Abstract
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.
Similar content being viewed by others
References
Bardossy G, Aleva GJJ (1990) Lateritic bauxites. Dev Econ Geol 27. Elsevier, Amsterdam, p 639
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 8:55–64
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 55:452–467
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. https://doi.org/10.1130/0091-7613(1994)022<1035:DMEITL>2.3.CO;2
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. https://doi.org/10.1016/0899-5362(96)00005-X
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 315–331
Basu NK, Mayila A (1986) Petrographic and chemical characteristics of the Panda Hill carbonatite complex, Tanzania. J Afr Earth Sci 5:589–598
Behnsen H (2013) Rare earth element investigations on the Schiel Alkaline Complex, South Africa, M.Sc thesis, University of Erlangen, Germany, pp 99
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. https://doi.org/10.1016/S0375-6742(02)00204-2
Bowie SHU, Horne JET (1953) Cheralite, a new mineral ofthe monazite group. Mineral Mag 30(221):93–99. https://doi.org/10.1180/minmag.1953.030.221.02
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. https://doi.org/10.1016/0016-7037(90)90373-S
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 38
Cox KG, Bell JD, Pankhurst RJ (1979) The interpretation of igneous rocks. George, Allen and Unwin, London. https://doi.org/10.1007/978-94-017-3373-1
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. https://doi.org/10.1180/0026461036750151
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. https://doi.org/10.2113/gscanmin.42.4.1139
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. https://doi.org/10.1007/s00126-015-0620-1
DePaolo DJ (1988) Neodymium isotope geochemistry: an introduction. Minerals and rocks 20. Springer-Verlag, New York, p 187. https://doi.org/10.1007/978-3-642-48916-7
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. https://doi.org/10.1016/j.clay.2005.12.006
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 241
Eriksson SC (1989) Phalaborwa: a saga of magmatism, metasomatism and miscibility. In: Bell K (ed) Carbonatites: genesis and evolution. Unwin Hyman, London, pp 221–254
Fandrich R, Gu Y, Burrows D, Moeller K (2007) Modern SEM-based mineral liberation analysis. Int J Miner Process 84(1-4):310–320. https://doi.org/10.1016/j.minpro.2006.07.018
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. https://doi.org/10.1016/j.epsl.2006.06.039
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. https://doi.org/10.1016/j.chemgeo.2008.03.005
Gieré R, Sorensen SS (2004) Allanite and other REE-rich epidote-group minerals. Rev Mineral Geochem 56(1):431–493. https://doi.org/10.2138/gsrmg.56.1.431
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 73–116
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. https://doi.org/10.1016/j.oregeorev.2014.02.012
Gu Y (2003) Automated scanning electron microscope based mineral liberation analysis. An introduction to JKMRC/FEI mineral liberation analyser. J Miner Mater Charact Eng 2:33–41
Jacobsen SB, Wasserburg GJ (1984) Sm-Nd evolution of chondrites and achondrites. II. Earth Planet Sci Lett 67: 137-150
Jiang N (2006) Hydrothermal alteration of chevkinite-(Ce) in the Shuiquangou syenitic intrusion, northern China. Chem Geol 227(1-2):100–112. https://doi.org/10.1016/j.chemgeo.2005.09.004
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 62
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 84
Kingsnorth DJ (2016) Curtin-IMCOA Rare Earth Quarterly Bulletin #13. Curtin Graduate School of Business. Ppt-presentation 20.01.2016, pp 43
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 209–236
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 45–74
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. https://doi.org/10.1016/S0301-9268(01)00147-4
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. https://doi.org/10.1016/j.epsl.2015.08.028
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. https://doi.org/10.2113/gscanmin.45.3.503
Lottermoser B (1989) Rare earth elements and ore formation process. Unpubl Thesis, University of Newcastle, New South Wales, Australia, pp 308
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. https://doi.org/10.1086/629673
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. https://doi.org/10.1016/j.chemgeo.2011.10.026
Mason R (1973) The Limpopo Belt—southern Africa. Phil Trans R Soc Lond A 273:463–485
McDonough WF, Sun SS (1995) The composition of the earth. Chem Geol 120(3-4):223–253. https://doi.org/10.1016/0009-2541(94)00140-4
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 52:1105–1125
Miyashiro A (1978) Nature of alkalic volcanic rock series. Contrib Mineral Petrol 66(1):91–104. https://doi.org/10.1007/BF00376089
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 227–255
Neuser RD, Bruhn F, Götze J, Habermann D, Richter DK (1995) Cathodoluminescence: methods and application. Zbl Geo Pal 1(2):287–306
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. https://doi.org/10.1111/j.1751-908X.1997.tb00538.x
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 46:79–94
Piccoli PM, Candela PA (2002) Apatite in igneous systems. In: Kohn MJ, et al (eds) Phosphates: geochemical, geobiological, and materials importance. Rev Mineral Geochem 48:255–292
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. https://doi.org/10.1007/978-1-4899-2617-3_4
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) LTD
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. https://doi.org/10.1016/j.gca.2005.10.001
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. https://doi.org/10.1016/0301-9268(92)90014-F
Stettler EH, Coetzee H, Rogers HJJ, Lubala RT (1993) The Schiel Alkaline Complex: geological setting and geophysical investigation. S Afr J Geol 96:96–107
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. https://doi.org/10.1016/0301-9268(92)90030-R
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. https://doi.org/10.1180/minmag.2007.071.3.347
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 2173–2191
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 291–300
Viljoen VE (1966) Volledige geologiese verslag op die Schiel fosfaatvorkoorkoms. Unpublished FOSKOR Report, pp 38
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. https://doi.org/10.1016/j.lithos.2006.12.003
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. https://doi.org/10.1016/0899-5362(92)90011-Z
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. https://doi.org/10.1007/s00410-013-0916-z
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 10–11
Webster JD, Piccoli PM (2015) Magmatic apatite: a powerful, yet deceptive, mineral. Elements 11(3):177–182. https://doi.org/10.2113/gselements.11.3.177
Wilson M (1989) Igneous petrogenesis. Unwin Hyman, London. https://doi.org/10.1007/978-1-4020-6788-4
Wilson MGC (1998) Copper. In: Wilson MGC, Anhaeusser CR (eds) The mineral resources of South Africa. Handbook 16. Council for Geoscience, Pretoria, pp 209–227
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 277:178–195
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 127:309–322
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. https://doi.org/10.1016/j.precamres.2016.11.009
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 204–205:46–56
Zenzén N (1916) Determinations of the power of refraction of allanites. Acta Univ Upsaliensis Bull Geol Inst 15:61–76
Acknowledgements
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
Reiner Klemd thanks the BGR (grant 203-10047988) for financial support.
Author information
Authors and Affiliations
Corresponding author
Additional information
Editorial handling: H. Frimmel
Electronic supplementary material
ESM 1
(DOCX 17 kb)
ESM Table S1
(DOCX 50 kb)
ESM Table S2
(DOCX 41 kb)
ESM Table S3
(DOCX 39 kb)
ESM Table S4
(DOCX 61 kb)
ESM Table S5
(DOCX 54 kb)
ESM Table S6
(DOCX 62 kb)
ESM Table S7
(DOCX 54 kb)
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)
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)
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)
Rights and permissions
About this article
Cite this article
Graupner, T., Klemd, R., Henjes-Kunst, F. et al. Formation conditions and REY enrichment of the 2060 Ma phosphorus mineralization at Schiel (South Africa): geochemical and geochronological constraints. Miner Deposita 53, 1117–1142 (2018). https://doi.org/10.1007/s00126-018-0791-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00126-018-0791-7