Mineralium Deposita

, Volume 48, Issue 1, pp 81–97 | Cite as

Compositional variations and morphological evolution in platinum beach placers, southern New Zealand

  • D. CrawEmail author
  • M. Mitchell
  • R. McCann
  • A. Reay


Morphologies of placer platinum group minerals (PGM) are more variable and resistant to modification during transport than placer gold grains. This study documents morphological evolution of PGM placer grains during up to 120 km of transport in beach placers after river transport from inferred sources up to 200 km inland. PGM morphological changes are calibrated with changes in morphology of associated placer gold. Most of the PGM are Pt-Fe alloy and have been fed into the beach placer system from a large river at the western end of the beaches on the south coast of New Zealand. The incoming fluvial PGM suite includes Os, Ir and Ru alloys which may have been derived from distal ophiolitic sources. More proximal sources have Ural-Alaskan affinities and these contributed cooperite and braggite, or sperrylite, locally, as well as Pt-Fe alloy grains. Some PGM may have been recycled through Cretaceous-Quaternary fluvial sediments before entering the modern placer system. Recycled placer PGM grains have also been derived from elevated Quaternary beaches near the coastline. PGM grains entering beach placers have rough surfaces, with remnants of crystal faces, and these evolve to smooth flakes with progressive long-shore transport. PGM flakes have slightly thickened rims caused by impacts by saltating sand on windy beaches, and the most distal beach placers contain flakes with incipient toroidal shapes. These PGM incipient toroids are poorly developed compared to accompanying well-formed toroidal gold that has developed in nearly all beach placers, including those on elevated Quaternary beaches. Typical PGM and gold placer grain size decreases with increasing distance of transport, from fluvial grain size of 400–1,000 to ∼200 microns on the most distal beaches, accompanied by eastward loss of equant PGM grains and associated increase in proportion of flakes. Although net transport distance is ∼120 km in the beach placer complex, frequent aeolian transport of grains from beach to dunes and subsequent recycling by storm surges substantially increased total transport distance in a dynamic windy tectonic environment.


Aeolian Placer Gold Platinum Alloy Fluvial Grain size Toroid 



This study was financed by University of Otago and the NZ Ministry for Science and Innovation. We are grateful for the generous assistance from the various miners in the study area, who provided local knowledge and samples of mineral concentrate. Discussions with Paul Ashley, Tony Christie, Doug MacKenzie, Nick Mortimer and Peter Waterman helped us to refine of the ideas expressed herein. Expert technical assistance was provided by Yosuke Kawachi, Kat Lilly, John Pillidge, Mike Trinder and Don Weston, and preparation of diagrams was ably assisted by Anna and Lisa Craw. Helpful comments by Bernd Lehmann and an anonymous reviewer substantially improved the presentation.


