Uvda Valley, Israel—An Interplay of Rock Control, Weathering and Debris Deposition in the Evolution of Hyper-Arid Rock Slopes

Looking at terrestrial hyper-arid rock slopesRock slopes, one would expect such landforms in areas characterized by climatic and tectonic stability coupled with sparse or no vegetation to show minor geomorphic changes. The Uvda Valley, located in the southern part of the Negev Desert, Israel, is an excellent area to examine different controls on rock-slope geomorphic evolution. The presence of large boulders (> 1 m long) on a 16 ka alluvial terraces beneath the rock slopesRock slopes challenges the concept of minor changes and indicates an ongoing dynamic erosion process. Hyper-arid rock-slope retreat models are mainly correlated to differential erosion processes (e.g., formation of mesas and cuestas), while models related to retreat of a single-lithology rock slopeRock slopes are based on limited field data. Quantifying weathering and transport processes in the Uvda Valley along sedimentary rock slopesRock slopes composed of a single lithology reveals a systematic spatial pattern of erosional features. Such weathering features coupled with rock debrisRock debris are suggested to play a major role in shaping rock-slope dynamics since the late Pleistocene.