IPlanethi yoMhlaba yindawo ekuguquguqukayo rhoqo, apho kungekho nto ihlala imile kangangezigidi zeminyaka. Esinye sezona ziganeko zibangela umdla nezingabonwanga kangako kubungakanani bomntu ngumjikelo welizwekazi elikhulu: inkqubo apho inyambalala yomhlaba idibana khona ukuze yenze amazwekazi amakhulu amakhulu, athi emva koko aqhekeke aze ahlukane, abangele amazwekazi amatsha kunye nembonakalo-mhlaba. Ukuqonda imbali yee-supercontinents kubalulekile ekuqondeni ukuba iplanethi yethu yavela njani kwaye inokutshintsha njani kwixesha elizayo..
Ngalo lonke ixesha le-geological, i-supercontinents iphawule izahluko ezinkulu kwi-evolution yomhlaba.Ukusuka kwi-Vaalbara engaqondakaliyo ukuya kwi-Pangaea edumileyo, umanyano kunye nokuqhekeka kwamazwekazi kube nefuthe kwimozulu, i-biodiversity, ukutshabalala okukhulu, kunye nokumila kweelwandle. Ukuphonononga umjikelo we-supercontinent kufana nokuphanda koomatshini abakhulu boMhlaba kunye nokufumanisa indlela iplanethi esebenza ngayo phantsi kweenyawo zethu.
Yintoni umjikelo we-supercontinental?
Umjikelo we-supercontinent uchaza inkqubo ephindaphindiweyo yokwakheka, ukuqhekeka, kunye nokuhlanganiswa kwakhona kweebhloko zomhlaba ezinkulu kumhlaba woMhlaba. Olu tshintsho lwenzeka kumakhulu ezigidi zeminyaka kwaye lunxulumene ngqo ne Amacwecwe eTectonic, ukuhamba kwamacwecwe e-lithospheric enza uqweqwe loMhlaba.
Ukufumana umbono, Iipleyiti zeTectonic zinokuhamba kancinane njengeesentimitha ezimbalwa ngonyaka, kodwa kumaxesha okwakheka komhlaba oku kwanele ukuba kubangele utshintsho olukhulu kakhulu: ukuvuleka nokuvalwa kweelwandle, udederhu lweentaba olunyukayo nokuwa, kunye namazwekazi ahlangana kunye aze ahlukane kwakhona.
I-supercontinent ngumhlaba omkhulu owenziwe liqela lenxalenye elungileyo okanye onke amazwekazi angoku.Ubukho bazo abusoloko buhleli. Bahlala bekunye amashumi okanye amakhulu ezigidi zeminyaka, de i-tectonic dynamics ibaqhekeze kwakhona, nto leyo ebangela ukuba kubekho ubuninzi belizwekazi elinokuthi lihlangane kwakhona kwizigaba ezizayo.
Umjikelo opheleleyo, ukusuka kwimanyano ukuya kukusasazwa kunye nomanyano olutsha, uthatha phakathi Iminyaka engama-400 nama-600 ezigidiSithetha nje siphakathi kwenqanaba lokusasaza elaqala emva kokuqhekeka kwePangea.
I-Plate tectonics: Injini yomjikelo we-supercontinent
I-Plate tectonics ngundoqo ekuchazeni umjikelo we-supercontinent. Umaleko ongaphandle woMhlaba, i-lithosphere, wohlulwe ube ngamaqhekeza amakhulu okanye iipleyiti "ezidadayo" kucwecwe lweplastiki olubizwa ngokuba yi-asthenosphere. La macwecwe ahlala eshukuma ngenxa yemisinga ye-convective kwingubo yoMhlaba. Kuxhomekeka kwindlela ezishukuma ngayo, ziyakwazi ukuhlukana (zenze iilwandlekazi ezintsha), zingqubane (ziyile iintaba kunye nokudibanisa amazwekazi), okanye zityibilike zidlula kwenye.
Kukho iintlobo ezahlukeneyo zemiphetho yepleyiti: eyakhayo (apho i-lithosphere entsha idalwe, njengakwimimango ephakathi kolwandle), eyonakalisayo (apho iplate enye ihlahlela ngaphantsi kwenye kwaye i-lithosphere itshatyalalisiwe), kwaye iguqule (xa i-slide lateral). Ezi nkqubo zichaza indlela iilwandle ezinokuvuleka ngayo, zisondele zenze udederhu lweentaba, zidibanise okanye zahlule amazwekazi.
