 | | Report (issue) | | high quality pink diamonds for which the Williamson mine is known and sold for US$15 million in FY 2016 ...Optimise recoveries Improving operating margins at each mine Drive efficiencies Maintaining a culture of effective...Petra Diamonds is a leading independent diamond mining group and a growing supplier of rough diamonds...Finsch 34 Cullinan 37 Koffiefontein 38 Combined Kimberley Operations 40 Williamson 41 Exploration 42 Risks...production by value decreased 4.1% to US$13.9 billion (Kimberley Process Statistics). 312.2 Petra Diamonds Dominion |  | | Journal (article/letter/editorial) | | Kimberlite-hosted diamond deposits of southern Africa: A review Matthew Field a,⁎, Johann Stiefenhofer...Southdale, 2135, South Africa c De Beers Group Services, PO Box 47, Kimberley, South Africa d De Beers Canada...deposits in central South Africa in the mid nineteenth century, it was at Kimberley where the volcanic...industrial development of southern Africa. Following the discoveries at Kimberley, even more valuable deposits...deposits were discovered in South Africa and Botswana in particular, but also in Lesotho, Swaziland and Zimbabwe |  | | Journal (article/letter/editorial) | | 3b7S02.W;O Ultramafic nodules from the Kimberley pipes, South Africa F. R. BOYD Geophysical Laboratory, Carnegie...from the Kimberley pipes differ from suites collected in a number of other areas in southern Africa in two...low-temperature (< 1100°C) peridotites from the Kimberley pipes have textures ranging from coarse to fluidal...mosaic-porphyroclastic. In most nodule suites from southern Africa and elsewhere in the world, these low-temperature...Petrographic and electron microprobe study of the Kimberley peridotites shows that they are depleted in basaltic |  | | Book (volume) | | rise and development of the diamond mines of South Africa, from an historical, economic and technical...days on the diamond fields when the mines in the Kimberley and Jagersfontein areas were the only diamond...information of a mining nature, which included, besides the data on under ground and surface mining operations...crystals with the object, if possible, of deter mining the conditions under which the diamond crystal...collect during my many visits to all parts of South Africa where kimberlite deposits occurred and the filing |  | | Journal (article/letter/editorial) | | something about the geology, cultural contexts and mining histories of the localities represented. The crystal...collection, a brief historical overview of diamond mining and a summary of the exotic geological “story”...dynasty (320–298 B.C.) who regulated an active local diamond trade (Maillard, 1980). Legends associated... Figure 4. A diamond crystal in “blue ground” from South Africa, probably from the collection of Gardner and...account of about 120 B.C. speaks tantalizingly of underground diamond mines with deep galleries (Maillard, |  | | Journal (article/letter/editorial) | | magma evolution of the De Beers dyke (Kimberley, South Africa) Ashton Soltys 1 & Andrea Giuliani 1,2...intrusion bordering the De Beers pipe (Kimberley, South Africa). Petrographic features and mineral compositions...metasomatism in the mantle (i.e., high Cr-Ti phlogopite); (2) entrainment of wall-rock material during...monticellite, calcite micro-phenocrysts, kinoshitalite-phlogopite, barite, and baddeleyite) and the mesostasis...compositions of antecrysts (i.e., high Cr-Ti phlogopite) and magmatic phases (e.g., olivine rims, magnesian |  | | Book | | Phase 5. Sample Treatment D) World Production E) South African Diamond Occurrences 1. Large Kimberlite...Finsch 1.4 Kimberley 1.5 Koffiefontein 2. Smaller mineralised kimberlites in South Africa 2.1 The Oaks... their relative production contributions in South Africa were, primary (kimberlite) 8.63 million carats...suggest approximately 40% for the Kimberley mines and 55% for Premier mine. The