 | | Journal (article/letter/editorial) | | Neoproterozoic ‘anomalous’ kimberlites of Guaniamo, Venezuela: mica kimberlites of ‘isotopic transitional’...Columbia, Canada V7S 3J1 Guaniamo Mining Company, Centro Gerencial Mohedano, Office 9D, La Castellana, Caracas...Caracas, Venezuela Received 27 June 2003; accepted 17 February 2004 Available online 17 July 2004 Abstract...Abstract In Venezuela, kimberlites have so far only been found in the Guaniamo region, where they occur as...emplacement age of the Guaniamo kimberlites is 712 F 6 Ma, i.e., Neoproterozoic. The Guaniamo kimberlites contain |  | | Journal (article/letter/editorial) | | pyrochlore-group minerals from the Guaniamo kimberlites, Venezuela Victor V. Sharygin a,⁎, Nikolai V....Novosibirsk, Russia Guaniamo Mining Company, Centro Gerencial Mohedano, Office 9D, La Castellana, Caracas...Caracas, Venezuela a r t i c l e i n f o Article history: Received 23 September 2008 Accepted 28 March...Keywords: Pyrochlore Betafite Perovskite Kimberlite Carbonatite Venezuela a b s t r a c t Oscillatory-zoned...minerals are found in the La Ceniza diamondiferous kimberlites, Guaniamo region, Venezuela. This is the first |  | Russell, Ashley K., Kitajima, Kouki, Strickland, Ariel, Medaris, L. Gordon, Schulze, Daniel J., Valley, John W. (2013) Eclogite-facies fluid infiltration: constraints from δ18O zoning in garnet. Contributions to Mineralogy and Petrology, 165 (1) 103-116 doi:10.1007/s00410-012-0794-9 | Journal (article/letter/editorial) | | results for d18O in garnets from orogenic and kimberlite-borne eclogites. The purpose of this study is...including orogenic eclogites and xenoliths in kimberlite, and (c) to examine the possible applications...eclogites, garnets from eclogite xenoliths in kimberlite were selected for analysis. These samples are...from eclogite xenoliths in the Roberts Victor kimberlite (Kaapvaal Craton, South Africa) and eclogitic...garnet xenocrysts from the La Ceniza kimberlite (Guaniamo Region, Venezuela). Among Roberts Victor xenoliths |  | | Journal (article/letter/editorial) | | fine-grained albite, quartz, magnetite and glass. Calcite, quartz and zeolite are common secondary minerals...are commonly filled in with secondary carbonate (calcite), quartz, biotite (the biotite is now altered and...and the resulting space is filled with secondary calcite that may have replaced the ash (Fig. 4b, c). Almandine... extensive alteration to and precipitation of calcite (Cc) and fracture-filling by biotite (Alt Biot)...Sukhda Tuff are commonly filled by zeolite and calcite, and are devoid of garnet. Therefore, a hydrothermal |  | | Journal (article/letter/editorial) | | peridotitic diamonds sampled by the Roberts Victor kimberlite tapped locally distinct mantle sources of carbon...the main Orapa kimberlite. Diamonds and xenoliths from the mine at the Orapa kimberlite have been extensively...grossular–calcite fractionation of Rosenbaum and Mattey (1995) with the forsterite– calcite fractionation...4 5 6 18O /‰ 8 9 10 11 8 9 10 11 /‰ Guaniamo Schulze et al. 2003, 2004 2 3 7 18O Finsch...garnet inclusions in diamond from the Finsch kimberlite. (F) Oxygen isotope ratios of garnet and coesite |  | Sobolev, N. V., Schertl, H.