3D Reflection Seismic Imaging for Gold and Platinum Exploration, Mine Development, and Safety

Manzi, M.; Hunt, Emma J.; Durrheim, Raymond

doi:10.1002/9781119290544.ch11

Cited by 3 publications

(13 citation statements)

References 37 publications

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“…The interpretations of the reflection seismic sections in this study are based on coherent event characteristics and comparison with borehole information, synthetic seismograms and previous research results (Campbell, 2011;Manzi et al, 2019) (Figures 7 and 8). The data were acquired in tunnels excavated for the MR exploitation ∼500 m below the ground surface (Figure 7a).…”

Section: Discussionmentioning

confidence: 74%

“…A site reconnaissance was conducted upon our arrival, consisting of equipment testing to observe different geophone responses (4.5, 14, 45 and 100 Hz resonance frequencies) and planning a cost-effective and successful data acquisition. Campbell (2011) and Manzi et al (2019) used 2D and 3D reflection seismic data sets and borehole information to provide detailed subsurface images of the BC for mineral exploration. They produced synthetic seismograms using wireline measurements of sonic velocity and density to show that the UG2 and UG1 pyroxenite-anorthosite contacts are the main seismic reflection markers in the area.…”

Section: Discussionmentioning

confidence: 99%

“…The complex is divided into five lobes, namely the Northern, Southern (or Bethal), Western, far Western and Eastern. At the current levels of erosion, it consists of three lobes, the Northern, Eastern and Western Lobe (Cawthorn et al,FIGURE 1 (a) The geology of the three major lobes and the three main suites of the Bushveld Complex, the index on the top left is the South African outline map indicating the position of Bushveld Complex (modified after Kinnaird, 2005 andManzi et al, 2019). (b) General stratigraphy of the Rustenburg Layered Suite (RLS) and the schematic enlargement of the Merensky Reef.…”

Section: Site Location and Background Geologymentioning

confidence: 99%

“…The seismic method has been well proven as an effective tool for mineral and hydrocarbon exploration, geoengineering, seismic risk assessment, and environmental and hydrogeological investigations (Brodic et al, 2017;Onyebueke et al, 2018Onyebueke et al, , 2020Manzi et al, 2020). The reflection seismic method provides information about subsurface structures with the advantage of deeper penetration depth and higher resolution compared to other geophysical techniques (Yilmaz, 2001;Malehmir et al, 2012;Manzi et al, 2012Manzi et al, , 2019Manzi et al, , 2020Westgate et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

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Integration of in‐mine seismic and GPR surveys to gain advanced knowledge of Bushveld Complex orebodies

Onyebueke,

Manzi,

Rapetsoa

et al. 2023

Near Surface Geophysics

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Improving the exploration of deep‐seated mineral deposits and assessing the stability of the mine pillars require that geophysical techniques are deployed in a fast and cost‐effective manner with minimal environmental impact. This research presents results from in‐mine reflection seismic experiments and a Ground Penetrating Radar (GPR) survey conducted at Maseve platinum mine, South Africa. The research aims to develop and implement methods to image Platinum Group Metal (PGM) deposits and geological structures near mine tunnels and assess the stability of pillars. The seismic experiments were conducted using a sledgehammer source (10 lb), conventional cabled geophones (14 Hz), and a landstreamer with 4.5 Hz vertical component geophones. The GPR survey was conducted using a Noggin 500 GPR system with 500 MHz centre frequency. An image of the underlying orebody and geological structures down to 100 m from the mine tunnel floor (∼ 500 m below ground surface) was produced. We correlated the coherent reflections beneath the tunnel floor with a known Upper Group (UG2) PGM orebody. The final seismic section shows that the UG2 mineralisation is dissected by near‐vertical dykes, faults and fractures. These structures, faults in particular, are interpreted to have been active post‐mineralisation, implying that they may have contributed to the current complex geometry of the deposit. Four GPR profiles were collected around a stability pillar adjacent to the seismic lines. The radargram sections were processed to improve the S/N. The results show different patterns of fracturing and stress‐ induced structures. Perhaps, these fracturing were shown to be subvertical and constituted complex micro‐structures within the pillar, which could compromise the pillar stability and integrity. The study demonstrates that in‐mine seismic and GPR surveys can be cost‐effective and valuable for mineral exploration.This article is protected by copyright. All rights reserved

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Section: Discussionmentioning

confidence: 74%

Section: Discussionmentioning

confidence: 99%

Section: Site Location and Background Geologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Integration of in‐mine seismic and GPR surveys to gain advanced knowledge of Bushveld Complex orebodies

Onyebueke,

Manzi,

Rapetsoa

et al. 2023

Near Surface Geophysics

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“…Over the last few decades, reflection seismic methods have been developed and improved for mineral exploration and mine planning, mainly 2D seismic surveys, due to their lower cost and footprints compared to 3D surveys (Wright et al, 1994;Milkereit et al, 1996;Eaton et al, 2003aEaton et al, , 2003bChen et al, 2004;Malehmir & Bellefleur, 2009;Dehghannejad et al, 2010;Cheraghi et al, 2011Cheraghi et al, , 2013Koivisto et al, 2012;Ahmadi et al, 2013;Malehmir et al, 2014Malehmir et al, , 2017aDonoso et al, 2019;Heinonen et al, 2019;Bräunig et al, 2020;Gil et al, 2021). Recently, however, there has been an increased use of 3D seismic surveys for this purpose in Canada (Adam et al, 2003;Cheraghi et al, 2015;Bellefleur et al, 2015), South Africa (Manzi et al, 2012(Manzi et al, , 2013(Manzi et al, , 2019, Australia (Urosevic et al, 2012), Finland (Malehmir et al, 2012(Malehmir et al, , 2018Singh et al, 2019) and Sweden (Malehmir et al, 2021). Here, we present the first 3D seismic survey in the mineral-endowed Bergslagen region for massive sulphides targeting in the Zinkgruvan mining area (Fig.…”

