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Provenance history of detrital diamond deposits, West Coast of Namaqualand, South Africa

Provenance history of detrital diamond deposits, West Coast of Namaqualand, South Africa The West Coast of Namaqualand in South Africa hosts extensive detrital diamond deposits, but considerable debate exists as to the provenance of these diamonds. Some researchers have suggested derivation of the diamonds from Cretaceous-Jurassic kimberlites (also termed Group I kimberlites) and orangeites (also termed Group II kimberlites) located on the Kaapvaal Craton. However, others favour erosion of diamonds from the ca.300 Ma Dwyka Group sediments, with older, pre-Karoo kimberlites being the original source(s). Previous work has demonstrated that 40Ar/39Ar analyses of clinopyroxene inclusions, extracted from diamonds, yield ages approaching the time(s) of source kimberlite emplacement, which can be used to constrain the provenance of placer diamond deposits. In the current study, 40Ar/39Ar analyses were conducted on clinopyroxene inclusions from two similar batches of Namaqualand detrital diamonds, yielding (maximum) ages ranging from 117.5 ± 43.6 Ma to 3684 ± 191 Ma (2σ) and 120.6 ± 15.4 Ma to 688.8 ± 4.9 Ma (2σ), respectively. The vast majority of inclusions (88%) produced ages younger than 500 Ma, indicating that most Namaqualand diamonds originated from Cretaceous-Jurassic kimberlites/orangeites, with few, if any, derived from the Dwyka tillites. The provenance of the Namaqualand diamonds from ca.115–200 Ma orangeites is consistent with Late Cretaceous paleo-drainage reconstructions, as these localities could have been sampled by the ‘paleo-Karoo’ River and transported to the West Coast via an outlet close to the current Olifants River mouth. At ca.90 Ma, this drainage system appears to have been captured by the ‘paleo-Kalahari’ River, a precursor to the modern Orange River system. This latter drainage is considered to have transported diamonds eroded from both ca.80–90 Ma kimberlites and ca.115–200 Ma orangeites to the West Coast, which were subsequently reworked along the Namibian coast, forming additional placer deposits. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Mineralogy and Petrology Springer Journals

Provenance history of detrital diamond deposits, West Coast of Namaqualand, South Africa

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Publisher
Springer Journals
Copyright
Copyright © 2018 by Springer-Verlag GmbH Austria, part of Springer Nature
Subject
Earth Sciences; Mineralogy; Inorganic Chemistry; Geochemistry
ISSN
0930-0708
eISSN
1438-1168
DOI
10.1007/s00710-018-0568-9
Publisher site
See Article on Publisher Site

Abstract

The West Coast of Namaqualand in South Africa hosts extensive detrital diamond deposits, but considerable debate exists as to the provenance of these diamonds. Some researchers have suggested derivation of the diamonds from Cretaceous-Jurassic kimberlites (also termed Group I kimberlites) and orangeites (also termed Group II kimberlites) located on the Kaapvaal Craton. However, others favour erosion of diamonds from the ca.300 Ma Dwyka Group sediments, with older, pre-Karoo kimberlites being the original source(s). Previous work has demonstrated that 40Ar/39Ar analyses of clinopyroxene inclusions, extracted from diamonds, yield ages approaching the time(s) of source kimberlite emplacement, which can be used to constrain the provenance of placer diamond deposits. In the current study, 40Ar/39Ar analyses were conducted on clinopyroxene inclusions from two similar batches of Namaqualand detrital diamonds, yielding (maximum) ages ranging from 117.5 ± 43.6 Ma to 3684 ± 191 Ma (2σ) and 120.6 ± 15.4 Ma to 688.8 ± 4.9 Ma (2σ), respectively. The vast majority of inclusions (88%) produced ages younger than 500 Ma, indicating that most Namaqualand diamonds originated from Cretaceous-Jurassic kimberlites/orangeites, with few, if any, derived from the Dwyka tillites. The provenance of the Namaqualand diamonds from ca.115–200 Ma orangeites is consistent with Late Cretaceous paleo-drainage reconstructions, as these localities could have been sampled by the ‘paleo-Karoo’ River and transported to the West Coast via an outlet close to the current Olifants River mouth. At ca.90 Ma, this drainage system appears to have been captured by the ‘paleo-Kalahari’ River, a precursor to the modern Orange River system. This latter drainage is considered to have transported diamonds eroded from both ca.80–90 Ma kimberlites and ca.115–200 Ma orangeites to the West Coast, which were subsequently reworked along the Namibian coast, forming additional placer deposits.

