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3D implicit modeling of the Sishen Mine: new resolution of the geometry and origin of Fe mineralization

  • B. Stoch
  • C. J. Anthonissen
  • M-J. McCall
  • I. J. Basson
  • J. Deacon
  • E. Cloete
  • J. Botha
  • J. Britz
  • M. Strydom
  • D. Nel
  • M. Bester
Article
  • 158 Downloads

Abstract

The Sishen deposit is one of the largest iron ore concentrations in current production. Hematite mineralization occurs along a strike length of 14 km, with a width of 3.2 km and a maximum vertical extent of 400 m below the original surface. The 986-Mt reserve incorporates a suite of individual orebodies, beneath a locally preserved tectonized unconformity, with a wide range of geometries, depths, and orientations. Fully constrained, implicit 3D modeling of the entire mining volume (> 70 km3), was undertaken to the original, pre-mining topography. The model incorporates 5287 mapping points and > 21,000 drillholes and provides exceptional insight into the original configuration of ore and its relationship to contacts, unconformities, and structures in the enclosing country rock. The bulk of ore occurs to the west of a strike-extensive, partially inverted normal fault (Sloep Fault), within an asymmetrical synclinal structure on its western flank. This linear, N-S distribution of deep, thick ore is punctuated by palaeosinkholes, wherein base-of-ore dips of greater than 45°, are concentrically arranged. Localized ore volumes also occur along faults and in fault-bounded, downthrown blocks, to the north of NW-SE- and NE-SW-trending strike-slip faults that show relatively minor uplift to the south, probably due to the Lomanian Namaqua-Natal Orogeny. The revised model demonstrates the proximity of ore to a tectonized unconformity and highlights the structural control on ore volumes, implying that Fe mineralization at Sishen cannot be exclusively attributed to supergene enrichment and concentric palaeosinkhole formation.

Keywords

Iron ore Structural interpretation Implicit modeling Leapfrog™ 

Notes

Acknowledgments

The authors thank Kumba Iron Ore, Anglo American for their permission to publish this study. Field assistance by Charlie Smal is acknowledged by Ian Basson. The authors express their gratitude to the reviewers for their valuable comments.