  1. Ashley P, Craw D, MacKenzie D, Rombouts M, Reay A (2012) Mafic and ultramafic rocks, and platinum mineralisation potential, in the Longwood Range, Southland, New Zealand. NZ J Geol Geophys 55:3–19CrossRefGoogle Scholar
  2. Auge T, Legendre O (1992) Pt-Fe nuggets from alluvial deposits in eastern Madagascar. Can Mineral 30:983–1004Google Scholar
  3. Barkov AY, Martin RF, Fleet ME, Nixon GT, Levson VM (2008) New data on associations of platinum-group minerals in placer deposits of British Columbia, Canada. Mineral Petrol 92:9–29CrossRefGoogle Scholar
  4. Begizov VD, Borisenko LF, Uskov ED (1975) Sulphides and natural solid solutions of platinoids from the ultrabasites of the Gusevogorskiy massif, Urals. Doklady Akad Nauk SSR 225:1408–1411 (in Russian)Google Scholar
  5. Brundin NH, Bergstrom J (1977) Regional prospecting for ores based on heavy minerals in glacial till. J Geochem Explor 7:1–19CrossRefGoogle Scholar
  6. Cabri LJ, Feather CE (1975) Platinum-iron alloys. Nomenclature based on a study of natural and synthetic alloys. Can Mineral 13:117–126Google Scholar
  7. Cabri LJ, Laflamme JHG, Stewart JM, Turner K, Skinner BJ (1978) On cooperate, braggite, and vysotskyite. Am Mineral 63:832–839Google Scholar
  8. Cabri LJ, Harris DC, Weiser TW (1996) Mineralogy and distribution of platinum-group mineral (PGM) placer deposits of the world. Explor Mining Geol 5:73–167Google Scholar
  9. Chapman RJ, Leake RC, Moles NR, Earls G, Cooper C, Harrington K, Berzins R (2000) The application of microchemical analysis of gold grains to the understanding of complex local and regional gold mineralization: a case study in Ireland and Scotland. Econ Geol 95:1753–1773Google Scholar
  10. Clifton HE, Luepke G (1987) Heavy-mineral placer deposits of the continental margin of Alaska and the Pacific Coast states. Circum-Pacific Council for Energy and Mineral Resources. Earth Sci Ser 6:691–738Google Scholar
  11. Coggon JA, Nowell GM, Pearson DG, Parman SW (2011) Application of the 190Pt-186Os isotope system to dating platinum mineralization and ophiolite formation: an example from the Meratus Mountains, Borneo. Econ Geol 106:93–117CrossRefGoogle Scholar
  12. Coombs DS, Landis CA, Norris RJ, Sinton JM, Borns DJ, Craw D (1976) The Dun Mountain Ophiolite Belt, New Zealand. Am J Sci 276:561–603CrossRefGoogle Scholar
  13. Cowden A, Ruddock R, Reay A, Nicolson P, Waterman P, Banks MJ (1990) Platinum mineralisation potential of the Longwood Igneous Complex, New Zealand. Mineral Petrol 42:181–195CrossRefGoogle Scholar
  14. Craw D, Burridge C, Anderson L, Waters JM (2007) Late Quaternary river drainage and fish evolution, Southland, New Zealand. Geomorphology 84:98–110CrossRefGoogle Scholar
  15. Crawford EC, Mortensen JK (2009) An ImageJ plugin for the rapid morphological characterization of separated particles and an initial application to placer gold analysis. Comp Geosci 35:347–359CrossRefGoogle Scholar
  16. Cullen DJ (1967) The submarine geology of Foveaux Strait. New Zealand Oceanographic Institute Memoir 33, Wellington, pp. 67Google Scholar
  17. Dawber KR, Edwards PJ (1988) Wind energy resources in Otago and Southland: Final Report on Phase II. Report 160, NZ Energy Research and Development Committee, Auckland, NZGoogle Scholar
  18. Dill HG, Klosa D, Steyer G (2009) The “Donauplatin”: source rock analysis and origin of a distal fluvial Au-PGE placer in Central Europe. Mineral Petrol 96:141–161CrossRefGoogle Scholar
  19. Dill HG, Weber B, Steyer G (2010) Morphological studies of PGM grains in alluvial-fluvial placer deposits from the Bayerischer Wald, SE Germany): hollingworthite and ferroan platinum. Neues Jahrb Mineral Abhandl 187:101–110CrossRefGoogle Scholar
  20. Falconer DM, Craw D (2009) Supergene gold mobility: a textural and geochemical study from gold placers in southern New Zealand. In: Supergene environments, processes and products. Econ Geol Spec Publ 14:77–93Google Scholar
