Geochemical evaluation of the in situ regolith at Madengi Hill, Dodoma, Tanzania: implications for bedrock mapping and delineating gold mineralization targets

Abstract

Successful gold exploration projects depend on a piece of clear information on the association between gold, trace elements and mineralization controlling factors. The use of soil geochemistry has been an important tool in pinpointing exploration targets during the early stage of exploration. This study aimed to establish the gold distribution, the elemental association between gold and its pathfinder elements such as Cu, Zn, Ag, Ni, Co, Mn, Fe, Cd, V, Cr, Ti, Sc, In and Se, and identify lithologies contributing to the overlying residual soils. From cluster analysis, a high similarity level of 53.93% has been shown with Ag, Cd and Se at a distance level of 0.92. Au and Se have a similarity level of 65.87% and a distance level of 0.68; hence, is proposed to be the most promising pathfinder element. Principal component analysis (PCA), factor analysis (FA) and the Pearson's correlation matrix of transformed data of V, Cu, Ni, Fe, Mn, Cr and Co, and a stronger correlation between Pb and U, Th, Na, K, Sn, Y, Ta and Be shows that source gold mineralization might be associated with both hornblende gneisses interlayered with quartzite, tonalite and tonalitic orthogneiss. From the contour map and gridded map of Au and its pathfinder elements, it has been noted that their anomalies and generated targets are localized in the northern part of the area. The targets trend ESE–WNW, nearly parallel to the shear zones as a controlling factor of Au mineralization emplacement. Supplementary material: Concentration data for each of the 44 elements analysed are available at https://doi.org/10.6084/m9.figshare.c.5721965