Bushveld, UG1 chromitite

Bushveld Complex, upper critical zone, South Africa

Magmatic (Ni-Cu-PGE, carbonatites)Cr (EGP)

Type: Upper critical zone chromitite in a layered intrusion

Chromitite layer of the upper critical zone of the Rustenburg Layered Suite (2.05 Ga), below the UG2 and the Merensky Reef; carries laurite. McCandless and Ruiz (1991): lowest 187Os/186Os of the three levels (1.28), above mantle Os at 2.0 Ga (about 0.9).

187Os/188Os isotope ratio, no unit Values of the same system

Standard : Rapport absolu, sans standard de référence

Value	Range	n	Mineral or matrix	Source
0.154	0.154 / 0.154	2	laurite-bearing UG1 chromitite (whole rock) Mean and standard deviation recalculated from 2 analyses, 0.1540 to 0.1540 (12UG15 0.1540; 11BV7613 0.1540). Published 187Os/186Os: 12UG15 1.280 ± 0.004 (locality b); 11BV7613 1.280 ± 0.001 (locality d). Localities b to d of Fig. 1 (eastern and western lobes). The authors attribute radiogenic Os to assimilation of pyritic shales or to hydrothermal fluids.	McCandless & Ruiz (1991), Osmium isotopes and crustal sources for platinum-group minerali…

Deposits of the same type

Bayan Obo China
Norilsk-Talnakh Russia
Bushveld, Merensky Reef South Africa
Bushveld, UG2 chromitite South Africa
Bushveld, Platreef South Africa
Sudbury Canada
Voisey's Bay Canada
Rössing Namibia

Cite this page

IsoFind Atlas (2026). Bushveld, UG1 chromitite, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/bushveld-chromitite-ug1/ (accessed 2026-10-21).

@misc{isofind2026bushveldug1chromititeisotopes,
  title = {Bushveld, UG1 chromitite, isotope signatures},
  author = {{IsoFind Atlas}},
  year = {2026},
  url = {https://www.isofind.tech/isotopes/en/deposits/bushveld-chromitite-ug1/},
  note = {Accessed 2026-10-21}
}

Updated : 2026-10-21