Raymond John Durrheim

• PhD
• Chair at University of the Witwatersrand

Rockbursts are the most serious and least understood hazard associated with deep underground excavations, typically involving violent energy release and the sudden ejection of rock fragments that may result in fatalities and damage to underground infrastructure. A ML2.8 seismic event with a source dimension of between 110 and 240 m affected two pri...

Cores recovered during the International Continental Scientific Drilling Program project “Drilling into Seismogenic zones of M2.0 to M5.5 earthquakes in deep South African Gold Mines” include fault breccia from within the aftershock cloud of the 2014 Orkney earthquake (M5.5). The breccia and surrounding intrusive rocks, probably lamprophyres rich i...

We investigated the architecture of the greater Congo Basin, one of the largest and least-well-studied sedimentary basins on any continent. Seismograms from a large number of M > 4.5 earthquakes within and surrounding the African plate were used to make event-to-station Rayleigh wave group velocity measurements between periods of 5 and 100 s. Group...

We present a 3D shear‐wave velocity model of the southern African upper mantle developed using 30–200 s period Rayleigh waves recorded on regional seismic networks spanning the subcontinent. The model shows high velocities (∼4.7–4.8 km/s) at depths of 50–250 km beneath the Archean nucleus and several surrounding Paleoproterozoic and Mesoproterozoic...

A high-resolution 3D reflection seismic dataset acquired over a deepwater exploration block in the Orange Basin, offshore of South Africa was used to achieve a detailed description of the contractional domain within a gravity-driven system. Conventional seismic analysis combined with novel horizon-based and volumetric seismic attributes highlight 5...

The presence of fault gouge and the generation of wear material between two sliding rock surfaces plays a critical role in slip weakening and propagation of ruptures along underground brittle shear fractures forming ahead of tabular excavations in deep and high stress gold mining. We performed two types of friction experiments: one with a fault gou...

An integrated geophysical approach using seismics and geoelectrical techniques was employed to investigate the architecture of historic narrow-reef workings and a proposed open-pit mine at Lancaster Gold Mine, near Krugersdorp, South Africa. The mining activities in the area were mainly carried out within the Kimberley Reef Package in the upper Cen...

Geological characterisation and U-Pb geochronology of detrital zircon grains has proven valuable in finding potential source terranes of siliciclastic sediments. Sediment transport and reworking from gold-bearing Archaean/Palaeoproterozoic granite-greenstone rocks are significant in the formation of conglomerate-hosted (Witwatersrand-type) gold dep...

The b-value of the Gutenberg-Richter frequency-magnitude relationship is an indicator of rock failure processes. Near-real-time analysis of the b-value has the potential to mitigate the risk posed by rockbursts, for example, by adjusting the geometry, sequence and rate of mining; or evaluating the re-entry time following a large seismic event. Ther...

A preliminary geophysical investigation involving high-resolution shallow seismic reflection was conducted at an abandoned coal mine site located in the outskirt of Johannesburg. The main objective of the study was to compare the vertical resolution of two vertical geophone types, in order to choose the appropriate geophone type that will be suitab...

The discovery of giant mineral and metal deposits needed to sustain long‐term global growth is a great challenge. An integrated exploration approach involving geological mapping, high‐resolution 3D seismic imaging, and drilling coupled with borehole geophysics will likely yield the best results. Seismic methods, in particular, have become, and will...

The source of gold in the ca. 2.66 Ga Black Reef Formation (BRF) has been investigated and constrained through petrographic, mineralogical, geochemical, and high-resolution three-dimensional reflection seismic data combined with drill core and underground geological mapping. The BRF is a strong seismic marker and consists of carbonaceous shale, qua...

A highly-stressed shaft pillar is prone to large seismic events, falls of ground and rockbursts, which may cause injuries and loss of production, especially in weak geotechnical zones. It is thus important to identify weak geotechnical zones in order to mitigate risks. In this study, we present integrated studies (underground mapping, petrology, ro...

24 A highly-stressed shaft pillar is prone to large seismic events, rockfalls and rockbursts, which may cause 25 injuries and loss of production, especially in weak geotechnical zones. It is thus important to identify weak 26 geotechnical zones in order to mitigate risks. In this study, we present integrated studies (underground 27 mapping, petrolo...

Southern Africa, here taken as the region that comprises the Kalahari and southern Congo Cratons, and the important orogenic belts that surrounded or separated them during the assembly of Gondwana, was situated in the heart of the supercontinent. As such, the region is an ideal site to study the lithospheric structure, composition and evolution of...

An integrated P- and S-wave cross-borehole tomographic survey was performed in the city center of Kuala Lumpur, Malaysia, with the aim of exploring a karstic limestone area near an area that previously encountered cavities. Horizontally polarized shear waves were generated with two opposing, perpendicular strike directions and recorded with a multi...

