Ixesha le-Ordovician

Elinye lamaxesha exesha lePaleozoic elalibonakaliswa ikakhulu kukunyuka kwamanqanaba olwandle kunye nokwanda kobomi kwizinto eziphilayo zaselwandle Ixesha le-Ordovician. Lixesha elibekwe kwangoko emva kwe Ixesha leCambrian nangaphambi koko I-Silurian. Ngeli thuba kwabakho ukuncipha okukhulu kwiyantlukwano yezityalo nezilwanyana ekugqibeleni okwavelisa umsitho wokuphela kwezinto.

Kweli nqaku siza kukuxelela zonke iimpawu, ijiology, imozulu, iintyatyambo kunye nezilwanyana zexesha le-Ordovician.

Iimpawu eziphambili

Eli xesha liye lahlala malunga neminyaka eyi-21 yezigidi. Iqale malunga neminyaka engama-485 yezigidi eyadlulayo yaze yahlala kwiminyaka emalunga nezigidi ezingama-433 eyadlulayo. Inomahluko omkhulu wemozulu okoko kwabakho umohluko omkhulu phakathi kokuqala kwamanqam. Ekuqaleni kwexesha, amaqondo obushushu ayephezulu kakhulu, kodwa kwenzeka iinguqu ezininzi kwindalo esingise kwixesha le-ice.

Njengoko besitshilo ekuqaleni kwenqaku, kwabakho ukuphela kwezinto ngobuninzi ekupheleni kwexesha elaphela malunga ne-85% yazo zonke iintlobo zezinto eziphilayo ezazikho ngelo xesha, ingakumbi izinto eziphila elwandle.

Eli xesha lahlulwe laba ngamathuba amathathu: Elisezantsi, eliphakathi neliphezulu le-Ordovician.

IGeology yoGqirha

Enye yeempawu ezibalulekileyo ngokubhekisele kwijoloji yeli xesha kukuba amanqanaba olwandle ayephezulu kuwo onke amaxesha. Ngalo lonke eli xesha bekukho ii-supercontinents ezi-4: IGondwana, iSiberia, iLaurentia kunye neBaltica. Njengakwimeko yexesha elidlulileyo, umhlaba osenyakatho weplanethi yayihlala ikakhulu kulwandlekazi iPanthalassa. Kuphela yi-Siberia enkulu kunye nenxalenye encinci yeLaurentia eyafunyanwa kule hemisphere.

Kumazantsi e-hemisphere, sinelizwekazi laseGondwana elalihlala phantse yonke indawo. Kwakukho nenxalenye yeBaltica neLaurentia. Iilwandle ezazikho ngeli xesha zezi: Paleo Tetis, Panthalasa, Lapetus kunye neRheico. Ininzi into eyaziwayo malunga nokwakheka komhlaba kwe-Ordovician kwiifosili zamatye eziye zafunyanwa. Uninzi lwezi fossil zifumaneka kumatye ahleliyo.

Enye yezona zinto zibonakalayo zejoloji ngeli xesha yiTaconic orogeny.. Le orogeny yaveliswa kukungqubana kwezinto ezimbini eziphambili. Olu nxibelelwano luqhubeke kangangeminyaka eli-10 yezigidi. Ngenxa yale nkqubo yejoloji, i Iintaba zeAppalachian.

Imozulu yexesha Ordovician

Njengoko besesitshilo ngaphambili, imozulu yexesha le-Ordovician yayishushu kwaye inohlobo lwetropiki. Ngokukodwa ekuqaleni kwexesha bekukho amaqondo obushushu aphezulu, nkqu nezimpawu zokuba kukho iindawo ezineerekhodi zamaqondo obushushu angama-60 degrees. Nangona kunjalo, ekupheleni kwexesha, amaqondo obushushu aqala ukwehla ngendlela eyakhokelela kwisithabazi esibalulekileyo. Olu glaciation luhlasele ikakhulu ilizwekazi laseGondwana. Ngeli xesha ilizwekazi eliphambili lalingezantsi lomhlaba weplanethi. I-glaciation yahlala malunga ne-1.5 yezigidi zeminyaka. Ngenxa yale nkqubo yokuhla kwamaqondo obushushu, inani elikhulu leentlobo zezilwanyana ezingakwaziyo ukuziqhelanisa neemeko zokusingqongileyo ezintsha zaphela.

