1887
Volume 71 Number 7
  • E-ISSN: 1365-2478
PDF

Abstract

Abstract

Near‐surface boulders can pose serious challenges to opencast mining. They often introduce complexities, delays in drilling, blasting and excavation programmes, which subsequently decrease mining efficiency, increase mining risks and costs. The location of subsurface boulders and the identification of other geological features that may impact mining activities (e.g. fractures, the presence of iron‐rich ultramafic pegmatites and the variation in weathering across a mining region) are necessary to reduce the challenges posed by these geological features, therefore optimizing mining efficiency. In this study, magnetics, electrical resistivity tomography, seismic refraction tomography, ground penetrating radar and borehole data are integrated for boulder delineation and mapping of other geological features that may impact mining using an unmined section at Tharisa Mine, Bushveld Complex (South Africa), as a test site. The results obtained from the different geophysical techniques are found to complement each other and successfully delineate boulders, fractures, iron‐rich ultramafic pegmatites and the variation in weathering and layering across the area. The incorporation of geophysical results can thus improve mining efficiency, while reducing mining risks and costs.

© 2023 European Association of Geoscientists & Engineers. © 2023 The Authors. Geophysical Prospecting published by John Wiley & Sons Ltd on behalf of European Association of Geoscientists & Engineers.
Loading

Article metrics loading...

/content/journals/10.1111/1365-2478.13322
2023-09-09
2026-02-10

  • From This Site

    /content/journals/10.1111/1365-2478.13322
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

/deliver/fulltext/gpr/71/7/gpr13322.html?itemId=/content/journals/10.1111/1365-2478.13322&mimeType=html&fmt=ahah

