the grand canyon of arizona-第19章

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ll　defined。　As　the　uplift　continues；　the　cherty　limestone　and　possibly　the　cross…bedded　sandstone　are　both　cut　through；　as　the　plateau　slowly　emerges。　Whether　the　process　of　uplift　is　slow　or　rapid；　as　soon　as　a　stratum　emerges；　it　becomes　subject　to　the　influences　of　weathering；　and　the　uppermost　strata　appearing　first；　they　are　weathered　most。　Hence　the　recession　of　the　uppermost　cliffs　is　greater　than　that　of　the　cliffs　lower　down。　The　differences　in　hardness　and　resistance　to　weathering　are　alone　responsible　for　the　step…like　profile　of　cliffs　and　terraces。　The　lower　platform　owes　its　width　entirely　to　the　rapid　weathering　and　recession　of　the　soft　shales；　which　overlie　the　Tonto　sandstones。　The　red…wall　limestone；　on　the　other　hand；　remains　standing　out　as　a　cliff　because　of　its　exceeding　durability。

The　Faults。　During　the　final　uplift；　the　river　cut　through　the　Cambrian　and　Algonkian　strata；　and　into　the　Granite　Gorge　as　we　find　it　to…day；　and　the　process　is　still　slowly　going　on。　During　these　various　periods　of　uplift；　there　were　other　changes　occurring。　Sometimes　the　uplift　was　uneven；　certain　parts　of　the　plateau　being　lifted　more　rapidly　than　other　parts；　then　occurred　breaks　in　the　strata；　called　faults。　There　are　a　great　number　of　these　faults　in　the　plateau　country；　most　of　them　crossing　the　Canyon　from　north　to　south。　This　faulting；　as　is　readily　seen；　would　produce　cracks；　and　as　the　uneven　uplift　continued；　the　strata　on　one　side　of　the　crack　would　be　lifted　higher　than　the　strata　on　the　other　side。　Or；　the　strata　on　one　side　of　the　crack　would　be　uplifted；　while　the　other　would　subside。

Bright　Angel　Fault。　El　Tovar　rests　directly　upon　the　strata　affected　by　the　Bright　Angel　Fault　line。　On　going　down　the　Bright　Angel　Trail；　one　cannot　fail　to　see；　as　he　passes　the　tap　of　the　cross…bedded　sandstone；　the　break　in　the　strata。　To　the　left　it　is　fully　one　hundred　and　fifty　to　two　hundred　feet　higher　than　it　is　on　the　right。　The　same　depression　may　be　observed　in　driving　out　to　Hopi；　Point；　or　returning。　The　stratum　on　which　the　road　is　made　should　be　at　the　same　level　as　the　stratum　on　which　El　Tovar　rests。

Fault　at　Bass　Camp。　This　fault　is　but　one　of　a　score　or　more　on　the　plateau。　At　Bass　Camp　there　was　a　fault　which　displaced　the　strata　on　each　side　of　the　〃break〃　to　the　extent　of　four　thousand　feet。　Later；　another　fault　occurred；　which　readjusted　the　displacement　somewhat；　and　reduced　the　difference　to　two　thousand　feet；　yet　left　the　evidences　of　the　former　wide　divergence。　It　was　also　during　these　uplift　periods　that　the　volcanic　mountains　of　the　region　came　into　existence；　as　the　San　Francisco　Range；　Mounts　Kendricks；　Sitgreaves；　Williams　and　Floyd　on　the　south；　and　the　UinkaretsMounts　Trumbull；　Logan；　Emmaon　the　north。

Lava　Flows。　In　one　place；　south　of　Mount　Emma；　Powell's　party　saw　where　vast　floods　of　lava　had　flowed　from　it　into　the　river。　They　declare　that　〃a　stream　of　molten　rock　has　run　up　the　Canyon　three　or　four　miles；　and　down；　we　know　not　how　far。　The　whole　north　side；　as　far　as　we　can　see；　is　lined　with　the　black　basalt；　and　high　up　on　the　opposite　wall　are　patches　of　the　same　material；　resting　on　the　benches；　and　filling　old　alcoves　and　caves；　and　giving　to　the　wall　a　spotted　appearance。〃　All　these　volcanic　mountains　can　be　seen　from　Hopi　or　Yavapai　points；　near　El　Tovar。

