Kraubath
Styria, Speik Complex, Austria
Magmatic (Ni-Cu-PGE, carbonatites)Cr (EGP)
- Type
- Podiform chromitites in an ophiolite
Metamorphosed dunite and harzburgite massif, dismembered mantle relic of an ophiolite (Speik Complex, Eastern Alps), probably Late Proterozoic to Early Paleozoic; podiform chromitites as small layers, lenses and pods (less than 0.5 m thick). Former chromite mining area south of the Sommergraben; Alpine amphibolite-facies imprint. Chromite with Cr# 74-87 and Mg# 44-61. Chromitite K 137 (mine dumps) is highly altered (talc, tremolite) and dominated by sperrylite, chromitite K 142 is fresh and dominated by laurite (Malitch et al., 2003).
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 |
|---|---|---|---|---|
| 0.12248 ± 0.00138 | 0.12026 / 0.12437 | 12 | laurite and ruarsite (single grains and assemblages), fresh chromitite K 142 Mean and standard deviation recalculated from 12 analyses, 0.12026 to 0.12437 (K 142-20 0.12026; K 142-15 0.12044; K 142-14 0.12133; K 142-9 0.12145; K 142-6 0.12180; K 142-101 0.12292; K 142-5 0.12299; K 142-70 0.12335; K 142-100 0.12337; K 142-95 0.12357; K 142-106 0.12395; K 142-103 0.12437). Spread larger than the uncertainties, inter-mineral fractionation according to the authors. All values stay below the present chondritic mantle (0.12863): subchondritic source. Model ages: K 142-20 1.147 Ga; K 142-15 1.122 Ga; K 142-14 1.000 Ga; K 142-9 0.984 Ga; K 142-6 0.936 Ga; K 142-101 0.782 Ga; K 142-5 0.773 Ga; K 142-70 0.723 Ga; K 142-100 0.721 Ga; K 142-95 0.693 Ga; K 142-106 0.641 Ga; K 142-103 0.584 Ga. | Malitch et al. (2003), Laurite and ruarsite from podiform chromitites at Kraubath and Hoc… |
| 0.12111 ± 0.00008 | 0.12105 / 0.12117 | 2 | ruarsite and laurite with secondary Ru oxide, highly altered chromitite K 137 Mean and standard deviation recalculated from 2 analyses, 0.12105 to 0.12117 (K 137-83 0.12105; K 137-121 0.12117). Values lower than most grains of the fresh chromitite: the Re-Os system of Os minerals was not disturbed by alteration and metamorphism. Model ages: K 137-83 1.038 Ga; K 137-121 1.022 Ga. | Malitch et al. (2003), Laurite and ruarsite from podiform chromitites at Kraubath and Hoc… |
| 0.116 ± 0.0003 | 0.1158 / 0.1162 | 2 | Ru-Os sulphides (laurite), fresh chromitite K 142, N-TIMS Mean and standard deviation recalculated from 2 analyses, 0.1158 to 0.1162 (K 142-11 0.1158; K 142-10 0.1162). Not verified: values of Malitch (2001) quoted in the text and Fig. 5 of Malitch et al. (2003). They are the least radiogenic ratios at Kraubath; with the 16 laser analyses, the total range of both massifs is 0.11580 to 0.12437 (n = 18). | Malitch et al. (2003), Laurite and ruarsite from podiform chromitites at Kraubath and Hoc… |
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). Kraubath, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/kraubath/ (accessed 2026-10-20).
@misc{isofind2026kraubathisotopesignatures,
title = {Kraubath, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/kraubath/},
note = {Accessed 2026-10-20}
}Updated : 2026-10-20