 | Luguet, Ambre, Behrens, Melanie, Pearson, D. Graham, König, Stephan, Herwartz, Daniel (2015) Significance of the whole rock Re–Os ages in cryptically and modally metasomatised cratonic peridotites: Constraints from HSE–Se–Te systematics. Geochimica et Cosmochimica Acta, 164. 441-463 doi:10.1016/j.gca.2015.06.016 | Journal (article/letter/editorial) | | isotopic system, eleven peridotites from the Letlhakane kimberlite pipe were investigated for whole rock...eruption) stabilisation of the Letlhakane mantle root and supports the Letlhakane mantle root being a westerly...Pt-tellurides) to highly refractory residues, such as the Letlhakane SP, reproduce well the HSE–Se–Te systematics...spinel- and garnet peridotites from the Letlhakane kimberlite (Botswana) in order to further understand the...cratonic peridotites is far from complete and the Letlhakane peridotites are suitable targets for such a study |  | | Journal (article/letter/editorial) | | Stiefenhofer Metasomatism in mantle xenoliths from the Letlhakane kimberlites: estimation of element ¯uxes Received:...of metasomatised xenoliths from the Letlhakane kimberlite (Botswana) forms a metasomatic sequence from...peridotite. Before the modal metasomatism, most of the Letlhakane xenoliths were depleted harzburgites that had...modally metasomatised xenoliths from the Letlhakane kimberlite (Botswana), approximately 800 km north of Kimberley...study of the phlogopitebearing xenoliths from Letlhakane and with the exception of the work by Stiefenhofer |  | | Journal (article/letter/editorial) | | silicate inclusions from the Orapa and Letlhakane diamond mines, Botswana. δ 13 C values are reported from...change in the nature of subducted carbon beneath Botswana and warrant further study to establish if this...Africa showing the location of the Orapa and Letlhakane diamond mines on the edge of the Zimbabwe Craton;...cathodoluminescence images of Orapa diamond 02 and Letlhakane diamond 09 respectively. Diamond OR02 has a yellow...from 16 diamonds from the Orapa and Letlhakane diamond mines, Botswana. Each diamond was first characterised |  | | Journal (article/letter/editorial) | | the discovery of diamonds in river deposits in central South Africa in the mid nineteenth century, it...valuable deposits were discovered in South Africa and Botswana in particular, but also in Lesotho, Swaziland...Jwaneng in Botswana, to mines that are both small and marginal, such as the Frank Smith Mine in South Africa...terrane; IIb: Central terrane; IIc: Pietersburg terrane; IId: Western terrane; IIIa: Central zone; IIIb:...inclusions and diamonds that are characteristic of each mine. A section covering 19 smaller-scale mines is then |  | Motsamai, Theetso, Harris, Jeffrey W., Stachel, Thomas, Pearson, D. Graham, Armstrong, John (2018) Mineral inclusions in diamonds from Karowe Mine, Botswana: super-deep sources for super-sized diamonds?. Mineralogy and Petrology, 112. 169-180 doi:10.1007/s00710-018-0604-9 | Journal (article/letter/editorial) | | Mineral inclusions in diamonds from Karowe Mine, Botswana: super-deep sources for super-sized diamonds...inclusions in diamonds from the Karowe Mine in north-east Botswana, along the western edge of the Zimbabwe...origin for the exceptionally large diamonds from this mine. Keywords Zimbabwe Craton . Orapa kimberlite cluster...carats Lesedi la Rona) at the Karowe mine in north-eastern Botswana raises the question: what controls...in a representative suite of diamonds from this mine. Based on recent conflicting views on the origin |  | | Journal (article/letter/editorial) | | 1972); half of the magnesium lattice diffusion in enstatite is ~180 kJ/mol (Schwandt et al., 1998). Therefore...Monastery, Kimberley, Jagersfontein, Orapa, and Letlhakane. Coarse-grained granular peridotites were selected...900–1150°C, 3.0–5.5 GPa (4) 93 Ma 270 µm 220 µm Letlhakane 950–1150°C, 4.0–5.5 GPa (5) 90 Ma 240 µm ...kimberlites of northern Lesotho and the Monastery mine, South Africa: Physics and Chemistry of the Earth...geochemistry of peridotite xenoliths from the Letlhakane kimberlites, Botswana: Contributions to Mineralogy and Petrology |  | | Journal (article/letter/editorial) | | Kimberley cluster of kimberlite pipes are located in central part of South Africa (Fig. 1), and that is one...end-members; Di (Diopside), Hd (Hedenbergite), En (Enstatite) and Fs (Ferrosilite). Two pyroxene solvus is...are found in metasomatised lherzolites from the Letlhakane kimberlite (Stiefenhofer et al., 1997). The studied...1973), Premier, Transvaal (Danchin, 1979), Letlhakane, Botswana (Stiefenhofer et al., 1997) and Jericho...including Lesotho (Boyd and Nixon, 1975), Letlhakane, Botswana (Stiefenhofer et al., 1997) and Jericho |  | | Journal (article/letter/editorial) | | mantle below Swaziland to that below southeastern Botswana, roughly following the surface outcrop pattern...Jagersfontein, Roberts Victor, Premier, Venetia, and Letlhakane do show some regional relationship to the seismic...(2003) 243–258 contain Cr-pyrope, diopside, enstatite, chromite, or olivine (Meyer and Boyd, 1972; Harris...seismic velocity (Table 1, Fig. 1). Jwaneng, Letlhakane, Orapa, and Premier diamonds were hosted in slower...eclogitic (Jagersfontein = JA, Jwaneng = JW, Letlhakane = LE, Orapa = O, Premier = P) and green squares |  | | Journal (article/letter/editorial) | | 200, Thaba Putsoa) Zimbabwe craton/Magondi Belt Letlhakane AK1, AK Proterozoic Namaqua – Natal terrane East...Lesotho province, (7) Premier cluster, (8) Orapa – Letlhakane cluster, (9) East Griqualand province, (10) Uintjiesberg...high-temperature xenoliths, that give rise to the central branch of the P –T array in Fig. 2a. The highest...BKN90 thermobarometer: (a) Kimberley, Finsch (west central Kaapvaal) (b) southern margin of Kaapvaal compared...Kimberley – Finsch array and the Frank Smith Mine, (c) Letlhakane (Zimbabwe Craton) compared with Kaapvaal |  | Aulbach, S., Jacob, D.E., Cartigny, P., Stern, R.A., Simonetti, S.S., Wörner, G., Viljoen, K.S. (2017) Eclogite xenoliths from Orapa: Ocean crust recycling, mantle metasomatism and carbon cycling at the western Zimbabwe craton margin. Geochimica et Cosmochimica Acta, 213. 574-592 doi:10.1016/j.gca.2017.06.038 | Journal (article/letter/editorial) | | the western margin of the Zimbabwe craton (central Botswana), were investigated in order to trace their...xenoliths, other 3 examples being Jwaneng (also in Botswana) as well as Premier, Roberts Victor and Kaalvallei...mantle geology The Orapa kimberlite cluster in central Botswana (Fig. 1) was emplaced into the Palaeoproterozoic...intruded some 20 km east of the Orapa mine, and the Letlhakane kimberlite, which was emplaced some 30...chemical composition of peridotite xenoliths from Letlhakane and on thermobarometry, which reveal that the |  | Xia, Jiuxing, Qin, Liping, Shen, Ji, Carlson, Richard W., Ionov, Dmitri A., Mock, Timothy D. (2017) Chromium isotope heterogeneity in the mantle. Earth and Planetary Science Letters, 464. 103-115 doi:10.1016/j.epsl.2017.01.045 | Journal (article/letter/editorial) | | spinel lherzolites and associated basalts from central Mongolia, spinel lherzolites and harzburgites from...(2011) found that carbonaceous, ordinary and enstatite chondrites have δ 53 Cr of −0.2h to ∼−0.4h, which...(2016) observed that carbonaceous, ordinary and enstatite chondrites have BSE-like stable Cr isotopic compositions...websterites. Mongolia: Mantle xenoliths from Tariat, central Mongolia, are well known for their high proportions...fresh facies of the Udachnaya-East kimberlite, central Siberia are wellknown for their large size, freshness |  | | Journal (article/letter/editorial) | | kimberlites (East Siberia, Northeastern Europe, India, Central Africa, North America, and Canada) and alkali basalts...Mongolia, southeastern China, southeastern Australia, Central Africa, South America, and the Solomon and Hawaiian...taking into account thermodynamic data for the enstatite –ferrosilite series in a quasichemical model for...India, and North America and alkali basalts in Central Africa, East Siberia, Mongolia, southeastern China...the Dharvar craton in India, the Wyoming, the Central Slave craton in North America and the Archaean |  | | Journal (article/letter/editorial) | | Jagersfontein, Roberts Victor, Premier, Venetia and Letlhakane show a regional relationship to the seismic velocity...predominately eclogitic (Jagersfontein=JA, Jwaneng=JW, Letlhakane=LE, Orapa=O, Premier =P) and green squares are...southern African diamonds. Kimberlite Jwaneng Letlhakane Orapa Premier Venetia De Beers Pool Finsch Roberts...cylinder of mantle centered