OREAS 91

OREAS 91 is one of a suite of nine copper CRMs (OREAS 90 to OREAS 98) prepared from material from the CSA mine located near the town Cobar in central western New South Wales, Australia. The copper ore body is hosted by the Early Devonian CSA Siltstone, a thinly bedded turbiditic sequence of carbonaceous siltstones and mudstones with minor coarser units. The CSA Siltstone is part of the Cobar Supergroup, consisting of lower syn-rift sediments and upper post-rift sag phase sediments. The mineralisation is structurally controlled and confined to a number of steeply dipping bodies within a major shear zone on the eastern margin of the Early Devonian Cobar Basin. It is characterised by low-grade greenschist alteration and epigenetic low-grade mineralisation enveloping higher-grade shoots of vein complexes or sub-massive to massive sulphides. The sulphides include chalcopyrite, pyrrhotite, pyrite, sphalerite, galena, bornite and cubanite. Iron-rich chlorite and silica are prominent alterations in the siltstone host.

Analyte Certified Value 1SD 95% Confidence Limits Low 95% Confidence Limits High Method
Cu, Copper (ppm) 265 13 258 271 4-Acid Digestion
Ag, Silver (ppm) < 0.300 IND IND IND 4-Acid Digestion
S, Sulphur (ppm) 841 78 799 882 4-Acid Digestion
Bi, Bismuth (ppm) 1.01 0.13 0.94 1.08 4-Acid Digestion
Co, Cobalt (ppm) 14.2 0.80 13.8 14.7 4-Acid Digestion
Pb, Lead (ppm) 5.16 0.85 4.74 5.59 4-Acid Digestion
Sb, Antimony (ppm) 0.85 0.10 0.80 0.89 4-Acid Digestion
Se, Selenium (ppm) 1.28 0.57 0.84 1.73 4-Acid Digestion
Sn, Tin (ppm) 7.47 0.660 7.08 7.87 4-Acid Digestion
Zn, Zinc (ppm) 66 6.0 63 70 4-Acid Digestion
Ag, Silver (ppm) 0.100 0.035 0.080 0.110 Aqua Regia Digestion
Bi, Bismuth (ppm) 1.07 0.17 0.98 1.15 Aqua Regia Digestion
Co, Cobalt (ppm) 14.2 1.30 13.5 14.9 Aqua Regia Digestion
Cu, Copper (ppm) 264 16 255 273 Aqua Regia Digestion
Pb, Lead (ppm) 4.29 0.49 4.03 4.55 Aqua Regia Digestion
S, Sulphur (ppm) 793 89 742 844 Aqua Regia Digestion
Sb, Antimony (ppm) 0.46 0.11 0.40 0.53 Aqua Regia Digestion
Se, Selenium (ppm) 0.97 0.16 0.87 1.08 Aqua Regia Digestion
Sn, Tin (ppm) 1.52 0.24 1.39 1.64 Aqua Regia Digestion
Zn, Zinc (ppm) 61 4.5 59 63 Aqua Regia Digestion
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Certificate DataPack SDS NRAM (255 KB)
Archived

This CRM is no longer available.
Information is provided for reference only.

Specifications