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Jagersfontein

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Journal Article

Majorite-indicative ultradeep (>300 km) xenoliths with spinel associations from the Jagersfontein kimberlite, South Africa. Available to Purchase

S.E. Haggerty
Published: 01 March 2017
South African Journal of Geology (2017) 120 (1): 1–20.
DOI: https://doi.org/10.25131/gssajg.120.1.1
...S.E. Haggerty Abstract Our earlier studies continued in a diligent search for rare ultradeep xenoliths in the kimberlite diatreme at Jagersfontein. The search has met with moderate success insofar as 20 majorite-bearing (decomposed to * gt + lamellar px) xenoliths are identified. Discrete gts (1...
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View PDF for article title, Majorite-indicative ultradeep (&amp;gt;300 km) xenoliths with spinel associations from the <span class="search-highlight">Jagersfontein</span> kimberlite, South Africa.
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Journal Article

Alkremite, garnetite and eclogite xenoliths from Bellsbank and Jagersfontein, South Africa Available to Purchase

Richard A. Exley, Joseph V. Smith, J. Barry Dawson
Published: 01 June 1983
American Mineralogist (1983) 68 (5-6): 512–516.
...Richard A. Exley; Joseph V. Smith; J. Barry Dawson Abstract Alkremites (gamet-spinel-corundum), garnetites, and eclogites (garnet-clinopyroxene) from Bellsbank and Jagersfontein kimberlites show textural and mineralogical evidence of crystal fractionation from evolving aluminous magma: e.g ., Ca...
View PDF for article title, Alkremite, garnetite and eclogite xenoliths from Bellsbank and <span class="search-highlight">Jagersfontein</span>, South Africa
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Jagersfontein isochron obtained from sulfides with visible cracks to the surface of the diamond. Six inclusions yield an imprecise date of 252 ± 42 Ma (Sonja Aulbach, unpublished data), which is younger than other diamond ages determined for Jagersfontein and significantly older than kimberlite eruption (86 Ma; Smith 1983). See text for further details.

Jagersfontein isochron obtained from sulfides with visible cracks to the su... Open Access

Published: 01 July 2022
Figure 13. Jagersfontein isochron obtained from sulfides with visible cracks to the surface of the diamond. Six inclusions yield an imprecise date of 252 ± 42 Ma (Sonja Aulbach, unpublished data), which is younger than other diamond ages determined for Jagersfontein and significantly older than
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P-T conditions for crystallization of the Monastery (Mon) and Jagersfontein (Jag) megacryst suites, adapted from Gurney et al., 1979. The kimberlite solidus is from Eggler and Wendlandt (1979). The dashed line marked CCO shows the approximate temperature at which the Wüstite-magnetite buffer crosses below the CCO buffer, permitting a stable carbon phase (graphite or diamond). Down-pointing arrows: “Mon” denotes the temperature range of megacryst crystallization at Monastery at 45 kb, with temperature intervals for crystallization of different phases shown to the left. “Jag” shows the temperature crystallization range for the Jagersfontein megacryst suite at 51 kb (from Hops et al., 1992).

P-T conditions for crystallization of the Monastery (Mon) and Jagersfontein... Available to Purchase

Published: 01 December 2014
Figure 7 P-T conditions for crystallization of the Monastery (Mon) and Jagersfontein (Jag) megacryst suites, adapted from Gurney et al., 1979 . The kimberlite solidus is from Eggler and Wendlandt (1979) . The dashed line marked CCO shows the approximate temperature at which the Wüstite
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SEM images and equivalent diagrams of two Jagersfontein grt + cpx + spl symplectites in garnet harzburgites. Dotted region = garnet, Dashed region = cpx + spl. The images show garnet replacing cpx + spl. (a) A garnet and garnet + spinel corona surrounds a core of cpx + spl. (b) A garnet containing a large included domain of symplectite cpx + spl, and several smaller cpx + spl domains. The garnet also contains several isolated spinel inclusions.

SEM images and equivalent diagrams of two Jagersfontein grt + cpx + spl sym... Available to Purchase

Published: 01 April 2008
F igure 6. SEM images and equivalent diagrams of two Jagersfontein grt + cpx + spl symplectites in garnet harzburgites. Dotted region = garnet, Dashed region = cpx + spl. The images show garnet replacing cpx + spl. ( a ) A garnet and garnet + spinel corona surrounds a core of cpx + spl. ( b
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TABLE 1. COMPOSITION OF MAJORITIC GARNET INCLUSIONS FROM JAGERSFONTEIN AS W... Available to Purchase

Published: 01 July 2005
TABLE 1. COMPOSITION OF MAJORITIC GARNET INCLUSIONS FROM JAGERSFONTEIN AS WELL AS CARBON ISOTOPIC COMPOSITION AND CRYSTAL SHAPE OF THE HOST DIAMONDS
Journal Article

