Proterozoic geologic and tectonic evolution of the Wadi Kid area, Sinai, Egypt, based on field and satellite remote sensing studies.

摘要

The Proterozoic Wadi Kid metamorphic belt in southeastern Sinai, Egypt represents a structurally and metamorphically complex assemblage of metasedimentary and metavolcanic rocks folded into a series of ENE-WSW trending antiforms and synforms. Spectral ratioing of selected bands of Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data of the area, in synergy with geological field observation, proved effective in resolving geological mapping problems in the region. A new ASTER band-ratio image (4/7-4/6-4/10) is applied successfully for lithological mapping in the Wadi Kid area, showing improvement over previous techniques in detailing the main rock units. Validating the use of the new ASTER band ratio image relied on both calculating statistical optimum index factor (01F), and matching interpreted lithological boundaries to field data and previously published geologic maps. A factor analysis technique is selected ASTER band ratios from the study area to reflect the interrelation between these ASTER band ratios. By examining the factor loadings of the selected ASTER band ratios, we find that the ASTER band ratio image (6/3-1/3-915) in BGR that give good results in lithological separation of the various rock units in the study area. Based on the specific variance calculations the ASTER band ratios we select ASTER band ratio image (8/6-8/7-4/7) in RGB that yield promising results in differentiating the main rock units in the study area. The adopted ASTER band ratio images of the Wadi Kid area prove successful for lithological mapping in the Arabian-Nubian shield and other arid areas.; From the current evidences about the structural and metamorphic history of the Wadi Kid metamorphic belt, we suggest a polyphase deformation history for the Wadi Kid belt (arc accretion and thrusting events) and low- to med- pressure metamorphic facies series in an arc environment better explains the origin of the belt than an extensional core complex model.