Rushewa da tectonics

Erosion and tectonics

Ma'amala tsakanin rushewa da tectonics ya kasance batun muhawara tun farkon shekarun 1990. Duk da yake Tasirin tectonic a kan matakai na farfajiyar kamar rushewa ƙasa an daɗe ana gane su (alal misali, samar da kogi sakamakon tasowa na tectonic), akasin haka (sakamakon rushewa akan aikin tectonic) an magance shi kwanan nan. Tambayoyi na farko da ke kewaye da wannan batun sune irin ma'amala da ke tsakanin rushewa da tectonics da kuma abin da ke tattare da waɗannan ma'amala. Duk da yake wannan har yanzu batun muhawara ne, abu daya a bayyane yake, yanayi duniya samfurin abubuwa ne guda biyu: tectonics, wanda zai iya haifar da yanayin ƙasa da kuma kula da taimako ta hanyar farfajiya da dutse, da kuma yanayi, wanda ke matsakanci hanyoyin rushewa waɗanda ke lalata yankunan tsaunuka a tsawon lokaci. Hadin gwiwar waɗannan matakai na iya samarwa, gyarawa, ko lalata siffofin geomorphic a farfajiyar Duniya.

Ma'amala da hanyoyin ra'ayoyi don tectonics da hanyoyin erosional

Tsarin tectonic

Kalmar tectonics tana nufin nazarin tsarin duniya da hanyoyin da yake canzawa a tsawon lokaci. Hanyoyin tectonic yawanci suna faruwa a iyakokin farantin waɗanda suke ɗaya daga cikin nau'ikan uku: iyakoki masu haɗuwa, iyakoki masu banbanci, ko iyakoki masu canzawa. Wadannan matakai suna samarwa da kuma canza yanayin ƙasa, yadda ya kamata suna kara taimako ta hanyar hanyoyin isostatic uplift, crustal thickening, da kuma lalacewa a cikin nau'in kuskuren da ninkawa. Ƙarin tsawo, dangane da matakan tushe na yanki, yana haifar da hauhawar tashar kogi da karuwa a cikin hazo na ƙasa, wanda ya haifar da karuwar yawan lalacewa. Yanayin ƙasa, da taimakon gaba ɗaya, na yankin da aka ba shi yana ƙayyade saurin da runoff zai gudana, a ƙarshe yana ƙayyades ƙarfin rushewar runoff. Tsawon tsaunuka masu tsawo suna da saurin raguwa mafi girma a lokacin ruwan sama mai yawa fiye da gajeren, yankuna masu saurin ragu. Don haka, manyan tsaunuka, da sauran yankuna masu tasowa, waɗanda aka kafa ta hanyar tasowa na tectonic za su sami ƙimar lalacewa mafi girma. Bugu da ƙari, tectonics na iya tasiri kai tsaye a kan ƙimar lalacewa a kan ɗan gajeren lokaci, kamar yadda yake a bayyane a yanayin girgizar ƙasa, wanda zai iya haifar da rushewar ƙasa da raunana dutsen da ke kewaye da shi ta hanyar rikicewar girgizar kasa.

Duk da yake tasowa na tectonic a kowane hali zai haifar da wasu nau'ikan karuwar tsawo, don haka mafi girman ƙimar lalacewa, an saita babban mayar da hankali kan tasowa na isostatic yayin da yake samar da haɗin kai tsakanin abubuwan da ke haifar da tasirin hulɗar erosional-tectonic.

Hawan isostatic

Fahimtar ka'idar isostasy muhimmiyar mahimmanci ce don fahimtar hulɗa da ra'ayoyin da aka raba tsakanin rushewa da tectonics. Ka'idar isostasy ta bayyana cewa lokacin da aka sami 'yanci don motsawa tsaye, lithosphere yana iyo a matakin da ya dace a cikin asthenosphere don matsin lamba a zurfin diyya a cikin asténosphere da ke ƙasa da tushe na lithosphere iri ɗaya ne. Isostatic uplift ne duka sanadiyar da kuma tasirin rushewa. Lokacin da lalacewa ta faru a cikin nau'in kauri na ɓawon burodi ana haifar da amsawar isostatic wanda ke haifar da kauri mai kauri ya nutse, kuma kewaye da kauri ya tashi. Sakamakon tashin hankali yana haifar da ingantaccen tsawo, wanda hakan ke haifar da rushewa. A madadin haka, lokacin da aka lalata adadi mai yawa daga farfajiyar duniya yana faruwa don kula da daidaitattun isostatic. Saboda isostasy, yawan lalacewa a kan manyan yankuna masu laushi na iya ɗaukar kayan aiki daga ƙananan ɓawon burodi da / ko mantle na sama. Wannan tsari an san shi da isostatic rebound kuma yana kama da martani na Duniya bayan cire manyan kankara.

