Landschaftswandel in der südlichen Levante während des Holozäns im Kontext von Staubablagerung und Landnutzung
Ägyptische und Vorderasiatische Altertumswissenschaften
Zusammenfassung der Projektergebnisse
The project investigated sediments in the context of various archaeological structures at Jabal Haroun near Petra in southern Jordan and at Horvat Haluqim in the Negev in Israel. The aim was a systematic comparison of these sediments in the context of different types of archaeological structures, geologies, relief positions, and locations with regard to trajectories of dust deposition. Samples of current dust were collected at several of the investigated sites in order to connect the historical record to presentday dust dynamics. We applied an interdisciplinary methodology combining various methods of soil and sediment analysis with archaeological excavations, systematic surveys of off-site scatters of archaeological material, and hydrological modeling. Two project workshops were organized in 2017; one at FAU Erlangen-Nürnberg and one at GJU Madaba. Results show that all types of archaeological structures in the southern Levant store aeolian sediments and are principally suited to reconstruct dust dynamics during the Holocene. Cisterns proved the least promising ruin type due to frequent disturbances connected with re-use, (partial) cleaning, and garbage disposal in times of disuse. However, it was possible to retrieve ostracod shells from cistern sediments, and it seems possible that the (probably rather recent) fills of disused open water basins are suited for reconstructions of environmental changes. The role of runoff-irrigated terraces was investigated applying several hydrological models, which confirmed that the terraces were effective both in managing and controlling runoff and with regard to desert agriculture. As terraces had in ancient times been built in large spatial extent, it seems likely that they had an effect on catchment scale, reducing the risk of flash floods and leading to the accumulation of fine sediments. These could be farmed as moisture supply was sufficiently elevated by runoff irrigation. Faeces biomarkers suggest planned manuring including the application of human excrements. However, very strong rain events could only be controlled to limited extent and would require constant repairs of the terraces, while droughts would induce crop failures. While sedimentation rates in terraces fluctuated and appear connected with the state of the runoff-collection system, the origin of terrace substrates is aeolian. Aeolian sediments were deposited, as well, in hilltop ruins after their abandonment. Hilltop ruins seem the most promising type of archaeological structure, suited to reconstruct Holocene dust deposition. There was no evidence of hiati, but sedimentation seems to take place continuously, in many cases till present day, exceeding deposition rates of Pleistocene hilltop loess in the Negev. Disturbances in hilltop ruins seemed minimal. Comparison with current dust suggests that aeolian deposition in the southern Levant is not only a function of remote dust sources, but also of accretion processes and varying contributions from local and regional sources. Numerous processes including fluvial comminution can provide silt, and local dust sources contributed significantly to ruin sediments in the Petra region. In addition, wind shadow effects of wall remains, (biological) soil crusts, clast-covered surfaces, and vegetation seem to play a major role for (selective) fixation of aeolian sediments. Current dust samples deposited with precipitation, in particular in case of snow, were exceptionally large. Snow led to minimal runoff and fostered vegetation and biological soil crusts. Therefore it seems possible that a disappearance of snow at the end of the Pleistocene is one main reason for diminishing formation of desert loess during the Holocene. Dust sources seem not to have changed, but temperatures and the connected types of precipitation, as well as human activities, may govern the dynamics of landscape changes in the southern Levant.
Projektbezogene Publikationen (Auswahl)
-
2016. Taming the torrents: The hydrological impacts of ancient terracing practices in Jordan. Journal of Hydrology 542, 913-922
Al Qudah, K., Abdelal, Q., Hamarneh, C., Abu-Jaber, N.
-
2019. Character, rates, and environmental significance of dust accumulation in archaeological hilltop ruins in the southern Levant. MDPI Geosciences 9(190), 1-60
Lucke, B., Roskin, J., Vanselow, K., Bruins, H. J., Abu-Jaber, N., Deckers, K., Lindauer, S., Porat, N., Reimer, P., Bäumler, R., Erickson-Gini, T., Kouki, P.
-
2019. Composition of Modern Dust and Holocene Aeolian Sediments in Archaeological Structures of the Southern Levant. MDPI Atmosphere 10, 1-84
Lucke, B., Sandler, A., Vanselow, K.A., Bruins, H.J., Abu-Jaber, N., Bäumler, R., Porat, N., Kouki, P.
-
2019. GIS-based hydrological modelling to assess runoff yields in ancient-agricultural terraced wadi fields (central Negev desert). Journal of Arid Environments 166, 91-107
Bruins, H. J., Bithan-Guedj, H., Svoray, T.
-
2019. Quartz grain surfaces – a potential microarchive for sedimentation processes and parent material identification in soils of Jordan. Catena 176, 209-226
Kemnitz, H., Lucke, B.
-
2019. Soils of ancient terraces in the southern Levant: archives of desert agriculture? Mitteilungen der DBG
Lucke, B., Birk, J.J., Kouki, P., Bäumler, R., Abu-Jaber, N.
