A Review of the Geology of Global Diamond Mines and Deposits

Abstract

Kjarsgaard et al.A Review of the Geology of Global Diamond Mines and Deposits 3 Table 1. Mineralogy of kimberlite, carbonate-rich olivine lamproite (CROL), and olivine lamproite. Minerals present Kimberlite Carbonate-rich olivine lamproite (CROL) Olivine lamproite Megacryst suite (> 1 cm) Common to absent Absent, rare Absent, ?very rare? Cognate and antecryst minerals Olivine Common to absent Rare to absent Rare to absent Phlogopite Minor to absent Common to minor Common, minor, rare Spinel Common to rare (spinel cores) Minor to absent (spinel cores) Minor to absent (spinel cores) Diopside Absent Rare to absent Rare to absent (Minor) Phenocryst /Microphenocrysts (0.2-1.0 mm) Olivine phenocrysts Common Common Common Olivine microphenocrysts Common Minor to rare Minor to rare Phlogopite phenocrysts Minor, rare, absent Common Common Phlogopite microphenocrysts Minor, rare (poikilitic) Common Common (poikilitic) Spinel phenocrysts Common to minor Minor to rare Minor to rare Diopside microphenocrysts Absent Variable: Common to absent Minor to absent Groundmass (<0.2 mm) Olivine Common Minor to rare Rare, absent Phlogopite Common, laths (poikilitic) Common (poikilitic) Common (poikilitic) Spinel Common to minor Minor to rare Minor to rare Glass Absent, exceptionally rare? Absent (not reported) Common, minor, rare Apatite Common to rare Common to minor Minor to rare Perovskite Common to minor, rare Minor to rare Minor to rare Carbonate (calcite, dolomite) Common to minor Common to minor Rare, absent

Representations of an Ebola ‘outbreak’ through Story Technologies

“…It is evident to social scientists, geologists, and the local population alike that there is abundant mineral wealth in Bumpeh 51 55. But throughout the past century, this wealth has been systematically expropriated from the region and then out of the country without the taxation necessary to develop and sustain an effective local health system 51 52 56.…”

Emplacement of the Argyle diamond deposit into an ancient rift zone triggered by supercontinent breakup

“…Examples include the East European Platform during Nuna breakup (c. 1250–1230 Ma 43 ), the Kimberley Craton during attempted Rodinia breakup (c. 840–800 Ma 44 ) and the Kaapvaal Craton during Gondwana/Pangea breakup (c. 200–120 Ma 45 , 46 ), amongst many others. However, the role of (super)continental breakup has only recently begun to be significantly appreciated for kimberlite emplacement during periods of continental breakup 2 , 38 , 42 . In all breakup-related cases, diatreme emplacement appears to be contemporaneous with breakup, but with a peak production of volatile-rich ultramafic rocks lagging behind the breakup period 41 , 42 .…”

“…The vast majority of primary economic diamond deposits are hosted in kimberlite diatremes located in Archean cratons 1 , 2 , with characteristically old and thick continental lithosphere thought to be necessary for sustained diamond growth 3 . However, the largest source of natural diamonds discovered to date, the Argyle mine in the Kimberley region of Western Australia, is one of only a few economic deposits found within a Paleoproterozoic orogen adjacent to cratonic regions underlain by Archean basement 2 , 4 . Moreover, Argyle is hosted in olivine lamproite, rather than kimberlite, and has yielded >90% of all pink diamonds discovered 5 .…”

Petrology, Age, and Rift Origin of Ultramafic Lamprophyres (Aillikites) at Mount Webb, a New Alkaline Province in Central Australia

“…Enrichment in TiO 2 is closely associated with higher values for FeO (see Sudholz, 2023). The Webb phlogopites are similar in terms of their Al 2 O 3 , TiO 2 , and FeO contents to groundmass phlogopite in kimberlite (e.g., Kjarsgaard et al, 2022;Mitchell, 1995) but lack the BaO enrichment that is common for many kimberlites. The relatively low BaO contents and enrichment in FeO and TiO 2 (Figure 4) of the Webb phlogopites are more typical of lamprophyres and consistent with the compositions observed for groundmass phlogopite in aillikites elsewhere (e.g., Prokopyev et al, 2020;Tappe et al, 2006).…”