  21. Filippov VE, Nikiforova ZS (1986) Transformation of particles of native gold in the process of aeolian action. Inst Geol Yakutia, Siberian Branch, USSR Acad Sci, Yukusk, pp. 1229–1232 (in Russian)Google Scholar
  22. Garden CJ, Craw D, Waters JM, Smith A (2011) Rafting rocks reveal marine biological dispersal: a case study using clasts from beach-cast macroalgal holdfasts. Estuar Coast Shelf Sci 95:388–394CrossRefGoogle Scholar
  23. Garnett RHT, Bassett NC (2005) Placer deposits. Econ Geol 100th Anniv vol: 813–843Google Scholar
  24. Giusti L (1986) The morphology, mineralogy and behavior of “fine-grained” gold from placer deposits of Alberta: sampling and implications for mineral exploration. Can J Earth Sci 23:1662–1672CrossRefGoogle Scholar
  25. Harris DC, Cabri LJ (1991) Nomenclature of platinum-group-element alloys; review and revision. Can Mineral 29:231–237Google Scholar
  26. Johan Z, Ohnenstetter M, Slansky E, Barron LM, Suppel D (1989) Platinum mineralization in the Alaskan-type intrusive complexes near Fifield, New South Wales, Australia. 1. Platinum-group minerals in clinopyroxenites of the Kelvin Grove prospect, Owendale intrusion. Mineral Petrol 40:289–309CrossRefGoogle Scholar
  27. Knight JB, Morison SR, Mortensen JK (1999) The relationship between placer gold particle shape, rimming and distance of fluvial transport; as exemplified by gold from the Klondike District, Yukon Territory, Canada. Econ Geol 94:635–648CrossRefGoogle Scholar
  28. MacPherson EO (1938) The Round Hill goldfield, Southland. NZ J Sci Tech 19:743–749Google Scholar
  29. Malitch KN, Melcher F, Mühlhans H (2001) Palladium and gold mineralization in podiform chromitite at Kraubath, Austria. Mineral Petrol 73:247–277CrossRefGoogle Scholar
  30. Malitch KN, Thalhammer OAR, Knauf VV, Melcher F (2003) Diversity of platinum-group mineral assemblages in banded and podiform chromitite from the Kraubath ultramafic massif, Austria: evidence for an ophiolitic transition zone. Mineral Deposita 38:282–297Google Scholar
  31. McClenaghan MB, Cabri LJ (2011) Review of gold and platinum group element (PGE) indicator minerals methods for surficial sediment sampling. Geochem Expl Environ Anal 11:251–263CrossRefGoogle Scholar
  32. Minter WEL (1999) Irrefutable detrital origin of Witwatersrand gold and evidence of eolian signatures. Econ Geol 94:665–670CrossRefGoogle Scholar
  33. Mortimer N, Gans P, Calvert A, Walker N (1999) Geology and thermochronometry of the east edge of the Median Batholith (Median Tectonic Zone): a new perspective on Permian to Cretaceous crustal growth of New Zealand. Island Arc 8:404–425CrossRefGoogle Scholar
  34. Nikiforova ZS, Gersaimov BB, Tulaeva EG (2011) Genesis of gold-bearing placers and their possible sources (Eastern Siberian Platform). Lith Mineral Res 46:17–29CrossRefGoogle Scholar
  35. NIWA (2012) National climate database, National Institute of Water and Atmospheric Research, NZ
  36. Nixon GT, Cabri LJ, Laflamme JHG (1990) Platinum-group-element mineralization in lode and placer deposits associated with the Tulameen Alaskan-type complex, British Columbia. Can Mineral 28:503–535Google Scholar
  37. Norris RJ, Carter RM, Turnbull IM (1978) Cainozoic sedimentation in basins adjacent to a major continental transform boundary in southern New Zealand. J Geol Soc London 135:191–205CrossRefGoogle Scholar
  38. Oberthür T, Melcher F, Gast L, Wohrl C, Lodziak J (2004) Detrital platinum-group minerals in rivers draining the Eastern Bushveld Complex, South Africa. Can Mineral 42:563–582CrossRefGoogle Scholar
  39. Patyk-Kara NG (2002) Placers in the system of sedimentogenesis. Lith Mineral Res 37:429–441CrossRefGoogle Scholar
  40. Patyk-Kara NG (2005) Evolution of placer formation in the shelf regions of Russia. Lith Mineral Res 40:389–400CrossRefGoogle Scholar