References

  1. Altermann W, Hälbich IW (1991) Structural history of the southwestern corner of the Kaapvaal craton and the adjacent Namaqua realm: new observations and a reappraisal. Pre Cambr Res 52(1):133–166.  https://doi.org/10.1016/0301-9268(91)90017-5 CrossRefGoogle Scholar
  2. Altermann W (1997) Sedimentological evaluation of Pb-Zn exploration potential of the Precambrian Griquatown fault zone in the Northern Cape Province, South Africa. Mineral Deposita 32(4):382–391.  https://doi.org/10.1007/s001260050104 CrossRefGoogle Scholar
  3. Altermann W, Nelson DR (1998) Sedimentation rates, basin analysis and regional correlations of three Neoarchaean and Palaeoproterozoic sub-basins of the Kaapvaal craton as inferred from precise U-Pb zircon ages from volcaniclastic sediments. Sediment Geol 120(1-4):225–256.  https://doi.org/10.1016/S0037-0738(98)00034-7 CrossRefGoogle Scholar
  4. Armstrong RA (1987) Geochronological studies on Archean and Proterozoic formations of the foreland of the Namaqua front and possible correlates on the Kaapvaal Craton. Dissertation Witwatersrand University, Johannesburg, p 274Google Scholar
  5. Basson IJ, Koegelenberg C (2016) Structural controls on Fe mineralization at Thabazimbi Mine, South Africa. Ore Geol Rev 80:1056–1071CrossRefGoogle Scholar
  6. Basson IJ, Anthonissen CJ, McCall MJ, Stoch B, Britz J, Deacon J, Strydom M, Cloete E, Botha J, Bester M, Nel D (2017) Ore-structure relationships at Sishen Mine, Northern Cape, Republic of South Africa, based on fully-constrained implicit 3D modelling. Ore Geol Rev 86:825–838.  https://doi.org/10.1016/j.oregeorev.2017.04.007 CrossRefGoogle Scholar
  7. Berry MV, Quigley ML (2004) Mining geology 2004 workshop. Bulletin 41:92Google Scholar
  8. Beukes NJ (1983) Paleoenvironmental setting of iron formations in the depositional basin if the Transvaal Supergroup, South Africa. In: Trendall AF, Morris RC (eds) Iron formation: facts and problems. Elsevier, Amsterdam, pp 131–210CrossRefGoogle Scholar
  9. Beukes NJ (1986) The Transvaal sequence in Griqualand west. Miner Depos of South. Africa 1:819–828Google Scholar
  10. Beukes NJ, Smit CA (1987) New evidence for thrust faulting in Griqualand west, south Africa; implications for stratigraphy and the age of red beds. South African J of Geol 90(4):378–394Google Scholar
  11. Beukes NJ, Gutzmer J, Mukhopadhy J (2002) The geology and genesis of high-grade haematite iron ore deposits. Proc Iron Ore 2002 Conf: 23–29, The Australasian Inst of Mining and Metallurgy: MelbourneGoogle Scholar
  12. Beukes NJ, Gutzmer J (2008) Origin and paleoenvironmental significance of major iron formations at the Archean–Paleoproterozoic boundary. In: Hagemann, S, Rosiere, C, Gutzmer, J, Beukes, NJ (eds) Banded iron formation-related high-grade iron ore, Reviews in economic geology, vol 15. Society of Economic Geologists, Littleton, Colorado, pp 5–47Google Scholar
  13. Birch C (2014) New systems for geological modelling—black box or best practice? J South Afr Inst Min Metall 114:1–7Google Scholar
  14. Bloomenthal J (1988) Polygonization of implicit surfaces. Computer Aided Geometric Design 5(4):341–355.  https://doi.org/10.1016/0167-8396(88)90013-1 CrossRefGoogle Scholar
  15. Bloomenthal J (ed) (1997) Introduction to implicit surfaces. Morgan Kaufmann Publishers, Inc, San Francisco, CaliforniaGoogle Scholar
  16. Boardman LG, (1948) The geology of iron ore and other minerals of the Thabazimbi area. Dissertation, University of PretoriaGoogle Scholar
  17. Carney MD, Mienie PJ (2003) Comparison of the Sishen and Sishen South (Welgevonden) iron ore deposits, N Cape Province, South Africa. Appl Earth Sci (Trans Inst Min Metall B) 112:B5CrossRefGoogle Scholar
  18. Carr JC, Beatson RK, Evans TR (2001) Reconstruction and representation of 3D objects with radial basis functions SIGGRAPH. Computer Graphics, pp 67–76Google Scholar
  19. Caumon G, Gray G, Antoine C, Titeux MC (2013) Three-dimensional implicit stratigraphic model building from remote sensing data on tetrahedral meshes: theory and application to a regional model of La Popa Basin, NE Mexico. IEEE Trans on Geoscience and Remote Sens 51(3):1613–1621.  https://doi.org/10.1109/TGRS.2012.2207727 CrossRefGoogle Scholar
