Sedimentolocic'al, petrographical and mineralogical subsurface study of Mukdadiya formation Central part of Iraq

Abstract EN

Sedimentological study of Mukdadiya Formation (Late Miocene – Pliocene) indicates that its sediments were deposited in fluviatile meandering channels system.

The sequence of the formation is composed of several fining-upward cycles in which three facies were recognized: The sandstones facies, represents channels deposits, the gravelly sandstones and conglomerates facies, represents a high energy environment reflecting a climatic or tectonic pulses in the source area, and the fine grained sediments facies, represents overbank deposits.

The petrographic study of the sandstones of Mukdadiya Formation indicates that they are immature, mostly poorly sorted and classified as litharenite.

They are composed mainly of quartz and sedimentary rock fragments; the predominant type of sedimentary fragments is carbonate.

The study of heavy minerals indicates that epidote group is forming the main heavy minerals, followed by amphibole, pyroxene and garnet.

The source rocks; based on petrographical and heavy minerals studies are interpreted to be composed essentially of sedimentary followed by igneous and metamorphic rocks.

The study of clay minerals indicates the presence of montmorillonite, chlorite, illite and kaolinite.

The origin of most of these minerals is detrital, however, the chlorite is considered to be partly diagenetic.