Mineralogy and geochemistry of aeolian sediments around Kerman

The Quaternary aeolian sands occur in northern and southern parts of the urban areas of the Kerman city. The important aeolian and interlayered sedimentary structures are cross- bedding and ripple mark. Diameter of the aeolian sands ranges from 0.06 to 2 mm, but coarse- grained (gravel size) alluvial deposits are interlayered within the aeolian sands. Mineralogy and petrography of the aeolian sands indicate the presence of rock fragments (30 % carbonate, 25 % igneous and 5 % metamorphic rocks), silicate minerals (15 %) and non-silicate minerals (25 %). The Aeolian sands contain calcite (10%), quartz - chert (12%), alkali feldspar- plagioclase (5%), iron-titanium oxides (5%), clinopyroxene (2%), amphibole (1%) and gypsum (5%). Normative minerals include 30% calcite, 15.4% quartz, 12.5% orthoclase, 10% albite, 2.5% anorthite, 2% diopside, 1% enstatite, 4.6% clay minerals, 0.37% apatite, 3% gypsum, 3% hematite, 0.45% brookite and 10% dolomite. Major element composition of 22 aeolian samples analyzed by XRF and ICP-OES methods shows the frequent occurrence of calcium oxide and lower content of silica compared to the aeolian sands of other regions of the world, though the other major oxides are similar to the aeolian sands of Iraq, Saudi Arabia, Mexico and Namibia. Geochemical diagrams of K2O/Al2O3 versus Na2O/Al2O3and SiO2/Al2O3versus Fe2O3/K2Oand Na2O/K2O suggest a combined provenance of the igneous, metamorphic and carbonate sedimentary rocks for the aeolian sands around the urban areas of the Kerman city.