A Middle to Late Holocene avulsion history of the Euphrates river: a case study from Tell ed-Dēr, Iraq, Lower Mesopotamia

Geoarchaeological research was performed to reconstruct the floodplain history in the surroundings of two ancient Mesopotamian cities: Tell ed-Dēr and Sippar. The mapping of the floodplain is based on facies analyses of the sedimentary succession of 225 hand-operated boreholes. The archaeological sites Tell ed-Dēr and Sippar are closely linked to a palaeochannelbelt of the Euphrates, located in the western part of the study area. Channel activity started at least in ca 3100 BC/5050 cal BP, until ca 1400-1000 BC/3350-2950 cal BP. The channel belt was part of an avulsion driven multiple Euphrates channel network that gradually became abandoned from the second half of the 2nd millennium BC. A second mapped Euphrates, Tigris or Joint Euphrates -Tigris palaeochannel belt became abandoned well before 3100 BC. Examples of natural processes as well as human interactions triggering avulsion are given. Moreover, textual, archaeological and geological data show clearly that flood-control techniques and the construction of large-scale dikes seemed to be a common practice.