صنایع سنگی محوطه چیاسبز شرقی، سد سیمره:تغییرات تکنولوژیکی از دوره انتقالی نوسنگی به نوسنگی بی سفال در غرب ایران

The first season of rescue excavation at East Chia Sabz resulted in distinguishing seven archaeological phases containing different material culture including architecture, ground stones, bone artifacts, human burial, plant and animal remains as well as a large amount of chipped stone artifacts, all spanning from the early 9th through early 7th millennium BC. The chipped stone artifacts of the site indicated technological changes from transitional Neolithic (ca.9.500-8.000 BC) to the succeeding Aceramic Neolithic time (ca.8.000-6.500 BC). It seems that chipped stone industry was firstly based upon flake or a combination of both blade and flake production in the lowermost phase which then changed into using pressure technique in the upper phase, in the way that M’lefatian tradition became predominant. At the same time, amorphous cores, uni/bidirectional flake cores and mixed cores were replaced by blade/bladelet cores such as bullet-shaped core around the beginning of the Neolithic period. It should be said that the lowermost phase of the site is entirely consisted of ash deposits, and this might have been resulted from seasonal occupation as seen at the basal layers of other sites. If so, a change from seasonal to the succeeding more permanent settlement in the upper phase is estimated. Such simultaneous change is also apparent at raw material. In the lowermost phase, locally-available reddish brown cobbles were mostly used to produce stone tools while the later phase was coincided by using flint too. Flint then became predominant through time. It is presumably believed that flint might have been exploited at a regional scale and distributed across the region. If so, a regional inter-relationship could be supposed for the Neolithic societies of Western Iran in the 8th millennium BC. Chemical sourcing analysis, however, will be informative to examine the nature of flint procurement in the region and that whether each settlement exploited it separately or it was limited to particular places. In addition, the three uppermost phases –dating from the late 8th to the early 7th millennium BC-witnessed a small amount of obsidian pieces which, as confirmed by a chemical analysis, imported from the Nemrut Dag source in southeastern Turkey. The presence of both obsidian core and debris could be taken as an indicator of on-site tool production. It is assumed that obsidian was imported through Western Zagros (Iraqi Kurdistan) since the late 8th millennium BC onward, and this issue might have been attributed to the role of nomadic society who were moving across the region and, therefore, distributed obsidian pieces among the villages.
   In sum, it should be noted that all changes seen in chipped stone industry of East Chia Sabz could be seemingly occurred at other simultaneous settlements across Western Iran. Stone artifacts of East Chia Sabz could be placed within a broader regional tradition which is originally derived from Zarzian. As mentioned above, some lithic criteria indicated a transition from late Epi-Paleolithic- Zarzian- to early Neolithic- M’lefatian. This issue is in line with locally occurrence of the Neolithization process in Western Iran. During the succeeding Neolithic period, however, M’lefatian tradition became prevalent. M’lefatian tradition was coincided with BAI and Navi-form cores in the western wing of the Fertile Crescent. The former is highly based on production of blade/let while the latter yielded various styles of arrow-head. This also, along with much more archaeological evidence, indicates a Neolithic world in Western Iran which was different from the Levant.