Katharina Streit performed an extensive statistical analysis of Ubaid archaeology in her 2013 master’s thesis under the direction of professor Yossi Garfinkel of the Institute of Archaeology at the Hebrew University of Jerusalem. Her master’s thesis, “Re-evaluating the Ubaid, synchronizing the 6th and 5th millennia BC of Mesopotamia and the Levant,” combined data from radiocarbon dating, pottery, buildings, and other artifacts from throughout the Middle East in a Bayesian statistical methodology in order to assess the origin of the Ubaid and their relationship to other groups in the Middle East. Streit concluded that the Ubaid were not an offshoot of the Hassuna, Halaf or of any other known group of ancient people.
Streit concluded that the lowest levels of Tell-Oueili, considered the first Ubaid settlement, should be dated 5800 BC +/- 100 years. In previous papers, some traditional archaeologists had dated the origin of Tell-Oueili and the Ubaid at 6190 BC; however, Streit argued that this date based on carbon dating of wood charcoal was a flawed measurement technique in arid regions because wood is used repeatedly in construction, sometimes for hundreds of years. In contrast, seeds from Tell-Oueili indicate that the later date of 5800 BC is the correct date.
Streit divided the Ubaid period into three phases. During the first phase (5800 – 5200 BC), the Ubaid were only in southern Mesopotamia: Eridu, Oueili, and Abada.
It was through extensive analysis of their pottery, houses, and figurines that Streit concluded that the Ubaid were not an offshoot of the Halaf culture, which was in northern Iraq. Instead, she found that the Ubaid had unique styles not related to the Halaf and were thus indigenous to southern Mesopotamia. Eventually, there was a gradual mixing of cultures as the two cultures came in contact with each other
Pottery analysis shows that there was little to no contact between the Halaf culture to the north and Ubaid phase 1 (5800-5200 BC). Ubaid pottery was most complex in the earliest Ubaid period. The Ubaid 0/1 culture (earliest) had extremely fine quality monochrome painted ware. Then it underwent a process of simplification. The typical Ubaid pottery and the later Ubaid 2 Haji Muhammed pottery was less busy and intricate. The Ubaid 3 pottery corresponds with expansion of Ubaid culture into northern Mesopotamia. Streit argued that the process of pottery simplification began in northern Mesopotamia and then spread back to southern Mesopotamia.
