3ppb Au + 23.1ppm Cu + 35.5ppm Zn (glacial till) OREAS 46 - 1kg

OREAS 46 is a Canadian glacial basal till sourced from outside of Chibougamau, Quebec by IOS Services Geoscientifique. The till composition reflects the geochemistry of the surrounding Archean greenstone belts and felsic intrusives. Cobbles were removed prior to processing and all material has undergone a sterilisation procedure upon receipt in Australia according to soil import regulations (ISO 11137). An augmented glacial till is also available that contains anomalous levels of PGE + REE + base metals + Li (see OREAS 47)

Twenty commercial analytical laboratories participated in the program to certify the analytes reported below.

The following methods were employed:

• Gold by 25-50g fire assay with ICP-OES (10 laboratories), ICP-MS (5 laboratories) and AAS (3 laboratories) finish;
• Gold by 15-50g aqua regia digestion with ICP-MS (14 laboratories), AAS (1 laboratory), graphite furnace AAS (1 laboratory) and ICP-OES (1 laboratory) finish;
• Lithium borate fusion or sodium peroxide fusion for full ICP-OES elemental suite (up to 15 laboratories depending on the element. Only two laboratories used sodium peroxide fusion);
• Lithium borate fusion or sodium peroxide fusion for full ICP-MS elemental suite (up to 14 laboratories depending on the element. Only two laboratories used sodium peroxide fusion);
• Thermogravimetry for LOI at 1000° C; (6 laboratories used a conventional muffle furnace and 5 laboratories used a thermogravimetric analyser);
• Four acid digestion for full ICP-OES elemental suite (up to 15 laboratories depending on the element);
• Four acid digestion for full ICP-MS elemental suite (up to 15 laboratories depending on the element);
• Aqua regia digestion (see note below) for full elemental suite ICP-OES (up to 11 laboratories depending on the element);
• Aqua regia digestion (see note below) for full elemental suite ICP-MS (up to 17 laboratories depending on the element).