Ngexesha Ixesha leCenozoic kwabakho utshintsho olwahlukileyo kwiplanethi kokubini ngokwejoloji nakwizityalo nakwizilwanyana. Namhlanje siza kuthetha nge-epoch yesithathu eyenze iCenozoic. Imalunga nayo Oligocene. I-Oligocene yaqala malunga ne-33.9 yezigidi zeminyaka eyadlulayo ukuya kwiminyaka engama-23 yezigidi eyadlulayo. Kuyo yonke le minyaka iplanethi yethu yenze utshintsho oluphawulekayo. Olu tshintsho lubangele ukwabiwa ngokutsha kwezinto eziphilayo, zombini izityalo nezilwanyana. Ukongeza, imozulu yadlala indima ebalulekileyo ngexesha lotshintsho kwizinto eziphilayo kuba idala iimeko ezithile ukuze izilwanyana okanye izityalo ezithile zikhule ngakumbi kwaye ezinye zingaphili. Ngale ndlela, indlela entsha yokhetho lwendalo yasekwa.
Kule nqaku siza kukuxelela yonke into ofuna ukuyifumana malunga ne-Oligocene.
Index
Iimpawu eziphambili
I-Oligocene lixesha elihlala linomdla kuzo zonke iingcali ezijolise ekufundeni Ixesha lejoloji. Bonke abo bachithe ixesha elaneleyo ukuba bakwazi ukwazi imiba efihliweyo yamanqanaba ohlukeneyo omhlaba weplanethi bashiywe zizinto ezinomdla ezithe zenzeka kwiplanethi yethu ngexesha le-Oligocene.
Lixesha eliye lahlala iminyaka eli-11 yezigidi. Ngeli xesha amazwekazi ahlelwe ngokutsha ngenxa yokuhamba kwamacwecwe elizwekazi. Le ntshukumo ibangele ukuba amazwekazi athathe izikhundla ezifanayo nezo bahlala namhlanje. I-Oligocene ikwabizwa ngokuba bubudala bezilwanyana ezanyisayo. Kwaye kukuba liqela lezilwanyana elinokufumana ulwahlulo olukhulu kunye nokwahluka ngeli xesha. Kukuli xesha leminyaka eli-11 lezigidi xa kwahlulwa ukwahlulwa kwezilwanyana ezanyisayo ezifana neempuku okanye iicanids.
Ngokumalunga nokwakheka komhlaba kweOligocene yayilixesha lomsebenzi omkhulu we-geological kunye ne-orogenic. Siyabona ukuba ukwahlulwa kwelizwekazi eliphambili iPangea kuqhubekile kwaye uninzi lwamaqhekeza alo lwalushenxiswa ukuze lube kwindawo efanayo naleyo banayo namhlanje. Iinkqubo ezimbini ezinkulu ze-orogenic zenzeka ngeli xesha: I-Laramide Orogeny kunye neAlpine Orogeny.
IOligocene Geology
Siza kuhamba kuzo zonke iimpawu zeOligocene nganye nganye. Siqala nge geology. Ukuqhekeka kwelizwekazi eliphambili elibizwa ngokuba yiPangea kuye kwacaca ngakumbi xa isiqwenga esihambelana noMzantsi Melika sahlulwa. Oku kushenxiswa kwelizwekazi kubangele ukuhamba kancinci ukuya ngasentshona ukuze kudibane uMntla Melika kwaye kwenze into esiyaziyo namhlanje njengelizwekazi laseMelika lilonke.
I-Antarctica yaqhubeka nokwahlukana kwayo namanye amazwekazi kwaye iqweqwe lomkhenkce laya lisiba nzulu njengoko lalisiya lisondela eSouth Pole. Zininzi iingcali eziziphikileyo izigqibo ezahlukeneyo ezinje ngeli xesha ipleyiti ehambelana nelizwekazi lase-Afrika yadibana ne-Eurasia kwaye ikwenze oko nesiqwengana esele sisazi ngoku njenge-India.
Ekupheleni kwe-Oligocene, bonke abantu bemihlaba babesele bekwimeko efanayo nale sinayo namhlanje. Kuyafana nakwiilwandlekazi. Iilwandle zazicwangciswe ngohlobo lokuba kubekho iilwandle ezininzi ezahlula ilizwekazi lanamhlanje. Phakathi kwezi lwandle singakhankanya i-Pacific Ocean, i-Atlantic Ocean kunye ne-Indian.