  20. Cornell DH, Zack T, Andersen T, Corfu F, Frei D, van Schindel V (2017) The U-Pb zircon geochronology of the Palaeoproperozoic Hartley formation porphyry by six methods with age uncertainty approaching 1 Ma. J S Afr Geol 119(3):473–494CrossRefGoogle Scholar
  21. Cowan EJ, Beatson RK, Fright WR, Mclennan TJ, Mitchell TJ (2002) Rapid geological modelling Applied Structural Geology for Mineral Exploration and Mining. International Symposium, 23–25 September 2002, Kalgoorlie, pp 23–25Google Scholar
  22. Cowan EJ, Beatson RK, Ross HJ, Fright WR, Mclennan TJ, Evans TR, Carr JC, Lane RG, Bright DV, Gillman AJ, Oshust PA, Titley M (2003) Practical implicit geological modelling. In: Dominy, S (Ed), Fifth Int Min Geol Conf Proc. AusIMM Publication Series No 8/2003, 89–99 pGoogle Scholar
  23. Cowan EJ, Spragg KJ, Everitt MR (2011) Wireframe-free geological modelling—an oxymoron or a value proposition? Eighth international mining geology conference. Australasian Ins Min Met, Queenstown, New ZealandGoogle Scholar
  24. Dalstra HJ, Rosière CA (2008) Structural controls on high-grade iron ores hosted by banded iron formation: a global perspective. Rev in Econ Geol 15:73–106Google Scholar
  25. De Villiers JE (1944) The origin of the iron and manganese deposits in the Postmasburg and Thabazimbi area. Trans Geol Soc S Afr 47:123–135Google Scholar
  26. De Villiers PR (1970) The geology and mineralogy of the Kalahari manganese field north of Sishen, Cape Province. S Afr Geol Surv, Mem 59:65Google Scholar
  27. De Villiers PR, Visser JHJ (1977) The glacial beds of the Griqualand West Supergroup as revealed by four deep boreholes between Postmasburg and Sishen. Trans of the Geol Soc of S Afr 80:1–8Google Scholar
  28. Driscoll TA, Heryudono ARH (2007) Adaptive residual subsampling methods for radial basis function interpolation and collocation problems. Comput Math Appl 53(6):927–939.  https://doi.org/10.1016/j.camwa.2006.06.005 CrossRefGoogle Scholar
  29. Du Preez JW (1944) The structural geology of the area east of Thabazimbi and the genesis of the associated ore. Anns University Stellenbosch 22A:264–360Google Scholar
  30. Fornberg B, Driscoll TA, Wright G, Charles R (2002) Observations on the behaviour of radial basis function approximations near boundaries. Comput Math Appl 43(3–5):473–490.  https://doi.org/10.1016/S0898-1221(01)00299-1 CrossRefGoogle Scholar
  31. Friese AEW, Alchin DJ (2007) New insights into the formation, structural development, and preservation of iron ore deposits in the Northern Cape Province, South Africa. Proc Iron Ore 2005 Conf, Australasian Ins Min MetGoogle Scholar
  32. Guillen G, Calcagno P, Courrioux G, Joly A, Ledru P (2008) Geological modelling from field data and geological knowledge. Part II: modelling validation using gravity and magnetic data inversion. Phys Earth Planet Inter 171(1-4):158–169.  https://doi.org/10.1016/j.pepi.2008.06.014 CrossRefGoogle Scholar
  33. Gutzmer J, Beukes NJ (1995) Fault-controlled metasomatic alteration of early Proterozoic sedimentary manganese ores in the Kalahari manganese field. S Afr J Econ Geol 90(4):823–844.  https://doi.org/10.2113/gsecongeo.90.4.823 CrossRefGoogle Scholar
  34. Gutzmer J, Chisonga BC, Beukes NJ, Mukhopadhyay JO (2008) The geochemistry of banded iron formation-hosted high-grade hematite-martite iron ores. Rev Econ Geol 15:157–183Google Scholar
  35. Hagemann SG, Angerer T, Duurin P, Rosière F, Silva RC, Lobato L, Hensler AS, Walde DHG (2016) BIF-hosted iron mineral system: a review. Ore Geol Rev 76:317–359.  https://doi.org/10.1016/j.oregeorev.2015.11.004 CrossRefGoogle Scholar
  36. Hälbich IW, Scheepers R, Lamprecht DF, De Kock NJ (1993) The Transvaal-Griqualand west banded iron formation: geology, genesis, iron exploitation. J Afr Earth Sci 16(1–2):63–120.  https://doi.org/10.1016/0899-5362(93)90162-J CrossRefGoogle Scholar
  37. Hilliard P (1999) Structural evolution and tectonostratigraphy of the Kheis Orogen and its relationship to the southwestern margin of the Kaapvaal Craton. Unpub PhD Thesis, University of Durban-Westville, 235 pGoogle Scholar
  38. Hillier M, de Kemp E, Schetselaar E (2013) 3D form line construction by structural field interpolation (SFI) of geologic strike and dip observations. J Struct Geol 51:167–179.  https://doi.org/10.1016/j.jsg.2013.01.012 CrossRefGoogle Scholar
  39. Jessell M (2001) Three-dimensional geological modelling of potential-field data. Computational Geoscience 27:455–465CrossRefGoogle Scholar
