Lec 1 & 2 v2

GEOLOGY OF IRAQ

Basics of Geology of Iraq

• Overview by Assist. Prof. Dr. Waleed Shingaly.

Introduction to Geology of Iraq

• Geological Framework: Iraq features thick sequences of marine and continental sedimentary rocks over poorly understood basement rock.

  • Located at the junction of the Arabian, Anatolian, and Iranian plates.

  • Geological study involves the systematic description and division of rocks into:

    • Groups

    • Formations

    • Members

    • Beds

• Terminology Importance: Knowledge of geological terminology is crucial for understanding the geology of Iraq.

  • Key terms:

    • Groups, formations, members, beds

    • Eon, Era, Period, Epoch, Age

    • Paleozoic, Mesozoic, Cenozoic periods

    • Specific rock types and terms like ooids, peloids, bioclasts, etc.

    • Environmental terms such as pelagic, neritic, benthonic, planktonic, etc.

Geography of Iraq

• Location: Iraq is located in Western Asia, bordering several countries with a small coastline along the Persian Gulf.

  • Borders include: Syria (NW), Turkey (N), Iran (E), Jordan (SW), Kuwait and Saudi Arabia (S).

• Physical Features:

  • Two major rivers: Tigris and Euphrates flowing NW–SE.

  • Northern Iraq is mountainous; the highest point is Cheekah Dar (3611 m).

Geological Overview

• Fertile Crescent: Iraq is near the center of this historically significant area.

• Stratigraphy: The geology reflects morphology, with youngest sedimentary rocks in the central depression and older strata on the flanks.

  • Southwest of the Euphrates River, strata dip NE.

• Regional Geology: Key geological features include:

  • Jezira area uplift with Miocene deposits.

  • Erosion along the Euphrates exposing older rocks.

  • Characteristic folding and synclines in the northern mountainous regions.

Geologic History

• Oldest Rocks: Cambrian and Ordovician age Khabour Quartzite Formation exposed.

  • Precambrian rocks likely exist below but are not frequently studied.

• Neo-Tethys Sea: Elongated oceanic basin between the Arabian and Iranian plates excited during the Jurassic and Early Cretaceous periods.

  • Varied sediment types deposited, reflecting geological phases.

Tectonics of Iraq

• Major Tectonic Divisions:

  • Most territory within the Arabian platform (95%).

  • Limited area in the Shalair terrane belonging to the Eurasian plate.

• Structural Units of Iraq: Geologically characterized by plates and terranes impacted by tectonic forces.

• Alpine Orogeny: Key mountain-building process affecting Iraq, primarily impacting the western and central regions and resulting in various geological formations and structures.

• Faults and Folds:

  • The Mosul and Greater Zab faults with significant geological impacts, affecting regional stability and morphology.

Significant Structural Features

1. Sinjar, Mosul, and Kirkuk Blocks:

   • Defined by significant geological faults and regions.

   • Fault systems affecting structure and tension throughout Iraq.

2. Mesopotamia Foredeep:

   • Located between the stable inner platform and the Zagros foothills, characterized by anticlines and structural activity.

3. Al-Jazira Plain:

   • Influenced by geological activity; significant extensional structures formed from tectonic processes.

4. Mesopotamia Plain:

   • Formed in the Mid-Late Triassic as a restricted rift, with important boundaries marked by fault zones.

5. Inner Arabian Platform:

   • Represents a stable geological area within Iraq, characterized by the western and southern deserts.

Summary

• Current State of Knowledge: Understanding the geology of Iraq is crucial in addressing its natural resources and geological hazards.

• Continued study focuses on the tectonic settings, evolving formations, and the application of geological terminology.