The　Algonkian　Strata。　The　Algonkian　strata　of　the　Grand　Canyon　are　by　far　the　most　interesting；　Major　Powell　was　the　first　to　call　attention　to　their　existence　in　his　report　of　explorations　of　1869…1872；　and　he　discusses　their　origin　and　history　as　far　as　was　possible　with　the　small　amount　of　data　he　had　at　hand。　Later　Dr。　Charles　D。　Walcott；　his　successor　as　Director　of　the　United　States　Geological　Survey；　and　now　the　Secretary　of　the　Smithsonian　Institution；　spent　a　full　winter　in　the　heart　of　the　Canyon；　especially　studying　the　unique　formations。　Unique　they　are；　for；　though　found　elsewhere　on　the　earth；　they　are　exceedingly　rare；　and；　up　to　this　time；　had　received　little　study　and　were　unknown　and　unnamed。　The　area　studied　by　Walcott　lies　at　the　very　entrance　to　the　Grand　Canyon；　near　where　the　Marble　Canyon　and　Little　Colorado　Canyon　join　the　main　one。　While　the　series　cross　the　river　and　are　a　fine　feature　of　Red　Canyon　Trail；　the　main　study　was　done　on　the　north　side。　Dr。　Walcott　thus　locates　the　site　of　his　studies：　〃This　area；　between　35　degrees　57　minutes　and　36　degrees　17　minutes　north　latitude；　and　between　111　degrees　47　minutes　and　112　degrees　west　longitude；　is　in　the　valley　portion　of　the　Canyon；　between　the　mouth　of　Marble　Canyon　and　a　point　south　of　Vishnu's　Temple；　a　little　west　of　where　the　Colorado　River　changes　its　course　from　south　to　southwest。　It　is　wholly　within　the　greater　depths　of　the　Grand　Canyon；　east　and　southeast　of　the　Kaibab　Plateau。　The　intercanyon　valleys　of　this　portion　of　the　Grand　Canyon　extend　back　from　three　to　seven　miles　west　of　the　river；　and　are　eroded　in　the　crest　of　the　Monoclinal　fold　that　forms　the　eastern　margin　of　the　Kaibab　Plateau。〃

There　are　also　interesting　remnants　of　Algonkian　directly　opposite　El　Tovar　to　the　west　of　the　Bright　Angel　Creek。　They　are　easily　discernible　by　their　brilliant　geranium　or　vermilion　color。　They　extend　for　a　mile　or　more　westward；　and　rise　above　the　Tonto　sandstones；　which　properly　belong　above　them。

The　most　remarkable　deposit　and　exhibition　of　Algonkian　strata　in　the　Canyon；　so　far　as　known；　occurs　directly　east　of　the　great　Kaibab　Plateau；　opposite　the　Little　Colorado　River。　Here　there　must　be　several；　possibly　five　or　six　thousand　feet　of　these　interesting　strata；　which　Nature　has　allowed　to　remain　up　to　our　day。　Geologists　are　now　investigating　them　more　thoroughly　than　ever　before；　and　we　may　expect；　when　they　publish　the　reports　of　their　labors；　that　our　geological　knowledge　of　the　Algonkian　epoch；　and　possibly　of　other　puzzling　matters；　will　be　much　increased　by　the　light　they　will　throw　upon　them。



CHAPTER　XIV。　The　CanyonAbove　And　Below

The　Canyon　Rim。　There　are　several　rather　remarkable　and　surprising　points　of　difference　between　the　Canyon　on　the　rim；　and　the　Canyon　in　its　depths。　Above；　the　whole　Canyon　region；　save　during　the　rainy　season；　is　waterless；　and　while　not　barren；　owing　to　the　growths　made　possible　by　winters'　snows　and　summers'　rains；　it　is　a　veritable　desert　as　far　as　water；　whether　in　streams；　creeks；　rivulets　or　springs；　is　concerned。

Drainage　of　the　Canyon。　On　both　sides　of　the　Canyon；　all　the　surface　water　of　the　rains　drains　away　from　the　Canyon　for　miles；　and　not　until　it　has　flowed；　perhaps　from　within　a　few　feet　of　the　edge　of　the　abyss　itself；　from　twenty　to　a　hundred　miles；　does　it　empty　into　the　drainage　channels　which；　burrowing　down　into　the　earth；　reconvey　the　water　back；　by　circuitous　routes；　into　the　depths　of　the　Canyon；　there　to　add　to　the　flow　of　the　Colorado。

Rain　at　El　Tovar。　Take　rain　that　falls；　for　instance；　at　El　Tovar　itself；　within　sight　of　the　Canyon。　After　a　heavy　storm；　the　visitor　may　see　it　dashing　down　the　Bright　Angel　Wash　（up　which　the　railway　runs）　to　Bass　Station；　where　it　turns　and　enters　the　narrower　section　of　the　Wash。　It　flows　in　a　general　southwesterly　direction；　and　enters　the　Coconino　Wash；　which　discharges　into　the　open　plain；　once　the　bed　of　the　great　inland　Eocene　Sea。　Here　it　disappears。

