Upload File

landsliding and mass movements in grand canyon and their implications ... › ... ›...

  • Home
  • Documents
  • Landsliding and Mass Movements in Grand Canyon and Their Implications ... › ... › Landslides-Mass-Movements-in-Grand-Can… · examples near Grand Canyon include those at the
2
Landsliding and Mass Movements in Grand Canyon and Their Implications for Canyon Evolution Jesse Robertson, Karl Karlstrom, Peter Huntoon, John Warme, Ryan Crow, Andy Darling, Laura Crossey What can landslides tell us about bedrock canyon evolution? To answer this question, we need to understand where, when, and how landslides occur as well as the effect of landslide dams on major rivers and canyon widening. Response of continental-scale river systems to landslide dams depends on stream power, channel shape, landslide volume, frequency, composition, and mechanism(s) of emplacement. New field and geochronology studies of landslide deposits in Grand Canyon are beginning to provide some answers. Well-known Toreva-style bedrock slumps and slides are preserved in and around Grand Canyon. Some examples near Grand Canyon include those at the Vermillion and Echo Cliffs (including the reactivation of an older landslide on February 20, 2013 that affected Highway 89) and Coconino Point at Gray Mountain. In Grand Canyon, notable landslides include Carbon Butte in eastern Grand Canyon, 133- Mile, Surprise Valley, Deer Creek, 205-Mile, and Peach Springs Canyon in western Grand Canyon (see figure). Other less well-known deposits cap Nankoweap Butte in eastern Grand Canyon and Fossil Creek in central Grand Canyon. In nearly all cases, failure occurred on weak shale horizons like the Bright Angel or Hermit shales. Paradoxically, Toreva-style landslides do not occur everywhere these lithologies are exposed, which suggests additional controls. Landslides between river miles (RM) 130-140 (including Surprise Valley) are the dominant landslides in Grand Canyon. They represent the largest volume of landsliding that records multiple generations of events in a single area. Our hypothesis is that 1) failures are first localized in the Bright Angel Shale or other weak horizons caused by either a) seismic triggering from nearby faults or b) increased pore fluid pressure, and that 2) in general, major catastrophic slides lead to subsequent smaller yet significant river damming slumps and slides (similar to recent Echo Cliffs event). The goal of my Master’s research is to examine the interplay between these multiple processes that may have operated within the study area to explain the localization of landslides, pre-and post-slide river incision rates and processes, and landslide dam removal. Landslides between RM 130-140 consist of several distinct slides of diverse age and character, some of which dammed the Colorado River. The major slides include 1) 133-Mile, 2) Surprise Valley, Cogswell Butte, and subsequent slides, 3) Pancho’s Radical Runup, and 4) younger reactivated slides off Cogswell Butte and Deer Creek. 133-Mile slide detached from the south rim, includes Tapeats through Redwall strata, and dammed the Colorado River as evidenced by gravels both above and below slide deposits. Surprise Valley (including multiple Toreva blocks north of the intersection of the Thunder River and Deer Creek Trails) formed when Cogswell Butte slightly back rotated and translated along a detachment that underlies it all. This detachment is beautifully exposed near Thunder Spring. Piano slide, a smaller slump off the over-steepened south face of Cogswell Butte, filled a Colorado River paleo-channel near the Granite Narrows (RM 135R). Another slump (Cogswell West) fills the oldest preserved Deer Creek paleo-channel and can be readily observed along the popular route between Tapeats and Deer Creeks. Pancho's Radical Runup, preserved directly across from Deer Creek Falls, involved thrust-style emplacement of a >1.5 km-wide, >5 m-thick slab of Muav through Redwall Limestones. Riding on a 1-3 m cushion of slope debris, river cobbles, and brecciated material, landslide debris traveled across the river and >200 m up the south side. This event dammed the river below Deer Creek and may or may not have been driven by the main Surprise Valley/Cogswell Butte landslide. The Deer Creek slide mass on river-right below Deer Creek Falls appears to be a younger, smaller reactivation of this initial catastrophic slide. This event diverted the Colorado River to the south – a paleo-river channel filled with Deer Creek slide debris is preserved a few meters above river level at RM 137.2R. This event diverted

Upload: others

Post on 28-May-2020

4 views

Category:

Documents


0 download

Report

TRANSCRIPT

Page 1: Landsliding and Mass Movements in Grand Canyon and Their Implications ... › ... › Landslides-Mass-Movements-in-Grand-Can… · examples near Grand Canyon include those at the

