Iraqi National Journal of Earth Sciences

Abstract

Stratigraphic units during Lower Cretaceous in southern of Iraq
were affected largely by tectonic agent. Neo-Tethys ocean
occupied the distance between passive margins of Arabian and
Iranian plates. South of Iraq represented the continental shelf of
passive margin of Arabian plate. This tectonic situation made the
sediments in eastern parts of passive margin in south of Iraq
effected by marine agents, and the sediments in western parts was
effected by continental agents, whereas the middle parts was
effected by both agents. As result of that, three sediment regions
were formed in south of Iraq. First, marine sediment region that
occupy the eastern part of south of Iraq near the Iraq-Iran borders.
Second, mixed sediment region that occupy Basra area and extend
toward north. Third, continental sediment region that occupy
western part of Basra near the western desert. Half graben basins
that formed by listric faults in the passive margin caused the local
changes in distribution of sediments in south of Basra. These three
sediment regions formed all during Lower Cretaceous and maybe
extend toward the middle of Iraq and north of Baghdad