Hawan isostatic da daidaitaccen lalacewa suna da alhakin samar da siffofin geologic na yanki da kuma tsarin yanki. Misalai guda biyu sun hada da:

Fayil:River anticline by, Michael Stevens.pdf

Kafawar kogin anticline

• Garkuwar nahiyar - Gabaɗaya manyan wuraren da ke da ƙananan taimako (<100 m) a cikin ɓawon burodi na Duniya inda ake fallasa duwatsu masu ƙarancin Precambrian da manyan duwatsu masu tasowa. Ana ɗaukar garkuwar a matsayin wuraren da ke da tsayayyen tectonic idan aka kwatanta da aikin da ke faruwa a gefen su da iyakokin tsakanin faranti, amma kafawarsu ta buƙaci adadi mai yawa na aikin tectonic da rushewa. Garkuwar, tare da dandamali masu ɗorewa, sune mahimman abubuwan tectonic na nahiyoyi, saboda haka fahimtar ci gaban su yana da mahimmanci don fahimtar ci gaban wasu siffofin ƙasa a Duniya. Da farko, an kafa belin dutse a gefen farantin da ya haɗu. Canjin belin dutse zuwa garkuwar ya dogara da dalilai biyu: (1) rushewar belin dutsen ta hanyar ruwa mai gudana da (2) gyare-gyare na isostatic wanda ya haifar da cire dutse saboda rushewa. Wannan tsari na rushewa wanda ya biyo bayan daidaitawar isostatic ya ci gaba har sai tsarin ya kasance a daidaitattun isostatic. A wannan lokacin babban lalacewa ba zai iya faruwa ba saboda farfajiyar ta lalace zuwa kusan matakin teku kuma tasowa ya ƙare saboda yanayin daidaitawar tsarin.

• Kogin anticlines - Tsarin Geologic da aka kafa ta hanyar mayar da hankali ga dutsen da ke ƙarƙashin wuraren da aka kulle na babban rushewa (watau, koguna). Isostatic rebound wanda ya haifar da saurin cire dutse mai zurfi, ta hanyar rushewa, yana haifar da yankunan da suka raunana na dutse don tashi daga saman kogi. Don ci gaban waɗannan tsarin ya faru, yawan lalacewar kogin dole ne ya wuce matsakaicin lalacewar yankin, da kuma yawan haɓaka orogen. Abubuwa biyu da ke tasiri ga ci gaban waɗannan tsarin sune ikon rafi na kogin da ke da alaƙa da kuma tsananin sassauci na ɓawon burodi a yankin. Haɗin karuwar ƙarfin rafi tare da raguwar rigidity yana haifar da ci gaban tsarin daga ƙetare zuwa ƙetare.

Gudun tashar

Gudun tashar yana bayyana tsarin da mai zafi, kayan ƙuƙwalwa ke gudana a kwance tsakanin saman ƙuƙwalwar da mantle na lithospheric, kuma a ƙarshe an tura shi zuwa farfajiya. Wannan samfurin yana da niyyar bayyana siffofin da aka saba da su ga yankunan da ke cikin rikice-rikice na wasu haɗari, musamman tsarin Himalaya-Tibetan Plateau. A cikin tsaunuka tare da ruwan sama mai yawa (saboda haka, yawan rushewa mai yawa) koguna masu zurfi za su kasance. Yayin da wadannan koguna suka lalace a saman duniya abubuwa biyu suna faruwa: (1) matsin lamba yana raguwa a kan duwatsu masu zurfi yadda ya kamata yana sa su raunana kuma (2) kayan da ke ƙasa suna motsawa kusa da saman. Wannan raguwar ƙarfin ɓawon burodi, haɗe da ɓarkewar ɓarkewa, yana ba da damar karkatar da tashar da ke ƙasa zuwa farfajiyar Duniya.

