干旱区生态环境知识资源中心

This article presents the first direct absolute dating method of a Qanat system obtained through optically stimulated luminescence (OSL) dating of grains in spoil heaps, using feldspar single-grain, feldspar multigrain and quartz multi-grain samples. This novel and highly promising approach to improving our understanding of the chronology of Qanats is more important than the final age results.

Hitherto, dating of Qanats has been based on indirect evidence from historical reports or archaeological investigations of nearby settlements. This study demonstrate the ability of OSL to date this type of subterranean irrigation feature, which is important in the study of both the archaeology of human settlement and palaeoenvironmental change in arid regions. This method can also be used for dating wells and handmade ditches and canals.

Our results show that advanced irrigation technologies existed at Miam in what is now north-east Iran much earlier than previously thought. Dating the now disused Qanat at 3.6-4.3 ka makes it the oldest known. Single-grain dating of sand-sized feldspar that overlie construction spoil show that the Miam Qanat was maintained until at least 1.6 ka. The early development of Qanat irrigation indicates that the causes of widespread societal collapse in eastern Iran in the Bronze Age might not have been driven purely by climatic pressures. (C) 2015 Elsevier Ltd. All rights reserved.