North America: cov nyem thiab nws cov nta

Struts Minerals North America - tag nrho cov kawm nyob rau hauv tsev kawm ntawv hnub no nyob rau hauv geography qhia. Paub txog cov teeb meem yog tsim nyog xwb tsis rau cov tub ntxhais, tab sis kuj rau tag nrho cov kev loj hlob. Tom qab tag nrho, peb txhua tus yuav tsum to taub hais tias yog tus nto ntawm cov ntiaj chaw uas peb nyob.

North America, lub nyem uas peb yuav sib tham txog nyob rau hauv no tsab xov xwm tsa lub hom ntsug phais South America. Haib siv ntawm cov Cordillera roob stretches raws thaj ntug dej hiav txwv rau 7000 km. Advantageously, lub tiaj tus yog cov sab hnub tuaj ib nrab ntawm cov mainland. Tag nrho cov no yuav qhia tau tias tus nyem ntawm qhov Americas muaj ib tug muaj zog sib ze. Txawm li cas los, muaj qhov sib txawv ntawm cov continents. Nyob rau hauv kev, raws li cov Cordillera roob system yog npaum li cas wider thiab complex qauv tshaj Andes (kuj hu ua Andean Cordillera). Lawv muaj xws li ntawm tag nrho cov system yog hom twg, txawv tectonic thiab geological qauv yog cov.

sab hnub tuaj tsam

Kom meej meej txawv yuav luag tag nrho cov tshaj lub Cordillera 5 orotektonicheskih longitudinal aav. Tus thawj ntawm no, rau sab hnub tuaj - Laramide orogeny ridges: Mount Mackenzie, Brooks Ntau, Ridge Eastern Sierra Madre, Rocky Toj siab. Cov yav tas yuav tsum tau muab faib raws li lub peculiarities ntawm Nroj tsuag mus rau hauv ob qhov chaw: sab qaum teb thiab sab qab teb. Nruab nrab ntawm lawv sawv txawv teb chaws Yellowstone toj siab. Leej straightness ntaub ntawv yog kaj orographic nta.

Pem hauv ntej Ntau ntawm cov mob Rocky Toj siab

Pem hauv ntej Ntau ntawm cov mob Rocky Toj siab (North America) muaj cov nram qab nyem: nws stretches yuav luag 2000 km nyob rau hauv ib tug ncaj kab, rau cov rooj saab laaj, ntseeg thiab uniformity ntawm nws geological qauv. Ridge kom meej meej tseg, crowned ntxhab siab peaks, lub qhov siab ntawm cov uas nce mus txog 4000 m. Nws maj mam descends nyob rau hauv lub sab hnub tuaj mus rau lub Great Plains. Pem hauv ntej Ntau mus rau sab hnub poob los ntawm tectonic txhaum nyob rau hauv sab qaum teb ib feem. Nyob rau hauv nruab nrab ntawm lub roob txo. Lawv hla cov dej pis, uas yog ib tug ntawm cov kev pab ntawm lub Mackenzie River. Pem hauv ntej Ntau nyob rau hauv lub yav qab teb ib feem ntawm expanding. Nws yog muab faib ua tej hom twg, lub qhov siab ntawm cov uas yog txiav txim siab: Lewis, Caribou, Selkirk. Nyob rau hauv no ib feem muaj qhov loj tshaj plaws peaks Pem hauv ntej Ntau. Robson yog ib lub roob (nce 3954 m), thiab lub Roob Columbia (3747 m). Alpine ntaub ntawv ntawm North America topography raug ntawm cov pem hauv ntej Ntau. Nws yog tseem yus muaj los ntawm rugged thiab tseem ceeb glaciation.

Rocky Toj siab nyob rau hauv lub yav qab teb ib feem

Tib caj Rockies tsis tsim nyob rau hauv lub yav qab teb ib feem. Ntawm no lawv tseem muaj li ntawm ib tug neeg arrays, tej zaum cais thiab sib cais los ntawm "chaw ua si" - wide phiab, cov sawv cev ib lub toj siab-ib yam li qhov uas hais txuas nrog ib tug loj pas dej ua ke Great Plains. Part ntawm lub ridges (Sangre de Cristo, Wasatch) ncav us txog yuav luag los ntawm sab qaum teb mus rau sab qab teb. Lwm yam (e.g., Uinta Toj siab) - nyob rau hauv sab hnub poob-sab hnub tuaj coj lawv mus rau lawv. Txiav txim siab qhov siab thiab dav ntawm lub roob no siv yog compensated los ntawm cov tsis muaj saab laaj. Cov ciam teb ntawm cov Great Plains thiab cov Rocky Toj siab yog kom meej meej heev qhia: lub ntseg phab ntsa - tus nqes hav ntawm lub roob. Yav qab teb seem - cov no yog cov raug epiplatform roob uas tau tsim tom qab qhib rua ntawm lub ntug ntawm ib qho ntawm lub ancient platforms.