LandslidingandMassMovementsinGrandCanyonandTheirImplicationsforCanyonEvolutionJesseRobertson,KarlKarlstrom,PeterHuntoon,JohnWarme,RyanCrow,AndyDarling,LauraCrosseyWhatcanlandslidestellusaboutbedrockcanyonevolution?Toanswerthisquestion,weneedtounderstandwhere,when,andhowlandslidesoccuraswellastheeffectoflandslidedamsonmajorriversandcanyonwidening.Responseofcontinental-scaleriversystemstolandslidedamsdependsonstreampower,channelshape,landslidevolume,frequency,composition,andmechanism(s)ofemplacement.NewfieldandgeochronologystudiesoflandslidedepositsinGrandCanyonarebeginningtoprovidesomeanswers.Well-knownToreva-stylebedrockslumpsandslidesarepreservedinandaroundGrandCanyon.SomeexamplesnearGrandCanyonincludethoseattheVermillionandEchoCliffs(includingthereactivationofanolderlandslideonFebruary20,2013thataffectedHighway89)andCoconinoPointatGrayMountain.InGrandCanyon,notablelandslidesincludeCarbonButteineasternGrandCanyon,133-Mile,SurpriseValley,DeerCreek,205-Mile,andPeachSpringsCanyoninwesternGrandCanyon(seefigure).Otherlesswell-knowndepositscapNankoweapButteineasternGrandCanyonandFossilCreekincentralGrandCanyon.Innearlyallcases,failureoccurredonweakshalehorizonsliketheBrightAngelorHermitshales.Paradoxically,Toreva-stylelandslidesdonotoccureverywheretheselithologiesareexposed,whichsuggestsadditionalcontrols.Landslidesbetweenrivermiles(RM)130-140(includingSurpriseValley)arethedominantlandslidesinGrandCanyon.Theyrepresentthelargestvolumeoflandslidingthatrecordsmultiplegenerationsofeventsinasinglearea.Ourhypothesisisthat1)failuresarefirstlocalizedintheBrightAngelShaleorotherweakhorizonscausedbyeithera)seismictriggeringfromnearbyfaultsorb)increasedporefluidpressure,andthat2)ingeneral,majorcatastrophicslidesleadtosubsequentsmalleryetsignificantriverdammingslumpsandslides(similartorecentEchoCliffsevent).ThegoalofmyMaster’sresearchistoexaminetheinterplaybetweenthesemultipleprocessesthatmayhaveoperatedwithinthestudyareatoexplainthelocalizationoflandslides,pre-andpost-slideriverincisionratesandprocesses,andlandslidedamremoval.LandslidesbetweenRM130-140consistofseveraldistinctslidesofdiverseageandcharacter,someofwhichdammedtheColoradoRiver.Themajorslidesinclude1)133-Mile,2)SurpriseValley,CogswellButte,andsubsequentslides,3)Pancho’sRadicalRunup,and4)youngerreactivatedslidesoffCogswellButteandDeerCreek.133-Mileslidedetachedfromthesouthrim,includesTapeatsthroughRedwallstrata,anddammedtheColoradoRiverasevidencedbygravelsbothaboveandbelowslidedeposits.SurpriseValley(includingmultipleTorevablocksnorthoftheintersectionoftheThunderRiverandDeerCreekTrails)formedwhenCogswellButteslightlybackrotatedandtranslatedalongadetachmentthatunderliesitall.ThisdetachmentisbeautifullyexposednearThunderSpring.Pianoslide,asmallerslumpofftheover-steepenedsouthfaceofCogswellButte,filledaColoradoRiverpaleo-channelneartheGraniteNarrows(RM135R).Anotherslump(CogswellWest)fillstheoldestpreservedDeerCreekpaleo-channelandcanbereadilyobservedalongthepopularroutebetweenTapeatsandDeerCreeks.Pancho'sRadicalRunup,preserveddirectlyacrossfromDeerCreekFalls,involvedthrust-styleemplacementofa>1.5km-wide,>5m-thickslabofMuavthroughRedwallLimestones.Ridingona1-3mcushionofslopedebris,rivercobbles,andbrecciatedmaterial,landslidedebristraveledacrosstheriverand>200mupthesouthside.ThiseventdammedtheriverbelowDeerCreekandmayormaynothavebeendrivenbythemainSurpriseValley/CogswellButtelandslide.TheDeerCreekslidemassonriver-rightbelowDeerCreekFallsappearstobeayounger,smallerreactivationofthisinitialcatastrophicslide.ThiseventdivertedtheColoradoRivertothesouth–apaleo-riverchannelfilledwithDeerCreekslidedebrisispreservedafewmetersaboveriverlevelatRM137.2R.Thiseventdiverted

Page 2: Landsliding and Mass Movements in Grand Canyon and Their Implications ... › ... › Landslides-Mass-Movements-in-Grand-Can… · examples near Grand Canyon include those at the

