Distribution of iron species in some "oil shales" of the Judea Desert, Israel

Iron-bearing minerals in "oil shales" of the Ghareb Formation have been investigated by Mössbauer and infrared spectroscopy and their chemical compositions have been determined. The minerals studied are: pyrite, kaolinite, iron oxides and iron hydroxides. Pyrite of two types is present, i.e. a framboidal or dispersed microcrystalline type and a very finely crystalline variety detected only by Mössbauer spectroscopy. These occurrences are probably related to differences in hydrophobic-hydrophilic properties of the associated organic matter. The distribution of Fe among oxides, hydroxides, silicates and pyrite in adjacent bituminous and non-bituminous samples indicates that only Fe from oxides and hydroxides has been available for pyrite formation. Fe was not detected in any organically bonded form.