A COMPARISON BETWEEN TWO TREATMENTS FOR THE REMOVAL OF IRON OXIDES FROM THIN SECTIONS OF A SOIL

Iron has been removed by two extradants (dithionite-citrate-bicarbonate and acid ammonium oxalate) from iron pedological features present in thin sections of undisturbed samples of a red-mediterranean soil. The effect of treatments has been investigated both optically and chemically. Dithionite-citrate-bicarbonate appeared more efficient on concretions, while iron of nodules was removed more efficiently by the oxalate treatment. The combination of optical and chemical methods seems to be a very promising approach in this kind of experiment.