SRK was asked to evaluate the extent of artisanal and small-scale mining (ASM) activities across a package of land in northeast Guinea prior to the Client entering potential investment negotiations.
Services such as Google Earth and ESRI World Imagery provide high-quality satellite imagery down to sub-metre spatial resolution. ASM activities result in characteristic land use patterns that can be easily identified in this imagery. Excavations and waste material piles have distinctly different colour compared to surrounding vegetation. Larger open pits can be seen by the way shadows are cast and even small shafts just a metre wide can be identified as round black points tracing long lines over underground tunnels following a gold-bearing vein or gravel horizon. If a site is being worked at the time the imagery was acquired, activity can be seen; be that people, small buildings, vehicles or stained water courses from the washing and panning of mined material.
SRK reviewed imagery taken over the last decade, delineating the extent of ASM workings over time. It was obvious that ASM activities had grown significantly since 2012. Prior to this, exploitation was restricted to drainages and within areas explored by exploration companies, evidenced by straight-cut access lines through the vegetation. In the years since, ASM has expanded into other areas, extensively covering hills, indicating exploitation of the deeper regolith, as opposed to just alluvial gold deposits.
Desktop studies such as this can be invaluable in assessing ASM activities before even getting to a project site, helping to make assessment of the potential scale of social engagement and community liaison that will be required from day one of exploration on the ground.
