Mineralium Deposita

, Volume 53, Issue 6, pp 835–853 | Cite as

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

  • B. StochEmail author
  • C. J. Anthonissen
  • M-J. McCall
  • I. J. Basson
  • J. Deacon
  • E. Cloete
  • J. Botha
  • J. Britz
  • M. Strydom
  • D. Nel
  • M. Bester


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.


Iron ore Structural interpretation Implicit modeling Leapfrog™ 



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.


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Copyright information

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

Authors and Affiliations

  • B. Stoch
    • 1
    Email author
  • 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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