An　Underground　Stream。　In　this　plain　are　some　breaks　in　the　rocky　bed；　which　allow　the　water　to　flow　down　to　join　the　underground　current　of　the　Havasu　（or　Cataract）　Creek；　which　runs　on　the　northern　slope　of　Bill　Williams　Mountain。　This　underground　stream　（as　explained　in　the　chapter　on　Havasu　Canyon）　emerges　at　the　head　of　the　village　of　the　Havasupai　Indians；　in　a　thousand　springs；　and　then　flows　on；　over　several　precipices；　to　the　lower　levels；　thus　making　the　exquisite　waterfalls　that　have　rendered　this　Canyon　world…famous。　It　finally　reaches　the　Colorado　some　fifteen　miles　away；　where　its　clear　blue　waters　are　soon　lost　in　the　muddy　flood　of　the　〃Red。〃

Water　in　the　Canyon。　After　one　has　ridden　in　the　hot　summer　sun　over　this　waterless　region；　and　seen　the　waterwagons　of　the　miners　and　sheep　men；　and　the　great　train　of　water…tanks　being　hauled　for　the　guests　at　El　Tovar；　it　is　a　surprise　and　a　wonder　to　find　below；　in　the　heart　of　this　rocky…walled　Canyon；　a　mighty　river　dashing　its　headlong　way　to　the　west。　Many　a　time；　after　a　week　of　riding　horseback　on　the　plateau　above；　until　every　particle　of　moisture　seemed　to　have　evaporated　from　my　body；　have　I　gone　down　the　trail　to　the　river　and　camped　there；　enjoying　a　swim　several　times　a　day；　and　rowing　up　and　down　one　of　the　quiet　stretches；　between　the　rapids；　where　boating　is　not　only　possible　but　reasonably　safe。　In　the　Bright　Angel　and　the　Shinumo　on　the　north　side；　and　the　Havasu　on　the　south　side；　one　may　swim；　or　at　least　soak　and　paddle；　in　cooling　waters；　where　waving　willows；　giant　sycamores；　and　green　cottonwoods　sway　above　the　streams；　and　rich　verdure　of　great　variety　lines　their　banks。　What　a　wonderful　contrast；above　and　below！

Difference　between　the　Rim　and　the　River。　Another　remarkable　difference；　or　surprise；　is　found　when　one　leaves　the　rim　above；　where　the　weather　is　lovely　and　there　is　not　a　sign　of　rain；　and　go　below　to　the　river；　which　gives　evidence　of　a　great　rise。　How　can　the　river　rise　without　rain？　Yet　it　seems　to；　and　one　almost　doubts　the　evidence　of　his　own　senses。

Experience　on　the　River。　Engineer　Stanton　tells　of　an　experience　as　his　party　went　through　the　river：　〃About　2：30　P。　M。　we　heard　a　deep；　loud　roar；　and　saw　the　breakers　ahead　in　white　foam。　With　a　great　effort　we　stopped　upon　a　pile　of　broken　rock　that　had　rolled　into　the　river。　When　we　went　ahead　to　look；　much　to　our　surprise；　the　whole　terrible　rapid　that　we　had　expected　to　see　had　disappeared；　and　there　was　only　a　rushing　current　in　its　stead。　While　we　stood　wondering；　there　rose　right　at　our　feet　those　same　great　waves；　twelve　to　fifteen　feet　in　height　and　from　one　hundred　to　one　hundred　and　fifty　feet　long　across　the　river；　rolling　down　stream　like　great　sea　waves；　and　breaking　in　white　foam　with　terrible　noise。　We　watched　and　wondered　and　at　last　concluded　that　this　was　the　forefront　of　a　vast　body　of　water　rolling　down　this　narrow　trough　from　some　great　cloud…burst　above。　（We　learned　afterwards　that　there　had　been　such　a　cloud…burst　on　the　head…waters　of　the　Little　Colorado。）　Believing　that　discretion　was　the　better　part　of　valor；　we　camped　right　there　on　that　pile　of　rocks；　fearing　that；　although　our　boats　would　ride　the　waves　in　safety；　we　might　be　caught　in　one　of　these　rolls　just　at　the　head　of　a　rapid；　and；　unable　to　stop；　be　carried　over　the　rapid　with　the　additional　force　of　the　rushing　breakers。〃

High　and　Low　Water。　The　piles　of　driftwood　found　on　the　rocks　in　the　Canyon　reveal　a　difference　of　upwards　of　two　hundred　feet　between　high　and　low　water。　This；　however；　does　not　refer　to　the　general　condition　of　high　water；　but　to　exceptional　cases。　As；　for　instance；　I　myself　once　saw　a　mass　of　rock；　the　whole　face　of　the　cliff；　containing　doubtless　millions　of　tons；　fall　into　the　trough　of　the　stream。　The　whole　course　was　at　once　dammed　up；　and　the　river　rose　sixty　feet　in　one　hour　before　the　principal　mass