Structural and Tectonic Evolution of EI-Faiyum Depression, North Western Desert, Egypt Based on Analysis of Landsat ETM＋, and SRTM Data

FalsecolorLandsatETM+(bands7,4,2inRGB)andSRTMimagesoftheEl-Faiyumdepression,Egypt,highlightsmajorNE-SWfaultsandotherlineamentstrendingNW-SEandN-S.AirbornemagneticdatarevealsomeE-WsubsurfacefaultswhicharenotrecognizedonLandsatETM+andSRTMimages.Ratioimages(5/7,3/1,4/3)and(5/7,5/1,4)wereusedforlithologicaldiscriminationofdifferentrocktypes.TheEl-FaiyumareaisoccupiedbysedimentaryrocksofMiddleEocene,UpperEocene,Oligocene,LowerMiocene,Pliocene,PleistoceneandHolocene.UnderstandingthestructuralregimeofEl-FaiyumdepressionintheWesternDesertofEgyptissignificantinrelationtotheneotectonicsoftheNileDeltaandtothedevelopmentofnewcommunitieswestofthedelta.TheareaiscoveredbyLateCretaceous,MiddletoLateEocenedeposits,Oligocenedeposits(comprisingfluviatilesedimentsandbasaltsheets)andPlioceneandQuaternaryalluviumandsanddeposits.Newgeologicalandstructuralmapswerepreparedatascaleof1:100000usingLandsatETM+andSRTMimagescoupledwithextensivefieldwork.ThemajorstructuraltrendsareE-W,ENE,NSandNW-thesametrendsobservedelsewhereinNorthAfricafromNWSudantoNEEgyptincludingnorthandcentralSinai.El-Faiyumdepressionisastructurally-controlledtectonicbasin,markedbynortheast-strikingfaultsalongitsnorthernmargin.ThesefaultsareparalleltosimilarfaultsoftheSyrianarcfoldbelt,whichincludesagroupofrelatedfaults,folds,push-upstructures,andbasins.QarunLakeislocatedinthenorthernpartofEl-Faiyumdepression,ataright-stepbetweentwostrandsoftheNEstrikingfaultsystem.WehavesuggestedelsewherethatEl-Faiyumdepressionisapull-apartbasinrelatedtoextensionbetweenthesemismatchedstrandsofstrike-slipfaults.TheE-WstructuresareprobablyrelatedtotherelativemotionbetweensouthEuropeandnorthEgyptandclosureoftheNeotethys.Thecontinuationofthesefaultsinthepresentareaisonlydetected