Lithogeochemistry of fatha formation in selected setions-Northenr Iraq

Abstract EN

A total of 52 samples collected from marl, limestone and gypsum lithological units of Fat'ha Formation (Middle Miocene).

These samples were firstly chemically analysed for ; SiO2, Al2O3, TiO2, CaO, MgO, Na2O, K2O, Fe2O3, SO3, Mn, Co, Ni.

Pb, Zn, and Cu, then mineralogical analyzed via x-ray technique.

Insoluble contents were also determined.

Mineralogical investigation showed the mineral assemblages are as follow ; gypsum, calcite and dolomite, feldspar, and quartz.

Clay minerals composed of illite, palygorskite, kaolinite, chlorite, montmorillonite, and chlorite-montmorillonite mixed layered in variable proportions.

Distributions of minor elements in Fat'ha lithological units are govern by their geochemical affinities and mineralogy.

The main digenetic processes affecting the studied rocks were found to be anhydrite hydration, recrystallization and dolomitization.

Moreover, diagenetic processes lead to changing the major and trace elements concentration due to remobilization of these elements during that processes.

The vertical distribution pattern of clay minerals suggests fluctuation in the salinity and detrital supply of erogenous materials throughout the deposition of Fat'ha Formation.