DeerCreektoitsmodernlocation,whereitthenincisedintotheTapeatsSandstone,carvingtheDeerCreekNarrowsandformingDeerCreekFalls.FieldrelationshipsandexistinggeochronologysuggestsaturationofshalestobethemaindriveroflandslidingintheSurpriseValleyarea.Differentheightsofrivergravelsburiedbeneaththedifferentslides(133-Mile,SurpriseValley,DeerCreek),insetrelationshipsofyoungerslideswithinolderones,andnoevidenceforalignmentalongafault,allargueagainsttheseismicinitiationhypothesis.Themodernpresenceofhigh-volumespringsnearSurpriseValley(i.e.Dutton,Thunder,andTapeatsSprings)suggestsgroundwatermayhaveplayedaroleinweakeningtheshalesandpromotedsliding.Additionalgeochronologyisunderwaytotestthesehypotheses;however,preliminarycosmogenicburialagedatesrecordingthetimeColoradoRivergravelsbecameburiedbeneathlandslidedebrisinpaleo-channels70and61maboveriverlevelgiveagesof940±240ka(1σ)and978±287ka(1σ),respectively.TheseagesprovidethemostdirectgeochronologytodateontheSurpriseValley-andPancho’sRadicalRunup-relatedlandslides.TheagreementofthetwodatesindifferentlocationsataboutthesameheightaboveriverlevelisinterpretedtogivetheapproximateageofboththemainSurpriseValley(CogswellButte)detachmentandPancho’sRadicalRunup.TheDeerCreekslidesmaybeasyoungasthe~21kaageonproposedlandslidedamlakedepositsatRM134.5L(Webbetal.,2005).

DigitalelevationmodelshowinglocationsofnotablelandslidesinandaroundGrandCanyon.Ingeneral,landslidesoccurredalongtherivercorridoraswellasnearmajorfaultsandfolds.MultipleeventstogetherrepresentingthelargestlandslidevolumeinGrandCanyonoccurrednearSurpriseValley.


SUBMITTING AN APPLICATION - PapillonApr 09, 2015  · the (Company) Papillon Airways Inc., Grand Canyon Airlines dba Scenic Airlines, Grand Canyon Coaches, Air Grand Canyon, Canyon

Geohazards Evaluation of Mass Movements in Grand Canyon National Park, Arizona Kaytan Kelkar Mosaics in Science Program 2013

Geohazards Evaluation of Mass Movements in Grand Canyon National Park, Arizona

The Grand Canyon BY STEPHANIE AND MIA The Grand Canyon National Park

Geohazards Evaluation of Mass Movements in Grand Canyon National Park, Arizona Kaytan Kelkar Deanna Greco GRCA 2013

Grand Canyon

Grand Canyon Trailsc001af38d1d46a976912-b99970780ce78ebdd694d83e551ef810.r48...Grand Canyon Trails The Grand Canyon is so internationally popular that there are more people wishing

Grand Canyon Vacation Guidebookgrandcanyon.com/wp-content/uploads/2014/04/grand-canyon-travel... · Grand Canyon Vacation Guidebook ... Lake Powell. Grand Canyon South Rim is also

Grand canyon demo

Grand Canyon - Welsh Governmentresources.hwb.wales.gov.uk/.../eng/the-grand-canyon/grand-canyon.… · Grand Canyon 1. Why do people visit the Grand Canyon? 2. What impact has the

California Condor Birds in the Grand Canyon by Grand Canyon Visitor Center

YOUNG BAND PREVIEW Grand Canyon Suite …listeninglab.stantons.com/.../8/3/4/5/grand-canyon-suite.pdfThemes from four of the five program-based movements of Grand Canyon Suite are

Grand Canyon Facts. Length of the Grand Canyon The Grand Canyon is 277 miles long; 443 kilometers

Grand Canyon

Grand canyon skywalk

Presentación grand canyon

Grand Canyon - Western River Expeditions · 2020-01-06 · GRAND CANYON 4 DAY EXPEDITION Grand Canyon 4 DAY EXPEDITION Before you begin your three day exploration of Grand Canyon,

The Grand Canyon Word Count: 213 THE Grand CANYON · The Grand Canyon Level H Ariona 4 A Canyon So Grand The Grand Canyon is so big that we can see it from space. It became a national

Antilope Canyon & Grand Canyon

THE GRAND CANYON THE GRANDEST OF GRAND CANYON TOURS Grandest of Grand... · The Grand Canyon • La Posada • Grand Canyon Railway • Winslow, Arizona • Grand Canyon Railway Hotel

The Grand Canyon The Grand Canyon By: Meaghan Shaw