Siv sab hauv plateaus thiab plateaus

Tom ntej no - siv nrog plateaus thiab plateaus tsim nyob rau hauv nevadiyskuyu folding rau lub mainland ntawm North America. Lub nyem yog yus muaj los ntawm daim ntau quav tso nevadiyskimi lug sawv cev peniplenami. Tsis pub dhau no tsam muaj ib lub toj siab, uas yog ceev "thooj" ntawm lub ancient North American platform thiab clamped Cordillera (Northern Mass, Colorado toj siab). Qhov loj tshaj plaws intermountain nras Fraser, Yukon, lub Great Phiab, Colombia, North thiab Central Mass, Colorado.

Great phiab

Great Phiab - denudation toj siab, qhov loj tshaj plaws nyob rau hauv cheeb tsam. Qhov no cheeb tsam, uas nws dav yog li 800 km, nyob rau hauv Feem ntau, yog ib qho alternation ntawm ca thiab roob chaw nrog ib tug predominance ntawm qhov qub. Nyob rau nruab nrab 1500m tsa toj siab nto. Txawm li cas los, loj hloov mus hloov los nyob rau hauv lub heights. Toj siab thaum uas tig mus ridges tshuam nrog heights ntawm txog 3 km (Wheeler ncov - 3982 m). Sib sib zog nqus depressions, hu ua Bolson, pw nruab nrab ntawm lawv. Nws yog semi-xa tuaj nrog thiab muab ntim rau lub phiab, uas yog ib thaj chaw ntawm Internal kua. Tuag Valley - ib tug ntawm lawv (-85 m).

Relict saum no feem ntau pom (xws li cones ntawm volcanoes).

Colorado toj siab thiab lub Grand Canyon

Colorado toj siab - yog ib tug ntawm cov feem ntau cov cim ntawm cov ces kaum ntawm peb ntiaj chaw, uas yog lub npe hu rau North America. Nws nyem yog heev zoo nkauj. Raws li nws cov geological qauv (kab rov tav board undisturbed roob sedimentary pob zeb ntawm txawv hnub nyoog - los ntawm ancient mus verhnepaleoziyskih dag nyob rau hauv crystalline qab daus) yog ib lub toj siab zoo ib yam li lub North American platform. Nws nto - cuam kawb tiaj, uas nce mus txog ib qhov siab ntawm 3860 m.

Attraction ntawm lub toj siab yog lub Grand Canyon (North America). Topography thiab kev nyab xeeb yog attracted rau qhov chaw no muaj ntau yam tourists. Grand Canyon (pictured hauv qab no) twb tsim los ntawm cov Colorado dej, nyob rau hauv nruab nrab ntawm nws cov hoob kawm. Nws nce mus txog ib tug tob ntawm 1800 m, ib tug dav ntawm 8 rau 25 km ntawm lub toj siab thiab rau 1km ntawm lub hauv qab theem. Steep slopes yog interesting, bizarre cov yam ntxwv ntawm lub Grand Canyon. Lawv sawv ntawm tus txheej txheem ntawm erosive kev puas tsuaj thiab weathering. Lub crystalline paus ntawm kos winding nqaim channel.

Puab roob siv

Qhov thib peb cheeb tsam - lub puab roob - ib tug siv nevadiyskih yog hom twg: Ntug dej hiav txwv Toj siab, lub Alaska Ntau, lub Cascade roob, lub Sierra Nevada, thiab cov transverse Volcanic Sierra Madre Occidental. Ncaj txawv ntawm cov ridges. Igneous pob zeb predominate nyob rau hauv lawv cov qauv. Cascade roob - batholith nrog volcanic cones, raug tua nyob rau hauv nws. Lub caj ntawm lub Sierra Nevada no yog ib qho asymmetric giant siv lead ua batholith nrog sloping ntxhab western thiab eastern slopes.

siv synclinoria

Qhov thib plaub tsam yog lub cheeb tsam synclinoria. Qhov no txos ntawm lub cheeb tsam, uas tau tsim nyob rau hauv lub Neogene. Ib feem ntawm nws yog tam sim no sawv cev los ntawm ntau yam marine bays, straits. Nyob rau teb chaws nws yog lub hav tuag, lub Great Central Valley, sab nce mus txog ntawm lub Colorado River.

Far West cheeb tsam

Tsib lub sij hawm - lub huab sab hnub poob. Nws yog ib nqaum txoj siv ntawm daim ntau quav tso alpine ridges li Aleut (muaj 25 active volcanoes), Kenai ceg av qab teb, Island Ridge rau Victoria Ncov (nce - 2,200 m), Chugachsky Ridge ceg av qab teb Victoria, ntug dej hiav txwv yog hom twg, kev khwv Sierra Madre del Sur. Tag nrho cov ntawm lawv yog cov medium-siab, tiam sis feem ntau mas peaks saum toj no 2 km.

Nyob ntawm seb raws li ntawm glaciation, lub heev ntawm orographic longitudinal aav, tectonic thiab erosional phais, tus Cordillera yog muab faib ua 4 morphostructural thaj av ntawd: Cordillera ntawm Mexico, lub tebchaws United States Cordillera Cordillera Cordillera ntawm Canada thiab Alaska.

