Playas and Middle Paleolithic settlement of the Iranian Central Desert: The discovery of the Chah-e Jam Middle Paleolithic site

Geomorphological studies indicate that the current Iranian Central Desert has previously consisted of several large lakes, the remains of which are still visible in the form of numerous playas across the desert. The Northern edge of the Iranian Central Desert has been subject to several seasons of systematic Paleolithic surveys from 2009. As a result of these surveys, several Paleolithic settlements have been recorded, the most significant of which include the Middle Paleolithic sites of Mirak, Soofi-Abad and Chah-e Jam. In order to test whether any Middle Paleolithic sites existed around the boundary of such playas, one of them (Chah-e Jam Desert), which is located at the southern outskirts of the modern city of Dāmghan (300 km east of Tehran), was selected for intensive walking survey in July–August 2014. During the course of the survey, a large exposure of lithic artefacts, 8.5 km in length, was discovered. Techno-typological analysis of the lithic assemblages indicates an abundance of Levallois technology and numerous retouched tool types (e.g., Levallois points, and all types of convergent scrapers), leading the site to be attributed to the Middle Paleolithic. The presence of some typological elements of later periods indicates the site has been inhabited during Upper/Epipaleolithic periods as well. This site, along with other Middle Paleolithic settlements in this landscape, indicate that climatic conditions during the Late Pleistocene were significantly different to present, and the presence of numerous lakes and associated vegetation permitted hominin populations to occupy currently arid areas.