Analysis of the Genesis and Decline of the Cheshmeh Ali Period Based on the Palaeoclimate Research

The Cheshmeh Ali (CA) cultural period (ca. 5300-4300 b.c), followed by the Sialk Iculture, not only covers the North of Central Iran region (NCI), but also it is evidenced inneighboring regions. The genesis of this culture has coincided with the consolidation ofsedentary-farming in this cultural region. This research is based on the paleoclimatologyof the Mid-Holocene and archaeological data of prehistoric sites belonging to the CAperiod in NCI. The paleoclimate research indicates that climatic condition of the 2nd halfof the 6th mill. bc is indicative of a moderate and humid climate that can well explainthe cultural flourishing of NCI. However, in the early 5th millennium bc, the occurrenceof a warming period probably caused the difficulty of living conditions and the gradualcultural decline of CA societies. According to absolute dating, archaeological sites ofNorthern Sialk, Cheshmeh Ali, Pardis and Ibrahim Abad collapsed between 5000 and4700 bc. During the next phase, which coincided with a relatively favorable climaticperiod, the number of settlements in this region increased but with the onset of anothersevere warm-dry climatic change at ca. 4400/4350 bc, many settlements again declined,and consequently, the CA period ended. Therefore, the result of this study shows thatthe CA period can be divided into two optimal phases, Early (ECA) 5300-5000 bc, Late(LCA) 4700-4300 bc, both of which are between dry periods.