Minor element geochemistry of the Paragominas bauxite, Brazil

Abstract

The Paragominas bauxite deposit in the eastern Amazon region lies within the Maranhao basin and appears to have developed in late Tertiary and early Quaternary sediments. The bauxitic zone extends over at least 100,000 hectares. In the area sampled for this study, the average thickness is 2.2 + or - .1 m. Estimated reserves are in excess of 10 9 metric tons.Spark source mass spectroscopy was used to determine the concentrations of 56 elements in samples from one profile. Concentrations are compared to the available corresponding information from other bauxite deposits and to crustal abundances.The elements (F, S, Cl, Sc, V, Ga, Ge, Se, Nb, Cd, In, La, Sm, Gd, Tb, Ho, Er, Tm, Yb, Pb, U) with concentrations similar to those in the earth9s crust number approximately the same as those (Cr, Co, Ni, Cu, Zn, Br, Rb, Sr, Y, Ag, Cs, Ba, Ce, Pr, Nd, Eu) whose levels are depleted. Enriched elements (B, As, Zr, Mo, Sn, Sb, I, Hf, Th, Bi) include those having refractory oxides and those exhibiting biological affinity.