Oldcorn, RC & Seago, RD 2007, 'Understanding the Bigger Picture - Interpretation of Geological Structure in Open Pit Rock Slope Stability', in Y Potvin (ed.), Slope Stability 2007: Proceedings of the 2007 International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering
, Australian Centre for Geomechanics, Perth, pp. 449-462, https://doi.org/10.36487/ACG_repo/708_30
Expert assessment of geological structure can significantly improve understanding of the open pit
geotechnical framework. A good structural model of the pit and surroundings is essential to understand the
potential for slope instability, though commonly only the local area is generally assessed. This can lead to
major features or deformation styles being missed. This paper demonstrates how structural evaluation has
been used to improve the geological and geotechnical understanding of the pit slope stability issues at two
very different sites.
The Kumtor open pit gold mine is located in the tectonically complex Tien Shan Mountains in Kyrgyzstan.
The structural geology is being reassessed, since it was proving difficult to understand styles of deformation
and hence predict what potential failures could develop as the pit expanded. Careful assessment of in-pit and
wider data has resulted in development of a comprehensive picture of the structural geology, from a regional
to pit scale, including interpretation of the structure to be expected in the final slopes. Work is continuing to
develop this interpretation, for long term mine planning purposes.
Taffs Well Quarry is located within Carboniferous Limestone of the South Wales syncline. A re-evaluation of
the geological structure was carried out, as a failure indicated changes in structural style not previously
expected. Structural mapping identified thrust faulting associated with major folding. These faults could
potentially lead to significant failures as the quarry was expanded. The model was used to predict the
structural scenario in the final quarry profile and allowed geotechnical design to be more confidently
Abeleira, A., Ansdell, K.M., Thomas, D., Heaman, L. and Melrose, D.L. (2000) Geology and Structural Evolution of
the Kumtor Region, Tien Shan, Kyrgyzstan. In Bucci L.A. and Mair J.L (editors), 2000. Gold in 2000. Poster
session, extended abstracts, Lake Tahoe, Nevada, Nov. 10-11, 2000, pp. 41-52.
Centerra Gold Inc. (2006) Technical Update Report on the Kumtor Gold Mine Kyrgyz Republic for Centerra Gold Inc.
and Cameco Corporation. Strathcona Mineral Services Limited.
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Great Britain, HMSO, p. 333.
Thomas, D. (1999) A review of the geological setting of the 3900 block area, Kumtor gold deposit, Kyrgyzstan. KOC
Wyllie, D.C. and Mah, C.W. (2004) Rock Slope Engineering, Civil and Mining. Spon Press.
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Understanding the Bigger Picture — Interpretation of Geological Structure in
Open Pit Rock Slope Stability R.C. Oldcorn, R.D. Seago
462 Slope Stability 2007, Perth, Australia