Mapping the distribution of weathered Pleistocene wadi deposits in Southern Jordan using ASTER, SPOT-5 data and laboratory spectroscopic analysis.

摘要

In the arid regions of the Levant, ancient wadi fills act as a terrestrial sedimentary archive with a high potential for preserving archaeological findings. This current study combines remote sensing with laboratory VIS-spectroscopy to investigate the spatial distribution of alluvial wadi fills in a small catchment in Southern Jordan. Due to its homogeneous sandstone geology, the composition of the alluvial sediments is highly influenced by the local bedrock whilst fluvial relocation and surface weathering processes initiated a secondary alteration of dominant iron oxides (Fe3+). The differences in mineralogical composition of the sediments enable the detection and mapping of wadi deposits by remote sensing using different spectral combinations of ASTER and SPOT-5 satellite images. Additionally, laboratory measurements of reflectance spectra were applied on selected surface samples and soil sections from the study area in order to verify the information derived from remote sensing and to quantify the degree of surface weathering and pedogenic processes. The results show that an initial transformation from hematite to goethite is the dominant process related to the recent arid conditions in the study area. Furthermore, it is possible to predict potential new archaeological finding areas using remote sensing techniques.