Isikhathi se-Eocene

Enye yezikhathi ezakha inkathi yePaleogene yenkathi ka Mesozoic yiyona Kulungile. Lesi ngesinye sezikhathi ezinezinguquko ezinkulu kusukela ekubukeni komhlaba nokwakheka kwezinto. Ngaso sonke lesi sikhathi, kwakhiwa izintaba ezinkulu ngenxa yokushayisana kwezixuku ezinkulu zamazwekazi. Lezi zixuku zezwekazi bezihamba zibonga umphumela we Ukukhukhuleka kwezwekazi.

Ngenxa yokubaluleka kwalesi sikhathi ekuthuthukiseni impilo, sizonikezela lo mbhalo ukuze sichaze konke odinga ukukwazi nge-Eocene.

Izici eziyinhloko

Yize kubonakala kungqubuzana nalokho esasikushilo ekuqaleni, kuyisikhathi sokwehlukana, njengoba izwekazi elikhulu iPangea, okwakukhona kuze kube manje okwakuwukuphela kwalo umhlaba, lalihlukanisa cishe lonke. Izinhlobo ezinkulu zezitshalo nezilwane zavela futhi zahlukahluka, kufaka phakathi izinyoni nezinye izilwane ezincelisayo zasolwandle.

Isikhathi esiphelele sale nkathi ngu cishe iminyaka eyizigidi ezingama-23, isatshalaliswe eminyakeni emi-4. Yisikhathi senguquko lapho iplanethi yethu yathola khona ukuguqulwa okuningi kusuka endaweni yokubuka komhlaba, okugqame kakhulu kube yileso esesikhulumile ngezwekazi elikhulu iPangea, elahlukahlukana lakha amazwekazi esiwaziyo namuhla. Kwakuyisikhathi esigcwele kakhulu imicimbi yesimo sezulu ebaluleke kakhulu njengomcimbi we-Azolla.

I-athikili ehlobene:

Isikhathi sePaleogene

I-Eocene Geology

Ngalesi sikhathi iplanethi yethu yabhekana nokusebenza okuphezulu komhlaba okwaholela ekuqhekekeni kwePangea. Ingxenye esenyakatho eyaziwa ngokuthi yiLaurasia yayihlukaniswe kabanzi futhi kwaholela ekwehlukaneni kwalokho okwaziwayo namuhla njengeGreenland, iYurophu neNyakatho Melika. Ngayinye yalezi zingcezu zezwekazi lasePangea lalihamba ngenxa yokukhukhumala kwezwekazi laze labekwa endaweni elinayo namuhla.

Ucezu lwe-Afrika, olwaziwa ngokuthi izwekazi laseNdiya lushayisane nezwekazi lase-Asia. Lokhu yilokho okwaziwa namuhla njengeNhlonhlo Yase-Arabia. Kubalulekile ukuthi ekuqaleni kwesikhathi sePliocene kube khona izingcezu zePangea ezazisahlangene. Kodwa-ke, ngenxa yomphumela wokuqhuma kwezwekazi zombili izingcezu zehlukaniswa. Ngakolunye uhlangothi, i-Antarctica yayihambela eningizimu futhi ihlala kulesi sikhundla esinaso njengamanje. Ngakolunye uhlangothi, i-Australia yashintshela kancane enyakatho.

Mayelana nezindikimba zamanzi, kube nezinguquko nasemisakazweni yolwandle ngaphandle kwezilwandle ngenxa yokuhamba kwalezi zinkumbi zomhlaba ezinkulu. Ngakolunye uhlangothi, Ulwandle iTetis lwagcina ngokunyamalala ngenxa yokuhlangana kabusha okwakukhona phakathi kwezwekazi lase-Afrika ne-Eurasia. Kwenzeka okuphambene noLwandlekazi i-Atlantic. Kulokhu, lolu lwandle lwalunwebeka futhi luzuza umhlaba omningi ngenxa yokunyakaza okubheke ngasentshonalanga kweNyakatho Melika. I-Pacific Ocean yahlala iwulwandle olujulile futhi olukhulu kunawo wonke emhlabeni njengoba lunjalo namuhla.