Kukho ezinye izifundo eziqinisekisa ukuba i-glaciation ide yanda nakwi-Iberia. Oku kuthetha ukuba inkolelo yokuba umkhenkce usasazeke kuphela kwiindawo ezisemazantsi ayizukuphikiswa. Oonobangela beli glaciation abaziwa. Kukho intetho yokwehla koxinzelelo lwekhabhon diokside njengonobangela onokubakho.

impilo

Ngexesha le-Ordovician, kwavela inani elikhulu le genera elivelisa iintlobo ezintsha. Ngokukodwa ubomi baphuhla elwandle. Siza kuhlalutya iintyatyambo kunye nezilwanyana ngokwahlukeneyo.

Flora

Ukuthathela ingqalelo ukuba uninzi lobomi luphucukileyo kwindalo yolwandle, kusengqiqweni ukucinga ukuba izityalo zikhule ngcono. I-algae eluhlaza yanda elwandle. Iindidi ezithile zomngundo bezikho nazo ezizalisekisa umsebenzi wokubola kunye nokwahlulwa kwezinto eziphilayo ezifileyo. Le yindlela ulwandle olunokuzilawula ngayo.

Imbali yokuthimba iinkqubo zasemhlabeni yayihlukile kuleyo yaselwandle. Kwaye ukuba iintyatyambo zaziphantse zazingekho. Kwakukho izityalo ezimbalwa kuphela ezincinci ezaqala ukukholisa ilizwekazi. Ezi zityalo zazindala kwaye zisisiseko. Njengoko kulindelekile, zazingezizo izityalo zemithambo, Oko kukuthi, babengenayo i-xylem okanye i-phloem. Kuba zazingezizo izityalo ezinemithambo, kwakufuneka zihlale kufutshane nezifundo zamanzi ukuze zikwazi ukufumana ukubakho okufanelekileyo. Ezi ntlobo zezityalo zifana neeboldworts esizaziyo namhlanje.

izilwanyana

Ngexesha le-Ordovician izilwanyana zazizininzi elwandle. Kwakukho iintlobo ezininzi zezinto eziphilayo ukusuka kwezona zincinci zincinci kunye nezona zakudala ziye kwezinye izilwanyana eziguqukileyo nezintsonkothileyo.

Saqala ukwenza iarthropods. Ngenye yemiphetho enobuninzi obaneleyo ngeli xesha. Kwii-arthropods esizifumanayo trilobites, oonomadudwane baselwandle kunye neebrachiopods, phakathi kwabanye. Iimollusk nazo zandiswa kakhulu ngendaleko. Cephalopods, bivalves kunye gastropods ubukhulu becala elwandle. Le yokugqibela yayidinga ukuya ngaselunxwemeni lolwandle, kodwa njengoko babengenakuphefumla kwemiphunga babengenako ukuhlala kwindawo yokuhlala yasemhlabeni.

Ke zona iikorale, baqala ukudibanisa ukwenza ifom izixhobo zokuqala zekorale kwaye zazenziwe ngemizekelo eliqela. Babeneendidi ngeendidi zeziponji ezazisele zahlukile ngexesha leCambrian.

Ukuphela kobunzima be-Ordovician

Ukuphela kobunzima kwenzeka malunga ne-444 yezigidi zeminyaka eyadlulayo kwaye kungqamene nokuphela kwexesha le-Ordovician kunye nokuqala kwexesha le-Silurian. Oonobangela kwangoko apho izazinzulu zibheja zezi zilandelayo:

• Ukuhla kwe-carbon dioxide esemoyeni. Oku kubangele ukuqaqamba komhlaba okunciphise inani lezilwanyana nezityalo.
• Ukuhla kwenqanaba lolwandle.
• I-glaciation ngokwayo.
• Ukuqhuma kwe-supernova. Le ithiyori yaphuhliswa kwiminyaka elishumi yokuqala yenkulungwane yama-XNUMX. Uthi kwabakho ukuqhuma esibhakabhakeni okusuka kwimbubhiso enkulu eyabangela ukuba umhlaba ugqobhoze yimitha yelanga. Imitha ye-gamma ibangele ukuba buthathaka kocingo lwe-ozone kunye nokulahleka kweefom zobomi bonxweme apho kukho ubunzulu obuncinci.

Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga nexesha le-Ordovician.