Outwash Plains and Eskers (U.S. National Park Service)

... (outwash plains) or beneath (eskers) that glacier ice. They are composed of glacial sediments that have been reworked by flowing water. SkiptoglobalNPSnavigation Skiptothemaincontent Skiptothefootersection NationalParkServiceLogo NationalParkService Search ThisSite AllNPS Search Open Menu ExploreThisPark × ContactUs OutwashPlainsandEskers Outwashplainsandeskersformduetotheflowofmeltwaterinfrontof(outwashplains)orbeneath(eskers)thatglacierice.Theyarecomposedofglacialsedimentsthathavebeenreworkedbyflowingwater. OutwashPlains TheoutwashplaininfrontoftheRedGlacierinLakeClarkNationalMonument(Alaska)endsfarawayfromtheglacierandischaracterizedbybraidedriversandsmallponds.NPSPhoto Outwashplainsoccurinfrontofmeltingglaciers.Theyareexpansive,generallyflatareasthataredominatedbybraidedriverswhentheglacierisactivelymelting.Inareasthatwereonceglaciated,oldoutwashplainscanbefoundbylookingforglacialsediment(till)thathasbeensortedbygrainorbouldersizeasitispickedupanddepositedbyflowingwater.Thismeansthatthesedimentistypicallyfinestfarthestawayfromtheglacier.Outwashplainscanextendformilesbeyondtheglaciermargin.  Eskers Eskersaremeanderingridgesofsedimentthatforminwaterchannelsbeneathorwithintheglacierice.Thefloorsofthesechannelscanberock,sediment,orice.Aswaterspeedsinthechannelsslow(duringretreatorduringperiodsoflowmelt),itdropsthesedimentitcarriesandbuildssmallpilesthattakeontheshapeofthechannels.  Tolearnmoreaboutglaciers,glacierfeatures,andglaciallandforms,seethe Glaciers&GlacialLandformsPage. RelatedLinks NPS—GeoscienceConcepts NPS—GeologicTour NPS—GeodiversityAtlas NPS—Geology Partofaseriesofarticlestitled GlacierLandforms. Previous: Drumlins YouMightAlsoLike Loadingresults... Tags glacierlandforms outwash outwashplain esker glaciers geology grd Lastupdated:February22,2018