The OSNACA Project (Ore Samples Noramlised to Average Crustal Abundance) is an open source project where assay data is freely available online. Representative ore samples from all over the globe are being donated to the project and assayed at Bureau Veritas' Ultratrace Laboratory in Perth. All funds contributed by industry go towards analytical costs.
The assay suite includes 62 ore, pathfinder, major and lithogeochemical elements. Almost all elements are analysed to a detection limit at, or below, average crustal abundance. The assay database is backed by a library of reference samples and laboratory pulps stored at the CET. These materials are publicly available for further study including additional geochemical analyses and microscopy.
Initial research on the data by CET staff and their collaborators is focused on multi-element ore signatures. A new technique has been developed that quantifies differences in multi-element signatures and makes it possible, for the first time, to create a map of “magmato-hydrothermal space”. The co-ordinate system of magmato-hydrothermal space is defined by the number of metallic elements included in a particular investigation. For example, 24 elements define a 24-dimensional mathematical space where each ore sample's signature is defined by its "enrichment vector".
The geochemical database being created by the OSNACA Project is critical in this regard because this mathematical approach requires an assay value for every element for every sample. No other publically available dataset fulfils this requirement. It is recognised that the data has many other potential uses, hence the inclusion of major elements and a wide range of lithogeochemical elements. It is up to geoscientists from around the world how these data are to be used.
The links below will take you to 1) OSNACA data, 2) Financial and Ore Sample Donation Forms, 3) additional information on analytical techniques and 4) additional information on the OSNACA mathematical treatment. The data page contains links to files containing the geochemical data, sample descriptions and the original laboratory assay files. If you would like to support OSNACA financially, or by providing ore samples, please visit the Donations page. For those who want more information on assay techniques, data selection or statistical treatment of the data follow the links to this additional information. The OSNACA Mathematical Technique page contains further links to a worked example of this new method and a poster of a matrix where 283 ore grade samples from the OSNACA database are arranged in “magmato-hydrothermal space”. This first attempt at making a map of magmato-hydrothermal space will be refined through further research and the accumulation of more geochemical data. Watch this space!