Journal

Mineralogy and Petrology – Springer Journals

Published: May 28, 2018

References

  • Constraints on the geomorphological evolution of Namibia from the offshore stratigraphic record
    Aizawa, M; Bluck, BJ; Cartwright, J; Milner, S; Swart, R; Ward, JD
  • Rb-Sr age determinations on South African kimberlite pipes
    Allsopp, HL; Barrett, DR
  • Rb-Sr and 40Ar-39Ar age determinations on phlogopite micas from the pre-Lebombo Group Dokolwayo pipe
    Allsopp, HL; Roddick, JC
  • The geochronology and significance of ash-fall tuffs in the glaciogenic Carboniferous-Permian Dwyka Group of Namibia and South Africa
    Bangert, B; Stollhofen, H; Lorenz, V; Armstrong, RA
  • The Orange River, southern Africa: an extreme example of a wave-dominated sediment dispersal system in the South Atlantic Ocean
    Bluck, BJ; Ward, JD; Cartwright, J; Swart, R
  • Geomorphology and global tectonics. John Wiley & Sons Ltd
    Brown, RW; Gallagher, K; Gleadow, AJ; Summerfield, M
  • 40Ar/39Ar laser probe dating of individual clinopyroxene inclusions in Premier eclogitic diamonds
    Burgess, R; Turner, G; Laurenzi, M; Harris, JW
  • 40Ar/39Ar laser probe studies of clinopyroxene inclusions in eclogitic diamonds
    Burgess, R; Turner, G; Harris, JW
  • Ar-Ar age determinations of eclogitic clinopyroxene and garnet inclusions in diamonds from the Venetia and Orapa kimberlites
    Burgess, R; Kiviets, GB; Harris, JW
  • The Karoo basins of south-central Africa
    Catuneanu, O; Wopfner, H; Eriksson, PG; Cairncross, B; Rubidge, BS; Smith, RMH; Hancox, PJ
  • The ages and uranium contents of zircons from kimberlites and associated rocks
    Davis, GL
  • Post-Gondwana drainage and the development of diamond placers in western South Africa
    Wit, MCJ
  • Late Mesozoic and Tertiary sediment supply to the Eastern Cape basins (SE Atlantic) and the palaeo-drainage systems in southwestern Africa
    Dingle, RV; Hendy, QB
  • The timing and duration of the Karoo igneous event, southern Gondwana
    Duncan, RA; Hooper, PR; Rehacek, J; Marsh, JS; Duncan, AR
  • Denudation and uplift at passive margins: the record on the Atlantic margin of southern Africa
    Gallegher, K; Brown, R
  • The geology of the coast diamond deposits of southern Africa. In: Haughton SH (ed) The geology of some ore deposits in southern Africa
    Hallam, CD
  • Mesoproterozoic magmatic and tectonic evolution in the Kalahari Craton
    Hanson, RE; Harmer, RE; Blenkinsop, TG; Bullen, DS; Dalziel, IWD; Gose, WA; Hall, RP; Kampunzu, AB; Key, RM; Mukwakwami, J; Munyanyiwa, H; Pancake, JA; Seidel, EK; Ward, SE
  • The properties of natural and synthetic diamonds
    Harris, JW
  • The Kalahari Craton during assembly and dispersal of Rodinia
    Jacobs, J; Pisarevsky, S; Thomas, RJ; Becker, T
  • Distinct brief major events in the Karoo large igneous province clarified by new 40Ar/39Ar ages on the Lesotho basalts
    Jourdan, F; Feraud, G; Bertrand, H; Watkeys, MK; Renne, PR
  • A feasibility study of U-Pb and Pb-Pb dating of kimberlites using groundmass mineral fractions and whole rock samples
    Kramers, JD; Smith, CB
  • On the volcanology of the Gibeon kimberlite field, Namibia
    Kurszlaukis, S; Franz, L; Lorenz, V
  • A redetermination of the isotopic abundances of atmospheric Ar
    Lee, J-Y; Marti, K; Severinghaus, JP; Kawamura, K; Yoo, H-S; Lee, JB; Kim, JS
  • Diamond formation and source carbonation: mineral associations in diamonds from Namibia
    Loest, I; Stachel, T; Brey, GP; Harris, JW; Rybchikov, ID
  • Die afsetting en verspreiding van spoeldiamante in Suid-Afrika
    Maree, BD
  • The crustal architecture of Archaean terranes in Northeastern Botswana
    McCourt, S; Kampunzu, AB; Bagai, Z; Armstrong, RA
  • The roles of primary kimberlitic and secondary Dwyka glacial sources in the development of alluvial and marine diamond deposits in Southern Africa
