OREAS 221 was prepared from a blend of Archean greenstone-hosted Wilber Lode primary ore from the Andy Well Gold Mine and barren Cambrian greenstone sourced from a quarry north of Melbourne, Australia. The Wilber Lode is a shear-hosted, narrow vein, quartz lode-style gold deposit situated within the Meekatharra-Wydgee greenstone belt in the Archean Yilgarn Craton of Western Australia. The common primary mineral assemblage, as stated by Mason and Harris (2011, 2012, cited in Hingston et al, 2014), is quartz, calcite, chlorite, fuchsite, pyrite, galena, sphalerite, chalcopyrite and gold. The host rock consists of a complex sequence of Archean meta-basalt and meta-porphyritic rocks derived from a primary mineralogy of albite, actinolite, chlorite, sericite, biotite, calcite, zoisite, muscovite, quartz and titanate. The Andy Well deposit is located approximately 45km north of Meekatharra in the Murchison region of Western Australia.
The approximate major and trace element composition of OREAS 221 is provided in Table 2. The non-certified values contained in this table are the means of duplicate assays from one laboratory.
|Analyte||Certified Value||1SD||95% Confidence Limits Low||95% Confidence Limits High||Method|
|Au, Gold (ppm)||1.06||0.036||1.05||1.07||Pb Fire Assay|
|Au, Gold (ppm)||1.04||0.039||1.03||1.06||Aqua Regia Digestion (sample weights 10-50g)|
|SG, Specific Gravity (Unity)||2.98||0.053||2.95||3.00||Gas / Liquid Pycnometry|
Each quarter, we will keep you up to date with news on the latest OREAS CRMs and QA/QC best practices in the analytical industry.