Imozulu yeOligocene
Ngokubhekiselele kwimozulu yeOligocene, iimeko zazimbi kakhulu. Ibonakaliswe ikakhulu ngamaqondo obushushu asezantsi kakhulu. Ngalo lonke eli xesha iAntarctica kunye neGreenland zahlala zigutyungelwe ngumkhenkce kwaye zisanda ngakumbi nangakumbi. Kwangokunjalo, xa iAntarctica yahlulwa ngokupheleleyo kuMzantsi Melika, yabangela ukuba imisinga eyahlukeneyo yaselwandle ijikeleze ngokupheleleyo. Olunye lwale misinga yolwandle yiCircumpolar Antarctica. Le yangoku elwandle ithathwa njengenye yezona zibalulekileyo, kuba yayinoxanduva lokugubungela lonke ilizwekazi laseAntarctica ngomkhenkce kunye nokwenziwa kwamakhephu omkhenkce.
Ukwehla kobushushu behlabathi kubangele iziphumo kulungelelwaniso lwendalo. Utyalo olwalubalasele yayilihlathi elishinyeneyo nelinqabileyo. Le mithi ikwazile ukusinda kwezi ndawo zigqithileyo kuba ziyakwazi ukuphila kumaqondo obushushu asezantsi.
Iintyatyambo kunye nezilwanyana
Bonke ubomi baba ngakumbi nangakumbi ngokwahluka-hlukeneyo kwizityalo nakwizilwanyana. Ngaphandle kwento yokuba iimeko zemozulu bezingathandeki kwaphela, izinto eziphilayo zikwazile ukuziqhelanisa nezi meko kwaye zisinda.
Makhe sithethe ngeentyatyambo kuqala. Iintyatyambo zeOligocene zibonakaliswa yinto yokuba ii-angiosperms zinokuqalisa ukusasazeka ngenani elikhulu leendawo zokuhlala. Ezi zityalo zide zafikelela kulawulo abanalo namhlanje. Ngalo lonke eli xesha, ukwehla kwamahlathi ashinyeneyo kunokubonwa ngenxa yokwehla kwamaqondo obushushu ehlabathi. La mahlathi ashinyeneyo athatyathelwa indawo zizityalo ezinamagqabi kunye nengca eziye zahlengahlengiswa kwimeko ezinobushushu obugqithisileyo. Ezi ndawo zinengca kunye nezityalo ezinamagqabi zisasazeka kuwo onke amazwekazi.
Kwaye zezityalo ezinamagqabi anempumelelo enkulu kwindaleko ngenxa yokuziqhelanisa neempawu zazo ekukhuleni. Ezi zityalo zinezinga eliqhubekayo lokukhula elingapheliyo. Ukongeza, ezi ntlobo zezityalo kwafuneka zijongane nokwenziwa kwezilwanyana ezahlukeneyo ezinje ngee-grazers ezazisitya kuzo. Le yindlela abanokuthi baphuhlise ngayo amandla oguquko ahlukeneyo ukuze bakwazi ukusinda kwezi meko-bume kwaye babenokwakha ubudlelwane bokubambisana nezinye izilwanyana. Kwaye izilwanyana ezininzi zibancedisile ukusasaza imbewu yabo ngelindle.
Ngeli xesha nako izityalo ezinemidumba ezifana neembotyi zaphuhliswa.
Ngokubhekisele kwizilwanyana, kukho amaqela amaninzi ezilwanyana abenako ukwahluka kwaye andise indawo yokuhambisa. Ngaphandle kweemeko zemozulu ezazifunyenwe phantsi kwazo, amaqela amaninzi ezilwanyana afana neentaka, izilwanyana ezirhubuluzayo kunye nezilwanyana ezanyisayo zandisa ukuhanjiswa kwazo.
Kwakukho iintaka nezirhubuluzi, nangona eyona nto idumileyo yathathwa zizilwanyana. Ngokubalulekileyo, iCenozoic ithathwa njengexesha lezilwanyana ezanyisayo.
Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi nge-Oligocene.
Yiba ngowokuqala ukuphawula