Geochemical Surveying
Geochemical methods are used to detect anomalous levels of major elements such as gold, silver and copper, together with minor pathfinder elements. Various methods are available. Minera Afrodita has applied the analysis of rocks at surface and of the weathered products of rocks, such as soils and sediments found in streams.Rock Sampling
When mineralized rocks are broken down by wind and rain (weathering), they are transported down slope by gravity and eventually accumulate as sediment in streams and rivers. These sediments are typically transported some distance from the source, but generally it can be assumed that the source is upriver or up slope, and that the sediment can be sampled as an indication of broad areas of anomaly. Stream sampling is the first stage in locating mineralization in an area, as it samples the broadest area at minimal cost.
Sampling
[Click to Enlarge] Stream Sediment Sampling
When mineralized rocks broken down by wind and rain (weathering), they are transported down slope by gravity, and eventually accumulate as sediment in streams and rivers. These sediments are typically transported some distance from the source, but generally it can be assumed that the source is upriver or up slope, and that the sediment can be sampled as an indication of broad areas of anomaly.
Soil Sampling
Similar to stream sediments, a geochemical anomaly can be detected in soils over or near weathered and eroded rocks which contain mineralization. In contrast to stream sediment anomalies, soil anomalies generally lie directly over the mineralization and are useful in outlining targets. In general, soil samples collected along a slope are assumed to have come from a local and topographically higher area. Since gravity and time work together to transport the broken down components of the mineralized rock into low laying areas such as valleys, it can be assumed that soil samples taken from the crests of ridges are closer to the origin of the mineralized rock.
Rock Sampling
Rock sampling provides the most direct method of detecting and measuring the tenor of mineralization. During regional surveys, rocks that crop out at surface are routinely mapped and sampled. Evaluation of anomalous values can provide insight into the location of the sample with respect to the mineralization (i.e., sample located on the fringes or in the core of a mineralized system). The interpretation of elemental associations and the rock types of the area through systematic surface sampling and mapping can help geologists vector toward the core of a mineralizing system. A subsurface geological interpretation, including estimates of mineral resources , subsequently requires drill testing.