Mineralium Deposita

, Volume 53, Issue 8, pp 1117–1142 | Cite as

Formation conditions and REY enrichment of the 2060 Ma phosphorus mineralization at Schiel (South Africa): geochemical and geochronological constraints

  • Torsten GraupnerEmail author
  • Reiner Klemd
  • Friedhelm Henjes-Kunst
  • Simon Goldmann
  • Helge Behnsen
  • Axel Gerdes
  • Reiner Dohrmann
  • Jay M. BartonJr
  • Rehan Opperman


Rocks of the rare-earth element (REY)-enriched apatite deposit in the eastern part of the Schiel Alkaline Complex (SAC; Southern Marginal Zone, Limpopo Belt) were studied for their whole-rock and mineral chemistry, REY mineral distribution and geochronology. Apart from phoscorite (sensu lato), pyroxenite and various syenitic rock types with quite variable apatite contents display P-REY enrichments. Field observations, mineralogical composition as well as major and trace element chemistry of soils make it possible to constrain the distribution of the hidden P-REY-rich rock types in the apatite deposit. Uranium-lead ages of zircon from phoscorite (sensu lato) and syenite are in the range of 2.06–2.05 Ga. Samarium-neodymium (εNd(t) −8.6 to −6.0) and in part Rb-Sr (87Sr/86Sr(t) 0.70819–0.70859) isotope data for whole-rock samples and mineral separates indicate an origin from an isotopically enriched and slightly variable source. Fluorapatite, early allanite and titanite are the main REY carriers at Schiel. Fluorapatite dominates the REY budget of pyroxenite and phoscorite, whereas early allanite hosts most of the REY in syenite. Three apatite types are distinguished based on their occurrence in the rocks, REYtotal contents and colouration in cathodoluminescence microscopy. Magmatic apatite in pyroxenite and in phoscorite (sensu lato) as well as early stage type I/II apatite in syenitic rocks have moderate to high REYtotal abundances (up to 3.2 wt%) with the mineral enriched in light REE. Early ferriallanite-(Ce) is strongly enriched in light REE and shows very high REYtotal values (13.7–26.4 wt%), while late allanite has lower REYtotal concentrations (6.9–14.9 wt%). Titanite is abundant in most syenitic rocks (REYtotal 1.7–6.4 wt%); chevkinite-(Ce) occurs locally and contributes to an REY enrichment in contact aureoles between syenite and different lithologies. Apatite-enriched rocks in the SAC in part contain significantly higher REYtotal concentrations in apatite grains compared to those in apatite-mineralized pyroxenite, phoscorite and carbonatite from Phalaborwa.


Schiel Alkaline Complex Apatite-mineralized rocks Soil geochemistry Rare-earth elements U-Pb, Lu-Hf, Sm-Nd and Rb-Sr isotopic compositions Cathodoluminescence 



The permission of the Chief of the area to carry out field campaigns at Schiel is greatly acknowledged. Fabian Kemner, Malte Junge, Andzani Ndhukwani and local field guides are thanked for help during field work in the Schiel Alkaline Complex. The authors are grateful to Oscar Laurent for providing pyroxenite samples and for discussion. Monika Bockrath, Siegrid Gerlach, Christian Wöhrl, Hans Lorenz and Nikola Koglin are acknowledged for analytical assistance at the BGR. Hiltrud Müller-Sigmund (University of Freiburg) and colleagues kindly performed mineral separation. This paper contributes to the project RoStraMet of the BGR. Two anonymous reviewers of Mineralium Deposita and the handling editor Hartwig Frimmel provided useful comments, which considerably improved the manuscript.

Funding information

Reiner Klemd thanks the BGR (grant 203-10047988) for financial support.

Supplementary material

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ESM Fig. S1 Regional geology and main tectonic features of the Limpopo Mobile Belt (modified after Kramers et al. (2006)). The Schiel Alkaline Complex is situated within the Southern Marginal Zone (SMZ) in close contact to the prominent Hout River Shear Zone (JPEG 11848 kb)
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ESM Fig. S2 Nomenclature diagram for the system 2REEPO4–CaTh(PO4)2–2ThSiO4 showing the endmember proportions of the monazite and thorite found in the SAC magmatites. Cation proportions were calculated on the basis of eight atoms of oxygen, H2O-free. Endmember proportions were calculated according to Linthout (2007) (JPEG 2664 kb)
126_2018_791_MOESM11_ESM.jpg (864 kb)
ESM Fig. S3 X-ray diffraction of oriented mounts of clay fractions of air-dry (AD, black) and ethylene glycol solvated (EG, blue) samples. a Sample Sch4. b Sample Sch5 (JPEG 864 kb)