proportion of gems in the...deposits is over 98%. The MIBA mine in the Congo and the Argyle mine in Australia have an average gem |  | | Book | | not attempted to describe diamond prospecting and mining and, although I have attempted to give some of...with whose research groups at the universities of Cape Town and Chicago I have had long and fruitful collaboration...collaboration. Much of my fieldwork in southern Africa has been carried out with the cooperation and assistance...7.3 2.8 2.9 Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . West Africa . . . . . . .... . . . . Central Africa. . . . . . . . . . . . . . . . . . . . . . . East Africa. . . . . . . . . . |  | Giuliani, Andrea, Soltys, Ashton, Phillips, David, Kamenetsky, Vadim S., Maas, Roland, Goemann, Karsten, Woodhead, Jon D., Drysdale, Russell N., Griffin, William L. (2017) The final stages of kimberlite petrogenesis: Petrography, mineral chemistry, melt inclusions and Sr-C-O isotope geochemistry of the Bultfontein kimberlite (Kimberley, South Africa) Chemical Geology, 455. 342-356 doi:10.1016/j.chemgeo.2016.10.011 | Journal (article/letter/editorial) | | isotope geochemistry of the Bultfontein kimberlite (Kimberley, South Africa) Andrea Giuliani, Ashton Soltys...isotope geochemistry of the Bultfontein kimberlite (Kimberley, South Africa), Chemical Geology (2016),...geochemistry of the SC RI PT Bultfontein kimberlite (Kimberley, South Africa) Andrea Giuliani1,2,3*, Ashton...hypabyssal sample (BK) from the Bultfontein kimberlite (Kimberley, South MA Africa). Sample BK consists of...(micro-) ED phenocrysts of olivine and lesser phlogopite, smaller grains of apatite, serpentinised monticellite |  | | Journal (article/letter/editorial) | | from 16 intrusions in Lesotho, the Republic of South Africa, and Tanzania have been investigated. The following...some cases, zircon contents of about 25 g/t (Bultfontein, cf. HOLMLS 1936; Rietfontein, A. G. BLOOMER...material studied (especially the zircons from the Kimberley mines) was subangular in shape, with one or a...predominate. Zircons from the Kimberley group of intrusions (i.e., Kimberley, Dutoitspan, De Beers, Wesselton...Wesselton and Bultfontein mines) and Nzega (Tanzania) are greyish, which might be attributed to their high |  | | Journal (article/letter/editorial) | | Constraints on kimberlite ascent mechanisms revealed by phlogopite compositions in kimberlites and mantle xenoliths...Keywords: Kimberlite Phlogopite Zoning Magma ascent Mantle xenoliths Kimberley a b s t r a c t Kimberlite...of kimberlite melts remain poorly constrained. Phlogopite is one of the few minerals that preserves a history...compositional data for phlogopite from the Bultfontein kimberlite (Kimberley, South Africa; i.e. the kimberlite...type-locality) and from entrained mantle xenoliths. Phlogopite macrocrysts (~ N 0.3–0.5 mm) and microcrysts |  | | Journal (article/letter/editorial) | | Æ A.P. Le Roex Trace element geochemistry of phlogopite-rich mafic mantle xenoliths: their classification...classification and their relationship to phlogopite-bearing peridotites and kimberlites revisited Received: 9...magmas from the Kimberley area of South Africa have sampled two main types of phlogopite-rich mafic xenoliths...characterised by the mineral association mica (phlogopite)–amphibole (K-richterite)–rutile–ilmenite–clinopyroxene...characterised by the mineral association mica (phlogopite)–ilmenite– clinopyroxene–minor rutile. The two |  | | Report (issue) | | SURVEY OF SOUTH AFRICA COUNCIL FOR GEOSCIENCE GEOLOGICAL SURVEY OF SOUTH AFRICA MINERALOGY OF SOUTH AFRICA:... COUNCIL FOR GEOSCIENCE GEOLOGICAL SURVEY OF SOUTH AFRICA Scientific Editor R.D. Dixon Linguistic and...Council for Geoscience (Geological Survey of South Africa), 280 Pretoria Street, Silverton, Pretoria or........................... 69 5.1 Overview of South African Occurrences ..............................LAYEREDSUITE,BUSHVELDCOMPLEX.... 