Application of soil geochemical survey in the sediment-covered area of eastern Angola
Angola,located on the southwestern edge of the ancient Congo Craton,boasts rich mineral re-sources.This study focuses on the eastern part of Angola(the region covered by Cenozoic sediments)to in-vestigate soil geochemical measurement techniques.The highest proportion of soil samples was found to have a grain size of-80 mesh,while the lowest was observed in samples with a grain size of-60 to+80 mesh.Excluding SiO2 and Au,the concentrations of all other components were generally below the background val-ues of stream sediments in northwest Angola.The optimal sampling depth was identified as 40-50 cm,with-80 mesh being the most suitable grain size for analysis.Notably,'three rare'elements,radioactive ele-ments,and certain non-ferrous metals within iron bauxite exhibited significant enrichment.In sandy soils,Au demonstrated a strong affinity for iron,co-enriching with ferrophilic elements.Only the contents of Cs and K2O in gleyed soil were marginally higher.