Geochemical variations in heavy minerals as provenance indications: application to the Tigris river sand, northern Iraq

Abstract

Heavy mineral assemblages of the Holocene sediments from the tigris river in northern Iraq include opaque minerals such as magnetite, chromite and/or chromian spinels, hematite, ilmenite, goethite and pyrite, and non-opaque minerals including epidotes, pyroxenes, amphiboles, garnet, zircon, tourmaline, rutile, kyanite, staurolite, olivine, sphene, apatite, white mica, biotite and chlorite. Mineralogical and chemical characteristics of the heavy minerals were determined using standard petrographic and electron microprobe analyses. Opaque minerals and epidotes increase in content downstream, mica decreases, whereas amphiboles, pyroxenes and garnet show irregular distributions. Chemical characteristics of selected heavy minerals suggest their derivation from a complex of metamorphic and igneous source rocks. Based on the mineralogical and geochemical signatures, heavy minerals closely reflect mafic and ultramafic igneous rocks, metamorphites, and the ophiolitic complexes of northeastern Iraq and southern turkey.