Subducting oceanic crust: The source of deep diamonds Available to Purchase

Ralf Tappert, Thomas Stachel, Jeff W. Harris, Karlis Muehlenbachs, Thomas Ludwig, Gerhard P. Brey
Journal: Geology
Published: 01 July 2005
Geology (2005) 33 (7): 565–568.
DOI: https://doi.org/10.1130/G21637.1
...TABLE 1. COMPOSITION OF MAJORITIC GARNET INCLUSIONS FROM JAGERSFONTEIN AS WELL AS CARBON ISOTOPIC COMPOSITION AND CRYSTAL SHAPE OF THE HOST DIAMONDS ...
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Journal Article

Silicate-bearing rutile-dominated nodules from South African kimberlites; metasomatized cumulates Available to Purchase

Daniel J. Schulze
Published: 01 February 1990
American Mineralogist (1990) 75 (1-2): 97–104.
...Daniel J. Schulze Abstract Rutile-dominated nodules from the Kampfersdam and Jagersfontein kimberlite pipes in South Africa contain euhedral olivines and spinels, graphic intergrowths of olivine and rutile, and massive rutile. In a similar nodule from the Pulsator dump in Kimberley, rutile...
View PDF for article title, Silicate-bearing rutile-dominated nodules from South African kimberlites; metasomatized cumulates
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Chondrite-normalized compositions of REE in majorites showing the wide spread of compositions from São Luiz, Jagersfontein and Monastery; and the lesser spread from Kankan. Only the overall range of compositions is given for São Luiz, Monastery and Kankan (which overlaps little with São Luiz). For Jagersfontein, individual sample compositions are also shown by the linked blue-grey dots. The average composition of N-MORB is shown for comparison. Based primarily on data from: Moore et al. (1991), Harte (1992), Stachel et al. (2000a) and Tappert et al. (2005a); and adapted from Tappert et al. (2005a).

Chondrite-normalized compositions of REE in majorites showing the wide spre... Available to Purchase

Published: 01 April 2010
F ig . 5. Chondrite-normalized compositions of REE in majorites showing the wide spread of compositions from São Luiz, Jagersfontein and Monastery; and the lesser spread from Kankan. Only the overall range of compositions is given for São Luiz, Monastery and Kankan (which overlaps little
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Figure 3. A: Carbon isotope composition (δ13C) of eclogitic diamonds with majoritic garnet inclusions from Jagersfontein kimberlite. Black—this study; gray—previous results (Deines et al., 1991). Distribution of δ13C results of diamonds with majoritic garnet inclusions from São Luiz, Brazil (Wilding, 1990; Hutchison et al., 1999; Kaminsky et al., 2001), and Kankan, Guinea (Stachel et al., 2002), are shown for comparison. B: Carbon isotope composition of eclogitic diamonds from Jagersfontein that formed in lithosphere. C: Isotopic ranges of carbon within various sedimentary source rocks (Schidlowski et al., 1983). PDB—Peedee belemnite.

Figure 3. A: Carbon isotope composition (δ 13 C) of eclogitic diamonds with... Available to Purchase

Published: 01 July 2005
Figure 3. A: Carbon isotope composition (δ 13 C) of eclogitic diamonds with majoritic garnet inclusions from Jagersfontein kimberlite. Black—this study; gray—previous results ( Deines et al., 1991 ). Distribution of δ 13 C results of diamonds with majoritic garnet inclusions from São Luiz, Brazil
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Figure 2. Chondrite-normalized rare earth element composition of majoritic garnet inclusions in Jagersfontein diamonds.

Figure 2. Chondrite-normalized rare earth element composition of majoritic ... Available to Purchase

Published: 01 July 2005
Figure 2. Chondrite-normalized rare earth element composition of majoritic garnet inclusions in Jagersfontein diamonds.
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Cretaceous kimberlite-related fractures from Sutherland to Kimberley. The fracture pattern around Kimberley – Postmasburg – Jagersfontein is taken from Greeff [10].

Cretaceous kimberlite-related fractures from Sutherland to Kimberley. The f... Available to Purchase

Published: 01 February 1997
Fig. 2. Cretaceous kimberlite-related fractures from Sutherland to Kimberley. The fracture pattern around Kimberley – Postmasburg – Jagersfontein is taken from Greeff [ 10 ].
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The Cr and Al contents of garnets in garnet harzburgites from Kimberley, and the bulk chemical composition of symplectites from Kimberley and Jagersfontein. The cation numbers of the bulk symplectites are based on a garnet formula.

The Cr and Al contents of garnets in garnet harzburgites from Kimberley, an... Available to Purchase

Published: 01 April 2008
F igure 12. The Cr and Al contents of garnets in garnet harzburgites from Kimberley, and the bulk chemical composition of symplectites from Kimberley and Jagersfontein. The cation numbers of the bulk symplectites are based on a garnet formula.
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(a) An outline of the Kaapvaal Craton, South Africa, surrounded by an orogenic belt, with the location of major tectonic blocks, selected stratigraphic units, and the main clusters of kimberlites. Jagersfontein lies close to the Colesberg Lineament and Monastery borders Lesotho, where the first recognition of diamond-inclusion majorite was made (modifiedfrom Schmitz et al. 2004). (b) The 150 km slice of the P-wave seismic velocity map of the Kaapvaal craton showing the locations of the main kimberlite fields: The southern cluster consists of Jagersfontein (JA), Koffiefontein (KO), Kimberley (D. De Beers, Dutoitspan and Wesselton), Finch (F), andRoberts Victor (R); and the northern province is composed of Premier (P), Venetia (V), Jwaneng (JW), Letlhakane (LE), and Orapa (O). The inset to the left are the relative locations of the Kaapvaal (K), Limpopo (L), and Zimbabwe (Z) cratons. The anomalies are considered to be compositionally-controlled-.fast (blue) areperidotitic; slow (red) are eclogitic (Shirey, et al., 2002), but as discussed in the text the assumption is notfullyjustified.

