Isikhathi se-Silurian

Esikhathini sePaleozoic sithola isikhathi esichazwe ngokusebenza okukhulu kwe-geological futhi okutholakala phakathi kwe-Ordovician ne I-Devonian. Kumayelana nesikhathi I-Silurian. Ngalesi sikhathi lapho kunomsebenzi ophakeme wokwakheka komhlaba, singathola ubufakazi besayensi ngokwakhiwa kwezintaba ezinkulu zezintaba kanye ne-supercontinent entsha eyaziwa nge-Euramérica.

Kulesi sihloko sizokutshela zonke izici, i-geology, isimo sezulu, izimbali nezilwane zenkathi yeSilurian.

Izici eziyinhloko

Isikhathi se-Silurian sithathe cishe iminyaka eyizigidi ezingama-25, kusukela eminyakeni eyizigidi ezingama-444 edlule kuya eminyakeni eyizigidi ezingama-419 edlule. Ngalesi sikhathi, kuyinto ejwayelekile ukuthi ibe semanzini angajulile ebusweni bamazwekazi ngoba ulwandle lwaluphakeme impela. Kososayensi, isikhathi seSilurian sithakazelisa impela ngoba sasinezinguquko zombili ezingeni le-geological kanye nasezingeni lezinhlobonhlobo zezinto eziphilayo.

Izitshalo zikwazile ukunqoba imvelo yasemhlabeni kwavela izinhlobo ezintsha ze-arthropods, amakhorali nezinhlanzi. Ezingeni lokwakheka komhlaba, futhi kungenzeka ukubona ukwakheka kwezinhlelo zezintaba ezahlukahlukene esizaziyo namuhla, njenge Izintaba ze-Appalachian.

Isikhathi se-Silurian geology

Ngalesi sikhathi izwekazi elikhulu elibizwa ngeGondwana laliseningizimu yeplanethi. Zonke ezinye izwekazi ezaziwa kakhulu ngokuthi yiLaurentia, iBaltic neSiberia zazisesikhundleni esenyakatho. Izinga lolwandle lalikhuphuke kakhulu ngenxa yokuncibilika kweqhwa kusukela ekuqhephuzeni kwasekupheleni kwesikhathi esedlule. Lokhu kuphakama kolwandle Kubangele ukuthi okuthiwa ulwandle lwe-epicontinental lwakhiwe ngaphezulu kwama-supercontinents. Lezi bekumizimba yamanzi emincane, engajulile enwelela kuwo wonke la mazwekazi.

Umphumela we Ukukhukhuleka kwezwekazi yaqhubeka nokushintsha amazwekazi. Yile ndlela ezahlangana ngayo izifundazwe ezinkulu ezibizwa ngeLaurentia, iBaltica ne-Avalonia ukwakha i-supercontinent enkulu kakhulu egama layo lingu-Euramérica.

Lesi sikhathi sabonakala ngokuvela kwezindawo ezinkulu zomhlaba. Izilwandle ezazikhona ngalesi sikhathi kwakunguPanthalassa, uPaleo Tethys, uRheico, uLapetus nolwandle lwase-Ural.

Isimo sezulu sesikhathi se-Silurian

Sonke lesi sikhathi, isimo sezulu seplanethi sazinza. Kwakungasekho zinguquko eziningi kangaka zesimo sezulu ezingeni lomhlaba jikelele. Ngokuyinhloko iSilurian yagqama ngokuba yisikhathi nesimo sezulu esifudumele. Izinguzunga zeqhwa ezazakhe ngesikhathi se-Ordovician zazibheke ngaseningizimu yeplanethi futhi ukuncibilika kwazo okwalandela kwadala ukwanda kolwandle.

Yize bekuyisikhathi esifudumele ngokujwayelekile, kunamarekhodi ezimbiwa phansi akhombisa ukuthi kwakuyisikhathi esinezivunguvungu ezimbalwa. Ngemuva kwalokho, izinga lokushisa komhlaba wonke libonakala liqala ukwehla, kupholisa imvelo kancane. Lokhu kwehla kwezinga lokushisa akubanga yisikhathi seqhwa. Ekupheleni kweSilurian futhi isivele ingene e-Devonia isimo sezulu besinomswakamo othe xaxa futhi sifudumele ngezimvula eziningi.