111 MINERALOGY OF SOUTH AFRICA: TYPE-MINERAL SPECIES AND TYPE-MINERAL NAMES |  | | Journal (article/letter/editorial) | | of Geochemistry, University of Cape Town, Rondebosch 7700 (South Africa) Received February 20, 1985; revised...mantle beneath the northern Lesotho margin of the Archaean craton in southern Africa are inferred to have...garnet lherzolite xenoliths from beneath the Kimberley area in the craton interior display internal isotopic...similar Cretaceous age, Bultfontein (Kimberley district) and Thaba Putsoa (northern Lesotho), was undertaken...orthopyroxene compositions indicate haba Putsoa Bultfontein (Kimberley cluster) 0 i . . . . 500 i km Fig |  | | Journal (article/letter/editorial) | | Department of Geochemistry University of Cape Town, Republic of South Africa arro R. V. DnNcurrq2 Anglo-American...ResearchLaboratory Crown Mines, Johannesburg, Republic of South Africa Abstract Two new opaquemineralsare describedfrom...Presentaddress: Stockdale Prospectint-Ltd., 60 Wiison Street, South yarra, Victoria 3141,Australia. 0003-004x/83/0505-M94$02...Associatedcharacteristic minerals are K-richterite, phlogopite, Nb-Cr-rutile and Nb-CrMg-ilmenite,togetherwith...from the De Beers kimberlite in the Republic of South Africa (RSA) and the mineral has since been recognized |  | | Journal (article/letter/editorial) | | SPINEL MACROCRYSTS FROM KIMBERLITES IN SOUTHERN AFRICA DANIEL J. SCHULZE§ Department of Geology, University...single-crystal macrocrysts in kimberlites from southern Africa (approximately 1500 grains from 20 kimberlites...from a variety of mantle xenoliths from southern Africa and North America (approximately 150 xenoliths)...partitioned into a different phase, such as metasomatic phlogopite. Such Cr-rich macrocrysts are more common in...Unusually Fe- and Ni-rich macrocrysts unique to the Lace mine are from Fe-rich orthopyroxene-bearing peridotites |  | | Report (chapter) | | of closely-related of the following minerals: phlogopite, carbonrock types rather than a single tightly-defined...having a highly micaceous matrix, and the vine, phlogopite, picroilmenite, chromian spiso-called 'basaltic'...relative to the other major difference in the phlogopite content of the macrocysts, all of which are not...minerals are commonly altered 1 In the case of S Africa, the micaceous by deuteric processes, mainly serpentinisation...by other high-K minor intrusives, as at the Helam Mine in the Swartruggens area of the western Transvaal |  | | Journal (article/letter/editorial) | | of some peridotites from the Kaapvaal craton (South Africa) Received: 27 October 2005 / Accepted: 15 January...precipitation of Fe–Cu-rich immiscible sulphide melts in phlogopite-(ilmenite–rutile) peridotites and (2) sulphidation...sulphidation reactions from an H2Srich fluid phase in phlogopite-K richterite peridotites. Introduction Cu–Fe–Ni...in peridotite xenoliths from Kaapvaal craton (South Africa) provided compelling evidence for the occurrence...high-grade Archean Terranes: the Western Terrane, the South-Eastern Terrane, the Central Terrane and the Pietermaritz |  | | Journal (article/letter/editorial) | | lherzolites resemble the less deformed varieties in the Kimberley pipes both in texture and in mineral chemistry...in other pipes in southern Africa in that none contain coarse phlogopite. Application of a number of...those for megacrysts from northern Lesotho and the Monastery Mine, South Africa. Both the diopside solvus...Laboratories, Crown Mines, Transvaal, Republic of South Africa 528 Lherzolites, eclogites, & megacrysts...intensively studied nodule suites from Lesotho and South Africa. It is unlikely that additional sam ples from |  | Hopp, Jens, Trieloff, M., Brey, G.P., Woodland, A.B., Simon, N.S.C., Wijbrans, J.R., Siebel, W., Reitter, E. (2008) 40Ar/39Ar-ages of phlogopite in mantle xenoliths from South African kimberlites: Evidence for metasomatic mantle impregnation during the Kibaran orogenic cycle. Lithos, 106 (3) 351-364 doi:10.1016/j.lithos.2008.09.001 | Journal (article/letter/editorial) | | t h o s 40 Ar/39Ar-ages of phlogopite in mantle xenoliths from South African kimberlites: Evidence...lithosphere Ar–Ar dating Metasomatism Southern Africa a b s t r a c t We applied the 40Ar/39Ar dating...