Clay mineralogy of the Miocene successions taken from northern Iraq
constitute an important paleoenvironmental indication for the evolution of
these sediments. Palygorskite is a common mineral especially in the lower
Miocene sediments of Euphrates
formation and the upper detrital part of the
Fat'ha Formation belonging to the middle Miocene. Scanning Electron
Microscope (SEM) study indicated that this mineral, was formed authigenically
by neoformation in suitable chemical conditions within the evaporitic
environments. Other minerals (kaoloinite and illite) have been most probable
formed in detrital system and were preserved in those evaporitic conditions.
Common kaolinites in the Injana clastic Formation (Upper Miocene) as well as
its habit in SEM images are indicators for its detrital origin in such continental
sediments.
