Identifying the Formation of Ourchin Dome, a Symbol of Tomb Architectural Structure in Southern Part of Iran

The close relationship between religion and burial architecture as well as the special respect and reverence of Muslims to the holy shrines was the main reason of the development of burial architecture. Thus, the structure of such constructions is associated with holiness and symbolic values, on the one hand, and with the religious and political identity of the deceased person, on the other hand Various types of dome such as rok, nar, and double-shelled have been introduced to the world and their functions have been investigated. In this architecture, ourchin dome, which is of typical characteristics of the tombs in southern part of Iran, has been neglected. Little information about this type of dome is available in the history of Iranian architecture. And this little information is limited to some reports and pictures from foreign tourists and unknown writers, including no more than a few names and dates of constructing of such structures. Therefore, the origin and the reason for the development of such domes as well as their role are still mysterious. In different parts of the present study, comparative, retrospective, and fieldwork studies have been used, whenever needed. In the current research, the root of the word, ourchin dome, and its meaning are pointed out. Also, the origin of Iranian architecture, which dates back to Seljuqid period, is introduced. Then, the geometric relationships of its sides are examined and different varieties of this dome [star and polygonal] are drawn. Studying the typology of the examples of this dome in Iran and Iraq revealed some remarkable points about the geometric, height, and shape of the dome, in addition to the number of its stories. Some factors, like the function of the crown, method of its construction, cover of the dome, and the system of the distribution of the load are clarified. Finally, by investigating the influential cultural and historical factors, we concluded that that the main reason for the development of the general structure of this type of dome was symbolic, not simply religious. This dome by its own or in combination with religious places has played an affective and functional role over time.