Introduction Background: It is well established that the direct, low level measurement of Au with Field Portable XRF (FPXRF) is not often feasible; however it has been proven as an invaluable tool for analyzing associated mineral suites, such as pathfinder and alteration assemblages that occur with Au.

FPXRF Use For Au Pathfinders Signatures:

The use of geochemical signatures and associated pathfinder element suites is becoming an increasingly useful tool for the delineation of deep buried, blind, ore systems in modern day Au exploration. Some typical applications utilizing these alteration assemblages include:

• mapping structural features & associated alteration zones (ie. potassic enrichment or depletion zones associated with Au mineralization)
• pseudo litho-geochemistry studies; mapping & classification of inferred rock types using elemental geochemistry (commonly using immobile elements such as Ti-Zr-Sr-Rb) - Light Element determination (+Mg-AI-Si) will also help to dramatically increase this function.
• rapidly establishing background & baseline geochemical surveys
• working with panned concentrates & stream sediment samples
• direct analysis of nuggety, high-grade, vein style mineralization Au > 100's ppm levels - managing sub-surface drilling programmes; has the hole gone deep enough?

Some Typical FPXRF LODs for Common Au Pathfinder Elements Element LOD (ppm)* As 12 Cu 35 Mo 20 Ag 30 Sb 30 Bi 12 Hg 10 W 26 *In typical soil matrix over 120s test time

Our Approach to Au Exploration and Pathfinder LODs

Olympus Innov-X has drawn on its superior depth of experience on this subject and established a proven protocol to fully utilize FPXRF for Au applications (particularly Au exploration). Most importantly, Au is NOT included on DELTA default exploration element suites. There are several reasons for this but the basis lies in our underlying philosophy to act responsibly within the resources industry. The most important reason for Au exclusion from our analytical suite lies in the inherent difficulty in preventing FPXRF's from reporting false positives for Au (there are many examples of this). Au lies in a 'crowded' area of the x-ray energy spectrum and is significantly affected by the presence of elements like Zn and W among others. False positives for Au can be very costly and the user can lose confidence in the accuracy of the other data, even when that data is of excellent quality. Au is normally visible under the hand lens of a geologist at 10 g/t and above so the value of the FPXRF becomes obsolete. Au is rarely assayed by commercial laboratories using larger powerful stand alone XRF's. Olympus Innov-X recognizes this and considers it inappropriate to suggest that portable XRF is capable of providing sufficiently accurate and precise Au data less than 10 g/t across the range of (particularly exploration) applications required. However, for applications where rapid Au data can add value to businesses (like grade control in a high grade vein type deposit) we can include Au in the quantitative analysis program and customize the element suite accordingly.