Gold in Plant: A Biogeochemical Approach in Detecting Gold Anomalies Undercover- A Case Study at Pelangio Gold Project at Mamfo Area of Brong Ahafo, Ghana

Abstract

Many plants have the ability to take up gold from soils and accumulate them in their tissues. Their concentrations and distributions reflect the nearby gold deposits masked by complex regolith. The 50 vegetation samples collected at Pelangio Tepa concession recorded low and subtle gold (Au) concentrations of 0.2 to 10.4 ppb at Pokukrom target, 0.3 to 28.3 ppb at Nfante East target and 0.1 to 1.7 ppb at Subriso target. Each target area had different concentration populations enough to distinguish the anomalous areas from the background contrary to Au-geochemical expressions derived from the gold in soils. So many uncertainties were placed on the soil-Au-geochemistry because the defined anomalies were not strong and generally appear patchy, weak and subtle that led to the assumption of no associated bedrock mineralisation. The gold in plant samples confirmed the Pokukrom anomaly that has been drilled and known to relate to underlying mineralisation. Much better and robust anomaly was defined by the biogeochemical Au data in plants sampled and analysed for Au at Nfante East target and isolated high patchy anomalies were identified at Subriso area. The case study at Pelangio Mamfo project reveals and recommends the significant application of biogeochemistry in mineral exploration particularly in the field of gold prospecting at the regional exploration stage and endorses it as being practically feasible in regolith-dominated terrains where regolith-landform modifications may impact on the true geochemistry in anomaly delineation.

Keywords: Biogeochemistry, Regolith-Dominated-Terrain, Plant, Gold, Pelangio