  1. Bardossy G, Aleva GJJ (1990) Lateritic bauxites. Dev Econ Geol 27. Elsevier, Amsterdam, p 639Google Scholar
  2. Barton JM, du Toit MC, van Reenen DD, Ryan B (1983) Geochronical studies in the southern marginal zone of the Limpopo mobile belt, southern Africa. Spec Publ Geol Soc S Afr 8:55–64Google Scholar
  3. Barton JM, Doig R, Smith CB, Bohlender F, van Reenen DD (1992) Isotopic and REE characteristics of the intrusive charno-enderbite and enderbite geographically associated with the Matok Pluton, Limpopo Belt, southern Africa. Precambrian Res 55:452–467Google Scholar
  4. Barton JM, Holzer L, Kamber B, Doig R, Kramers JD, Nyfeler D (1994) Discrete metamorphic events in the Limpopo belt, southern Africa: implications for the application of P-T pathsin complex metamorphic terrains. Geology 22(11):1035–1038.<1035:DMEITL>2.3.CO;2 CrossRefGoogle Scholar
  5. Barton JM, Barton ES, Smith CB (1996) Petrography, age and origin of the Schiel alkaline complex, northern Transvaal, South Africa. J Afr Earth Sci 22(2):133–145. CrossRefGoogle Scholar
  6. Barton JM, Klemd R, Zeh A, (2006) The Limpopo Belt: a result of Archean to Proterozoic, Turkic-type orogenesis? In: Reimold WU, Gibson RL (eds) Processes on the Early Earth: Geol Soc Amer Spec Pap, 405 pp 315–331Google Scholar
  7. Basu NK, Mayila A (1986) Petrographic and chemical characteristics of the Panda Hill carbonatite complex, Tanzania. J Afr Earth Sci 5:589–598Google Scholar
  8. Behnsen H (2013) Rare earth element investigations on the Schiel Alkaline Complex, South Africa, M.Sc thesis, University of Erlangen, Germany, pp 99Google Scholar
  9. Belousova EA, Griffin WL, O’Reilly SY, Fisher NI (2002) Apatite as an indicator mineral for mineral exploration: trace-element compositions and their relationship to host rock type. J Geochem Expl 76(1):45–69. CrossRefGoogle Scholar
  10. Bowie SHU, Horne JET (1953) Cheralite, a new mineral ofthe monazite group. Mineral Mag 30(221):93–99. CrossRefGoogle Scholar
  11. Braun J-J, Pagel M, Muller J-P, Bilong P, Michard A, Guillet B (1990) Cerium anomalies inlateritic profiles. Geochim Cosmochim Acta 54(3):781–795. CrossRefGoogle Scholar
  12. Coetzee H (1993) Interpretation of an airborne radiometric survey of the Schiel Complex, using the ternary colour mapping technique. Unpublished Report Geol Sur S Afr 1993-0005, pp 38Google Scholar
  13. Cox KG, Bell JD, Pankhurst RJ (1979) The interpretation of igneous rocks. George, Allen and Unwin, London. CrossRefGoogle Scholar
  14. Dawson JB, Hinton RW (2003) Trace-element content and partitioning in calcite, dolomite and apatite in carbonatite, Phalaborwa, South Africa. Mineral Mag 67(5):921–930. CrossRefGoogle Scholar
  15. De Toledo MCM, Lenharo SLR, Ferrari VC, Fontan F, Leroy G (2004) The compositional evolution of apatite in the weathering profile of the Catalão I alkaline-carbonatitic complex, Goias, Brazil. Can Mineral 42(4):1139–1158. CrossRefGoogle Scholar
  16. Decrée S, Boulvais P, Tack L, Andre L, Baele J-M (2016) Fluorapatite in carbonatite-related phosphate deposits: the caseof the Matongo carbonatite (Burundi). Mineral Deposita 51(4):453–466. CrossRefGoogle Scholar
  17. DePaolo DJ (1988) Neodymium isotope geochemistry: an introduction. Minerals and rocks 20. Springer-Verlag, New York, p 187. CrossRefGoogle Scholar
  18. Dohrmann R (2006) Cation exchange capacity methodology I: an efficient model for the detection of incorrect cation exchange capacity and exchangeable cation results. Appl Clay Sci 34(1-4):31–37. CrossRefGoogle Scholar
  19. Du Toit MC (1979) Die geologie en struktuur van die gebiede Levubu en Bandelierkorp in Noord-Transvaal. Ph. D thesis, Rand Afrikaans University, Johannesburg, South Africa, pp 241Google Scholar