  40. Jessell M, Aillères L, Kemp E, Lindsay M, Wellmann F, Hillier M, Laurent G, Carmichael T, Martin R (2014) Next generation three-dimensional geologic modeling and inversion. Soc Econ Geol Spec Pub 18:261–272Google Scholar
  41. Lascelles DF (2002) A new look at old rocks: a non-supergene origin for BIF-derived in situ high-grade iron ore deposits. Proceedings Iron Ore 2002 Australasian Ins Min Met, Perth, 107–126 pGoogle Scholar
  42. Lascelles DF (2007) Genesis of the Koolyanobbing iron ore deposits, Yilgarn Province, WA, Australia. Appl Earth Science (Trans Inst Min Metall B) 116(2):86–93.  https://doi.org/10.1179/174327507X167055 CrossRefGoogle Scholar
  43. Lascelles DF (2012) Banded iron formation to high-grade iron ore: a critical review of supergene enrichment models. Australian J of Earth Sciences 59(8):1105–1125CrossRefGoogle Scholar
  44. Laurent G, Caumon G, Jessell M (2015) Interactive editing of 3D geological structures and tectonic history sketching via a rigid element method. Computers and Geoscience 74:71–86CrossRefGoogle Scholar
  45. Li Z, Chi G, Bethune KM, Thomas D, Zaluski G (2017) Structural controls on fluid flow during compressional reactivation of basement faults: insights from numerical modeling for the formation of unconformity-related uranium deposits in the Athabasca Basin, Canada. Econ Geol 112(2):451–466.  https://doi.org/10.2113/econgeo.112.2.451 CrossRefGoogle Scholar
  46. Lindsay MD, Aillères L, Jessell MW, de Kemp E, Betts PG (2012) Locating and quantifying geological uncertainty in three-dimensional models: analysis of the Gippsland Basin, southeastern Australia. Tectonophys 546–547:10–27CrossRefGoogle Scholar
  47. Lindsay MD, Aillères L, Jessell MW, de Kemp E, Betts PG (2013) Geodiversity: exploration of 3D geological model space. Tectonophys 594:27–37.  https://doi.org/10.1016/j.tecto.2013.03.013 CrossRefGoogle Scholar
  48. Martin DM, Li ZX, Nemchin AA, Powell CM (1998) A pre-22 Ga. Age for giant hematite ores of the Hamersley province, Australia? Econ Geol 93(7):1084–1090.  https://doi.org/10.2113/gsecongeo.93.7.1084 CrossRefGoogle Scholar
  49. McLellan JG, Oliver NHS, Ord A, Zhang Y, Schaubs PM (2003) A numerical modelling approach to fluid flow in extensional environments: implications for genesis of large microplaty hematite ores. J Geochem Exploration 78-79:675–679.  https://doi.org/10.1016/S0375-6742(03)00126-2 CrossRefGoogle Scholar
  50. McLellan JG, Oliver NHS, Schaubs PM (2004) Fluid flow in extensional environments; numerical modelling with an application to Hamersley iron ores. J Struct Geol 26(6-7):1157–1171.  https://doi.org/10.1016/j.jsg.2003.11.015 CrossRefGoogle Scholar
  51. Moore M, Tsikos H, Polteau S (2000) Deconstructing the Transvaal Supergroup, South Africa: implications for Palaeoproterozoic palaeoclimate models. J Afr Earth Sci 33:437–444CrossRefGoogle Scholar
  52. Morey GB (1999) High-grade iron ore deposits of the Mesabi range, Minnesota: product of a continental-scale Proterozoic ground-water flow system. Econ Geol 94(1):133–141.  https://doi.org/10.2113/gsecongeo.94.1.133 CrossRefGoogle Scholar
  53. Mortimer B (1995) Report on structural geological analysis: Sishen. Internal Company Report, 71 pGoogle Scholar
  54. Oliver J (1986) Fluids expelled tectonically from orogenic belts: their role in hydrocarbon migration and other geologic phenomena. Geol 14(2):99–102.  https://doi.org/10.1130/0091-7613(1986)14<99:FETFOB>2.0.CO;2 CrossRefGoogle Scholar
  55. Papadopoulos V (2016) Mineralogical and geochemical constraints on the origin, alteration history and metallogenic significance of the Manganore iron-formation, Northern Cape Province, South Africa. MSc (Unpub), Rhodes University, 1–223 pGoogle Scholar
  56. Powell CMA, Oliver NHS, Li ZX, Martin DMB, Ronaszeki J (1999) Synorogenic hydrothermal origin for giant Hamersley iron oxide ore bodies. Geol 27(2):175–178.  https://doi.org/10.1130/0091-7613(1999)027<0175:SHOFGH>2.3.CO;2 CrossRefGoogle Scholar
  57. Savchenko VV, Pasko AA, Okunev OG, Kunii TL (1995) Function representation of solids reconstructed from scattered surface points and contours. Computer Graphics Forum 14(4):181–188.  https://doi.org/10.1111/1467-8659.1440181 CrossRefGoogle Scholar
