Identification of Lithology & Base Metal Anomalies – Pathfinders for Gold Exploration Using Thermo Scientific Portable XRF Analyzers

Importance of the Topic

Gold remains one of the most sought-after metals due to its stability, conductivity, and economic value. Its low natural abundance requires highly sensitive exploration techniques. Geochemical approaches that can rapidly measure gold and associated pathfinder elements in the field are critical to reducing exploration risk and accelerating decision-making.

Objectives and Study Overview

This study demonstrates the application of a portable X-ray fluorescence (XRF) analyzer for identifying lithologies and base metal anomalies that serve as pathfinders for gold mineralization. Using the Blackwater gold deposit in British Columbia as a case example, the work compares in-field XRF data against conventional laboratory assays to evaluate accuracy, speed, and practical benefits during core drilling campaigns.

Methodology and Instrumentation

Core samples from diamond drilling at the Blackwater project were analyzed on-site with a Thermo Scientific Niton XL3t GOLDD+ portable XRF instrument. Key steps:

• Spot analyses performed every 30–50 cm along core in open-face boxes.
• Two filter settings (“Main” and “Low”) applied for 15 s each per spot.
• No sample preparation required; analyses conducted directly on core surfaces.
• Parallel conventional sampling at 1 m intervals sent to a commercial lab for full assay comparison.

Instrumentation Used

Thermo Scientific Niton XL3t GOLDD+ portable XRF analyzer equipped with main and low filters for enhanced trace metal detection.

Main Results and Discussion

Strip log comparisons between portable XRF and laboratory assays demonstrated strong correlation for both base and pathfinder elements:

• Zinc showed the highest fidelity as a pathfinder for gold mineralization.
• Lead, copper, and arsenic anomalies aligned closely with lab data, defining hydrothermal alteration zones.
• Major element data (Ti, Ca, Fe, Mn, K) provided clear discrimination of volcanic lithologies and alteration assemblages.

Fine-grained gold associated with sulfide phases was successfully inferred through elevated pathfinder concentrations, enabling rapid identification of mineralized intervals.

Benefits and Practical Applications

Portable XRF offers significant advantages for gold exploration:

• Immediate, quantitative geochemical feedback in the field supports real-time drill targeting.
• Eliminates delays and costs associated with sample shipping and laboratory turnaround.
• Enables detailed mapping of lithological variations and hydrothermal alteration patterns.
• Accessible to non-specialist users for broad deployment across exploration programs.

Future Trends and Opportunities

Advancements likely to enhance portable XRF utility include:

• Improved detection limits for ultra-trace elements and gold itself.
• Integration with 3D geological modeling and geophysical datasets for comprehensive interpretation.
• Automation, data analytics, and AI-driven interpretation tools to streamline field decision-making.
• Expansion into environmental monitoring, process control, and other mineral deposit types.

Conclusion

Field deployment of portable XRF analyzers represents a robust, cost-effective approach for on-site geochemical characterization in gold exploration. By delivering lab-comparable results for key pathfinder elements and major lithological indicators, portable XRF enhances the speed and precision of targeting mineralized zones and reduces operational uncertainties.

References

No formal references were cited in the original text.