THE CHRONOLOGICAL MAP OF IRAQ WITH AGE-LITHOLOGY RELATION OF THE EXPOSED GEOLOGICAL FORMATION

Abstract

The Iraqi territory is covered mainly by sedimentary rocks of wide age range that extends from Paleozoic to Pliocene and Quaternary sediments. Moreover, very small parts, in the northeastern parts are covered by igneous and metamorphic rocks. The Quaternary sediments cover considerable parts in Iraq, especially in the central al., 1986).

1.1. Materials Used In order to compile the Chronological Map of Iraq, the and southern parts, which represent the Mesopotamian Flood Plain; they are represented by different types of alluvial sediments of the Tigris and Euphrates Rivers flood plains, and their tributaries. They form the main Mesopotamian Land.

1.2. Aim The aim of this study is to compile the Chronological Map for Iraq, using ArcGIS techniques. Such map can be used for different applications, such as economic potential within a certain age, deducing the regional tectonic framework of the country, and to indicate the spatial distribution of the formations age wise

1.3. Previous Works Almost no similar work has been performed, as the Iraqi territory is concerned, except the presented chronological map within the Neotectonic Map of Iraq (Sissakian and Deikran, 1998). However, the map was constructed manually, by conventional method. Therefore, it is not precise as the present constructed map; moreover, the present map includes more details as compared with the previous one. Moreover, the concerned chronological map depends on the updated geological map of Iraq (Sissakian and Fouad, 2012), whereas the aforementioned map was based on the geological map of Iraq (Jassim et geological map of Iraq (Sissakian and Fouad, 2012) was used as a base map to indicate the age of the exposed geological formations and the existing Quaternary sediments, which are presented on the map. ArcGIS program and extensions were used for digitization of the geological map of Iraq, and then to compile the present chronological map.

1.4. Methodology In order to compile the Chronological Map of Iraq, the ages of the exposed 89 geological formations and units, and the 18 types of Quaternary sediments were reviewed in order to establish the chronological units (Table 1.1). The chronological units were established depending on the age of the formations presented on the Geological Map of Iraq (Sissakian and Fouad, 2012), starting from Holocene down to Paleozoic.

Each geological formation, and each type of Quaternary sediments, present on the Geological Map of Iraq (Sissakian and Fouad, 2012), is assigned to a certain chronological unit (Table 1.1). The age of each exposed geological formation and each type of the Quaternary sediments is indicated from the best available data in Iraq Geological Survey archive, with the help of Bellen et al. (1959), which defines the type section of each geological formation, hence the age is indicated too. Moreover, data presented by Buday (1980), Jassim et al. (1984), Jassim and Goff (2006), Aqrawi et al. (2010), and Sissakian and Fouad (2012) were used too to indicate the age of each geological formation and each type of Quaternary sediments. Consequently, the Chronological Map of Iraq was compiled, by means of GIS techniques (Fig.1.1). However, due to scale limitations, some formations locally are grouped together on the geological map of Iraq (Sissakian and Fouad, 2012). In such cases, certain chronological units were established to include the grouped formations; hence the same formation(s) was assigned to another chronological unit, which includes wider age than the age of the assigned formation.