Hanyoyin rushewa

Wani baka na halitta wanda aka samar ta hanyar rushewar dutse mai banbanci a Jebel Kharaz (Jordan)

Kalmar rushewa tana nufin ƙungiyar matakai na halitta, gami da yanayin yanayi, rushewa, abrasion, lalatawa, da sufuri, wanda ake lalata kayan daga farfajiyar Duniya don a kai su kuma a ajiye su a wasu wurare.

• Rugujewar bambance-bambance - Rugujewa da ke faruwa a cikin daidaitattun ko bambance-mbance, wanda ya haifar da bambance-buce a cikin juriya da ƙarfin kayan ƙasa; duwatsu masu laushi da raunana suna lalacewa cikin sauri, yayin da duwatsu masu ƙarfi da masu tsayayya suka kasance don samar da tuddai, tuddai, ko duwatsu. Rugujewar bambance-bambance, tare da yanayin tectonic, sune biyu daga cikin mahimman sarrafawa akan juyin halitta na yankuna a Duniya.

Ana ba da ra'ayi game da rushewa a kan tectonics ta hanyar jigilar farfajiyar, ko kusa da farfajilar, taro (dutse, ƙasa, yashi, regolith, da dai sauransu) zuwa sabon wuri. Wannan sake rarraba kayan na iya samun tasiri mai zurfi a kan yanayin damuwa a yankin, wanda ya dogara da girman nauyin da aka ɗauka. Saboda matakai na tectonic sun dogara sosai da halin da ake ciki a yanzu na damuwa, sake rarraba kayan farfajiyar na iya haifar da aikin tectonic. Duk da yake rushewa a duk siffofinsa, ta hanyar ma'anar, yana cire kayan daga farfajiyar Duniya, tsarin lalacewar taro a matsayin samfurin zurfin ruwa yana da mafi girman tasirin tectonic.

Rashin amfani da yawa

 

Talus cones da aka samar ta hanyar lalacewa, arewacin Svalbard)" id="mwew" rel="mw:WikiLink" title="Isfjord (Svalbard)">Isfjord, Svalbard, Norway.

Mass wasting shine tsarin geomorphic wanda kayan saman ke motsawa a kan tudu yawanci a matsayin taro, galibi a ƙarƙashin ƙarfin nauyi Yayin da koguna ke gudana a kan duwatsu masu gangara, zurfin canjin yana faruwa yayin da kogin ke lalata dutsen da ke ƙasa. Babban canjin tashar a hankali yana rage yawan ƙarfin da ake buƙata don wani abin da ya faru na rashin nasara ya faru, a ƙarshe yana haifar da lalacewar taro. Cire adadi mai yawa na farfajiyar a cikin wannan salon zai haifar da amsawar isostatic wanda ke haifar da ɗagawa har sai an kai ga daidaituwa.

Tasirin juyin halitta

Nazarin da aka yi kwanan nan ya nuna cewa matakai na erosional da tectonic suna da tasiri a kan juyin halitta na wasu siffofin geologic, mafi mahimmanci orogenic wedges. Misalai masu amfani da sandar akwatin, wanda ake matse yashi a hankali a kan baya, sun nuna cewa geometries, tsarin, da kinematics na orogenic wedge formation tare da kuma ba tare da rushewa da sedimentation ba sun bambanta sosai. Misalai na lambobi sun kuma nuna cewa juyin halitta na orogens, tsarin tectonic na ƙarshe, da kuma yiwuwar ci gaban babban tudu, duk suna da hankali ga yanayin dogon lokaci a kan duwatsu, alal misali, maida hankali ga hazo a gefe ɗaya na orogen saboda ɗagawar orographic a ƙarƙashin jagorancin iska.

Dubi kuma

• Yanayin ƙasa mai ƙarfi
• Gishiri mai ƙanƙara
• Rushewar Orogenic
• Bayan sake dawowa daga kankara