Initial results of the southeastern Wadi Araba, Jordan Geoarchaeological Study: Implications for shifts in late quaternary aridity

Abstract

Wadi Araba is a linear valley that follows the northeast-trending Dead Sea-Jordan transform (DST) fault zone ca. 165 km north from the Gulf of Aqaba to the escarpment overlooking the Southern Ghor of the Dead Sea. An archaeological survey and geologic investigation was conducted along the southeast 75 km of Wadi Araba during three field seasons. The geoarchaeological study focused on analyzing sediments and soil development at sites and air photo interpretation of fluvial systems draining into Wadi Araba. The region is sparsely vegetated with a mean annual precipitation of < 50 mm. The topography of the area is characterized mountains of granitic basement rock that rise steeply above the valley floor along DST escarpment. The valley floor is covered with Holocene to Pleistocene alluvial fan sediments emanating from the range front, mudflat (sabkha) sediments in localized valley axis depressions, and sand dune fields. Three dominant phases of valley floor alluviation occurred during the latest Pleistocene, middle Holocene, and historical times. Preliminary results of the Southeast Araba Archaeological Survey show a large number of Chalcolithic–Early Bronze and Nabataean/Roman–Byzantine age sites and a marked paucity in sites of other ages. Chalcolithic–Early Bronze sites are concentrated on alluvial terraces approximately 3–5 m above the wadi bed tributaries to Wadi Araba and form tells (Tell Magass and Tell Ghuzlan) on an alluvial fan surface north of Aqaba. Other major cultural expansions in the southeastern side of the valley include Nabataean/Roman to Byzantine sites that are situated predominately on the valley floor, and less frequently on low alluvial terraces. The lack of continuous occupation at sites in the southeast Araba valley suggests that the extremely arid climatic conditions lessened during parts of the Holocene. The extensive distribution of archaeological sites of Chalcolithic–Early Bronze Age and Nabataean/Roman–Byzantine age and the associated development of soils indicate that these periods were marked by wetter or cooler climates. These data agree with other climatic proxy data from the Negev Desert and the Dead Sea regions. Although the evidence from the southeast Wadi Araba is not conclusive, it does suggest a southern shift of precipitation belts at approximately 6–5 ka. © 1999 John Wiley & Sons, Inc.