Rapid exploration in remote terrains

Oliver Bayley, Rob Bowell, Jessica Charles
Wednesday, December 6, 2017
First presented: 
SRK ES Insights

Exploration, particularly field access is challenging in many remote environments due to lack of infrastructure and vehicle access takes several hours driving over sand dunes and dry river beds or relying on air access only.  A major challenge for exploration is decision making in the field, particularly with respect to identifying field anomalies.  SRK recognised the need for reliable field methods so has invested in various field portable instruments to accomplish in field exploration and use this to direct a programmes development.  These vary from portable X-ray florescence for element analysis where elements have a mass number higher than sodium and laser induced breakdown spectrometry for lithium, boron, beryllium, gold and REE analysis; Terraspec FTIR spectrometry for mineralogy; gamma spectrometry and radiation scintillometers. In addition, SRK ES has invested in several geophysical methods in order to provide clients with reliable field based approach to collecting data.

A reconnaissance level exploration programme in a remote part of Namibia has been completed by staff from SRK ES and SRK Consulting (UK) to determine the geological extent and controls on uranium mineralisation and use this to determine potential viability of such deposits. Historic data combined with geophysical data were used to identify potential areas of interest for confirmation. In addition, several lower grade anomalies were also discovered during the course of the work by geochemical analysis in the field. 

Bedrock geology in the area comprises of high thorium granites with highly variable but generally low concentration of uranium that has complicated identification of potential radiometric targets requiring ground based studies to distinguish uranium anomalies.  Detailed investigation of the identified uranium anomalies found mineralisation was confined to the regolith only with high grade uranium (VI) mineralisation confined to ferric oxide-rich aeolian sand horizons and black weathered biotite schist horizons, indicating the mineralisation was likely of secondary origin. In addition to initial anomalies several more were identified and a drilling programme designed on the field data.

The use of portable, rapid analysis, equipment greatly improved the efficiency of the reconnaissance programme reducing the time required for the work, removing the long delays associated with waiting on laboratory analysis and allows for efficient planning of further work.

SRK Africa