The East African Rift System is the major active tectonic feature of the Sub-Saharan Africa region. Although the seismicity level of this divergent plate boundary can be described as moderate, several damaging earthquakes have been reported in historical times, and the seismic risk is exacerbated by the high vulnerability of the local buildings and...

While mining-induced earthquakes in the deep gold mines of South Africa pose a risk to mines, mineworkers, and the public, they also provide an unusual opportunity to study the physics of earthquakes. The source zone of a M5.5 earthquake that occurred near Orkney, South Africa on 5 August 2014 was well-defined by tens of thousands of aftershocks re...

A high-resolution 3D reflection seismic dataset was used to achieve a detailed description of the half-graben bounded AK Fault in the Ibhubesi gas field of the offshore Orange Basin. Seismic analysis of the fault involved the combination of both the conventional seismic interpretation and seismic attributes. The main objective of the study was to p...

GPS position time series usually contain apparent seasonal variations that are caused by tectonic and nontectonic deformations, residual atmospheric delays, measurement noise, etc. The analysis of GPS position time series is of fundamental importance in Earth science studies because it provides useful information on geodynamics, crustal deformation...

The lithosphere ofMadagascar was initially amalgamated during the Pan-African events in the Neoproterozoic. It has subsequently been reshaped by extensional processes associated with the separation from Africa and India in the Jurassic and Cretaceous, respectively, and been subjected to several magmatic events in the late Cretaceous and the Cenozoi...

A plan to drill into seismogenic zones of M2.0 - M5.5 earthquake in deep South African gold mines (DSeis) was introduced, which International Continental Scientific Drilling Program accepted in August 2016.

Volumetric and horizon-based seismic attributes were carried out on the 3D reflection seismic data acquired on the deep crystalline rock environments of the Witwatersrand Basin (South Africa). This study aimed at improving the delineation of minor faults that cross-cut the gold-bearing quartz pebble conglomerate horizons (termed reefs) in the compl...

The potential economic and energy security opportunities of a medium to large shale gas resource could be substantial for South Africa; as are both the potential social and environmental risks associated with a domestic gas industry in the Central Karoo. The development of shale gas using vertical and horizontal drilling and hydraulic fracturing or...

New Broadband 3D seismic data, acquired for the Witwatersrand goldfields in South Africa, have significantly improved the imaging of the deep (~ 2.5 - 4.0 km) gold-bearing reefs and faults that offset them. Images appear more continuous and reveal numerous stratigraphic details that were not clear in the old conventional 3D seismic data. The high q...

Geodynamic models predict that rifting of thick, ancient continental lithosphere should not occur unless it is weakened by heating and magmatic intrusion. Therefore, the processes occurring along sections of the western branch of the East African Rift, where similar to 150 km thick, Palaeoproterozoic lithosphere is rifting with no surface expressio...

The historical 2D seismic data, initially acquired for gold exploration in 1980s, have been reprocessed and interpreted for the development of coalbed methane (CBM) reservoirs, a potentially important new energy source in the Kalahari Basin, Botswana. The seismic data are characterized by a seismic zero phase wavelet with the dominant peak frequenc...

A multi-disciplinary study of the response of the rock mass to mining and mining-induced earthquakes has been conducted in six gold mines in South Africa at sites deeper than 3 km, or with equivalent stress. More than 80 holes (with a total length of more than 2.8 km) were drilled in earthquake-prone areas to locate faults and install instruments....

Downsizing an overcoring diameter to 60 mm (BX), the Compact Conical-ended Borehole Overcoring technique (BX CCBO) proved suitable for adverse conditions and difficult access from surface in deep levels South African gold mines. BX CCBO in-situ stress measurements have been carried out at seven sites at depths of 1.0 to 3.4 km, the measured maximum...

Large magnitude earthquakes have been observed in Sub-Saharan Africa in the recent past, such as the Machaze event of 2006 (Mw, 7.0) in Mozambique and the 2009 Karonga earthquake (Mw 6.2) in Malawi. The December 13, 1910 earthquake (Ms = 7.3) in the Rukwa rift (Tanzania) is the largest of all instrumentally recorded events known to have occurred in...

To mitigate the uncertainties in assessing the geohazards and rock conditions that affect the nuclear, mining (including hydrocarbon extraction) and civil engineering activities in South Africa, the authors are working to improve the data coverage concerning the present day stress field. In principle, this implies constraining the principal compres...

The composition of the Lithosphere beneath Cameroon and the origin of the Cameroon volcanic Line (CVL) are still under debate in the Science Community. Although many studies based on regional or global observations provide good explanations to the setting of the CVL, none of them is strong enough to be unique. In this work, we computed new Rayleigh...

