Phanerozoic

Kwisikali sexesha le-geologic kukho ii-eons, amaxesha, kunye ne-epochs. Enye yazo yi-aeon Phanerozoic. Kwaziwa ngokuba sisikali sexesha esenzekayo ekupheleni kweProterozoic. Umahluko ophambili kukuba izinto eziphilayo ziqala ukuthatha iifom ezinzima kakhulu kwaye ziphuhlise. Le yindlela eguquka kakhulu ukuya kwinqanaba lokuba neentlobo ezininzi zezinto eziphilayo.

Kweli nqaku siza kukuxelela yonke into omele uyazi malunga ne-Phanerozoic, iimpawu zayo, i-evolution kunye ne-biodiversity.

Phanerozoic Aeon

I-Phanerozoic lixesha elaqala kwi-590 yezigidi zeminyaka eyadlulayo. Le yeyona eon imfutshane kwimbali yonke yomhlaba. Isaqhubeka nanamhla. Enye yeenyaniso ezifanelwe ingqalelo kukuphuka kwe-supercontinent Rodinia. Nangona kunjalo, amaqhekeza athile akwazi ukumanyana de kwadaleka iPangea yelizwekazi elikhulu.

Xa kuziwa kubomi bezilwanyana, le yenye yezona zinto zitshintshayo kwihlabathi, njengoko zaqala ukukhula ukusuka kwizakhiwo ezinjengamaqokobhe kunye neecrustaceans ukuya kwimbonakalo yee-vertebrates. Inokwahlulwa ibe ngamaxesha amathathu: Paleozoic, Mesozoic, kunye Cenozoic. Enye yezona zinto zibalulekileyo ezenzekayo yayikukuphuhla kobomi bendalo. Olu phuhliso lulula ukuba izazinzulu ziluqonde, kuba uninzi lwezilwanyana zexesha lePhanerozoic zineendawo ezinzima (amaqokobhe okanye amathambo). Ngokungafaniyo nala malungu athambileyo, namhlanje sinokuzifumana iifosili zala malungu aqinileyo. Ngaphandle kwamagobolondo kunye namathambo, amaninzi amatye e-Phanerozoic anokufumaneka. Oosonzululwazi banokufumanisa imozulu kunye nokuvela kwezityalo kunye nezilwanyana kula matye.

Kwaqala kwiCambrian. Xa kwavela izilwanyana zokuqala ezinoqweqwe oluqinileyo, igama lazo lithatyathwe kwigama lesiGrike lamandulo elithi phanerós, elithetha “okubonakalayo,” nelithi zôon, elithetha “isidalwa,” yaye xa zidibene zithetha “ubomi obubonakalayo.” Igama elithi "Phanerozoic" lamkelwa yi-geologist yaseMelika uGeorge Halcott Chadwick (1876-1953) ngo-1930. Ngumlandeli we-Precambrian ultrasound, equka uHarbin Dick, Gufeng, kunye neProterozoic.

Ubude bexesha lePhanerozoic yaqala ngokubonakala ngokukhawuleza koluhlu lwezilwanyana zezilwanyana (iintlobo zentlangano ezibekwe phakathi kwezikumkani kunye nezilwanyana), eziye zavela ngeendlela ezahlukeneyo, ukuphuhliswa kwezityalo eziyinkimbinkimbi, ukuvela kweentlanzi kunye nokuvela kwezinambuzane kunye nokubonakala kwezilwanyana ezine kunye nokuphuhliswa kwezilwanyana zanamhlanje.

Amazwekazi

Amazwekazi ngoku esiwaziyo - iYurophu, iAsia, iAfrika, iOceania, i-Antarctica, uMntla Melika, kunye noMzantsi Melika - abumba ilizwekazi kwakudala. Eli zwekazi liphezulu libizwa ngokuba lilizwekazi lasePangu. Ngenxa yongquzulwano phakathi kwamazwekazi, iintaba ziyakhiwa, kanye njengeAppalachians eUnited States. Ngaphakathi kweli zwekazi elikhulu, umntla kunye nomzantsi kwenziwa, ohlulwe yi-Tethys yolwandle olutsha.

Emantla kwakusithiwa yiLaurasia, ngoxa emazantsi kwakusithiwa yiGondwana. Kamva, iLaurasia yahlulwa yaba nguMntla Merika, iGreenland, iYurophu neAsia. Ilizwekazi laseGondwana lalibunjwe nguMzantsi Merika, iAfrika, iIndiya, iOstreliya, neAntarctica. Ngexesha leJurassic (phakathi kwe-205 kunye ne-135 yezigidi zeminyaka eyadlulayo), amazwekazi amabini ahluke kakhulu. Amazwekazi ahamba kancinci ukuya apho akhoyo ngoku. IAfrika, uSingasiqithi weArabia, neIndiya zangqubana neYurophu neAsia. Omnye wemiphumo yolo ngquzulwano yiHimalaya neMount Everest, eyona ntaba iphakamileyo ehlabathini (iimitha ezingama-8850). Olu ngquzulwano lwaba namandla kangangokuba iiHimalaya zisaqhubeka zikhula ngesantya seesentimitha ezimbalwa ngonyaka. Ngeli xesha udederhu lweentaba ezikunxweme olusentshona loMntla noMzantsi Merika kunye neziqithi ezininzi ezikunxweme olusempuma yeAsiya zazalwa nazo.

