Geomorphology: July 23-August 2, 2007
Our geomorphology team of Prof. Gert Verstraeten, Dr. Véronique De Laet (Center for Archaeological Sciences, K.U. Leuven), and Bert Dusar and Evelien Janssens (both K.U. Leuven) resumed its work in the valley of the Bügdüz Çayi in the western part of the territory of Sagalassos from July 23 through August 2. Since prehistoric times, this valley formed the shortest and easiest connection between the plain of Burdur and the valley of the Aglasun Çayi below Tepe Düzen and Sagalassos. Therefore, it is likely that Neolithic to Chalcolithic farmers used this route for spreading their activities toward the Sagalassos area, where--according to our pollen record documenting the clearing of oak woodland on the lower hill slopes, the drainage of the valley bottom, and the introduction of anthropogenic plants--they settled around 4200 B.C.
The geomorphogical research has two major aims. First of all, reconstructing the changes in valley topography and valley landscape. Second, the total amount of sediments stored within this valley system will be quantified for different time periods. In a later stage, spatial variability in sedimentation rates within the Bügdüz Çayi will be coupled with information on settlements patterns throughout time. During the 2007 campaign, they extracted in total 32 detailed sediment cores along four transects across the central part of the Bügdüz Çayi valley. Preliminary results indicate that a large ancient river is now buried under 2-3 meters of fine sediment. This ancient river, which is characterized by a thick sequence of coarse bedload material (coarse sand and gravel) was at some places more than 100 m wide, whereas the current river is only 1-5 m wide. On top of this old riverbed deposit, fine overbank deposits accumulated in later periods. However, the major parts of the upper sediments are colluvial deposits originating from the nearby slopes and not transported by the river itself. At present, we have no indications to which period the buried river corresponds. However, several charcoal samples found in the vicinity of the buried river deposits will most probably shed some light about the age of this ancient river. Anyway, since that period, topsoil erosion on the hillslopes in the catchment of the Bügdüz Çayi was so intense that the valley bottom became clogged with fine earth material creating the current landscape.