The Mehran Plain During the Early Urbanism Period

Contemporary with late 4th millennium B.C. and starting the early Urbanism Period, the local differences has raised more than before and for the first time after such a long time, the local traditions of Iran and Mesopotamia have evolved separately once again. The Mehrān plain due to its geographical situation in which located between the two main core zones of Urbanism Southwest Iran and Mesopotamia, had surely play an important role in the interactions of given regions. According to our knowledge, the Dehluran and Mehrān plains have stable pattern and settlement trajectory similar to Mesopotamia other than Susiana plain which was specialized on inter-regional trade. Generally, there are 8 settlements with material related to the early Urbanism period have identified in Mehrān plain: Chogha Ahowan, Chogha Boichegh, Chogha Gap, Bahram Abad, Mansour Abad, Zarroush, Shamah Ver and Cam-e Papi of them 5 site are newly assessed. The interesting point on these sites is, they are on the margin of the fertile part of the plain, the place on which there no trace of earlier phases. The settlements related to the early Urbanism Period, can be categorized in 3 ranks with different functions; Chogha Ahowan in the biggest center with inter-regional role, while located on the northern margin of the plain, as it was big center with ca. 10 hectare in size by the Proto-Urbanism and extending to a city with more than 20 hectares in size by the time being discussed. Another rank is a big center on the center of the plain named Chogha Boichegh which was ca. 5 hectare by the last Phase extending to ca.8 hectare in size by the early Urbanism period. The rest of the settlements are rural and small with ca.1 hectare in size distributed on the plain while one of them is located on the isolated area but close to the Plain. It seems that the main change in this period is extending of the Chogha Ahowan from big village of the Late Village Period to big center of the Proto- Urbanism and a city by the early Urbanism Period, the change which is in harmony with known pattern of other adjacent plains. The role of such centers in Susiana, Dehluran and Mesopotamia is almost the same. Unlike the main center, the material recovered from the 2nd and 3rd rank sites are strongly related to agriculture based economy. It seems the main factor on such nature of the given sites is the landscape and environmental potential as the sites permanently affected by such factors. For example, at some parts of the plain the sites with Islamic period material have covered by the sediments of the rivers. A glance at the map no. 3 which is provided on the basis of 7 main environmental factors such as fertile soil, fresh water, vicinity of rivers, slope, water table, vicinity to the pasture and vicinity to the wild resources, finely revealed that the settlement pattern of the Period is strongly matched with agriculture based economy although the only site showing different story is Chogha Ahowan which was based on agriculture by the earlier times but no longer continued by the 4th millennium and 3rd millennium B.C. Most of the sites of the Period are single-period while the reason is still ambiguous to us but some hypothesis can be made; the reason either can be attributed to the political changes of the early 3rd millennium B.C in Mesopotamia or the climate changes by the time being discussed. By the given time, exploiting the wild resources seems to be continued as earlier time but more effective as the data found from Chogha Ahowan supports this idea.