Iron Oxide Mineralogy of Asnawa Soils, Sulaimani Province, Kurdistan region

Sherwan Kafoor1 & Carman Q. Maulood1

1Department of Soil Science, College of Agriculture, Salahaddin University, KRG,

Forty soil samples from three different zones (A, B and C) in Asnawa area were
studied to identify and characterize the forms of Fe oxides in the <2 mm soil fractions
using chemical extractions and XRDA technique. Neither citrate dithionite nor aqua
regia solution were not effective enough to extract free Fe oxides in the soil samples. The
maximum amounts of Fe oxides obtained were when five successive treatments with
aqua regia solution had done. Soils of the quarry area (zone A) contained the highest
amount of Fe oxides followed by soils from zone B and C. They were ranged from
52.1%, 38.6% and 15.1% respectively. XRD traces of the studied soils showed peaks
characteristics of magnetite at 0.297, 0.256, 0.210, 0.161 and 0.147 nm. Other peaks of
hematite at 0.271 nm, and wustite (Fe(1-X)O at 0.88 were also present. Diffraction peaks
of magnetite after a single treatment with citrate dithionite and aqua regia were still
evident on the X-ray chart whereas the diffraction peaks of hematite and wustite were

Key Words: Asnawa, aqua regia, citrate dithionite magnetite wustite 

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