Mimeralogical Maturity and the Effect of Climate and Topeography on The Sandstones of Injana Formation in Selected Areas From Iraq

Petrographic description of sandstones of the Injana Formation (Upper Miocene) from several selected sections in Iraq shows similarity in mineralogical composition. This is represented by litharenite and feldspathic litharenite eroded from precursor sedimentary, metamorphic and igneous rocks and transported for short distance to be deposited within the fluvial environment. Generally, the sandstone are mineralogically immature; due to increased rates of erosion and deposition associated with dominant mechanical weathering and subdued chemical action.
Presentation of petrographic results as specific relationships point to the deposition under semiaridsemihumed climatic conditions accompanied by little ineffective chemical weathering induced by high relief of source area . Likewise semiarid conditions promoted sparse plant cover, thus providing large quantities of eroded sediments.