Imozulu yePhanerozoic kunye nomoya

Imozulu yePhanerozoic iye yafumana ukuguquguquka okuninzi. Izitena zomkhenkce zazisiba ngamaxesha ahlukeneyo zize zigqume umhlaba. Malunga nezigidi ezingama-500 kwiminyaka eyadlulayo (Ordovician), iindawo zoMntla Afrika noMzantsi Merika zazigutyungelwe ngumkhenkce. Kutshanje, phakathi kwama-350 kunye nama-250 ezigidi zeminyaka eyadlulayo (iCarboniferous nePermian), umkhenkce wagubungela ilizwekazi laseGondwana. Emva koko, kwiminyaka ezizigidi ezingama-65 eyadlulayo, uninzi lweAntarctica, uMntla Melika, kunye neYurophu zazigqunywe ngumkhenkce.

I-Phanerozoic yenye yeeon ezihlupheke kakhulu Utshintsho lwemozulu, ukusuka ekubeni ngumqwebedu ekuqaleni, ekubeni shushu nokufuma. Kwaye ekugqibeleni ubushushu bayo behla kwaye amaxesha omkhenkce amaninzi aqala. Umoya ojikeleze umhlaba uyaqhubeka ukufumana ioksijini kwizinto eziphilayo eziqhuba lo moya ifotosinthesis, ngokufanayo noko kwenziwa zizityalo namhlanje.

Ngaphambi kwePaleozoic, kwakungekho moya njengoko siyazi namhlanje. Kungeli xesha apho inani le-oksijini liqala ukwanda. Ekugqibeleni, umoya uneoksijini eninzi kakhulu, eyenza i-ozone layer. Kwiindawo eziphakamileyo, iimolekyuli zeoksijini zohlulwa yimitha yeultraviolet evela elangeni. Ezi molekyuli zeoksijini ziyadibana zenze iozone.

Kukho i-ozone engqingqwa kumphakamo we-15 ukuya kwi-35 yeekhilomitha. Lo maleko uqinisekisa ukuba imitha eyingozi evela elangeni ayifiki emhlabeni. Ngaphambi kokuba olu maleko lukhule, izilwanyana zixhomekeke ngokuyintloko emanzini ukuze zikhuseleke. Emva koko izityalo nezilwanyana zinokuqalisa ukuphila emhlabeni. Izityalo zokuqala zomhlaba zakhula kwixesha leSilurian (iminyaka eyi-450 yezigidi eyadlulayo). Zizityalo ze-vascular, njenge-ferns. Ngokukhawuleza kwavela izilwanyana ezininzi ezingenamqolo. Ii-Amphibians zavela kwi-Devonian kunye nezirhubuluzi kwiCarboniferous. Kumqobo weTriassic kunye neJurassic (iminyaka eyi-200 yezigidi ngaphambili) ezanyisayo zokuqala zavuka kwaye ekugqibeleni zavuka iintaka. Izilwanyana ezanyisayo ziza kudlala indima ephambili emva kokuphela kweedinosaurs ekupheleni kwexesha leCretaceous (iminyaka eyi-65 yezigidi ngaphambili).

impilo

Awona mathambo amadala afunyenwe asusela kwixesha elifanayo nawona matye amadala. Awona mathambo amadala aneebhiliyoni ezi-3.400 ubudala kwaye ubume bawo bungqukuva kwaye bunemicu, efana naleyo yentsholongwane. I-Stromatolites efunyenwe ngokuyinhloko e-Shark Bay (unxweme olusentshona ye-Australia) kunye ne-Yellowstone National Park (USA) yayixhaphake kwi-Paleozoic kunye ne-Proterozoic.

Iziponji zokuqala zavela ekupheleni kweProterozoic malunga ne-700 yezigidi zeminyaka eyadlulayo. Ngokuqhelekileyo, izilwanyana zinokwahlulwa zibe ziindidi ezimbini: izipontshi nezingezizo izipontshi. Owona mahluko mkhulu kukuba izipontshi azinayo inkqubo yokwetyisa, njenge jellyfish kunye ne octopus. Ekuqaleni kwePaleozoic, izilwanyana ezinomqolo ezingezizo izipontshi zakhula ngokugqabhukileyo. Iifosili zibonisa ukuba zonke izilwanyana ezingenamqolo ezikhoyo namhlanje zazikho kwiminyaka eyi-500 yezigidi eyadlulayo. Izilwanyana zokuqala ezinomqolo zavela kwi-Ordovician, ezi ziyintlanzi.

Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga ne-Phanerozoic kunye neempawu zayo.