Archaeomagnetism at Ebla (Tell Mardikh, Syria). New data on geomagnetic field intensity variations in the Near East during the Bronze Age

The article presents the results of a research about the variation in magnetic fields intensity in ceramic fragments from Ebla, from different periods. A comparison was made with similar researches about climatic fluctuations, with the aim to create a more refined chronological chart of the Bronze and Irons ages in Syria

Thanks to systematic excavations conducted at Tell Mardikh/Ebla (Syria) during more than 40 years, we collected eleven groups of Bronze Age ceramic fragments defining a series of seven time intervals dated to between similar to 2300 BC and similar to 1400 BC. Archaeointensity experiments were performed using the Triaxe protocol that takes into account both anisotropy thermoremanent magnetization and cooling rate effects. The results, complemented by three other data previously obtained from Ebla, allow the recovery of geomagnetic field intensity variations over nearly 1000 years characterized by a V-shape, with a distinct relative intensity minimum around the 18th century BC. They also permit to constrain the occurrence of an intensity maximum between similar to 2300 and similar to 2000 BC. Together with other archaeointensity data obtained from Syrian, Levantine and Anatolian regions, the results from Ebla help to make emerging a coherent pattern of geomagnetic field intensity variations in the Near East over the entire Bronze period. This evolution was marked by distinct intensity maxima at similar to 2600-2500 BC, similar to 2300-2000 BC, similar to 1550-1350 BC and at the very beginning of the first millennium BC (Iron Age), the latter showing a much higher magnitude than the three older ones. We discuss the fact that the detected geomagnetic field intensity maxima could be associated with the occurrence of archaeomagnetic jerks that appear synchronous, within age uncertainties, with significant regional climatic fluctuations. (C) 2013 Elsevier Ltd. All rights reserved.