(dominantly garnet bearing) from the mines of Bultfontein (South Africa), Letseng-laTerae and Liqhobong (Lesotho)...meaningful and assigned to metasomatism of the local cratonic mantle during the advent of Kibaran orogenesis...consequences of our findings are: (i) The argon system of phlogopite can remain closed for long time scales, even |  | | Report (chapter) | | mantle events and diatreme ascent rates in southern Africa and Malaita, Solomon Islands JO-ANNE WARTHO* &...mantle. With the realization that some Ar/Ar phlogopite grain core ages may be indicative of geological...xenoliths and megacrysts from Kimberley, Monastery and Letseng in southern Africa, and Malaita, in the Solomon...Solomon Islands, to test whether other mantle phlogopite cores may yield meaningful ages. Modelling of Ar...Ar diffusive loss profiles from phlogopite grain boundaries to cores provides information on both the |  | | Journal (article/letter/editorial) | | case study of the archetypal Bultfontein kimberlite (Kimberley, South Africa) Ashton Soltys, Andrea Giuliani...case study of the archetypal Bultfontein kimberlite (Kimberley, South Africa). The address for the corresponding...case study of the archetypal Bultfontein kimberlite (Kimberley, South Africa) a SC RI PT Ashton Soltysa*...kimberlite (sample BK-1) from the MA Bultfontein mine (Kimberley, South Africa). The accuracy of this whole-rock...evolution. The primitive melt parental to the Bultfontein kimberlite is estimated to contain 17.4- AC |  | | Journal (article/letter/editorial) | | lamproite Frances G. Waters Department of Geochemistry, University of Cape Town, Rondebosch, Cape 7700,... South Africa Abstract. Chemical, mineralogical and isotopic studies have been made on nodules of the...presence of additional water), were predominantly phlogopite and diopside (4- K-richterite, + ilmenite, +...thought to be either partial melts of metasomatised phlogopite peridotite, or small volume asthenospheric melts...ascent. Introduction A distinctive group of phlogopite-dominated xenoliths found in southern African |  | | Journal (article/letter/editorial) | | in polymict xenoliths from the Bultfontein kimberlites, South Africa: implication for low bulk-rock oxygen...Polymict mantle xenoliths from the Bultfontein kimberlites, South Africa, contain abundant ilmenites (30%...of Geochemistry, University of Cape Town, Rondebosch 7700, South Africa Editorial responsibility: T.L...homogeneous high-Ti silicate melt. Keywords South Africa á Polymict xenolith á Oxide mineral á Ilmenite...(GP), garnet phlogopite peridotites (GPP), phlogopite peridotites (PP), and phlogopite K-richterite peridotites |  | Bell, D. R., Grégoire, M., Grove, T. L., Chatterjee, N., Carlson, R. W., Buseck, P. R. (2005) Silica and volatile-element metasomatism of Archean mantle: a xenolith-scale example from the Kaapvaal Craton. Contributions to Mineralogy and Petrology, 150 (3) 251-267 doi:10.1007/s00410-005-0673-8 | Journal (article/letter/editorial) | | garnet harzburgite mantle xenolith from Kimberley, South Africa, suggests metasomatism of a severely melt-depleted...orthopyroxene, forming additional garnet and introducing phlogopite, and small quantities of sulfide and probable...reaction with peridotitic mantle. Garnet and phlogopite trace element compositions indicate a fluid rich...Ga subduction and continental collision in the Kimberley region. The veined sample reflects the silicic...of a spectrum of compositions generated in the Kimberley mantle lithosphere by the metasomatizing effects |
|
