Origin of the iron ore of the Umm Gerifat area, Egypt

Abstract

The present work is a continuation of the studies carried out by the authors, to reveal the origin of the ochreous deposits in the Umm Gerifat area. This work is mainly concerned with the geochemical investigations of the ochre and the associated iron-bearing sediments. The chemical composition of the iron ore and the associated sediments was found to be exceedingly variable. The major differences in bulk compositions are mainly in the ratio of FeO Fe 2 O 3 . The SiO 2 content varies chiefly with the relative amounts of either detrital or secondary quartz. The CaO and MgO contents increase or decrease according to the relative abundance of dolomite through the succession. The increase in the iron content of the ochreous deposits, generally entails some increase in the alpha radioactivity. It was concluded that these iron deposits are of sedimentary shallow marine origin, which were affected by later alteration processes.