Physical property studies to elucidate the source of seismic reflectivity within the ICDP DSeis seismogenic zone: Klerksdorp goldfield, South Africa

Characteristics of Fault Rocks Within the Aftershock Cloud of the 2014 Orkney Earthquake (M5.5) Beneath the Moab Khotsong Gold Mine, South Africa

“…(2019) and Nkosi et al. (2022). Except for the core‐loss zone, continuous core samples were successfully recovered from Hole B. Subsamples for the analyses of this study were taken from the Hole B cores at downhole distances between 530 and 660 m below the drill collar (hereafter, all core positions are downhole distances).…”

“…The spatial relationship of the damaged core zone with the aftershock cloud suggests that it corresponds to the source fault of the 2014 Orkney earthquake (Figure 1c; Ogasawara et al, 2019). The DSeis onsite team undertook post-drilling core logging, downhole logging, and core curation, as documented by Ogasawara et al (2019) and Nkosi et al (2022). Except for the core-loss zone, continuous core samples were successfully recovered from Hole B. Subsamples for the analyses of this study were taken from the Hole B cores at downhole distances between 530 and 660 m below the drill collar (hereafter, all core positions are downhole distances).…”

Possible Sources of Trace Metals in Obese Females Living in Informal Settlements near Industrial Sites around Gauteng, South Africa

“…Additionally, prolonged human exposure to Pb has been reported to decrease performance in the nervous system; cause weakness in the wrists, fingers and ankles; and increase blood pressure and anemia [ 32 ]. In South Africa, Nkosi et al [ 33 ] reported that those living around mining areas have high levels of blood pressure. The study of Zunpuski et al [ 34 ] further showed that children and adults living around gold mine tailings may have detectable amounts of uranium with higher concentrations in children’s hair when compared to adults.…”

Frictional properties of rocks recovered form aftershock cloud of the 2014 Orkney earthquake (M5.5), South Africa, by ICDP-DSeis

“…The fault-related samples from Holes B and C are the first to be retrieved from within the aftershock cloud of a natural tectonic earthquake (M > 5) and provide a rare opportunity to improve our understanding of seismogenic processes and the stress state in a seismogenic zone. Nkosi et al (2022) and Ogasawara et al (2019) summarized the post-drilling core logging, downhole logging, and core curation of the ICDP-DSeis project. They found that the source fault occurred in a dike that intruded the Crown Formation of the Jeppestown Subgroup of the West Rand Group.…”

“…The Crown Formation comprises Archean flood basalt dated to 2,914 Ma (Armstrong et al, 1991; the Crown Formation in Hole B is hereafter referred to as the Crown Lava, the name used by local mine geologists and rock engineers). Nkosi et al (2022) reported that the density ρ, porosity φ, P-wave velocity Vp, and S-wave velocity Vs, of the Crown Lava are 2720-2830 kg/m 3 , 0.79-1.01%, 5989-6530 m/s, and 3017-3922 m/s, respectively. Those of the dike are ρ = 2880-3090 km/m 3 , φ = 0.96-1.02%, Vp = 5399-6743 m/s, and Vs = 3083-4126 m/s.…”