Lub sab hnub tuaj ib feem ntawm lub teb chaws

Yuav ua li cas ib tug nyem rau North America nyob rau hauv lub sab hnub tuaj? Wb fim nws. Raws li peb tau sau tseg, rau North American topography yog feem ntau tiaj nyob rau hauv lub sab hnub tuaj ib feem ntawm lub teb chaws. Yeej nws yog sublime (Central, Laurentian) thiab siab nras. Lowland yog raws coastline: Primeksikanskaya, Atlantic cheeb tsam, Prigudzonskaya thiab Mississippi nyob rau hauv lub qis nce mus txog ntawm lub tib lub hav dej.

Appalachian roob siv

Nyob rau hauv North America, nyob rau hauv sib piv rau lub South, lwm roob siv stretches nrog rau sab hnub tuaj ntug dej hiav txwv - Appalachian. Qhov no system roob ranges, los ntawm lub Gulf ntawm St. pov tseg. Lawrence mus txog 33-32 ⁰ s. m., uas yog yuav luag 2,300 kilometers. Cov kob ntawm Newfoundland yog lub sab qaum teb link. Appalachian - nws epiplatform tej roob siab siab. Qhov tseem ceeb sib txawv ntawm yav qab teb thiab sab qaum teb qhov chaw ntawm lub roob ntau tshwm sim los tectonic yam ntxwv thiab geological qauv. Graben Hudson yog tus ciam ntawm lub sab qaum teb thiab yav qab teb Appalachian. Northern Appalachians raws li ib tug tag nrho - nws yog undulating toj siab. Nws yog yeej los ntawm ib tug neeg roob ranges los yog roob yog hom twg. Northern Appalachian sib tshooj lub Quaternary glaciation. Yog li ntawd, qhov zoo ntawm roob tam sim no - tiaj tus, tsuas yog tus siab tshaj plaws peaks nyob circuses nrog ntxhab phab ntsa.

yav qab teb Appalachians

Alternation ntawm ntev thaum uas tig mus nram hav thiab ridges ntawm txawv yav qab teb Appalachians. Los ntawm sab hnub tuaj thiab sab hnub poob cuag nrog tus taw ntawm lub toj siab. Nws Piedmont nyob rau hauv lub sab hnub poob - ib tug ca tiaj ntawm denudation, uas yog tsim los ntawm lub Early Cambrian crystalline pob zeb. Los ntawm nws nce steeply rau sab hnub poob saw ntawm roob ranges, yuav luag tas mus li (Kohut, Unakite, Dub, muaj pa taws, loj, xiav, thiab lwm yam), qhov siab - 1-1.5 km. Qhov no "laus roob" - tuab cores Caledonide, npaj denudation.

Siv ridges thiab nram hav

Ib qho ntawm feem zoo kawg li qhov chaw ntawm lub Appalachian Toj siab yog nyob rau sab hnub poob ntawm lawv. Qhov no thiaj li hu ua hluas Roob, los yog siv ntawm ridges thiab nram hav. Ntawm no yog ib co nthuav nta ntawm lub nyem ntawm North America. Sedimentary pob zeb ntawm lub Paleozoic era yog muaj li ntawm tag nrho cov chaw uas zoo heev: yog hom twg - shales thiab sandstones ntawm lub hav - Dolomites thiab limestones. Ncav us txog rau pua pua ntawm kilometers mus rau sab qab teb-hnub poob mus rau sab qaum teb-sab hnub tuaj ntawm lub kab stretch ntawm roob, dav nram hav lwm nrog pav ca-topped los yog zuag nrog nqaim ridges. Nyob hauv ib lub qhov chaw siab tshaj ntawm 500-600 meters, lub hauv qab ntawm hav. ridges peaks mus txog 1-1.2 km. Valley tectonically sawv cev anticlinoria thiab ridges yog synclinoria. Uas yog, nyob rau ntawm no point yog kom meej meej pom mismatch hom tectonic qauv ntawm cov niaj hnub daim ntawv, uas muaj ib tug nyem no nyob rau hauv North America. Cov duab Appalachia yog hais hauv qab no.

Qhov no yog ib qho piv txwv ntawm kev, los yog inversion hom nyem. Nws yog pom nyob rau hauv lub roob yog heev tsawg, thiab feem ntau lug nyob rau hauv lub Appalachians. Qhov no hom ntawm nyem raws kab pib yuav tsum tau hu ua "Appalachian nyem." Siv "cov tub ntxhais roob" nyob rau hauv lub sab hnub poob interrupts cov Appalachian toj siab (Cumberland, Allegheny). Nws yog ib tug protrusion uas nws qhov siab yog 300-400 m. Qhov no yog ho muaj dua toj siab Piedmont. Nws saum npoo sab hnub tuaj ntug lus dag hauv ib qhov siab ntawm txog 1.2 km, thiab sab hnub poob - 500 m toj siab chaw heev dissected nram hav ntau yam dej ntws (noj tsau hwv lawm bottoms nrog nqaim thiab ntxhab qhov chaw siab tshaj) ..

Zoo, tam sim no hais tias lub nyem ntawm North America twb luv luv rov los xyuas dua nyob rau hauv no tsab xov xwm, peb cia siab tias nws yuav ua tau yooj yim dua rau nws kom nws kev nthuav qhia.