around each diamond mine and extending from 150km to 225km depths. In the...1998) when they contain Cr-pyrope, diopside, enstatite, chromite, or olivine (Meyer and Boyd, 1972; Harris |  | Katayama, Ikuo, Michibayashi, Katsuyoshi, Terao, Ryuji, Ando, Jun-Ichi, Komiya, Tsuyoshi (2011) Water content of the mantle xenoliths from Kimberley and implications for explaining textural variations in cratonic roots. Geological Journal, 46 (2) 173-182 doi:10.1002/gj.1216 | Journal (article/letter/editorial) | | including Lesotho (Boyd and Nixon, 1975), Letlhakane in Botswana (Stiefenhofer et al., 1997) and Jericho...experiments demonstrate that water solubility in enstatite shows a systematic increase with increase in pressure...ppm wt H2O) is close to that of water-saturated enstatite at P ¼ 30 kbar. The analysed garnets are characterized...kimberlites of northern Lesotho and the Monastery mine, South Africa. Physics and Chemistry of Earth 9...fabrics of the Cima di Gagnone peridotite massif, Central Alps, Switzerland: evidence of deformation at low |  | | Journal (article/letter/editorial) | | based on two mantle xenoliths from the Letlhakane kimberlite, Botswana (van Achterbergh et al. 2001). Their...and JSL261 mantle xenoliths from the Letlhakane kimberlite (Botswana); bulk compositions calculated from...in the range 900–1100°C and Al2O3 isopleths of enstatite in the spinel field. Contrib Mineral Petrol 66:189–201...(1968) Travel times of P waves to 30 degrees in Central United States and upper mantle structure. Bull...system MgO–Al2O3–SiO2: solubility of Al2O3 in enstatite for spinel and garnet peridotite compositions |  | | Journal (article/letter/editorial) | | Jagersfontein, Roberts Victor, Premier, Venetia, and Letlhakane show a regional relationship to the seismic velocity...averaged. This cylinder is centered below each diamond mine and extends from 150 to 225 km depth. Seismic data...peridotitic when they contain Cr-pyrope, diopside, enstatite, chromite, or olivine (Meyer and Boyd, 1972; Gurney...southern African diamonds Kimberlite Jwaneng Letlhakane Orapa Premier Venetia De Beers Pool Finsch Roberts...eclogitic [Jagersfontein (JA), Jwaneng (JW), Letlhakane (LE), Orapa (O), Premier (P)] and green squares |  | | Journal (article/letter/editorial) | | crystals and intergrowths of the minerals olivine, enstatite, garnet, clinopyroxene, phlogopite, ilmenite and...Colossus 532 Venetia 519 River Ranch Orapa AK1 93 Letlhakane Jwaneng 240 Palmietfontein Premier 1202 Schuller...deeply weathered. The hypothesis of olivine and enstatite corrosion is supported by the general rarity of...these orangeites that contain garnet, but not enstatite or olivine megacrysts. Sample and data sources...precisely. Megacrysts in several orangeites from the central part of the Kaapvaal craton show a similar evolution |  | | Journal (article/letter/editorial) | | inclusion-bearing diamonds from the mines of South Africa and Botswana was begun by Gurney and Harris (multiple papers...diamonds is not known. In early work (1973–1985) run-of-mine diamonds in the sieve class −6 + 5 (1.83 mm aperture...+ 5 sieve class) in run-of-mine productions from South Africa and Botswana are listed in Table 1 and range...comparison of two studies (1975 and 1985) for the Finsch Mine shows a sevenfold increase in the abundance of inclusionbearing...inclusion-bearing diamonds in mines from South Africa and Botswana Diamonds examined South Africa DeBeers, 1980 Bultfontein |  | | Journal (article/letter/editorial) | | evaluation geophysics was first used successfully in Botswana (de Wit 2018): the contrasting petrophysical INTRODUCTION...user D ecember 2019 Kimberlite geology is the central thread running through diamond exploration, and...For example, the Cretaceous Orapa kimberlite in Botswana was discovered by recognizing a significant post–Orapa...variable diamond content e.g., the Orapa field (Botswana) (Preston et al. 2012). In summary, the xenocryst...Catocoa Koala North Cullinan (Premier) Wesselton Letlhakane Victor Liqhobong Zarnitsa Damtshaa US Karowe |  | Howell, D., Stachel, T., Stern, R.A., Pearson, D.G., Nestola, F., Hardman, M.F., Harris, J.W., Jaques, A.L., Shirey, S.B., Cartigny, P., Smit, K.V., Aulbach, S., Brenker, F.E., Jacob, D.E., Thomassot, E., Walter, M.J., Navon, O. (2020) Deep carbon through time: Earth’s diamond record and its implications for carbon cycling and fluid speciation in the mantle. Geochimica et Cosmochimica Acta, 275. 