  20. Eriksson SC (1989) Phalaborwa: a saga of magmatism, metasomatism and miscibility. In: Bell K (ed) Carbonatites: genesis and evolution. Unwin Hyman, London, pp 221–254Google Scholar
  21. Fandrich R, Gu Y, Burrows D, Moeller K (2007) Modern SEM-based mineral liberation analysis. Int J Miner Process 84(1-4):310–320. CrossRefGoogle Scholar
  22. Gerdes A, Zeh A (2006) Combined U–Pb and Hf isotope LA-(MC-)ICP-MS analyses of detrital zircons: comparison with SHRIMP and new constraints for the provenance and age of an Armorican metasediment in Central Germany. Earth Planet Sci Lett 249(1-2):47–61. CrossRefGoogle Scholar
  23. Gerdes A, Zeh A (2009) Zircon formation versus zircon alteration – new insights from combined U–Pb and Lu–Hf in-situ LA–ICP–MS analyses, and consequences for the interpretation of Archean zircon from the Central Zone of the Limpopo Belt. Chem Geol 261(3-4):230–243. CrossRefGoogle Scholar
  24. Gieré R, Sorensen SS (2004) Allanite and other REE-rich epidote-group minerals. Rev Mineral Geochem 56(1):431–493. CrossRefGoogle Scholar
  25. Graupner T, Opperman R, Tongu EL (2014) Rare-earth elements. In: Buchholz P (ed) Investor’s and procurement guide South Africa, part 1: heavy minerals, rare earth elements, antimony. DERA, label D Druck + Medien GmbH, Berlin, pp 73–116Google Scholar
  26. Graupner T, Mühlbach C, Schwarz-Schampera U, Henjes-Kunst F, Melcher F, Terblanche H (2015) Mineralogy of high-field-strength elements (Y, Nb, REE) in the world-class Vergenoeg fluorite deposit, South Africa. Ore Geol Rev 64:583–601. CrossRefGoogle Scholar
  27. Gu Y (2003) Automated scanning electron microscope based mineral liberation analysis. An introduction to JKMRC/FEI mineral liberation analyser. J Miner Mater Charact Eng 2:33–41Google Scholar
  28. Jacobsen SB, Wasserburg GJ (1984) Sm-Nd evolution of chondrites and achondrites. II. Earth Planet Sci Lett 67: 137-150Google Scholar
  29. Jiang N (2006) Hydrothermal alteration of chevkinite-(Ce) in the Shuiquangou syenitic intrusion, northern China. Chem Geol 227(1-2):100–112. CrossRefGoogle Scholar
  30. Joubert P (1964) The geology of the apatite occurrence and associated rocks on Shiel 54 LT, Sibasa District. Unpubl. Rep. Geological Survey South Africa 1964–0043, pp 62Google Scholar
  31. Kemner F (2013) Petrology of the Schiel Alkaline Complex, Southern Marginal Zone of the Limpopo belt, South Africa. M.Sc thesis, GeoZentrum Nordbayern, University of Erlangen, Germany, pp 84Google Scholar
  32. Kingsnorth DJ (2016) Curtin-IMCOA Rare Earth Quarterly Bulletin #13. Curtin Graduate School of Business. Ppt-presentation 20.01.2016, pp 43Google Scholar
  33. Kramers JD, McCourt S, van Reenen DD (2006) The Limpopo Belt. In: Johnson MR, Anhaeusser CR, Thomas RJ (eds) The geology of South Africa. Geol SocS Afr, Johannesburg/Council for Geoscience, Pretoria, pp 209–236Google Scholar
  34. Krasnova NI, Petrov TG, Balaganskaya EG, Garcia D, Moutte J, Zaitsev AN, Wall F (2004) Introduction to phoscorites: occurrence, composition, nomenclature and petrogenesis. In: Wall F, Zaitsev AN (eds) Phoscorites and carbonatites from mantle to mine: the key example of the Kola Alkaline Province. The mineral Soc Series 10. Black Bear Press, Cambridge, pp 45–74Google Scholar
  35. Kreissig K, Holzer L, Frei R, Villa IM, Kramers JD, Kröner A, Smit CA, van Reenen DD (2001) Geochronology of the Hout River shear zone and the metamorphism in the Southern Marginal Zone of the Limpopo Belt, Southern Africa. Precambrian Res 109(1-2):145–173. CrossRefGoogle Scholar
  36. Laurent O, Zeh A (2015) A linear Hf isotope-age array despite different granitoid sources and complex Archean geodynamics: example from the Pietersburg block (South Africa). Earth Planet Sci Lett 430:326–338. CrossRefGoogle Scholar
