Babak Shaikh Baikloo Islam - Department of History and Archaeology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Ahmad Chaychi Amirkhiz - Archaeological Research Centre, Tehran, Iran.
Hamidreza Valipour - Department of Archeology, Shahid Beheshti University, Tehran, Iran.

Prehistoric archaeological sites in the center of the Iranian Plateau suddenly disappeared around the end of the ۴th millennium BCE. At Tepe Sialk, near Kashan, the last cultural period, namely Sialk IV - probably established around ۳۴۰۰ BCE after the last settlements of Sialk III۶-۷b - was abandoned approximately after ۵۰۰ years. The material culture of this period, known as Proto-Elamite period, is very different from the previous one, showing similarities with Susa III. This period belongs to the same horizon of Uruk III in Mesopotamia and similar evidences were discovered also at sites such as Sofalin, Shoghali, Pardis, Chaltasian, Meymanat Abad, Gholi Darvish, Maral Tepe (Uzbeki), Ghabristan, Arisman and Hissar. With the abandonment of Sialk IV, cultures affected by Uruk in Near East were simultaneously abandoned. This trend of abandonment documented in the center of the Iranian Plateau continued for about ۵۰۰-۱۵۰۰ years. Palaeo-climatological studies show that this period coincides with a cold and dry period dated approximately between ۳۲۰۰ and ۲۷۰۰ BCE. Apparently, these climate fluctuations threatened life more at the center of the Iranian Plateau than in Mesopotamia and Khuzestan, by virtue of the presence of overflowing and permanent rivers in these territories (Euphrates and Tigris above all), probably forcing the migration of people from the center of the Iranian plateau to more favourable areas. The present comparative study suggests that climate changes were the main reason for the cultural collapse attested in the region.

Iranian Plateau, Sialk IV, Middle Holocene, late Holocene, Climate Changes