Kudin da aka samu

Kudin da aka samu
Bayanai
Ƙaramin ɓangare na	landform (en) da tudu
Bangare na	Ilimin Kimiyyar Juyin Sifar Kasa (Geomorphology)

Sashe na giciye na uku cuestas, tuddai da ke fuskantar hagu, da kuma tsaunuka masu wuya a cikin launuka masu duhu fiye da masu taushi

Magaliesberg Range, Transvaal, Afirka ta Kudu

A cuesta (Spanish for 'gashi') wani tudu ne ko tudu tare da mai laushi a gefe ɗaya, da kuma gangara mai tsawo a ɗayan. A cikin ilimin ƙasa, ana amfani da kalmar musamman ga tudu inda dutse mai wuya ya rufe wani nau'i mai laushi, duk an karkata shi daga kwance. Wannan yana haifar da tsawo da taushi mai laushi wanda ake kira tudun da ke tattare da raguwar tsayayya, wanda ake kira Caprock. Inda rushewa ta fallasa gaban wannan, wani gangara mai tsawo ko tsawo yana faRuwa. Za'a iya kiran filin da ya samo asali a matsayin scarpland.

Ma'anar

A cikin amfani gabaɗaya, cuesta tudu ne ko tudu tare da gangara mai laushi (baya) a gefe ɗaya, da gangara (frontslope) a ɗayan. Kalmar ta fito ne daga Mutanen Espanya: "gefen ko gangaren tudu; tudu, dutse, ƙasa mai gangara". A cikin ilimin ƙasa da ilimin ƙasa, cuesta yana nufin musamman ga wani tudun da ba daidai ba tare da tsawo mai laushi wanda ake kira gangaren da ya dace da nutsewar wani tsari mai tsayayya ko strata, wanda ake kira caprock. Yankin caprock yana samar da tsaunuka ko ma dutse mai kama da dutse (ƙwanƙwasawa), yana yankewa ta cikin ɓangarorin da ke ƙunshe da cuesta.^[1]^[2]

Kafawa

Cuestas su ne bayyanar da ɗimbin ɓangarorin ɓangarorin tsomawa a hankali, yawanci raƙuman ruwa, waɗanda ke ƙunshe da madaidaicin gadaje masu rauni ko sassauƙan siminti, misali shale, dutsen laka, da marl da tauri, madaidaicin madauri, misali yashi da dutsen farar ƙasa . Fuskokin dutsen da ke da wuya, mai jure wa yazawa sun zama ɗigon dutsen baya (dip-slope) na cuesta, inda zaizayar ƙasa ta fi son kawar da rarrauna. Gangar gaban cuesta ta ƙunshi ƙulle-ƙulle wanda ya rataye saman gadon gadon da ke ɗauke da shi. Saboda yanayin nutsewa a hankali na madaidaicin da ke samar da cuesta, babban canji a cikin wuri a kwance zai faru yayin da ake saukar da shimfidar wuri ta hanyar zaizayar kasa . ^[1] ^[3] Saboda gangaren cuesta yana nutsewa daidai da madaidaicin madauri, ana iya ƙididdige kusurwar dip na wannan gadon (θ) ta ( v / h ) = tan (θ) inda v daidai yake da nisa a tsaye kuma h daidai yake da nisa a kwance daidai da yajin gadon.

Cuestas, homoclinal ridges, da Hogbacks sun ƙunshi jerin siffofin ƙasa waɗanda ke samar da ci gaba na gradational. Wadannan siffofin ƙasa sun bambanta ne kawai a kan tsawo na baya da bambance-bambance na dangi a cikin karkatawar baya da gaba. Wadannan bambance-bambance sun dogara ne akan ko nutsewar sassan da aka rushe su ko dai kusan tsaye ne, nutsewa a matsakaici, ko nutsewa cikin hankali. Saboda yanayin su na gradational, ainihin kusurwar baya wanda ke raba waɗannan siffofin ƙasa yana da son rai kuma wasu bambance-bambance a cikin takamaiman kusurwoyin da aka yi amfani da su don bayyana waɗannan siffofin ƙasar suna faruwa a cikin wallafe-wallafen kimiyya. Hakanan yana iya zama da wahala a rarrabe membobin da ke kusa da wannan jerin siffofin ƙasa saboda yanayin su na gradational.^[1]^[3]

Misalan

A Arewacin Amurka, sanannun cuestas guda biyu a yamma / tsakiyar New York da kudancin Ontario sune Onondaga escarpment da Niagara Escarpment. Rashin Onondaga yana da kimanin ƙafa 40 a kowace mil (kimanin 7.6 m / km) zuwa kudu. A cikin sassan da suka fi yawan jama'a duka gefen tsaunuka suna fuskantar arewa, suna gudana kusan daidai da kudancin Tekun Ontario kuma, ga tsohon, Kogin Mohawk.

Yankin Gulf Coastal Plain a Texas yana cike da jerin cuestas da ke daidai da bakin teku, kamar yadda yawancin filayen bakin teku suke. Reynosa Plateau shine mafi yawan bakin teku, wanda ke da faɗakarwa tare da Bordes-Oakville escarpment, a gefen arewa maso yamma da ƙananan tudu a kan iyakar gabas, wanda ake kira Reynosa Cuesta, inda ajiyar ta nutse a ƙasa da ajiyar Pliocene-Pleistocene na Willis da Lissie Formations.

Cuestas suna da ƙananan maganganu a cikin Ƙasar Ingila, tare da sanannun misalai guda biyu waɗanda ke fuskantar arewa maso yammacin dutsen White Horse Hills na Cretaceous da kuma irin wannan dutsen dutse na Jurassic a cikin Cotswolds, wani lokacin ana kiransa Cotswold Edge. Sauran misalai sun haɗa da Brecon Beacons, Wenlock Edge, Chilterns, Arewa da Kudancin Downs da Greensand Ridge na Kent da Surrey

A cikin nahiyar Turai, Swabian Alb yana ba da kyawawan ra'ayoyi na musamman a cikin dutsen Jurassic . A Faransa, kalmar cuesta daidai yake da na bakin teku:^[] sune yankunan da ake noman ruwan inabi na Cote d'Or .

Machinchang Formation ya mamaye tsibiran Langkawi da ke gabar tekun arewa maso yammacin Malaysia . Samuwar tana ɗaya daga cikin tsoffin rukunan dutsen da aka fallasa a kudu maso gabashin Asiya kuma yana da ɗimbin ɓatacce mai ɗorewa na hoto-wanda ya dawo Cambrian.

Manazarta

1 2 3 Simonett, SD (1968) Cuesta. In RW Fairbridge, ed., pp. 233, The Encyclopedia of Geomorphology (Encyclopedia of Earth Sciences, Volume III), Reinhold, New York, 1296 pp. ISBN 978-0879331795
↑ Jackson, JA, J Mehl and K Neuendorf (2005) Glossary of Geology. American Geological Institute, Alexandria, Virginia. 800 pp. ISBN 0-922152-76-4
1 2 Empty citation (help)

[Simonett1968a-1] 1 2 3 Simonett, SD (1968) Cuesta. In RW Fairbridge, ed., pp. 233, The Encyclopedia of Geomorphology (Encyclopedia of Earth Sciences, Volume III), Reinhold, New York, 1296 pp. ISBN 978-0879331795

[Jackson2005a-2] Jackson, JA, J Mehl and K Neuendorf (2005) Glossary of Geology. American Geological Institute, Alexandria, Virginia. 800 pp. ISBN 0-922152-76-4

[Twidale1993-3] 1 2 Empty citation (help)

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