Lithological map of Iraq, compiled using GIS techniques

Abstract EN

The Iraqi territory is covered mainly by sedimentary rocks, Quaternary sediments and very rare igneous and metamorphic rocks.

The sedimentary rocks are represented mainly by carbonates and clastics, with subordinate gypsum, marl and shale.

The igneous rocks are represented mainly by gabbros, whereas the metamorphic rocks are represented mainly by serpentines.

In order to compile the lithological map of Iraq, the 89 exposed geological formations and units, and 18 types of Quaternary sediments are classified into 14 lithological units, depending on the main constituent of each geological formation and different types of Quaternary sediments, which appear on the Geological Map of Iraq at scale of 1: 100 000.

Each lithological unit is given a certain color depending on its main lithological constituent.

Using GIS techniques, the exposed geological formations and Quaternary sediments that are presented on the Geological Map of Iraq at scale of 1: 1000 000 are assigned to 14 lithological units.

However, on the Geological Map of Iraq, many formations are grouped together, age wise, due to scale limitation.

This case is found only in the northern and northeastern parts of Iraq, which are mountainous areas, with intensely folded and thrusted strata, besides to the wide age range of the exposed formations, which extends from Precambrian to Pleistocene.

In such cases, the lithology of the most predominant geological formation in the group is taken in consideration for assigning the group to a certain lithological unit.

Moreover, the coverage area of each lithological unit is determined, also using ArcGIS software.