Description
The geology of Iraq can be divided into three major zones because of its location within a subduction region. The western portion of Iraq is subducting beneath the eastern portion of the country, forming a portion of the major Zagros Mountain belt along this east-dipping subduction zone. The Precambrian Arabian plate composes the western portion of the country and is composed of fairly rigid rocks of the stable Arabian shield. The easternmost portion of the country is composed of small mountain ranges that are part of the Zagros orogenic zone, which is the upper plate above the subducting Arabian plate. The major valley between the upper and lower plates of the subduction complex is filled with sediments deposited by the major Tigris and Euphrates Rivers, which flow along the length of the subduction system and cover most of the faults of the system. These meandering rivers are filling a wedge-shaped basin on which the city of Baghdad sits. Baghdad is built on these superficial deposits and is just west of the major subduction seismic zone, so has been built with some regard for seismic shaking. In a military and humanitarian aid setting, the geology of Iraq and the imagery of the country can help military and humanitarian assistance leaders better understand the ground conditions, susceptibility to shaking, and potential for underground facilities. The Arabian shield areas are composed of strong and seismically rigid rocks that are also likely to support heavy vehicle traffic, but are not likely to contain major underground facilities. Seismic shaking in this region from impacts or earthquakes would be quite different than for similar impacts in the Baghdad sedimentary fill. In contrast to the Arabian shield region, digging subsurface facilities in the region of the sedimentary fill of sand, gravel, and mud associated with the Tigris and Euphrates River region would be very straightforward to do. The Zagros Mountain belt contrasts with both the Arabian shield and sedimentary fill in being composed of folded sedimentary rocks, much like the desert region around Las Vegas, Nevada and the anticlines and synclines of the Appalachian Mountains. Determining the geologic setting for water for refugee camps, sand areas amenable to laying mines, and topography or geology used to hide military facilities are all aided by geologic analysis and remote sensing. Landsat 7 scenes of the Baghdad area and the major reservoirs of the country offer particularly insightful views that will be useful to anyone involved in military or UN search for Weapons of Mass Destruction (WMD). Military and no-hit humanitarian targets can be better located and their site conditions understood by studying the geology of the region and providing this information to both decision makers and humanitarian efforts to help the people of this region.