El Wilson umjikelo, ebizwa ngegama le-geophysicist uJ. Tuzo Wilson, ingcamango ephambili kwi-plate tectonics. Ichaza indlela isitya solwandle esivuleka ngayo ngokuqhekeka, ukukhula, ukuzinza, kunye nokuvala ngokuthoba, de amazwekazi ebewahlula adityaniswe kwakhona. Lo mjikelo uhlala phakathi kwe-300 kunye ne-500 yezigidi zeminyaka, nangona kunqabile ukuba udibane ngqo nomjikelo we-supercontinent.
Xa imijikelezo emininzi yeWilson idibanisa izigaba zabo zokuvala, ukwakheka kwe-supercontinent kunokwenzeka.Oku kwenzeka ngaxeshanye kukhokelela kwiziqendu ezikhulu zongquzulwano lwelizwekazi kunye nokuhlanganiswa kobuninzi bomhlaba.
Iimodeli zokubunjwa kwe-supercontinent kunye nokutshatyalaliswa
Nangona zonke ii-supercontinents zenziwe ngokungqubana kwabantu belizwekazi, kukho iimodeli ezahlukeneyo zokuchaza ukuhlangana kunye nokuqhekeka kwabo.Phakathi kwezona ziqatshelweyo ziimodeli ezingeniswayo kunye nezandisiweyo.
Imodeli engenisiweyo: Ucebisa ukuba, emva kokuqhekeka kwe-supercontinent, kwenziwa izisele ezintsha zangaphakathi zolwandle, ezithi emva koko zivale ukudibanisa amaqhekeza angaphambili. Inkqubo ifana ne "accordion," apho imiphetho yekhefu efanayo iphetha ngokungqubana kwakhona.
Imodeli eyongeziweyo: Uthi emva kokuqhekeka, amaqhekeza e-continental ayahlukana, kwaye kamva, ukuvalwa kwenzeka kwiilwandle zangaphandle, oko kukuthi, ezo zijikeleze i-supercontinent yangaphambili. Ngaloo ndlela, indibano ayenzeki apho imida yangaphambili yayikhona, kodwa kwiindawo ezisecaleni.
Zombini iimodeli zifumana imizekelo kwimbali yoMhlaba kwaye zinokudityaniswa. Ubungqina bangoku bejoloji bubonisa ukuba umsebenzi wongquzulwano kunye ne-orogeny (uluhlu lweentaba) ukwakheka Ayitshintshi, kodwa iyenzeka kumathuba amafutshane kodwa abukhali, ahlulwe ngamaxesha amade okuzola. Ezi ncopho zomsebenzi zidla ngokungqamana nokusekwa kwamazwekazi rhoqo kwi-400-500 yezigidi zeminyaka.
I-Supercontinents kwimbali yonke
Imbali yoMhlaba iphawulwe ngokusekwa kwamazwe ngamazwe ahlukeneyo, nangona inani lawo elichanekileyo kunye nokulandelelana kwazo zisaxoxwa. Ngokobungqina obuninzi obamkelweyo kunye neerekhodi zejoloji, sinokuchonga ubuncinci ama-supercontinent amathandathu amakhulu:
- Vaalbara (malunga ne-3.800-3.300 yeebhiliyoni zeminyaka eyadlulayo): i-hypothetical supercontinent yokuqala esinayo nayiphi na ingcaciso malunga nayo, ngokusekelwe kwi-paleomagnetic kunye nezifundo ze-geochronological zemimandla emibini yakudala kakhulu: iKaapvaal eMzantsi Afrika kunye nePilbara eNtshona Ostreliya. Ubukho bayo abukaqinisekiswa ngokupheleleyo, kodwa ivula umnyango wokuqonda iitectonics zakuqala zomhlaba.
- Ur (malunga ne-3.000 yeebhiliyoni zeminyaka eyadlulayo): mhlawumbi ingaphantsi kakhulu kune-Australia yangoku, yenziwe kwi-Archean kwaye yasinda amakhulu ezigidi zeminyaka. Kamva yathatha inxaxheba ekusekweni kwamanye amazwekazi amakhulu.