Section: Introductionmentioning

confidence: 99%

3D reflection seismic imaging of the Zinkgruvan mineral‐bearing structures in the south‐eastern Bergslagen mineral district (Sweden)

Gil

Malehmir

Ayarza

et al. 2022

Geophysical Prospecting

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Mineral exploration is facing greater challenges nowadays because of the increasing demand for raw materials and the lesser chance of finding large deposits at shallow depths. To be efficient and address new exploration challenges, high‐resolution and sensitive methods that are cost‐effective and environmentally friendly are required. In this work, we present the results of a sparse 3D seismic survey that was conducted in the Zinkgruvan mining area, in the Bergslagen mineral district of central Sweden. The survey covers an area of 10.5 km2 for deep targeting of massive sulphides in a polyphasic tectonic setting. A total of 1311 receivers and 950 shot points in a fixed 3D geometry setup were employed for the survey. Nine 2D profiles and a smaller 3D mesh were used. Shots were generated at every 10 m, and receivers were placed at every 10–20 m, along the 2D profiles, and 40–80 m in the mesh area. An analysis of the seismic fold coverage at depth was used to determine the potential resolving power of this sparse 3D setup. The data processing had to account for cultural noise from the operating mine and strong source‐generated surface waves, which were attenuated during both pre‐ and post‐stack processing steps. The processing workflow employed a combination of 2D and 3D refraction static corrections, and post‐stack FK filters along inlines and crosslines. The resulting 3D seismic volume is correlated with downhole data (density and P‐wave, acoustic impedance, reflection coefficient), synthetic seismograms, surface geology and a 3D model of mineral‐bearing horizons in order to suggest new exploration targets at depth. The overall geological architecture at Zinkgruvan is interpreted as two EW overturn folds, an antiform and a synform, affected by later NS‐trending folding. Two strong sets of shallow reflections, associated with the Zn–Pb mineralization, are located at the hinge of an EW‐trending antiform, while a strong set of reflections, associated with the main mineralization, is located at the overturned apex of the EW synform. The NS Knalla fault that crosses the study area terminates the continuation of the mineral‐bearing deposits at depth towards the west, a conclusion solely based on the reflectivity character of the seismic volume. This study illustrates that sparse 3D data acquisition, while it has its own challenges, can be a suitable replacement for 2D profiles while line cutting, and environmental footprints can totally be avoided.

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New insights from legacy seismic data: reprocessing of legacy 2D seismic data for imaging of iron‐oxide mineralization near Sishen Mine, South Africa

Westgate

Manzi

James³

et al. 2020

Geophysical Prospecting

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Two overlapping legacy seismic profiles, 130 km long end to end, were shot in the 1990s over the Kuruman Hills on the western margin of the Kaapvaal Craton in southern Africa. The 6‐s profiles were aimed at investigating the crustal structure of the western Kaapvaal Craton as well as to locate potential continuation of the Witwatersrand gold‐bearing horizons beneath the cover rocks, the latter of which was unsuccessful. In this study, the legacy seismic data are reprocessed and used to image the iron‐oxide (mainly haematite) mineralization found in the Kuruman Formation of the Griqualand‐West Supergroup, which outcrops along the two seismic profiles. The seismic profiles are located close to the Sishen open pit iron mine, where one of the world's largest iron ore concentrations (986 Mt) is mined. The reprocessed and merged seismic data are combined with magnetic, magnetotelluric, borehole and outcrop data to constrain the interpretation, and all indicate the mineralization host rocks to have ∼500 m thickness and 950 m depth. The seismic data further reveal seismic reflections associated with multiple iron ore horizons, which are affected by a first‐order scale syncline and numerous near‐vertically dipping (∼65–80°) normal and reverse faults of various orientations and throws, thus providing insight into the structurally controlled iron ore mineralization in the area. Seismic tomography and magnetotellurics characterize the sediments to have a velocity ranging between 5000 and 6000 m/s and a resistivity of <10 Ωm. The seismic imaging of the syncline and associated structural disruptions is important for future mining purposes and plans in the area as these structures might have preserved iron‐oxide mineralization from erosion. The reprocessed data thus provide information that could be incorporated in potential future underground mine planning in the area, improving the resource evaluation of the iron‐oxide deposit. Legacy seismic data are thus shown to hold intrinsic quality and possible untapped potential that can be realized via data reprocessing.

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3D Reflection Seismic Imaging for Gold and Platinum Exploration, Mine Development, and Safety

Cited by 3 publications

References 37 publications

Integration of in‐mine seismic and GPR surveys to gain advanced knowledge of Bushveld Complex orebodies

Integration of in‐mine seismic and GPR surveys to gain advanced knowledge of Bushveld Complex orebodies

3D reflection seismic imaging of the Zinkgruvan mineral‐bearing structures in the south‐eastern Bergslagen mineral district (Sweden)

New insights from legacy seismic data: reprocessing of legacy 2D seismic data for imaging of iron‐oxide mineralization near Sishen Mine, South Africa

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