Depositional Environments and Climatic Events in the Mesopotamian Plain: the Sumerian Site of Abu Tbeirah (original) (raw)

2019, 34th IAS International Meeting of Sedimentology.

The Mesopotamian culture flourished on the banks of the Tigris and Euphrates Rivers, in a landscape that was interested by several changes in the last 6000 yr after the stabilization of the sea-level following the last post-glacial rise. Evidence suggests that the shoreline was located about 250-260 km inland from the present coastline and that two delta apparatuses, Tigris and Euphrates, respectively, were well developed, as an integral part of this coastline. Southern Mesopotamian urbanization was strongly connected to the exploitation of these fluvial systems and their peculiar environment. Therefore, the complex morphodynamic processes of the Holocene, influenced by climatic changes and sea-level fluctuations, had a major impact on the Sumerian society and its development. The interaction between Sumerians and their environment, ethno-historically documented by cuneiform sources, is evident from the anthropic activities recognized by archaeological investigations, such as the hydraulic management of natural channels and the realization of artificial irrigation canals. In this study, Abu Tbeirah, a medium-size 3rd millennium BC city, located near the Sumerian capital of Ur (Nasiriyah), is considered as an example of the past interactions between man and environment. The site was indeed dependent on a main channel visible from the satellite imagery: this watercourse, fundamental for the everyday life of Abu Tbeirah’s inhabitants, crossed the site from the Northwest to the Southeast and was linked to an artificial basin, interpreted as an ancient harbour, from which a secondary artificial canal was derived. The abandonment of the site at the end the 3rd millennium BC might be linked to an abrupt and marked increase in aridity, the so-called “4.2 ka event”, a climatic change attested in Northern Mesopotamia, Syria and other areas of the Mediterranean and Middle East Regions. On this basis we retain that Abu Tbeirah’s economy and life, based on the surrounding water resources, might have been hampered by this megadrought. In order to verify this hypothesis, field-testing on the channel/canals and boreholes were realized at Abu Tbeirah and in its proximities aiming at detecting the palaeoenvironmental evolution of the area in relation to the evidence of climatic switch. The preliminary results of the sedimentological, paleontological, palaeobotanical and 14C analyses, carried out on samples collected during the field surveys, will be presented and related to the archaeological evidence.