- Kenorland (malunga ne-2.700–2.100 yeebhiliyoni zeminyaka eyadlulayo): ubunzima belizwekazi elikhulu kunabo bangaphambili, obunjwe ziicratons namhlanje ezibumba uMntla Melika, iGreenland, iScandinavia, iinxalenye zoMzantsi Melika, iAfrika, iAsia, neOstreliya. Ukuqhekeka kwayo kwaphawula utshintsho olubalulekileyo lwemozulu, njengokunyuka kweoksijini kunye ne-Huronian glaciation.
- Nuna okanye Columbia (malunga ne-1.800–1.500 yeebhiliyoni zeminyaka eyadlulayo): Yayiquka phantse onke amazwekazi elo xesha kwaye yayiyindawo yee-orogenies ezinkulu. Iatmosfera yayisele ineoksijini, kwaye ubomi babuguqukela kwiindlela ezintsonkothileyo zemulticellular.
- Rodinia (malunga ne-1.100-750 yezigidi zeminyaka eyadlulayo): Indibano yayo mhlawumbi yenzeke ngemodeli ekhutshweyo kwaye yaphawula ixesha lokutshintsha okubalulekileyo, kuquka ukuvela kwezinto zokuqala ze-eukaryotic kunye neziqephu zehlabathi zomkhenkce ezaziwa ngokuba yi "Snowball Earths." Ukuqhekeka kwayo kwakhokelela ekusekweni kwamazwekazi amatsha.
- Pannotia okanye Vendia (malunga ne-600 yezigidi zeminyaka eyadlulayo): inde kwaye imile okwe-V, yenye yezona ndawo zibalaseleyo zokugqibela ngaphambi kwePangaea. Ukwahlukana kwayo kwangqamana nokuvela kwezilwanyana ze-Ediacaran kunye nogqabhuko-dubulo lweCambrian, olusisiseko sokuvela kobomi eMhlabeni.
- Pangea (malunga ne-300-180 yezigidi zeminyaka eyadlulayo): ngokungathandabuzekiyo i-supercontinent eyaziwa kakhulu. Kwavela ekupheleni kwePaleozoic kwaye yahlukana ngexesha leMesozoic. Ukuqhekeka kwayo kuxanduva lokucwangciswa kwangoku kwamazwekazi.
Abanye ababhali baqwalasela ubukho bamanye amazwe amakhulu okanye amazwekazi, afana ne-Atlantica kunye neNena, eyathatha inxaxheba ekusekweni kweebhloko ezinkulu ezikhankanywe. Okucacileyo kukuba uMhlaba uqokelele kwaye wasasaza amazwekazi awo izihlandlo ezininzi kwimbali yawo, echaphazela nemozulu kunye nobomi.
Ukubunjwa kunye nokuqhekeka kwePangaea: i-supercontinent yokugqibela
IPangea ngowona mzekelo wamva nje nofundwe welizwekazi elikhulu, kwaye imbali yalo iphawula ukuqala kwejografi njengoko sisazi. Yasekwa ekupheleni kwePaleozoic, malunga ne-300 yezigidi zeminyaka eyadlulayo, ngokungqubana kunye nokudityaniswa kwazo zonke izihlwele zelizwekazi ezazikho ngaphambili, emva kwezigaba ezilandelelanayo zokungqubana (ezifana neVariscan okanye iHercynian orogeny).
Ngexesha lobukho bePangaea, amaqondo olwandle ayephantsi ngokwentelekiso, njengoko imihlaba yayixinene kwaye kukho indawo encinane yamanzi olwandle. Imozulu yombindi wePangaea yayibharhile kwaye igqithise, ngenxa yomgama omde ukusuka elwandle kunye nokungabikho kwemvula.
Ukuqhekeka kwePangea kwaqala ngexesha leJurassic, xa umsebenzi we-tectonic wavelisa iziphene kunye nemimandla ye-rift eyahlula i-supercontinent kuqala kwiibhloko ezimbini: iLaurasia ukuya emantla kunye neGondwana ukuya emazantsi, kunye ne-Tethys Ocean phakathi. Ukusuka apho, ukuqhekeka okungakumbi kunye nokuvulwa kweenduli ezisembindini wolwandle (iAtlantiki, eIndiya) kwakhokelela ekwahlukaneni kwamazwekazi esiwaziyo namhlanje.
