Origin and Forming of Hacham Island in Khor Al-Zubair Channel, Southern Iraq

Abstract

The marine geophysical survey was conducted using Sub Bottom Profiler and Side Scan Sonar techniques, integrated by petrographic analyses including grain size distribution, mineralogical and fauna analyses of the Hacham island and surrounding area. The island is located in the south part of the Khor Al Zubair channel southwest of the Basrah, Southern Iraq. The study aims to determine the origin and stages of the island formation. This study concluded that there is more than one factor that contributes forming this island represented by tectonic, morphological and sedimentological factors. The results of marine geophysical surveys revealed that the island and its surroundings were affected by the neotectonic activity that exposed the lower part of the Mesopotamian Basin, which in turn caused the lower part of the Khor Al-Zubair channel to meander eastward because of its impact by the fault that separated Warbah island from the Iraqi coast, forming Khor Shaitanah. The meandering of the Khor Al-Zubair course was accompanied by a decrease in flow velocity and thus a decrease in the channel’s ability to carry more sediments, therefore the Khor has to take another course, this waterway separated the island from the main east Iraqi coast. The results of the grain size distribution, mineral identification and fauna analyses indicated a variety of sediment supplying sources of the island, represented by the floods deposits of rivers and side drifts of the surrounding area, in addition to the aeolian deposits transported from the west and northwest Dibdibba Formation. The present study also concluded that the central East shore part of the island is exposed to erosion as a result of a submerged wreck in the waterway that separates the island from the coast.