Namhlanje siza kuthetha ngohlobo lobume bejoloji olwenziwe kwisiqabu somkhenkce. Imalunga nayo igubu. Eli gama livela kwi "droim" yaseIreland okanye "idrim" kwaye lithetha "indawo yenduli". Ukwakheka kwayo kuvela kumtyibilizi womkhenkce kwaye ayisiyonto ngaphandle kwesiduli esincinci esinamathambeka agudileyo amile okomnenga oleleyo. Ziveliswa yimodeli yomkhenkce kwicala lokuhamba komkhenkce ngamaxesha e-ice Age.
Kweli nqaku siza kukuxelela zonke iimpawu, uqeqesho kunye nomdla wedrum.
Iimpawu eziphambili
Sithetha ngohlobo lwesiduli esincinci esenziwe ngamathambeka agudileyo. Amathambeka agudileyo anobunewunewu okoko umkhenkce womkhenkce kunye namaxesha onyibilikiso abangela ukhukuliseko. Ubume begubu ngumnenga oleleyo kwaye uveliswa ngu ulwalathiso lwendlela umkhenkce ohamba ngayo ubukhulu becala ngexesha lomkhenkce.
Ngenxa yokuba igubu lifunyenwe ecaleni kweediphozithi ze-moraine, zithathwa njengeziqendu ezivela kwi-moraine eveliswa emazantsi e-glacier. I-Moraines siseti se-glacial sediment eqokelela kumacala esakhiwo se-glacial. Banokubonakala bodwa kodwa kuqheleke kakhulu ukuba kufumaneke kumaqela anje ivela kwingingqi yePatagonia yaseChile. Kwaye iseti yeziseko ezenza i-moraines ezihamba zisiya kwicala lomkhenkce nomoya oxhaphakileyo. Siyazi ukuba umkhenkce nawo unentshukumo yawo kuxhomekeke kwithambeka nakumaxesha obudala bomkhenkce.
Ukuyilwa kwegubu
Masibone ukuba yeyiphi inkqubo eyenziwa yidrum. Siyazi ukuba bayinxalenye yomhlaba obunjwe sisenzo somkhenkce. Zininzi iingxoxo malunga nemvelaphi yedrumlin, nangona ithiyori ichaphazeleka ngolu hlobo lulandelayo:
- Yimveliso eveliswe ngomkhukula phantsi komkhenkce. Le alluvium iyakwazi ukuhambisa izinto ezininzi ngexeshana elinye kwaye iqokelela kumajelo omkhenkce ongaphantsi. Le mijelo kulapho amanzi ahamba khona, abanda, kodwa asezantsi nawo aqhubeka kwimeko yolwelo. Siyazi ukuba umkhenkce ubambelele kwintlenge kodwa awumkhenkce ngokupheleleyo. Icandelo elisezantsi lomkhenkce elijikeleza intlenge kwaye umhlaba uhlala ukwindawo engamanzi kwaye unoxanduva lokuhamba komkhenkce.
- Yenziwe ngumkhenkce omkhulu kakhulu okhe wawurhabaxa umhlaba. Xa sibhekisa kukukrwela umphezulu womhlaba sithetha ngohlobo lokhukhuliseko olubizwa ngokuba kukukrala komhlaba. I-Abrasion yinkqubo eyenziweyo ngokurhuqa i-sediment kunye nobunzima bento nganye. Oko kukuthi, xa umkhenkce urhubuluza unqumle umphezulu, uvelisa umvalo ngenxa yolwakhiwo kunye nomhlaba ukhukulisekile kwaye unendawo egudileyo.
Ukwenziwa kwegubu kudityaniswa nodidi lwezinto ezenza ezi nduli. Kwaye kukuba ukungena kwezidalwa kubonakala kudlala indima ebalulekileyo kwinkqubo yokubumba. Ukuba intlenge engaphantsi komkhenkce eqokelelwe ngamaxesha ekhephu iyangena, kunzima ngakumbi ukuba ihlanjwe kuba iza kucoca.
Izinto zeDrumlin
Makhe sibone ukuba zeziphi ezona zinto ziphambili ezenziwe ngalo igubu. Okokuqala konke kukwazi ukuba yintoni enziwe ludaka lomkhenkce. Olu daka lomkhenkce lwaziwa ngegama le till. Ngumxube wodongwe, isanti kunye negrabile ezinemiphetho emboxo kwaye ngamanye amaxesha ineebhloko zamatye. Umkhenkce urhuqa kwaye utyhalele ezi zinto kwaye uzibeke emazantsi. Ngale ndlela, yayingumathiriyeli ofumanekayo ukuba ungahanjiswa ngumkhenkce osezantsi onamanzi amaninzi.
Ngamanye amaxesha intlenge inokwenza igubu elenziwe kukuhamba kwamanzi kwimilambo ejikeleza phantsi komkhenkce. Njengoko besesitshilo ngaphambili, phantsi komkhenkce kukho umaleko wamanzi kwimeko yolwelo njengomlambo. Kumaxesha ambalwa kakhulu umkhenkce ubumkhenkce ngokupheleleyo. Ingakumbi kwixesha lokunyibilika, elona candelo liba lulwelo ngokukhawuleza yeyona ndawo yangaphakathi yomkhenkce. Kule meko, xa idrumlin yenziwe ngu Imilambo ejikeleza phantsi komkhenkce yenziwe ngamatye eerabhile.
Iifom zokuqokelela
Ukusukela kwixesha lokugqibela lomkhenkce, elenzeka kwiminyaka emalunga ne-18.000 eyadlulayo, umkhenkce uye wehla, utyhila imbuyekezo ezuzwe njengelifa kuyo yonke indawo eyayihlala kuyo kwiminyaka yokugqibela ye-ice. Oko kukuthi, ngalo lonke ixesha lokunyibilika kunye nokuncitshiswa kobuso obugqunywe kuyo, ityhila isiqabu kwimodeli yomkhenkce.
Iidipozithi zomkhenkce ezaziwa ngokuba kude kube zizidalwa ezenziwe ngezinto ezifakwe ngokuthe gca ngumkhenkce. Ezi zinto azina stratification kwaye iziqwenga zazo zibonisa imithambo ngenxa yokufuduka kunye nokukhuhlana nomhlaba. Ama-moraines ngohlobo olwenziwe ngamatola aqokelelana kumacala omkhenkce. Ukuba umkhenkce uyabuya umaleko wee-till ezimile njenge-wavy ezibizwa ngokuba yi-basal moraine ifakiwe. Nje ukuba iqhubeke nokubuyela umva, umphambili unokuzinzisa kwaye wenze i-moraine yokubuyela umva.
Imowain moraines ihlala ixhaphake ngakumbi kwimikhenkceko yentlambo. Banoxanduva lokuhambisa yonke intlenga ecaleni konxweme lwayo kwaye bafakwa kwimigangatho emide. Xa ii-moraines ezisecaleni zidityaniswa kukuhlangana kweentlambo ezimbini, i-moraine esembindini iyenziwa.
Okokugqibela, zakuba izidalwa zibekwe ngaphandle komkhenkce kwaye zavuthelwa ngumoya kunye nokusebenza kwezinye iiarhente zejoloji, idrumlin iyenziwa. Kukho ezinye iindlela zokwakheka komhlaba ezibangelwa kukukhululeka komkhenkce kwaye zenziwe ngobutyobo obuluqilima kwaye i-kame, i-kame terrace kunye ne-eskers.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga negubu kunye neempawu zalo.