As part of JAGUARS (JApanese-German Underground Acoustic emission Research in South Africa), high-resolution tiltmeters were installed during 2007 at Mponeng gold mine, South Africa, in an attempt to study and understand the risks posed by in-mine seismic events and to subsequently use the knowledge gained to mitigate these risks. In December 2007,...

Mining-induced seismic events pose a serious risk to workers in deep mines. Accurate numerical simulations are useful in analyzing the problem and developing mitigation strategies. Here we tackle the problem of guided interfacial elastic wave propagation in a periodically joined interface of two half spaces. The problem is viewed as a mixed boundar...

a b s t r a c t In recent decades, civil wars in the eastern provinces of the Democratic Republic of Congo have caused mas-sive social disruptions, which have been exacerbated by volcanic and earthquake disasters. Seismic data were gathered and analysed as part of an effort to monitor the volcanoes and quantitatively assess the earth-quake hazard....

Mine tremors and their aftershocks pose a risk to mine workers in the deep gold mines of South Africa. The statistical properties of mine-tremor aftershocks were investigated as part of an endeavour to assess the hazard and manage the risk. Data from two gold mines in the Carletonville mining district were used in the analysis. Main shocks were ali...

A probabilistic approach was used to map the seismic hazard in Democratic Republic of Congo and surrounding areas, and assess the seismic hazard level for 14 cities in the region. Seismic hazard maps for 2%, 5% and 10% chance of exceeding the indicated ground accelerations in 50 years were prepared using a homogenised 90-year catalogue compiled for...

We introduce a procedure based on Wadati diagrams to assess and improve the consistency of P- and S-wave travel-time picks with the assumption of propagation at constant wave-speed. Wadati diagrams are plots of S-P vs P-wave travel-times and they are expected to lie along a straight line for a medium of constant velocity. Our procedure automaticall...

For one week during September 2007, we deployed a temporary network of field recorders and accelerometers at four sites within two deep, seismically active mines. The ground-motion data, recorded at 200 samples/sec, are well suited to de-termining source and ground-motion parameters for the mining-induced earthquakes within and adjacent to our netw...

11th South African Geophysical Association Biennial Conference and Exhibition, Swaziland, 16-18 September 2009 AfricaArray (www.africaarray.org) is a long-term programme to build geosciences capacity in Africa in support of the mineral, petroleum, groundwater and environmental sectors. It seeks to do this by establishing effective Africa-based educ...

The southern African Plateau is marked by anomalously high elevations, reaching 1-2 km above sea level. There is much debate as to whether this topography is compensated by a lower mantle source or by elevated temperatures in the upper mantle, which may be manifested as either an anomalously thin lid and/or as an anomalously slow low-velocity zone...

In this study, receiver functions and Rayleigh wave group velocities have been jointly inverted to model subsurface structure across southern Africa. The broadband data used for this study come from the Southern African Seismic Experiment (SASE), which consisted of 82 stations deployed between 1997 and 1999, the Kimberly Broadband Array, which was...

Copyright: 2009 American Geophysical Union The nature of the lower crust across the southern African shield has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations located in Botswana, South Africa and Zimbabwe. For large parts of both Archaean and Proterozoic terrains, the...

The SAVUKA gold mine is located in the northwestern edge of the Witwatersrand basin, a Late Archean (3.07- 2.71~Ga) intracratonic basin in South Africa that hosts the largest known gold-uranium-pyrite ore deposits in the world. Seismic events related to the mine activity span several orders of magnitude through a variety of sources that include min...

The DEEPMINE Research Programme sought to develop the technology and competence to mine gold safely and profitably at depths of 3 to 5 km. Among the many issues addressed was the stability and support of rockpasses at ultra-depth. It was found that high virgin and mining-induced stresses could cause the walls of rockpasses to spall, leading to the...

The seismicity of the Witwatersrand Basin and Bushveld Complex has been analysed, revealing significant differences in source and damage mechanisms. A comparison of mining taking place at similar depths and extraction ratios indicates that the seismic energy release rate is considerably lower in the Bushveld Complex. Technologies introduced in the...

This paper investigates whether a micromechanical model developed to investigate the relation between the basic failure processes at grain-scale and the macroscopic failure pattern can be applied to model the fracturing around large-scale excavations. The simulated fracture pattern around a vertical shaft is compared to the fracturing around a shaf...

The DEEPMINE Collaborative Research Programme was established to create the technological and human resources platform that would make it possible to mine gold safely and profitably at depths of 3 to 5 km. The DEEPMINE Programme has four goals: to acquire knowledge of and develop appropriate technology for new ultra-deep level mines, to stimulate e...