  37. Linthout K (2007) Tripartite division of the system 2REEPO4–CaTh(PO4)2–2ThSiO4, discreditation of brabantite, an recognition of cheralite as the name for members dominated by CaTh(PO4)2. Can Mineral 45(3):503–508. CrossRefGoogle Scholar
  38. Lottermoser B (1989) Rare earth elements and ore formation process. Unpubl Thesis, University of Newcastle, New South Wales, Australia, pp 308Google Scholar
  39. Lubala RT, Frick C, Rogers HJJ, Walraven F (1994) Petrogenesis of syenites and granites of the Schiel Alkaline Complex, Northern Transvaal, South Africa. J Geol 102(3):307–316. CrossRefGoogle Scholar
  40. Marks MAW, Wenzel T, Whitehouse MJ, Loose M, Zack T, Barth M, Worgard L, Krasz V, Eby GN, Stosnach H, Markl G (2012) The volatile inventory (F, cl, Br, S, C) of magmatic apatite: an integrated analytical approach. Chem Geol 291:241–255. CrossRefGoogle Scholar
  41. Mason R (1973) The Limpopo Belt—southern Africa. Phil Trans R Soc Lond A 273:463–485CrossRefGoogle Scholar
  42. McDonough WF, Sun SS (1995) The composition of the earth. Chem Geol 120(3-4):223–253. CrossRefGoogle Scholar
  43. Milani L, Bolhar R, Frei D, Harlov DE, Samuel VO (2017) Light rare earth element systematics as a tool for investigating the petrogenesis of phoscorite-carbonatite associations, as exemplified by the Phalaborwa complex, South Africa. Mineral Deposita 52:1105–1125CrossRefGoogle Scholar
  44. Miyashiro A (1978) Nature of alkalic volcanic rock series. Contrib Mineral Petrol 66(1):91–104. CrossRefGoogle Scholar
  45. Morteani G, Preinfalk (1996) REE distribution and REE carriers in laterites formed on the alkaline complexes of Araxá and Catalão (Brazil). In: Jones AP et al (eds) Rare Earth Minerals: chemistry, origin and ore deposits. The Mineral Soc Series 7. Chapman and Hall, London, pp 227–255Google Scholar
  46. Neuser RD, Bruhn F, Götze J, Habermann D, Richter DK (1995) Cathodoluminescence: methods and application. Zbl Geo Pal 1(2):287–306Google Scholar
  47. Pearce NJG, Perkins WT, Westgate JA, Gorton MP, Jackson SE, Neal CR, Chenery SP (1997) A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostand Newslett 21(1):115–144. CrossRefGoogle Scholar
  48. Petrik I, Broska I, Lipka J, Siman P (1995) Granitoid allanite-(Ce) substitution relations, redox conditions and REE distributions (on an example of I-type granitoids, Western Carpathians, Slovakia). Geol Carpath 46:79–94Google Scholar
  49. Piccoli PM, Candela PA (2002) Apatite in igneous systems. In: Kohn MJ, et al (eds) Phosphates: geochemical, geobiological, and materials importance. Rev Mineral Geochem 48:255–292Google Scholar
  50. Pouchou J-L, Pichoir F (1991) Quantitative analysis of homogeneous or stratified microvolumes applying the model “PAP” in microprobe analysis. In: Heinrich KFJ, Newbury DE (eds) Electron probe quantitation. Plenum Press, New York, pp 31–75. CrossRefGoogle Scholar
  51. Prins D, Van Graan SJ, Du Rand HGJ, Oberholzer JW (1981) Schiel-phosphate deposit: an order of magnitude feasibility study. Technocom Mineral Development Services (PTY) LTDGoogle Scholar
  52. Schulz B, Klemd R, Brätz H (2006) Host rock compositional controls on zircon trace element signatures in metabasites from the Austroalpine basement. Geochim Cosmochim Acta 70(3):697–710. CrossRefGoogle Scholar
  53. Smit CA, Roering C, van Reenen DD (1992) The structural framework of the southern margin of the Limpopo Belt, South Africa. Precambrian Res 55(1-4):51–67. CrossRefGoogle Scholar
  54. Stettler EH, Coetzee H, Rogers HJJ, Lubala RT (1993) The Schiel Alkaline Complex: geological setting and geophysical investigation. S Afr J Geol 96:96–107Google Scholar
  55. Stevens G, van Reenen D (1992) Partial melting and the origin of metapelitic granulites in the Southern Marginal Zone of the Limpopo Belt, South Africa. Precambrian Res 55(1-4):303–319. CrossRefGoogle Scholar
