The phosphate sedimentary basin of Togo [Maastrichtian-Eocene]: stratigraphy, environments and evolution

Studies carried out in the quarries at Tabligbo (klinker feed materials) Ha hotoe and Kpogame (phosphate extraction), coupled with core sample analyses of five boreholes, have led to a more precise stratigraphy of the Togo coa stal basin and a younger age for the Tabligbo Limestones (Upper Palaeocene) and the palygorskite fissile-laminated Clays (Early Eocene). An outline of the depositional environment of the phosphate deposits is proposed through the sedimentary and dynamic evolution of the basin: transgression on to th e continental margin, followed by a progressive deepening of the basin with deposition and preservation of organic matter; phosphates at the start of the regression; differential displacements of faulted blocks make a structu ral trap for the phosphates; accumulation and alteration of the phosphareni te. (C) 2000 Elsevier Science Limited. All rights reserved.