In this study, techniques used to design earthquake-resistant structures are applied to the deep-level mining environment. Earthquake engineers seek to identify the cause of potentially damaging resonance, and design or reinforce structures to reduce these effects. Similar techniques have been used to analyze the dynamic behaviour of the rock mass...

The objective of this work is to quantify the effect of the rock mass surrounding a stope or a tunnel on the seismic signal so that the rockburst damage on the excavation can be derived. It has been shown that the transfer function of rock mass surrounding an excavation can be modelled using a damped oscillator. The method of estimating the transfe...

Measurements of the geomagnetic field can be used to help determine the structure of the Earth, since rocks often contain magnetic minerals. Measurements of the strength of the Earth's gravitational field can also be used, since the more dense the rocks, the stronger the field. The interpretation of large amounts of data can be aided by "automatic"...

The violent failure of a peninsular remnant at a depth of 2300 m below surface occurred in a mine in the Carletonville Goldfield of South Africa, severely damaging a stope mining the Ventersdorp Contact Reef (VCR). At the rockburst site the VCR is 1–2 m thick with a lava hangingwall and quartzite/conglomerate footwall. The remnant had been formed a...

Detailed investigations have been conducted into 21 rockbursts which caused damage to excavations in deep South African gold mines, in many instances resulting in the death or serious injury of workers. The objective of this study is to determine the principal factors controlling the severity and distribution of damage, so that strategies to reduce...

The Pretoria Saltpan Crater is located in the southern portion of the Bushveld Igneous Complex, some 40 km NNW of Pretoria, South Africa, at 25 deg 24 min 30 sec S/28 deg 4 min 59 sec E. An origin by impact for this crater structure was recently confirmed. The results of the only gravity reconnaissance carried out over the crater to date failed to...

Mineralogical and chemical analyses of granophyric rocks are reviewed, with new morphological, petrographical, and chemical results presented. Observations of deformation phenomena (multiple fracturing and pseudotachylite occurrences) in granophyre are analyzed, and major- and trace-element data on the granophyre and on sedimentary inclusions are s...

The Bezuidenhout Valley outlier, which is a large half-graben structure, forms a prominent feature in the geology of the central Witwatersrand. The stratigraphic succession within the graben consists of a lower sedimentary unit (VCR correlative - 30 m thick), overlain by a volcanic unit (Klipriviersberg Group - 650 m thick) and an upper sedimentary...

The crustal structure and composition of the Congo craton is not well understood due to the scarcity of appropriate geophysical data. The most important source of insights into this craton has been seismic refraction measurements. However, much still remains unknown about the gross crustal architecture of the craton, largely due to the presence of...

A magnitude 5.3 seismic event occurred on 9 March 2005 in the Klerksdorp district of South Africa. The event and aftershocks shook the nearby town of Stilfontein, causing serious damage to several buildings and minor injuries to 58 people. At a nearby deep gold mine, two mineworkers lost their lives and 3200 mineworkers were evacuated under difficu...

Rockbursts are a major hazard in South African deep-level gold mines. The severity of damage due to a seismic event often varies greatly over small distances. The goal of this project is to discover the reasons for this variation in the severity of damage. It is believed that a detailed understanding of the damage mechanisms, and the application of...

2008 Monitoring Research Review: Ground-Based Nuclear Explosion Monitoring Technologies, Portmouth, Virginia 23-25 Septemebr 2008; Also available on Cd and Online at this link: https://na22.nnsa.doe.gov/gnem/mrr2008 In this project, the authors are developing and exploiting a unique seismic dataset to address the characteristics of small seismic ev...

11th South African Geophysical Association Biennial Technical Meeting and Exhibition, Swaziland, 16-18 September 2009 The Far West Rand mining district is known for its deep gold mines and the associated high levels of seismic activity. Thousands of tremors are recorded every day by geophones installed in the mine workings. These events range in to...

11th South African Geophysical Association Biennial Technical Meeting and Exhibition, Swaziland, 16-18 September 2009 A probabilistic approach was used to assess the seismic hazard in Democratic Republic of Congo and surrounding areas. Seismic hazard maps were prepared using a 90-year catalogue compiled for homogeneous Ms magnitudes; the attenuatio...

11th South African Geophysical Association Biennial Technical Meeting and Exhibition, Swaziland, 16-18 September 2009 Mining-induced earthquakes pose a hazard to workers in deep South African mines, while natural earthquakes pose a hazard to people living close to plate boundaries. Researchers introduce a 5-year Japanese-South African collaborative...

Southern African Institute of Mining and Metallurgy, Hard Rock Safe Safety Conference 2009. Sun City, South Africa, 28-30 September, 2009. pp 1-20 Mining-induced seismicity poses a hazard to workers in deep South African mines, while natural earthquakes pose a hazard to people living in Japan and other regions of the world that are close to plate b...