Determining the Tectonic Origin of the Gara and Mateen Anticlines Using Geomorphological and Structural Forms, Iraqi Kurdistan Region

Abstract

Gara and Mateen are 2 major anticlines in the northern part of the Iraqi Kurdistan Region, located in the vicinity of the town Amadiyah. Both anticlines are oriented in an almost east–west (E–W) trend with a steep southern limb. The length and width of the Gara and Mateen anticlines are 87 km and 63 km, and 11 km and 9.5 km, respectively. The 2 anticlines are separated by a wide and shallow syncline filled by the Tertiary rocks of the Pliocene–Pleistocene age. The oldest exposed rocks in the Gara and Mateen anticlines are from the Triassic age. The carapace of both anticlines is built up by the Bekhme and Qamchuqa formations. The geomorphological and structural features were studied through satellite images and geological maps. Based on these studies, it was found that both anticlines show clear geomorphological and structural features that indicate their lateral growth. Among those features are water and wind gaps, different shapes of valleys that indicate lateral growth, abandoned alluvial fans, whale-back shapes, en-echelon plunges, and multiple dome anticlines. Furthermore, the rate of upward movements was calculated using neotectonic data. In addition, the rate of river and stream incisions was calculated on the basis of the height of the river terrace levels.

Keywords

• lateral growth
• water and wind gaps
• fork-shaped valleys
• abandoned alluvial fans
• en-echelon plunges