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The phosphorite deposit of Abu-Tartur plateau, Western Desert, Egypt is one of the largest phosphorite deposits of the world. Previous investigations had revealed that these deposits contain appreciable amounts of rare earth elements (REE) reaching up to 2000 ppm. The distribution pattern of REE indicate terrestrial origin, whereas the phosphorites are of marine origin. This situation suggests that the REE have been remobilized and incorporated into the phosphorites postdepositionally. For this reason it was found of interest to investigate the REE distribution within the overlying shales and their association with different minerals. Samples from the phosphorites and overlying shales have been provided by the Geological Survey and Mining Authority, Egypt. Both ICP-AES and ICP-MS techniques were used for the quantitative determination of the individual REE. Normalized distribution patterns prove that REE in both phosphorites and shales are of terrestrial origin. The vertical distribution of REE in m% within the overlying shales and the abnormally high concentrations of REE in this formation relative to their normal background values in addition to the association of REE with aluminum silicate minerals and not with apatite (which is found in very low concentrations) all suggest that the provenance of REE is the overlying shales. More detailed studies have to be carried out to verify this finding. (C) 1998 Elsevier Science S.A.