  58. Schalkwyk G (2005) Genesis and characteristics of the Wolhaarkop chert breccia and associated Manganore iron formation Johannesburg. Dissertation, University of JohannesburgGoogle Scholar
  59. Schlegel GCJ (1988) Contribution to the metamorphic and structural evolution of the Kheis Tectonic Province, Northern Cape, South Africa. S Afr J of Geol 91(1):27–37Google Scholar
  60. Schütte SS (1992) Ongeluk volcanism in relation to the Kalahari manganese deposits. Dissertation, University of Natal, DurbanGoogle Scholar
  61. Smith AJB, Beukes NJ (2016) Palaeoproterozoic banded iron formation-hosted high-grade hematite iron ore deposits of the Transvaal Supergroup. S Afr Episodes 39(2):269–284.  10.18814/epiiugs/2016/v39i2/95778 CrossRefGoogle Scholar
  62. Strauss CA (1964) The iron ore deposits at Thabazimbi area, Transvaal. In: Haughton, SH (Ed), The Geology of Some Ore Deposits of Southern Africa. Geol Soc S Afr, Johannesburg, pp 383–392Google Scholar
  63. Stowe CW (1986) Synthesis and interpretation of structures along the north-eastern boundary of the Namaqua tectonic province, South Africa. S Afr J Geol 89(2):185–198Google Scholar
  64. Thomas RJ, Cornell DH, Moore JM, Jacobs J (1994) Crustal evolution of the Namaqua-Natal Metamorphic Province, southern Africa. S Afr J Geol 97:8–14Google Scholar
  65. Tsikos H, Beukes NJ, Moore JM, Harris C (2003) Deposition, diagenesis, and secondary enrichment of metals in the Paleoproterozoic Hotazel iron formation, Kalahari manganese field, South Africa. Econ Geol 98:1449–1462Google Scholar
  66. Van Deventer JL, Eriksson PG, Snyman CP (1986) The Thabazimbi iron ore deposit, north-western Transvaal. Mineral deposits of Southern Africa, vol 1: Geol Soc S Afr, Johannesburg, 923–930Google Scholar
  67. Van Wyk JP (1980) Die geologie van die Rooinekke-Matsap-Wolhaarkop in Noord-Kaapland met spesiale verwysing na die Koegas Subgroep en die Transvaal Supergroep. Randse Afrikaans University, Johannesburg, South Africa, DissertatiomGoogle Scholar
  68. Van Schalkwyk JF, Beukes NJ (1986) The Sishen iron ore deposit, Griqualand West. Anhaeusser, CR and Maske, S, Eds, Mineral deposits of Southern Africa, vol I: Geol Soc S Afr, Johannesburg 931–956Google Scholar
  69. Visser JNJ (1971) The deposition of the Griquatown glacial member in the Traansvaal Supergroup transactions of the Geological Society of South. Africa 74:187–199Google Scholar
  70. Vollgger S, Cruden RA, Ailleres L, Cowan EJ (2015) Regional dome evolution and its control on ore-grade distribution: insights from 3D implicit modelling of the Navachab gold deposit, Namibia. Ore Geol Rev 69:268–285.  https://doi.org/10.1016/j.oregeorev.2015.02.020 CrossRefGoogle Scholar
  71. von Plehwe-Leisen E, Klemm DD (1995) Geology and ore genesis of the manganese ore deposits of the Postmasburg manganese-field, South Africa. Mineral Deposita 30(3):257–267, DOI:  https://doi.org/10.1007/BF00196361
  72. Wagener PA (1921) Report on the Crocodile River iron deposits: Pretoria. Geological Survey, South Africa Memo 17:65 pGoogle Scholar
  73. Walraven F, Burger AJ, Allsopp HL (1982) Summary of age determinations carried out during the period April 1980 to march 1981. Ann Geol Soc S Afr 16:107–114Google Scholar
  74. Wellmann JF, Horowitz FG, Schill E, Regenauer-Lieb K (2010) Towards incorporating uncertainty of structural data in 3D geological inversion. Tectonophys 490(3-4):141–151.  https://doi.org/10.1016/j.tecto.2010.04.022 CrossRefGoogle Scholar
  75. Wooldridge AM, King JA, Doyle GS, Basson IJ, Nel D, Mac Gregor S (2016) Using geophysical data to create a 3D conceptual geological model for the Maremane Dome, Northern Cape, South Africa. Extended abstract and presentation, 35th IGC, Cape TownGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2017

Authors and Affiliations

  • B. Stoch
    • 1
  • C. J. Anthonissen
    • 1
  • M-J. McCall
    • 1
  • I. J. Basson
    • 1
    • 4
  • J. Deacon
    • 2
  • E. Cloete
    • 2
  • J. Botha
    • 2
  • J. Britz
    • 3
  • M. Strydom
    • 3
  • D. Nel
    • 3
  • M. Bester
    • 3
  1. 1.Tect Geological Consulting, Unit 3Metrohm HouseCape TownSouth Africa
  2. 2.Sishen Iron Ore Company (Pty) Ltd.KathuSouth Africa
  3. 3.Kumba Iron Ore, Corporate OfficeCenturion GateCenturionSouth Africa
  4. 4.Department of Earth SciencesStellenbosch UniversityStellenboschSouth Africa

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