References

  1. Barnes, S.J. & Maier, W.D. (2002) Platinum‐group element distribution in the Rustenburg Layered Suite of the Bushveld Complex, South Africa. In: Cabri, L.J. (Ed.) The geology, geochemistry, mineralogy and mineral beneficiation of platinum‐group elements, special vol. 54. Montreal: Canadian Institute of Mining, Metallurgy and Petroleum, pp. 431–458.
     [Google Scholar]
  2. Binley, A. & Kemna, A. (2005) DC resistivity and induced polarization methods. In: Rubin, Y. & Hubbard, S.S. (Eds.) Hydrogeophysics, water science and technology library, vol. 50. Dordrecht: Springer, pp. 129–156. https://doi.org/10.1007/1‐4020‐3102‐5_5.
     [Google Scholar]
  3. Blanchy, G., Saneiyan, S., Boyd, J., McLachlan, P. & Binley, A. (2020) ResIPy, an intuitive open source software for complex geoelectrical inversion/modeling. Computers & Geosciences, 137, 104423.
     [Google Scholar]
  4. Campbell, G. (2006) High resolution aeromagnetic mapping of “loss‐of‐ground” features at platinum and coal mines in South Africa. South African Journal of Geology, 109, 439–458. https://doi.org/10.2113/gssajg.109.4.439.
     [Google Scholar]
  5. Cardarelli, E., Cercato, M., Cerreto, A. & Di Filippo, G. (2010) Electrical resistivity and seismic refraction tomography to detect buried cavities. Geophysical Prospecting, 58, 685–696. https://doi.org/10.1111/j.1365‐2478.2009.00854.x.
     [Google Scholar]
  6. Carollo, A., Capizzi, P. & Martorana, R. (2020) Joint interpretation of seismic refraction tomography by cluster analysis to detect buried cavities. Journal of Applied Geophysics, 178, 1–21. https://doi.org/10.1016/j.jappgeo.2020.104069.
     [Google Scholar]
  7. Cawthorn, R.G. (2015) The Bushveld Complex, South Africa. In: Charlier, B., Namur, O., Latypov, R. & Tegner, C. (Eds.) Layered intrusions. Berlin: Springer, pp. 517–587. https://doi.org/10.1007/978‐94‐017‐9652‐1.
     [Google Scholar]
  8. Cawthorn, R.G. & Webb, S.J. (2001) Connectivity between the western and eastern limbs of the Bushveld Complex. Tectonophysics, 330, 195–209. https://doi.org/10.1016/S0040‐1951(00)00227‐4.
     [Google Scholar]
  9. Cawthorn, R.G., Barnes, S.J., Ballhaus, C. & Malitch, K.N. (2005) Platinum Group Element, Chromium, and Vanadium Deposits in Mafic and Ultramafic Rocks. One Hundredth Anniversary Volume. https://doi.org/10.5382/av100.09
  10. Cooper, G.R.J. & Cowan, D.R. (2008) Edge enhancement of potential‐field data using normalized statistics. Geophysics, 73, H1–H4. https://doi.org/10.1190/1.2837309.
     [Google Scholar]
  11. Dan, M.F.M., Mohamad, E.T. & Komoo, I. (2016) Characteristics of boulders formed in tropical weathered granite: a review. Jurnal Teknologi, 78, 23–30. https://doi.org/10.11113/jt.v78.9635.
     [Google Scholar]
  12. Dunlop, D.J., Ozdemir, O. & Alvarez, V.C. (2010) Magnetic properties of rocks of the Kapuskasing uplift (Ontario, Canada) and origin of long‐wavelength magnetic anomalies. Geophysical Journal International, 183, 645–658. https://doi.org/10.1111/j.1365‐246X.2010.04778.x.
     [Google Scholar]
  13. Durgin, P.B. (1977) Landslides and the weathering of granitic rocks. Geological Society of America III, pp. 127–131.
     [Google Scholar]
  14. Eales, H.V., Botha, W.J., Hattingh, P.J., De Klerk, W.J., Maier, W.D. & Odgers, A.T.R. (1993) The mafic rocks of the Bushveld Complex: a review of emplacement and crystallization history, and mineralization, in light of recent data. Journal of African Earth Sciences, 16, 121–142. https://doi.org/10.1016/0899‐5362(93)90163‐K.
     [Google Scholar]
  15. Eales, H.V. & Cawthorn, R.G. (1996) The Bushveld Complex. In: Layered intrusions. Amsterdam: Elsevier, pp. 181–229. https://doi.org/10.1016/S0167‐2894(96)80008‐X.
     [Google Scholar]
  16. Ettinger, S., Manville, V., Kruse, S. & Paris, R. (2014) GPR‐derived architecture of a lahar‐generated fan at Cotopaxi volcano, Ecuador. Geomorphology, 213, 225–239. https://doi.org/10.1016/j.geomorph.2014.01.013.
     [Google Scholar]
  17. Felletti, F. & Beretta, G.P. (2009) Expectation of boulder frequency when tunnelling in glacial till: a statistical approach based on transition probability. Engineering Geology, 108, 43–53. https://doi.org/10.1016/j.enggeo.2009.06.006.
     [Google Scholar]
  18. Fletcher, R.C., Buss, H.L. & Brantley, S.L. (2006) A spheroidal weathering model coupling porewater chemistry to soil thicknesses during steady‐state denudation. Earth and Planetary Science Letters, 244, 44–457. https://doi.org/10.1016/j.epsl.2006.01.055.
     [Google Scholar]
  19. Gomez, C., Lavigne, F., Hadmoko, D.S. & Wassmer, P. (2018) Insights into lahar deposition processes in the Curah Lengkong (Semeru Volcano, Indonesia) using photogrammetry‐based geospatial analysis, near‐surface geophysics and CFD modelling. Journal of Volcanology and Geothermal Research, 353, 102–113. https://doi.org/10.1016/j.jvolgeores.2018.01.021.