Mayelana ne-Eocene orogeny, sithola ukuthi bekuyisikhathi esinemisebenzi ephezulu yokwakheka komhlaba lapho kwakhiwa khona inani elikhulu lezintaba ezisele namuhla. Ekushayisaneni esesikubalulile phakathi kwamanje okuyiNdiya nezwekazi lase-Asia, yilona elakha uchungechunge lwezintaba olunamanani aphakeme kakhulu emhlabeni abizwa ngeCordillera del Himalaya. INyakatho Melika nayo ibinomsebenzi obalulekile we-orogenic lapho iholele ekwakhiweni kwezintaba Ama-Appalachians.

I-athikili ehlobene:

Ukuthi izintaba zaseHimalaya zaqala kanjani

Isimo Sezulu Esilungile

Izimo zezulu ngesikhathi se-Pliocene bezizinzile. Ekuqaleni kwalesi sikhathi kwakukhona ukuhlolwa izinga lokushisa elincane eliphakeme elicishe libe ngu-7-8 degrees ngokwesilinganiso. Lokhu kukhuphuka kwenzeka kuphela ekuqaleni. Ngalesi sikhathi kwakwaziwa ngokuthi yi-Paleocene thermal maximum. Ekupheleni kwe-Eocene, kwenzeke omunye umcimbi owaguqula kakhulu izimo zemvelo ezazikhona. Lowo mcimbi ubizwa nge-Azolla.

Ukwenyuka kwamazinga okushisa ekuqaleni kwePliocene kwenzeka eminyakeni eyizigidi ezingama-55 edlule. Phakathi nalolu hlelo kwakungekho neze iqhwa emhlabeni. Ezindaweni lapho kunezindawo eziyiqhwa namuhla, kwake kwaba khona imvelo yamahlathi apholile. Ngaphezu kwalokho, ukwenyuka kwamazinga okushisa embulunga yonke kukholakala ukuthi kube umphumela wokukhishwa kwe-carbon dioxide emkhathini ngenxa yokwanda kwentaba-mlilo.

Zonke lezi zimo zemvelo zizinza ngokuhamba kwesikhathi, futhi isimo sezulu saqala ukufudumala ngenxa yamazinga okushisa aphezulu kanye nemvula encane. Nokho, ngokuhamba kwesikhathi lezi zimo zabonakala zizinza futhi nemvula eningi yabuya. Ngenxa yalokhu isimo sezulu seplanethi kwaba nomswakama futhi kwafudumala kwahlala kuyo yonke ingxenye enkulu ye-Eocene.

Maphakathi ne-Eocene, lesi senzakalo sezulu senzeka, esisibize ngokuthi i-Azolla. Lokhu ukwehla kwamazinga okushisa ngenxa yokuncipha kwezinga le-carbon dioxide emkhathini. Lezi zimo zaholela ekwandeni okungalawuleki kwe-fern ebizwa ngokuthi i-Azolla folliculoides, yingakho igama lalesi senzakalo.

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Izinguquko ezinkulu zesimo sezulu emlandweni womhlaba

Izimbali nezilwane

Izimo zemvelo zeplanethi zivumele ukukhula okuhle kwezinhlobo ezahlukahlukene, zombili izilwane nezitshalo. Kuyo yonke inkathi ye-Eocene kwakukhona inala enkulu nokwehluka kwezinto eziphilayo ngenxa yesimo sezulu esiswakeme nesifudumele.

Mayelana nezitshalo, kube nezinguquko eziphawulekayo ngenxa yezimo zezulu. Kwakukhona inala yamahlathi namahlathi kanye nobufakazi obuncane bezigxobo ngenxa yamazinga okushisa aphezulu. Ezindaweni zemvelo okuwukuphela kwazo okwakukhona kuzo okungenani inani lezitshalo kwakulezo zindawo zemvelo zasogwadule.

Ngokuqondene nezilwane, amaqembu ezilwane, ikakhulukazi izinyoni nezilwane ezincelisayo, ahlukene kakhulu. Izinyoni zaphumelela kakhulu ngenxa yezimo zemvelo ezivumayo futhi ezinye zalezi zinhlobo zaba izilwane ezidla amaqembu amabili ezidalwa eziphilayo. Kwakukhona amaqembu ezinyoni ezazibonakala ngobukhulu bazo obukhulu, okuye kwafakazelwa ukuba khona kwamarekhodi ezinsalela.