites and related rocks, GSA Special Publication no. 14, v. 1, 592

Trautman, 1997, A comparison of the microdiamonds from kimberlite and lamproite of Yakutia and Australia, Geologiya i Geofizika (Russian Geology and Geophysics), 38, 323

Watson, 2004, A conceptual model for near-surface kinetic controls on the trace-element and stable isotope composition of abiogenic calcite crystals, Geochim. Cosmochim. Acta, 68, 1473, 10.1016/j.gca.2003.10.003

Woods, 1986, Platelets and infrared absorption of type Ia diamonds, Proceedings of Royal Society. London, A407, 219

Zedgenizov, 1998, Microdiamonds from the Udachnaya kimberlite pipe, Geologiya i Geofizika (Russian Geology and Geophysics), 39, 745

Zedgenizov, 2004, Microscale variations of δ13C and N content in diamonds with mixed-habit growth, Chem. Geol., 205, 169, 10.1016/j.chemgeo.2003.12.016

Zedgenizov, 1998, Inclusions in microdiamonds from some Yakutian kimberlite pipes, Dokl. RAN, 359, 74

Zedgenizov, 1999, The internal structure of microdiamonds from the Udachnaya kimberlite pipe, Geologiya i Geofizika (Russian Geology and Geophysics), 40, 113