-P., Valley, J. W., Page, F. Z., Kita, N. T., Spicuzza, M. J., Neuser, R. D., Logvinova, A. M. (2011) Oxygen isotope variations of garnets and clinopyroxenes in a layered diamondiferous calcsilicate rock from Kokchetav Massif, Kazakhstan: a window into the geochemical nature of deeply subducted UHPM rocks. Contributions to Mineralogy and Petrology, 162 (5) 1079-1092 doi:10.1007/s00410-011-0641-4 | Journal (article/letter/editorial) | | and garnet-pyroxene rocks with dolomite and Mg-calcite matrices occur with UHPM diamondiferous biotite...include different lithologies. Dolomite-rich and calcite-rich layers, with minor amounts of garnet and clinopyroxene...dolomite-rich and garnetclinopyroxene-rich (in Mg-calcite matrix) layers. Dark layers are characterized by...dolomite matrix, while light gray layers have Mg-calcite matrix. Both layers including their contact zone...compositions (Table 1). The contact zone between Mg-calcite matrix and dolomite 1081 matrix is about 1 mm |  | | Journal (article/letter/editorial) | | No. 1-2, 2003 Lead isotopic systematics of major river sediments: a new estimate of the Pb isotopic composition...peridotitic garnet xenocrysts from the La Ceniza kimberlite, Guaniamo, Venezuela —Daniel J. Schulze, John W. Valley...Savelli 671 717 Vol. 63, No. 1, 2003 Discovery of Kimberlite pipes in Gadwal Area, Mahbubnagar district, Andhra... and Cristian Panaiotu Magmatic anhydrite and calcite in the ore-forming quartzmonzodiorite magma at...geochronology of regional volcanism hosting the Bajo de la Alumbrera Cu-Au deposit: implications for porphyry-related |  | Wang, Zhengrong, Bucholz, Claire, Skinner, Brian, Shimizu, Nobumichi, Eiler, John (2011) Oxygen isotope constraints on the origin of high-Cr garnets from kimberlites. Earth and Planetary Science Letters, 312 (3) 337-347 doi:10.1016/j.epsl.2011.09.061 | Journal (article/letter/editorial) | | Editor R.W. Carlson Keywords: garnet peridotite kimberlite oxygen isotope sub-calcic garnet metasomatism...Introduction Oxygen isotope compositions of garnets from kimberlite have been extensively studied. E-type garnets...standards were interspersed with measurements of kimberlite minerals. Results for standards are as follows:...for the generation of high-Cr garnet in P-type kimberlite. This component could be fluid and/or melt penetrating...fractionation factor between Calcite–H2O is from O'Neil et al., 1969, between Forsterite–Calcite is from Chiba et |  | | Journal (article/letter/editorial) | | Collier 4 kimberlite pipe, Juina, Brazil: subducted protoliths, carbonated melts and primary kimberlite magmatism...Walter, M. J., 2016. Diamonds from the Machado River alluvial deposit, Rondoˆnia, Brazil, derived from...carbon isotope fractionations between CO2 and calcite. Geochimica et Cosmochimica Acta, 55, 2867–2882... The isotopic composition of carbonatite and kimberlite carbonate and their bearing on the isotopic composition... Extended Abstracts of the 7th International Kimberlite Conference, Cape Town, pp. 230– 232. Giuliani |  | GORDON, S. M., LUFFI, P., HACKER, B., VALLEY, J., SPICUZZA, M., KOZDON, R., KELEMEN, P., RATSHBACHER, L., MINAEV, V. (2012) The thermal structure of continental crust in active orogens: insight from Miocene eclogite and granulite xenoliths of the Pamir Mountains. Journal of Metamorphic Geology, 30 (4) 413-434 doi:10.1111/j.1525-1314.2012.00973.x | Journal (article/letter/editorial) | | strike-slip fault/shear zone 73° 40°N Oksu river Rushan-Pshart (Bangong-Nujiang) suture (reactivated...30Fe0.11–0.12)CO3 cut the rock, and 100–500 lm calcite grains (Ca0.96Mg0.02Fe0.02) CO3 are spatially associated...garnet and kyanite grains, and is associated with calcite (Ca0.95–0.97 Mg0.01Fe0.01–0.04)CO3 nodules, which...peridotitic garnet xenocrysts from the La Ceniza kimberlite, Guaniamo, Venezuela. International Geology Review |
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