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nyerereite

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Journal Article
Published: 01 October 2009
Mineralogical Magazine (2009) 73 (5): 797-816.
...F. Kaminsky; R. Wirth; S. Matsyuk; A. Schreiber; R. Thomas Abstract Nyerereite and nahcolite have been identified as micro- and nano-inclusions in diamond from the Juina area, Brazil. Alongside them are Sr- and Ba-bearing calcite minerals from the periclase-wüstite series, wollastonite II (high...
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Journal Article
Published: 01 August 2008
The Canadian Mineralogist (2008) 46 (4): 843-860.
.... The carbonatite samples contain two mineral assemblages: the first consists of relict primary magmatic minerals: nyerereite, fluorite, apatite-(CaF), barite, magnetite and khanneshite. The second consist of low-temperature subsolidus minerals: pirssonite, calcite, shortite, nahcolite, trona, thermonatrite...
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Journal Article
Published: 01 August 2008
The Canadian Mineralogist (2008) 46 (4): 1079-1095.
... in the groundmass of the host kimberlite. Rasvumite occurs in chloride–“nyerereite” and carbonate clasts, where it forms prismatic crystals (up to 5 mm) or is associated with djerfisherite in a rim around pyrrhotite. Djerfisherite is the omnipresent sulfide in all types of chloride-containing clasts, in which...
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Journal Article
Published: 01 February 2006
Mineralogical Magazine (2006) 70 (1): 103-114.
...R. H. Mitchell Abstract Natrocarbonatite lavas erupted from hornitos T37B and T49B at Oldoinyo Lengai (Tanzania) during 23–30 July, 2000 are unusual in containing sylvite and fluorite microcrysts together with fluorite-nyerereite intergrowths. The latter are relatively coarse grained and exhibit...
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Journal Article
Published: 01 May 1984
Journal of the Geological Society (1984) 141 (3): 580.
... calcite pseudomorphs as secondary after nyerereite, in the knowledge that lath-shaped primary nyerereite occurs in the 1960 natrocarbonatite lava from the carbonatite volcano of Oldoinyo Lengai in N Tanzania. Dr Le Bas emphasized that very similar pseudomorphs can be obtained after melilite, and also...
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BSE images of groundmass <b>nyerereite</b> and barian <b>nyerereite</b> in lava (T37B). N...
Published: 01 February 2006
F ig . 4. BSE images of groundmass nyerereite and barian nyerereite in lava (T37B). Note that the barian nyerereite forms epitaxial mantles on the nyerereite laths. x = khannesite/burbankite; g = groundmass gregoryite-like mineral; n = nyerereite; b = barian nyerereite. Fluorite (mid-grey
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Compositions of <b>nyerereite</b>, barian <b>nyerereite</b> and gregoryite plotted in the...
Published: 01 February 2006
F ig . 5. Compositions of nyerereite, barian nyerereite and gregoryite plotted in the system Na 2 CO 3 -K 2 CO 3 -CaCO 3 (mol.%). Note that compositions of barian nyerereite are not ternary and are plotted only for comparison with those of groundmass nyerereite. G = gregoryite; NY = nyerereite
Journal Article
Published: 01 August 2008
The Canadian Mineralogist (2008) 46 (4): 971-980.
... temperatures are on the order of 825°C, with a depression on the liquidus to 750°C at about 23 wt.% halide corresponding to a piercing point. Liquids that are poor in halides relative to the composition of the piercing point have a nyerereite-like (Na,Ca,K) carbonate as the primary liquidus phase; it coexists...
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Journal Article
Published: 01 February 2002
The Canadian Mineralogist (2002) 40 (1): 103-120.
...), calcio-ancylite-(Ce), and minor burbankite, khanneshite, nyerereite, shortite, bradleyite, strontianite, britholite-(Ce) and barite. Three mineral parageneses differing in the mode of occurrence of calcite are distinguished: (1) calcite – magnesiohastingsite – diopside rock, (2) segregations...
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Journal Article
Published: 01 April 1990
Journal of the Geological Society (1990) 147 (2): 213-216.