     [Google Scholar]
  20. Harding, K.A., Morris, W.A., Balch, S.J., Lapointe, P. & Latham, A.G. (1988) A comparison of magnetic character and alteration in the three granitic drill cores from Eastern Canada. Canadian Journal of Earth Sciences, 25, 1141–1150. https://doi.org/10.1139/e88‐112.
     [Google Scholar]
  21. Hunt, E., Latypov, R. & Horvah, P. (2018) The Merensky cyclic unit, Bushveld Complex, South Africa: reality or myth?Minerals, 8, 1–35.
     [Google Scholar]
  22. Jee, W.W. & Ha, S. (2007) Feasible boulder treatment methods for soft ground shielded TBM. In: Underground space – the 4th Dimension of Metropolises. pp. 217–22.
  23. Khaidukov, V., Landa, E. & Moser, T.J. (2004) Diffraction imaging by focusing‐defocusing, an outlook on seismic superresolution. Geophysics, 69(6), 1478–1490. https://doi.org/10.1190/1.1836821.
     [Google Scholar]
  24. Kruger, F.J. (2005) Filling the Bushveld Complex magma chamber: lateral expansion, roof and floor interaction, magmatic unconformities, and the formation of giant chromitite, PGE and Ti‐V‐magnetitite deposits. Mineralium Deposita, 40, 451–472. https://doi.org/10.1007/s00126‐005‐0016‐8.
     [Google Scholar]
  25. Lapointe, P., Morris, W.A. & Harding, K.L. (1986) Interpretation of magnetic susceptibility: a new approach to geophysical evaluation of the degree of rock alteration. Canadian Journal of Earth Sciences, 23, 393–401. https://doi.org/10.1139/e86‐041.
     [Google Scholar]
  26. Leng, Z., Fan, Y., Gao, Q. & Hu, Y. (2020) Evaluation and optimization of blasting approaches to reducing oversize boulders and toes in open‐pit mine. International Journal of Mining Science and Technology, 30, 373–380. https://doi.org/10.1016/j.ijmst.2020.03.010.
     [Google Scholar]
  27. Lu, S.‐G., Xue, Q.‐F., Zhu, L. & Yu, J.‐Y. (2008) Mineral magnetic properties of a weathering sequence of soils derived from basalt in Eastern China. Catena, 73, 23–33. https://doi.org/10.1016/j.catena.2007.08.004.
     [Google Scholar]
  28. Malehmir, A., Durrheim, R., Bellefleur, G., Urosevic, M., Juhlin, C., White, D.J., Milkereit, B. & Campbell, G. (2012) Seismic methods in mineral exploration and mine planning: a general overview of past and present case histories and a look into the future. Geophysics, 77, WC173–WC190. https://doi.org/10.1190/geo2012‐0028.1.
     [Google Scholar]
  29. Monjezi, M., Bahrami, A. & Varjani, A.Y. (2011) Prediction and controlling of flyrock in blasting operation using artificial neural network. Arabian Journal of Geosciences, 4, 421–425. https://doi.org/10.1007/s12517‐009‐0091‐8.
     [Google Scholar]
  30. Moser, T.J. & Howard, C.B. (2008) Diffraction imaging in depth. Geophysical Prospecting, 56, 627–641. https://doi.org/10.1111/j.1365‐2478.2007.00718.x.
     [Google Scholar]
  31. Musil, M., Maurer, H., Green, A.G., Horstmeyer, H., Nitsche, F.O., Muhll, D.V. & Springman, S. (2002) Shallow seismic surveying of an Alpine rock glacier. Geophysics, 67, 1701–1710. https://doi.org/10.1190/1.1527071.
     [Google Scholar]
  32. Onyebueke, E.O., Manzi, M.S.D. & Durrheim, R.J. (2018) High‐resolution shallow reflection seismic integrated with other geophysical methods for hydrogeological prospecting in the Nylsvley Nature Reserve, South Africa. Journal of Geophysics and Engineering, 15, 2658–2673. https://doi.org/10.1088/1742‐2140/aadbe3.
     [Google Scholar]
  33. Park, J. & Kim, K. (2020) Use of drilling performance to improve rock‐breakage efficiencies: a part of mine‐to‐mill optimization studies in a hard‐rock mine. International Journal of Mining Science and Technology, 30, 179–188. https://doi.org/10.1016/j.ijmst.2020.03.010.
     [Google Scholar]
  34. Perritt, S. & Roberts, M. (2007) Flexural‐slip structures in the Bushveld Complex, South Africa?Journal of Structural Geology, 29, 1422–1429. https://doi.org/10.1016/j.jsg.2007.06.008.
     [Google Scholar]
  35. Raina, A.K., Murthy, V.M.S.R. & Soni, A.K. (2015) Flyrock in surface mine blasting: understanding the basics to develop a predictive regime. Current Science, 108, 660–665.
     [Google Scholar]
  36. Reid, D.L. & Basson, I.J. (2002) Iron‐rich ultramafic pegmatite replacement bodies within the Upper Critical Zone, Rustenburg Layered Suite, Northam Platinum Mine, South Africa. Mineralogical Magazine, 66, 895–914. https://doi.org/10.1180/0026461026660066.
     [Google Scholar]
  37. Roberts, M.K.C. & Clark‐Mostert, V. (2010) Is there some commonality between the geological structures in the Bushveld Complex and the Great Dyke? In: The 4th international platinum conference, platinum in transition ‘Boom or Bust’, The Southern African Institute of Mining and Metallurgy.