Ulungelelwaniso lwangoku lwamazwekazi lusesisiphumo sale nkqubo yokusasazwa kwaye, ngokutsho koguquko oluphawulweyo, lusaqhubeka. Ulwandle lweAtlantiki, umzekelo, luyaqhubeka luba banzi, ngelixa uLwandlekazi lwePasifiki luncipha ngenxa yomsebenzi omkhulu wokuthoba ecaleni komda walo (iPacific Ring of Fire).
Iziphumo zemozulu kunye nebhayoloji yomjikelo we-supercontinental
Umjikelo welizwekazi elikhulu awungombandela nje wejografi; ineempembelelo ezinzulu kwimozulu, kwizinto eziphilayo, kunye nokuvela kwezinto eziphilayo eMhlabeni.
Umgangatho wolwandle Kuyahluka ngokuxhomekeka ekubeni amazwekazi ahlangene okanye ahlukene. Xa i-supercontinent ikhona, inqanaba lolwandle liphantsi; xa amaqhekeza asasazeka, umgangatho wolwandle unokunyuka ukuya kwimbali yembali. Ngokomzekelo, ngexesha lokubunjwa kwePangea okanye iPannotia, amanqanaba olwandle ayephantsi, kodwa aya kuphakama ngexesha leCretaceous, xa amazwekazi ahlakazeka.
Izinto ezifana nobudala be-oceanic crust, ubunzulu bentlenga yolwandle, kunye nobukho bamaphondo amakhulu anegneous adlala indima ebalulekileyo kolu tshintsho. Olu tshintsho luchaphazela imozulu ngokubanzi, ngamanye amaxesha luvelisa imikhenkce yehlabathi xa uninzi lommandla womhlaba udityaniswe ndawonye (imbonakalo enkulu yelanga kunye nokufuma okusezantsi).
Inguquko yobomi nayo ixhomekeke kumjikelo we-supercontinentUlwakhiwo ngalunye lubangela ukusebenzisana kweentlobo ezizimeleyo, luvelisa amathuba amatsha okuziphendukela kwemvelo, ukuphela, kunye nogqabhuko-dubulo lwezityalo nezilwanyana ezohlukeneyo ezilandela iindibano ezinkulu. Ngaphaya koko, iintshukumo zelizwekazi zinefuthe ekujikelezweni kolwandle kunye ne-atmospheric, iguqula ukuthuthwa kobushushu kunye nezondlo.
Iithiyori ezizezinye kwimbali yamazwekazi amakhulu
Akukho mvumelwano ipheleleyo malunga nokuba ixesha elide kangakanani imijikelo ye-supercontinent ekhoyo okanye mangaphi amazwekazi okwenene akhoyo. Kukho iimbono ezimbini eziphambili zenzululwazi:
Imbono yesiNtu: Uxhasa ubukho bokulandelelana okuqhubekayo kwee-supercontinents ezivela eVaalbara, nge-Ur, Kenorland, Columbia, Rodinia, Pannotia kunye nePangaea, ngokusekelwe kwizifundo ze-paleomagnetic kunye ne-geological kunye nokusabalalisa amaminerali athile kunye neefosili.
Imbono yeProtopangea-Paleopangea: Icebisa ukuba imijikelo ye-supercontinental yayingekho ngaphambi kweminyaka engama-600 yezigidi eyadlulayo. Endaweni yee-supercontinents ezininzi, ubunzima obukhulu, obuzingisileyo belizwekazi bebuya kuba bukho ukusuka kwi-2.700 yezigidigidi ukuya kwi-600 yezigidi zeminyaka eyadlulayo, kunye nohlengahlengiso oluncinci emaphethelweni. Ngokwabaxhasi bayo, idatha ye-paleomagnetic ibonisa izikhundla zepali ze-quasi-static kwizithuba ezide, ezibonisa uqweqwe oluphantse lungaguqukiyo lwelizwekazi. Lo mbono uye waphikisana kwaye wagxekwa ngokutolika kwayo irekhodi le-paleomagnetic.
Los iiminerali kwiidayimani zakudala Bakwacebisa inguqu ekubunjweni kwengubo yoMhlaba kunye noqweqwe olujikeleze i-3.000 yezigidigidi zeminyaka eyadlulayo, bebonisa ukuba umjikelo we-supercontinent unokuba mdala njenge-plate tectonics ngokwayo.