    Moore, JM; Moore, AE
  • The olvine melilitite-“kimberlite”-carbonatite suite of Namaqualand and Bushmanland, South Africa
    Moore, JM; Verwoerd, WJ
  • Of diamonds, dinosaurs and diastrophism: 150 million years of landscape evolution in southern Africa
    Partridge, TC
  • Argon and halogen chemistry of phlogopite from South African kimberlites: a combined step-heating, laser probe, electron microprobe and TEM study
    Phillips, D
  • Provenance studies from 40Ar/39Ar dating of mineral inclusions in diamonds: Methodological tests on the Orapa kimberlite, Botswana
    Phillips, D; Harris, JW
  • Diamond provenance studies from 40Ar/39Ar dating of clinopyroxene inclusions: An example from the west coast of Namibia
    Phillips, D; Harris, JW
  • Ultra-high precision 40Ar/39Ar ages for Fish Canyon Tuff and Alder Creek Rhyolite sanidine: new dating standards required?
    Phillips, D; Matchan, E
  • 40Ar/39Ar laser probe dating of diamond inclusions from the Premier kimberlite
    Phillips, D; Onstott, TC; Harris, JW
  • A petrographic and 40Ar/39Ar geochronological study of the Voorspoed kimberlite, South Africa: Implications for the origin of Group II kimberlite magmatism
    Phillips, D; Machin, KJ; Kiviets, GB; Fourie, LF; Roberts, MA; Skinner, EMW
  • Gurney JJ
    Phillips, D; Kiviets, GB; Barton, ES; Smith, CB; Viljoen, KS; Fourie, LF
  • 40Ar/39Ar analyses of clinopyroxene inclusions in African diamonds: implications for source ages of detrital diamonds
    Phillips, D; Harris, JW; Kiviets, GB
  • Mineral chemistry and thermobarometry of inclusions from the Be Beers Pool diamonds, Kimberley, South Africa
    Phillips, D; Harris, JW; Viljoen, KS
  • Astronomical calibration of 40Ar/39Ar reference minerals using high-precision, multi-collector (ARGUSVI) mass spectrometry
    Phillips, D; Matchan, EL; Honda, M; Kuiper, KF
  • Archean subduction recorded by Re-Os isotopes in eclogitic sulfide inclusions in Kimberley diamonds
    Richardson, SH; Shirey, SB; Harris, JW; Carlson, RW
  • Carbon in Earth
    Shirey, SB; Cartigny, P; Frost, DJ; Keshav, S; Nestola, F; Nimis, P; Pearson, DG; Sobolev, NV; Walter, MJ
  • Early Archaean tectonics and mantle redox recorded in Witwatersrand diamonds
    Smart, KA; Tappe, S; Stern, RA; Webb, SJ; Ashwal, LD
  • Pb, Sr and Nd isotopic evidence for sources of southern African Cretaceous kimberlites
    Smith, CB
  • Emplacement ages of Jurassic–Cretaceous South African kimberlites by the Rb–Sr method on phlogopite and whole rock samples
    Smith, CB; Allsopp, HL; Kramers, JD; Hutchinson, G; Roddick, JC
  • Stratigraphy of South Africa Part 1: Lithostratigraphy of the Republica of South Africa, South West Africa/Namibia, and the Republics of Bophuthatswana, Transkei and Venda
  • Subcommission on geochronology: Convention on the use of decay constants in geo- and cosmochronology
    Steiger, RH; Jäger, E
  • Incised valley fill stratigraphy of the Upper Cretaceous succession, proximal Orange Basin, Atlantic margin of southern Africa
    Stevenson, IR; McMillan, IK
  • Single-zircon U-Pb dating of Carboniferous-Permian tuffs, Namibia and the intercontinental deglaciation cycle framework
    Stollhofen, H; Werner, M; Stanistreet, IG; Armstrong, RA
  • The transport and sorting of diamonds by fluvial and marine processes
    Sutherland, DG
  • The Kibaran of southern Africa: tectonic evolution and metallogeny
    Thomas, RJ; Agenbacht, ALD; Cornell, DH; Moore, JM
  • Possible effects of 39Ar recoil in 40Ar-39Ar dating
    Turner, G; Cadogan, PH
  • Mineral Deposits of Southern Africa
    Wyk, JP; Pienaar, LF
  • Deglaciation sequences in the Permo-Carboniferous Karoo and Kalahari basins of southern Africa: a tool in the analysis of cyclic glaciomarine basin fill
    Visser, JNJ