  38. Santana, G.P., Fabris, J.D., Goulart, A.T. & Santana, D.P. (2001) Magnetite and its transformation to hematite in a soil derived from steatite. Revista Brasileira de Ciencia do Solo, 25, 33–42. https://doi.org/10.1590/S0100‐06832001000100004.
     [Google Scholar]
  39. van Schoor, M. & Fourie, C.J.S. (2015) A guide for applying geophysics to coal mining problems in South Africa. South Africa: Struik Nature.
     [Google Scholar]
  40. Scoates, J.S., Wall, C.J., Friedman, R.M., Weis, D., Mathez, E.A. & VanTongeren, J.A. (2021) Dating the Bushveld Complex: timing of crystallization, duration of magmatism, and cooling of the World's largest layered intrusions and related rocks. Journal of Petrology, 62, egaa107. https://doi.org/10.1093/petrology/egaa107.
     [Google Scholar]
  41. Scoon, R.N. & Mitchell, A.A. (1994) Discordant iron‐rich ultramafic pegmatites in the Bushveld Complex and their relationship to iron‐rich intercumulus and residual liquids. Journal of Petrology, 35, 881–917. https://doi.org/10.1093/petrology/35.4.881.
     [Google Scholar]
  42. Shao, J., Zhang, Q., Wu, X., Lei, Y., Wu, X. & Wang, Z. (2020) Investigation on the water flow evolution in a filled fracture under seepage‐induced erosion. Water, 12(11), 3188. https://doi.org/10.3390/w12113188.
     [Google Scholar]
  43. Sherrod, L., Schlosser, K., Kozlowski, A., Bird, B., WerkemaJr, D.D. & Swiontek, J. (2014) Geophysical characterization of the Keene valley landslide in New York state. Journal of Environmental and Engineering Geophysics, 19, 139–155. https://doi.org/10.2113/JEEG19.3.139.
     [Google Scholar]
  44. Soumya, G.S., Asanulla, R.M. & Radhakrishna, T. (2017) Rockmagnetism in relation to magnetic mineralogy of anorthosites in the southern granulite region of the Indian shield. Geophysical Journal International, 209, 1768–1778. https://doi.org/10.1093/gji/ggx134.
     [Google Scholar]
  45. Taylor, C.D., Schulz, K.J., Doebrich, J.L., Orris, G.J., Denning, P.D. & Kirschbaum, M.J. (2009) Geology and nonfuel mineral deposits of Africa and the Middle East. U.S. Geological Survey Open‐file Report 2005‐1294‐E, pp. 1–246.
  46. Twidale, C.R. & Romani, J.R.V. (2005) Landforms and geology of granite terrains. London, United Kingdom: Taylor & Francis Group.
     [Google Scholar]
  47. Jinghong, W., Caineng, Z. & Rukai, Z. (2011) Characteristics and controlling factors of fractures in igneous rock reservoirs. Petroleum Exploration and Development, 38, 708–715. https://doi.org/10.1016/S1876‐3804(12)60005‐6.
     [Google Scholar]
  48. Udden, J.A. (1914) Mechanical composition of clastic sediments. Bulletin of the Geological Society of America, 55, 655–744. https://doi.org/10.1130/GSAB‐25‐655.
     [Google Scholar]
  49. Wilson, A.H., Jermy, C.A. & Ridgeway, M. (2005) Rock strength and physical properties of Norites of the Merensky and Bastard Units, western Bushveld Complex. Geological Society of South Africa, 108, 525–540. https://doi.org/10.2113/108.4.525.
     [Google Scholar]
  50. van School, M. (2002) Detection of sinkholes using 2D electrical resistivity imaging. Journal of Applied Geophysics, 50, 393–399. https://doi.org/10.1016/S0926‐9851(02)00166‐0.
     [Google Scholar]
  51. Vitale, S. & Isaia, R. (2014) Fractures and faults in volcanic rocks (Campi Flegrei, southern Italy): insight into volcano‐tectonic processes. International Journal of Earth Science, 103, 801–819. https://doi.org/10.1007/s00531‐013‐0979‐0.
     [Google Scholar]
  52. von Dobeneck, T., Muller, M., Bosbach, B. & Klugel, A. (2021) Ground magnetic susceptibility and mapping across weathered basalt dikes reveal soil creep and pedoturbation. Frontiers in Earth Science, 8, 1–8. https://doi.org/10.3389/feart.2020.592986.
     [Google Scholar]
  53. Yang, X., Zeng, X., Pu, C. & Xiao, D. (2018) Effects of the pre‐existing fissures with different fillings in PMMA on blast‐induced crack propagation. Advances in Materials Science and Engineering, 17, 1–17. https://doi.org/10.1155/2018/7378282.
     [Google Scholar]
  54. Zhihui, W., Xiangmin, C., Jiayong, Y., Jiming, W., Yu, L. & Lei, Z. (2018) Using the integrated geophysical methods detecting active faults: a case study in Beijing, China. Journal of Applied Geophysics, 156, 82–91. https://doi.org/10.1016/j.jappgeo.2017.01.030
     [Google Scholar]
/content/journals/10.1111/1365-2478.13322
Loading
Integrated geophysical methods for boulder delineation to improve mining
Geophysical Prospecting 71, 1226 (2023); https://doi.org/10.1111/1365-2478.13322
/content/journals/10.1111/1365-2478.13322
/content/journals/10.1111/1365-2478.13322
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): GPR; magnetics; resistivity; seismics; tomography

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error