  41. Shcheka GG, Solianik AN, Lehmann B, Bieniok A, Amthauer G, Topa D, Laflamme JHG (2004a) Euhedral crystals of ferroan platinum, cooperite and mertieite-II from alluvial sediments of the Darya river, Aldan Shield, Russia. Mineral Mag 68:871–885CrossRefGoogle Scholar
  42. Shcheka GG, Lehmann B, Gierth E, Gömann K, Wallianos A (2004b) Macrocrystals of Pt-Fe alloy from the Kondyor PGE placer deposit, Khabarovskiy Kray, Russia: trace-element content, mineral inclusions and reaction assemblages. Can Mineral 42:601–617CrossRefGoogle Scholar
  43. Slansky E, Johan Z, Ohnenstetter M, Barron LM, Suppel D (1991) Platinum mineralization in the Alaskan-type intrusive complexes near Fifield, NSW, Australia. Part 2. Platinum-group minerals in placer deposits at Fifield. Mineral Petrol 43:161–180CrossRefGoogle Scholar
  44. Spandler C, Eggins SM, Arculus RJ, Mavrogenes JA (2000) Using melt inclusions to determine parent magma compositions of layered intrusions: applications to the Greenhills Complex (New Zealand), a platinum-group-minerals-bearing, island arc intrusion. Geology 28:991–994CrossRefGoogle Scholar
  45. Spandler C, Worden K, Arculus R, Eggins S (2005) Igneous rocks of the Brook Street Terrane, New Zealand: implications for Permian tectonics of eastern Gondwana and magma genesis in modern intra-oceanic volcanic arcs. NZ J Geol Geophys 48:167–183CrossRefGoogle Scholar
  46. Tolstykh ND, Sidorov EG, Kozlov AP (2004) Platinum group minerals in lode and placer deposits associated with the Ural-Alaskan type Gal’moenan Complex, Koryak-Kamchatka platinum belt, Russia. Can Mineral 42:619–630CrossRefGoogle Scholar
  47. Tolstykh ND, Sidorov EG, Krivenko AP (2005) Platinum-group element placers associated with Ural-Alaska type complexes. In: Mungall JE (ed) Exploration for platinum-group element deposits. Mineral Assoc Canada Short Course 35: 113–143Google Scholar
  48. Tolstykh N, Sidorov E, Kozlov A (2009) Platinum-group minerals from the Olkhovaya-1 placers related to the Karaginsky ophiolite complex, Kamchatskiy Mys peninsula, Russia. Can Mineral 47:1057–1074CrossRefGoogle Scholar
  49. Townley BK, Herail G, Maksaev V, Palacios C, de Parseval P, Sepuldeva F, Orellana R, Rivas P, Ulloa C (2003) Gold grain morphology and composition as an exploration tool: application to gold exploration in covered areas. Geochem Expl Environ Anal 3:29–38CrossRefGoogle Scholar
  50. Turnbull IM, Allibone AH (2003) Geology of the Murihiku area. Inst Geol Nuclear Sci 1:250 000 geological map 20. Lower Hutt, NZGoogle Scholar
  51. Turnbull IM, Uruski CJ (1993) Cretaceous and Cenozoic sedimentary basins of western Southland, South Island, New Zealand. Inst Geol Nuclear Sci Monogr 1: 86Google Scholar
  52. Turnbull IM, Allibone AH, Jongens R (2010) Geology of the Fiordland area. Inst Geol Nuclear Sci 1:250 000 geological map 17. Lower Hutt, NZGoogle Scholar
  53. Ward CM (1988) Marine terraces of the Waitutu district and their relation to the late Cenozoic tectonics of the southern Fiordland region. J R Soc NZ 18:1–28CrossRefGoogle Scholar
  54. Williams GJ (1974) Economic geology of New Zealand. Austral Inst Mining Metall Monogr 4: 490Google Scholar
  55. Wood BL (1969) Geology of the Tuatapere Subdivision, western Southland. NZ Geol Surv Bull 69Google Scholar
  56. Youngson JH (2005) Diagenetic silcrete and formation of silcrete ventifacts and aeolian gold placers in central Otago, New Zealand. NZ J Geol Geophys 48:247–263CrossRefGoogle Scholar
  57. Youngson JH, Craw D (1999) Variation in placer style, gold morphology, and gold particle behavior down gravel bed-load rivers: an example from the Shotover/Arrow-Kawarau-Clutha river system, Otago, New Zealand. Econ Geol 94:615–634CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  1. 1.Geology DepartmentUniversity of OtagoDunedinNew Zealand

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