Investigating the high Zr values in the fine fraction of stream sediments in Nigeria

Regional geochemical surveys in Nigeria have consistently found very high concentrations of Zr in the fine ( 2150 Ma, 2200 Ma) to match published absolute ages from the migmatitic gneisses of Nigeria. The ‘anomalous’ high values of Zr, as well as other elements concentrated in resistant ‘heavy’ minerals in Nigeria’s streams is predominantly due to in-stream winnowing processes and may not reflect anomalous concentrations of these elements in the bedrock of catchment areas of the collected stream sediment samples. This conclusion has important implications for using stream sediment chemistry as an exploration tool for primary metal deposits associated with heavy minerals. However, Zr appears to be a good pathfinder element for placer deposits of heavy minerals.