...B. T. NGWENYA; D. K. BAILEY Abstract Fine grained carbonatite in the Kaluwe complex has been inferred, on textural grounds, to be calcified natrocarbonatite. Electron microprobe analysis, however, shows that the brown laths thought to be pseudo-nyerereite are dolomitic, with Sr values much higher...
Journal Article
Published: 01 April 2013
Mineralogical Magazine (2013) 77 (3): 213-226.
...A. N. Zaitsev; T. Wenzel; T. Vennemann; G. Markl Abstract The Tinderet volcano (19.9 to 5.5 Ma), located within the Kavirondo rift in Kenya, contains blocks of carbonatite lavas with calcite, minor apatite, fluorite, spinel-group minerals, accessory perovskite and ‘plumbopyrochlore’; nyerereite...
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Journal Article
Published: 01 June 1997
Mineralogical Magazine (1997) 61 (3): 351-355.
... sought to discredit the magmatic origin of this sovite specimen by arguing that it was derived from natrocarbonatite lava through extreme alteration (calcitization) in which process the original nyerereite was replaced by calcite in near-perfect pseudomorphs. We suggest that the arguments advanced...
Journal Article
Journal: Geology
Published: 01 October 1983
Geology (1983) 11 (10): 599-602.
... of premodern natrocarbonatite volcanism. The principal carbonate mineral was nyerereite, which is the dominant mineral in modern natrocarbonatite lava flows of the adjacent volcano Oldoinyo Lengai. The nyerereite of Kerimasi was leached of its alkalis by meteoric water and is now represented by calcite...
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HAADF image of a large single crystal of <b>nyerereite</b> intergrown with a lath-...
Published: 01 October 2009
F ig . 3. HAADF image of a large single crystal of nyerereite intergrown with a lath-shaped olivine (Ol), several zoned spinel grains (Sp), apatite and phlogopite. Foil #1659.
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EDX spectrum indicating the chemical composition of the <b>nyerereite</b> crystal ...
Published: 01 October 2009
F ig . 4. EDX spectrum indicating the chemical composition of the nyerereite crystal from inclusion in foil #1659, displayed in Fig. 3 .
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Na-Ca-K composition diagram for <b>nyerereite</b> from different localities. Data ...
Published: 01 October 2009
F ig . 5. Na-Ca-K composition diagram for nyerereite from different localities. Data on nyerereite from natrocarbonatites after Gittins and McKie ( 1980 ), Peterson ( 1990 ), Zaitsev and Chakhmouradian ( 2002 ), Mitchell ( 2006 ), Zaitsev et al . ( 2008 a , b ). Data on nyerereite from
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Primary liquidus <b>nyerereite</b>-like Na-Ca-K carbonate (Nyr) set in a single-ph...
Published: 01 August 2008
F ig . 6. Primary liquidus nyerereite-like Na-Ca-K carbonate (Nyr) set in a single-phase halide-rich groundmass (Na,K) Cl. Nyr + 20 wt.% (KCl + NaCl) at 650°C. Back-scattered electron image.
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Primary liquidus <b>nyerereite</b>-like Na–Ca–K carbonate (dark grey) set in a two...
Published: 01 August 2008
F ig . 9. Primary liquidus nyerereite-like Na–Ca–K carbonate (dark grey) set in a two-phase halide-rich groundmass. Note that both KCl and NaCl have undergone exsolution Bulk composition Nyr + 80 wt.% (KCl + NaCl) at 500°C. Back-scattered electron image.
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Primary liquidus <b>nyerereite</b>-like Na–Ca–K carbonate (nyr) set in quenched im...
Published: 01 August 2008
F ig . 10. Primary liquidus nyerereite-like Na–Ca–K carbonate (nyr) set in quenched immiscible halide liquids. Nyr + 50 wt.% (KCl + NaCl) at 600°C. Back-scattered electron image.
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REPRESENTATIVE COMPOSITIONS OF <b>NYEREREITE</b>
Published: 01 August 2008
TABLE 2. REPRESENTATIVE COMPOSITIONS OF NYEREREITE