99-122 doi:10.1016/j.gca.2020.02.011 | Journal (article/letter/editorial) | | 1990), so carbon isotope data for diamonds from this mine of known paragenesis (e.g. Appleyard et al., 2004;...Attawapiskat (Ontario) kimberlites of the eastern and central Superior Craton, respectively, show a temporal...carbon and strontium isotope analyses of Orapa and Letlhakane diamonds. Although Timmerman et al. (2017) discerned...subdivision with age. In fact, Orapa, and nearby Letlhakane, (Timmerman et al., 2017) are the only deposits...variability in the mantle below the Orapa kimberlite, Botswana, Africa. Geochimica et Cosmochimica Acta, 57(12) |  | | Journal (article/letter/editorial) | | Methodological tests on the Orapa kimberlite, Botswana D. Phillips a,⁎, J.W. Harris b a b School of...diamonds from the ∼ 93 Ma Orapa kimberlite in Botswana. Low temperature steps and crushing experiments...eclogitic clinopyroxene inclusions from Premier mine diamonds, which yielded ages of 1198± 28 Ma (Phillips...inclusion-bearing diamonds from the Orapa kimberlite, Botswana. Specific aims of the study are as follows: i)...largest diamond mines, is located in north-eastern Botswana, some 240 km west of Francistown (Fig. 1). The |  | | Journal (article/letter/editorial) | | Africa) and Botswana pipe clusters - A.E. Moore AMPAL Pty) Ltd., Box (n’) Gaborone botswana. C’) Present...Exploration (Pty) Ltd., Private Bag 00351, Gaborone, Botswana. e-mail: nlock@info.bw ABSTRACT Megacrysts (clinopyroxene...of pipes in Botswana. Two of these pipes - both from the Orapa field in central Botswana - are economic...the KN-70 kimberlite, Kokong cluster, western Botswana. Note that ilmenites in other kimberlites from...available by Falconbridge Explorations Botswana Ltd.) Ihnenites from Botswana kimberlites Ilmenite data for seven |  | van Acken, D., Luguet, A., Pearson, D.G., Nowell, G.M., Fonseca, R.O.C., Nagel, T.J., Schulz, T. (2017) Mesoarchean melting and Neoarchean to Paleoproterozoic metasomatism during the formation of the cratonic mantle keel beneath West Greenland. Geochimica et Cosmochimica Acta, 203. 37-53 doi:10.1016/j.gca.2017.01.006 | Journal (article/letter/editorial) | | peridotite suites, e.g., xenoliths from the Letlhakane kimberlites, Botswana (Stiefenhofer et al., 338 1997;...BMS in fertile xenoliths from the 412 Massif Central by Alard et al. (2011), and attributed to reaction...mantle Re-Os isotopes beneath the French Massif Central. Geochimica et Cosmochimica Acta 74, 293 - 320...Calibration and testing of a Cr-in-Cpx barometer and an enstatite-in-Cpx thermometer. Contrib. Mineral. Petrol....geochemistry of peridotite xenoliths from the Letlhakane kimberlites, Boswana. Contrib. Mineral. Petrol |  | | Journal (article/letter/editorial) | | been reported in garnet peridotite xenolith from Botswana (van Achterbergh et * Present address: Laboratory...subduction-related Taupo Volcanic Zone of the central North Island, and the intraplate Northland and...Garnet peridotite Yakutia 11 Garnet peridotite Botswana 12 Spinel peridotite Canary Islands 13 WFQ019...mantle xenoliths from Yakutia (Sobolev et al.1997), Botswana (van Achterbergh et al. 2001) and Canary Islands...Secondary orthopyroxene replacing olivine is enstatite, and contains remarkably low Al2O3 (0.18–0.57 |  | Kostrovitsky, S.I., Yakovlev, D.A., Soltys, A., Ivanov, A.S., Matsyuk, S.S., Robles-Cruz, S.E. (2020) A genetic relationship between magnesian ilmenite and kimberlites of the Yakutian diamond fields. Ore Geology Reviews, 120. 103419 doi:10.1016/j.oregeorev.2020.103419 | Journal (article/letter/editorial) | | Electron microprobe analyses were carried out in the Central Analytical Laboratory of the Botuobia Exploration...Premier (South Africa – Danchin, 1979), Letlhakane (Botswana – Stiefenhofer et al., 1997), and Jericho...kimberlites of Northern Lesotho and the Monastery Mine, South Africa. In: Physics and Chemistry of the...mineral chemistry of a kimberlite from the Premier Mine: Implications for the evolution of kimberlitic magmas...Lesotho. Orange Free State (South Africa) and Botswana pipe clusters. S. Afr. J. of Geol. 104, 23–38 |
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