Table 2.

Osmium isotopic and HSE composition data, obtained by isotope dilution, for IIC irons, Wiley, Cratheús (1931) and Pará de Minas.

Sample	Wt.	Re	Os	Ir	Ru	Pt	Pd	187Os/188Os	2σ	187Re/188Os	2σ	ΔOs	2 σ
Darinskoe	0.037	1072	13790	11970	12090	16910	3893	0.12380	0.00010	0.3743	0.0004	−9.9	2.0
Duplicate	0.037	1051	13680	11340	12050	16740	4090	0.12396	0.00010	0.3702	0.0004	−5.2	2.0
Cratheús (1950)	0.054	992.6	13070	11310	11650	16110	3385	0.12426	0.00010	0.3658	0.0004	1.3	2.0
Perryville	0.091	985.6	12860	11170	11730	15810	3689	0.12470	0.00010	0.3691	0.0004	3.2	2.0
Ballinoo	0.130	793.7	10510	9234	10320	14670	3778	0.12418	0.00010	0.3637	0.0004	2.1	2.0
Kumerina	0.034	774.2	9945	8947	10540	14880	3603	0.12491	0.00010	0.3750	0.0004	0.3	2.0
Salt River	0.076	590.9	7005	7143	9740	13930	3765	0.12748	0.00010	0.4065	0.0004	1.7	2.0
Unter Mässing	0.072	415.9	4114	5170	9440	13300	4347	0.13388	0.00010	0.4875	0.0004	2.6	2.0
Wiley	0.092	194.3	1064	6949	25870	35050	4884	0.16504	0.00010	0.8845	0.0004	4.5	2.0
Cratheús (Field Museum)	0.088	252.7	2606	2444	4026	6664	3699	0.13229	0.00010	0.4676	0.0004	2.2	2.0
Pará de Minas	0.059	247.4	2540	2402	4052	6245	4021	0.13227	0.00010	0.4696	0.0004	0.5	2.0

Samples are in order of decreasing Re concentration.

Unit of weight are in g. All other concentrations are in ppb.

The uncertainties for Re and Os concentrations are ± 0.1% and the uncertainties for Ir, Ru, Pt and Pd concentrations are <2%.

Δ_Os is calculated by Δ_Os = 10⁴ (¹⁸⁷Os/¹⁸⁸Os _IIC – (0.0956 + 0.078 × ¹⁸⁷Re/¹⁸⁸Os _IIC)), where 0.0956 is the IIC initial ¹⁸⁷Os/¹⁸⁸Os and 0.078 is the slope of the IIC isochron.