Petrography and Provenance of the Sandstone of Injana and Mukdadiya Formations (Upper Miocene/Pliocene) at Duhok Governorate, Northern Iraq
A total of 23 samples are collected from Injana and Mukdadiya Formations representing: sandstone (14 samples from Injana Formation and 9 samples from Mukdadiya Formation). 19 sandstone samples are thin sectioned for petrographic study (10 thin sections from Injana and 9 thin sections from Mukdadiya) and 23 sandstone samples are selected for heavy minerals study (14 samples from Injana and 9 samples from Mukdadiya). The petrographic investigations revealed that the sandstone of Injana and Mukdadiya Formations are composed primarily of rock fragments (sedimentary, igneous and metamorphic), quartz (monocrystalline and polycrystalline) and feldspars (orthoclase, microcline and plagioclase). The matrix is subordinate and the cement is mostly carbonate. The amount of quartz in Injana sandstone is more than of that in Mukdadiya sandstone and the amount of rock fragment in Injana sandstone is less than of that in Mukdadiya sandstone. Provenances of the Injana and Mukdadiya Formations consist primarily sedimentary and igneous rocks and subordinate metamorphic rocks. These sandstones are classified as Litharenites and are mineralogically immature. The heavy minerals assemblages include opaque minerals as major component, epidotes, garnet, amphiboles, clinopyroxenes, orthopyroxenes, chromian spinal, zircon, tourmaline, rutile, chlorite, biotite, muscovite and others (kyanite and staurolite). These assemblages indicate that the heavy minerals are derived from mafic igneous and metamorphic rocks mainly as well as acidic igneous and reworked sediments. The tectonic provenances of both Injana and Mukdadiya Formations can be described as transitional and lithic recycled of recycled orogen.