  56. Torab FM, Lehmann B (2007) Magnetite–apatite deposits of the Bafq district, Central Iran: apatite geochemistry and monazite geochronology. Mineral Mag 71(3):347–363. CrossRefGoogle Scholar
  57. Verwoerd WJ (1986) Mineral deposits associated with carbonatites and alkaline rocks. In: Anhaeusser CR, Maske S (eds) Mineral deposits of Southern Africa. Geol Soc S Afr, Johannesburg, pp 2173–2191Google Scholar
  58. Verwoerd W, du Toit M (2006) The Phalaborwa and Schiel complexes. In: Johnson MR et al (eds) The geology of South Africa. Geol SocS Afr, Johannesburg/Council for Geoscience, Pretoria, pp 291–300Google Scholar
  59. Viljoen VE (1966) Volledige geologiese verslag op die Schiel fosfaatvorkoorkoms. Unpublished FOSKOR Report, pp 38Google Scholar
  60. Vlach S, Gualda G (2007) Allanite and chevkinite in A-type granites and syenites of the Graciosa Province, southern Brazil. Lithos 97(1-2):98–121. CrossRefGoogle Scholar
  61. Walraven F, Frick C, Lubala RT (1992) Pb-isotope geochronology of the Schiel Complex, northern Transvaal, South Africa. J Afr Earth Sci 15(1):103–110. CrossRefGoogle Scholar
  62. Walters AS, Goodenough KM, Hughes HSR, Roberts NMW, Gunn AG, Rushton J, Lacinska A (2013) Enrichment of rare earth elements during magmatic and post-magmatic processes: a case study from the Loch Loyal Syenite Complex, northern Scotland. Contrib Mineral Petrol 166(4):1177–1202. CrossRefGoogle Scholar
  63. Watanabe Y (2008) Rare-earth: resource exploration and development. In: Nakamura M (ed) Rare Metals. National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, pp 10–11Google Scholar
  64. Webster JD, Piccoli PM (2015) Magmatic apatite: a powerful, yet deceptive, mineral. Elements 11(3):177–182. CrossRefGoogle Scholar
  65. Wilson M (1989) Igneous petrogenesis. Unwin Hyman, London. CrossRefGoogle Scholar
  66. Wilson MGC (1998) Copper. In: Wilson MGC, Anhaeusser CR (eds) The mineral resources of South Africa. Handbook 16. Council for Geoscience, Pretoria, pp 209–227Google Scholar
  67. Wu FY, Yang YH, Bulakh AG, Bellatreccia F, Mitchell RH, Li QL (2010) In situ U–Pb and Nd–Hf–(Sr) isotopic investigations of zirconolite and calzirtite. Chem Geol 277:178–195CrossRefGoogle Scholar
  68. Wu FY, Yang YH, Li QL, Mitchell RH, Dawson JB, Brandl G, Yuhara M (2011) In situ determination of U–Pb ages and Sr–Nd–Hf isotopic constraints on the petrogenesis of the Phalaborwa carbonatite complex, South Africa. Lithos 127:309–322CrossRefGoogle Scholar
  69. Xie H, Kröner A, Brandl G, Wan Y (2017) Two orogenic events separated by 2.6 Ga mafic dykes in the Central Zone, Limpopo Belt, Southern Africa. Precambrian Res 289:129–141. CrossRefGoogle Scholar
  70. Zeh A, Gerdes A (2012) U–Pb and Hf isotope record of detrital zircons from gold-bearing sediments of the Pietersburg Greenstone belt (South Africa)—is there a common provenance with the Witwatersrand Basin? Precambrian Res 204–205:46–56CrossRefGoogle Scholar
  71. Zenzén N (1916) Determinations of the power of refraction of allanites. Acta Univ Upsaliensis Bull Geol Inst 15:61–76Google Scholar

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© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Bundesanstalt für Geowissenschaften und RohstoffeHannoverGermany
  2. 2.GeoZentrum NordbayernUniversität Erlangen-NürnbergErlangenGermany
  3. 3.Economic Geology Research CenterJames Cook UniversityTownsvilleAustralia
  4. 4.Institut für GeowissenschaftenGoethe UniversitätFrankfurt am MainGermany
  5. 5.Department of GeologyUniversity of Fort HareAliceSouth Africa
  6. 6.Council for GeosciencePretoriaSouth Africa

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