Ikamva: iyakuba yintoni i-supercontinent elandelayo?
Okwangoku, umjikelo wokusasazeka owaqala emva kokuqhekeka kwePangea uyaqhubeka, kodwa iimeko ezahlukeneyo zithathelwa ingqalelo kwikamva loMhlaba malunga ne-200 ukuya kwi-250 yezigidi zeminyaka. Iingcali ze-Geologists ziye zacebisa iingcamango ezininzi ezichaza indlela i-supercontinent elandelayo enokuthi yenze ngayo:
1. Novopangea: Ukuba intshukumo yepleyiti iyaqhubeka, kunye neAtlantiki ekhulayo kunye nePasifiki iyancipha, iMelika iya kungqubana ne-Antarctica efudukayo ukuya emantla kwaye emva koko i-Afrika kunye ne-Eurasia, ngoku idityanisiweyo, yenze i-supercontinent entsha ngokuchasene nale yangoku.
2. IPangea Okokugqibela: Ukuba iAtlantiki iyeka ukwanda kwaye iqala ukuvala, izihlwele zelizwekazi ziya kuhlangana kwakhona, zenze i-supercontinent ejikelezwe luLwandlekazi olukhulu lwePasifiki.
3. I-Aurica: Kule meko, iilwandlekazi zeAtlantiki kunye nePasifiki ziya kuvala ngaxeshanye, zenze ulwandle kwindawo ebizwa ngokuba yiAsia ngoku, iOstreliya isembindini welizwekazi elitsha. Imida ye-Eurasia kunye neMelika yayiza kuhlangana kwimida yazo.
4. Amasiya: Onke amazwekazi, ngaphandle kwe-Antarctica, aya kufudukela kwiNorth Pole ukuze adibane, enze i-supercontinent ejikeleze iNorth Pole, evulekileyo okanye encitshisiweyo yolwandlekazi lweAtlantiki kunye nePasifiki.
Ngokutsho kweengcali, imeko ye-Novopangea yeyona nto inokwenzeka phantsi kwe-plate dynamics yangoku, nangona ezinye iimodeli azinqunywanga, njengoko zixhomekeke ekuziphendukeleni komsebenzi we-tectonic.
Impembelelo yee-supercontinents ezintsha kubomi bexesha elizayo kunye nemozulu
Ukwenziwa kwelizwekazi elitsha kuya kuba neempembelelo ezinzulu kwimozulu kunye neentlobo-ntlobo zezinto eziphilayo.Iimozulu ezigqithisileyo zinokwenzeka ngaphakathi kwe-supercontinent, kunye notshintsho kwimisinga yolwandle kunye nokutshintsha kokusasazwa kweentlobo. Umsebenzi we-volcanic kunye ne-orogenic nawo uya kwanda ngeli xesha, kubangela utshintsho olubalulekileyo lwendalo.
Ukufika kwe-supercontinent entsha kuya kubangela umngeni ekuziqhelaniseni ubomi eMhlabeni, kunye nokuphela kobunzima obunokwenzeka kunye namathuba okukhanya okutsha kwe-radiation.
Umjikelo we-supercontinent kunye nokuvela koMhlaba: ukubaluleka kunye neembono
Ukufunda umjikelo we-supercontinent kubalulekile ekuqondeni imbali enzulu yeplanethi.Inqanaba ngalinye, ukusuka ekubunjweni ukuya ekuqhekekeni, kubangela utshintsho kwimozulu, ukujikeleza kolwandle kunye ne-atmospheric, kunye ne-biological evolution.
Ii-orogeni ezihamba nezi nkqubo Badala iintaba ezintsha, baguqule iikhosi zemilambo, kwaye bavelise izixhobo zendalo ezifana neeminerali kunye neoli. Ngaphaya koko, amaqonga avela emva kokusasazwa yimimandla engundoqo yokuqokelelana kwentlenga kunye nophuhliso lwenkqubo yendalo yaselwandle ebalulekileyo kubomi.
Ukuqonda umjikelo we-supercontinent kukwanceda ukuqikelela indlela yokuziphatha kwesijikelezi-langa kwixesha elizayo., esivumela ukuba silindele utshintsho lwemozulu kwaye sikhokele ukuhlolisiswa kwezibonelelo okanye ukufunda kwezinye iiplanethi ezine-tectonic dynamics.
