Al-Batin Alluvial Fan, Southern Iraq

Abstract

Al-Batin alluvial fan is one of the largest alluvial fans in Iraq, especially in the Iraqi Southern Desert. Its eastern and southern limits form parts of the Iraqi-Kuwait international borders. The fan is deposited by Wadi Al-Batin, the last apex being on the southern limits of the main wide depression formed by the active Abu Jir-Euphrates Fault Zone. The main trend of the fan is almost SW-NE. The length and the maximum width of the fan are 110.192 Km and 119.1 Km, respectively, whereas the slope along its length is 0.7˚. The fan is covered by gypcrete sheet with thickness varying from (0.5 - 1.5) m. Four stages were recognized within the fan, which is dated to be Pleistocene in age. The four stages are marked by clear height differences. The deposition of the alluvial fan is highly affected by the activity of the active Abu Jir-Euphrates Fault Zone, which is represented on the surface as a wide shallow depression in which the fan is laid down by Wadi Al-Batin. The continuous deposition of the fan has affected the course of the Euphrates Formation within Hammar Marsh and also the course of Khor Al-Zubair in its upper reaches south of Al-Qurna, where the Euphrates and Tigris rivers merge together. Also there is a trace of ancient distributary of the Euphrates River that was flowing directly to the Arabian Gulf, through an estuary, which is abandoned and does not exist anymore.