Geochemistry is now used in virtually every exploration program, not only to determine the grade and concentration of the material to be mined. Exploration geochemistry has evolved from its early origins in assaying, to using the chemistry of geologic environment to locate economic mineral deposit.
Geochemical resource exploration is based on identifying anomalies in area; keeping in mind that the difference between the concentration an economic deposit is often more than 10-times higher than the average concentration of the same element in a given area. Geochemical mapping has played important in identifying areas that may contain concealed resources.
Ideally, geochemical exploration is carried out in several phases, starting with a maximum surface area and low sampling density. The results of the first stage of sample will determine whether sampling proceeds to the next stage. If the results were promising, in the next phase, sample areas are considerably reduced, and the sampling density is correspondingly higher. A third stage may also be entered, where surface area and sample spacing change accordingly.
The choice of the sampling medium may change as the sampling density increases; Stream sediments, soil (instu, sprolite, lag) sampling, rock (bedrock, chip), Termite mound, vegetation, water sampling are among the choices for various stages of geochemical prospecting.
– Regional scale
– Local scale
Interpretation & Reporting