(a) An outline of the Kaapvaal Craton, South Africa, surrounded by an oroge... Available to Purchase

Published: 01 March 2017
Figure 2. (a) An outline of the Kaapvaal Craton, South Africa, surrounded by an orogenic belt, with the location of major tectonic blocks, selected stratigraphic units, and the main clusters of kimberlites. Jagersfontein lies close to the Colesberg Lineament and Monastery borders Lesotho, where
Journal Article

The thermal equation of state of FeTiO 3 ilmenite based on in situ X-ray diffraction at high pressures and temperatures Available to Purchase

E.J. Tronche, M. van Kan Parker, J. de Vries, Y. Wang, T. Sanehira, J. Li, B. Chen, L. Gao, S. Klemme, C.A. McCammon, W. van Westrenen
Published: 01 November 2010
American Mineralogist (2010) 95 (11-12): 1708–1716.
DOI: https://doi.org/10.2138/am.2010.3410
...E.J. Tronche; M. van Kan Parker; J. de Vries; Y. Wang; T. Sanehira; J. Li; B. Chen; L. Gao; S. Klemme; C.A. McCammon; W. van Westrenen Abstract We present in situ measurements of the unit-cell volume of a natural terrestrial ilmenite (Jagersfontein mine, South Africa) and a synthetic reduced...
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Journal Article

Age, paragenesis and composition of diamonds and evolution of the Precambrian mantle lithosphere of southern Africa Available to Purchase

Steven B. Shirey, Stephen H. Richardson, Jeffrey W. Harris
Published: 01 June 2004
South African Journal of Geology (2004) 107 (1-2): 91–106.
DOI: https://doi.org/10.2113/107.1-2.91
... in the P-wave velocity (±1%) that the mantle lithosphere shows at depths within the diamond stability field (150 to 225km). Silicate inclusions in diamonds and their host diamond compositions for the above kimberlites, Finsch, Jagersfontein, Roberts Victor, Premier, Venetia and Letlhakane show a regional...
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Journal Article

Garnet–olivine equilibration during cooling in the mantle Available to Purchase

Douglas Smith, Clark R. Wilson
Published: 01 February 1985
American Mineralogist (1985) 70 (1-2): 30–39.
... inclusions, and compositions of these olivine inclusions depend upon their size. Calculated temperatures for the olivine–garnet pairs are near 550°C. Garnets in three nodules from the Jagersfontein kimberlite pipe are not Fe–Mg zoned in contact with olivine, and calculated temperatures for the three nodules...
View PDF for article title, Garnet–olivine equilibration during cooling in the mantle
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Journal Article

Cobalt in kimberlites Available to Purchase

R. S. Young, D. A. Benfield, K. G. A. Strachan
Published: 01 February 1954
American Mineralogist (1954) 39 (1-2): 143–144.
...R. S. Young; D. A. Benfield; K. G. A. Strachan Abstract Nickel has been reported as a constituent of Jagersfontein kimberlite in quantities from 0.08 to 0.14%, and as a component of nodules of eclogite, pyroxenite, phlogopite, and chrome diopside found in kimberlites, in amounts from a trace...
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The Al contents per formula unit of pairs of discrete and symplectite opx grains in the same sample. Triangles represent discrete ox and circles represent symplectite opx. Discrete opx is always enriched in Al with respect to the symplectite opx. The situation is identical at Kimberley (filled circles) and Jagersfontein (open circles).

The Al contents per formula unit of pairs of discrete and symplectite opx g... Available to Purchase

Published: 01 April 2008
at Kimberley (filled circles) and Jagersfontein (open circles).
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Comparative histograms of δ13C values for diamonds from individual localities. (a) Venetia (South Africa) represents a typical locality, while (b) Guaniamo (Venezuela), (c) Argyle (Australia), (d) New South Wales (Australia), and (e) Jagersfontein (South Africa) are atypical localities. Vertical axis is number of diamonds.

Comparative histograms of δ 13 C values for diamonds from individual locali... Available to Purchase

Published: 01 March 2005
FIGURE 3 Comparative histograms of δ 13 C values for diamonds from individual localities. ( a ) Venetia (South Africa) represents a typical locality, while ( b ) Guaniamo (Venezuela), ( c ) Argyle (Australia), ( d ) New South Wales (Australia), and ( e ) Jagersfontein (South Africa