Flora

Ngaphandle kokuthi ekugcineni kwe-Ordovician kwaba nomcimbi omkhulu wokuqothulwa, ngesikhathi sempilo kaSilurian yathuthukiswa ngempumelelo emvelweni yasolwandle, ikakhulukazi. Zonke izinhlobo ezikwazi ukusinda ekupheleni kwe-Ordovician zikwazile ukwehlukahluka zaze zaphendukela ezigabeni ezahlukahlukene.

Ake siqale sihlaziye izimbali. Ezingxenyeni zezinto eziphilayo zasolwandle kwakukhona inani elikhulu le-algae, ikakhulukazi eluhlaza, okusize ukukhiqiza ibhalansi emvelweni. Lokhu kungenxa yokuthi bayingxenye yamaketanga e-trophic abekhula. Ngalesi sikhathi cIzitshalo ze-Vascular zaqala ukukhula ezinemikhumbi yokuhamba eyi-xylem ne-phloem.

Ekuqaleni kwalesi sikhathi isimo sasemhlabeni sasihluke kakhulu kunasolwandle. Emvelweni yasolwandle, impilo yathuthuka futhi yahlukahluka ngokwengeziwe. Ngokuphambene nalokho, kuzo zonke izindawo zokuhlala komhlaba lesi sici sasiyincithakalo futhi somile ngokwengeziwe. Kwakunezindawo ezimbalwa kuphela ezinamadwala kanye nehlane kanye nama-humus ambalwa. Izitshalo ezithuthukiswe endaweni yasemhlabeni zidinga ukuhlala eduze kwemizimba yamanzi. Yile ndlela abakwazi ngayo ukuthi lezi zinto nezakhi zitholakale. Le ndlela yaba khona izitshalo zokuqala esizaziyo njengama-bryophytes.

Fauna

Ngokuqondene nezilwane, ekugcineni kwe-Ordovician kwakukhona inqubo yokuqothulwa okukhulu okwathinta kakhulu izilwane. Kodwa-ke, kuso sonke lesi sikhathi, amaqembu ezilwane ezinjenge-arthropods athuthuka. Kusukela kulesi sikhathi sebeluleme cishe izinsalela ezingama-425 ezimele abantu bakule phylum. Izinjabulo bezincipha esikhathini esedlule futhi zaqhubeka nokuba khona kuzinto eziphilayo zasolwandle. Kodwa-ke, endaweni, baphela.

Ngokufanayo, ngesikhathi seSilurian bavele okokuqala kanye nama-myriapods nama-chelicerates. Lawa maqembu ezilwane aqala ukugcwala izindawo zokuhlala zasemhlabeni. Iqembu lama-mollusk limelwe ngalesi sikhathi yizinhlobo zama-bivalves nama-gastropods. Babehlala ikakhulu olwandle.

Ama-crinoids, abonwa njengama-echinoderms amadala kakhulu emhlabeni njengoba nawo ayekhona ngalesi sikhathi. lezi zazine-peduncle eyayisiza ukuba ifakwe kwi-substrate. Baphela ekupheleni kweSilurian.

Emkhakheni wezinhlanzi sinokuhlukahlukana okukhulu. Esikhathini esedlule ama-ostracoderms ayesevele evela. Lezi izinhlanzi ezingenamhlathi futhi zibhekwa njengezilwane ezinomgogodla ezindala kunazo zonke embhalweni wezinsalela. Ezinye izinhlobo zezinhlanzi zaqala ukuvela, phakathi kwazo ezazinemihlathi eyaziwa ngokuthi ama-placoderms zagqama. Esinye sezici ezimele zalesi silwane ukuthi Zine-cuirass ngaphambili komzimba. Abanye ochwepheshe baqinisekisa ukuthi ekupheleni kwalesi sikhathi kwavela izinhlanzi ezinesigaxa.

Imifula yamakhorali nayo ibaluleke kakhulu selokhu yavela ngalesi sikhathi. Kulapha lapho kwakhiwa khona izixhobo zamakhorali ezinkulu ngempela. Lokhu kungenxa ye- izinhlobo zamakhorali ezikhona zingahlukaniswa ngokuzama ukubonga ngemisebe eguqukayo.

Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi mayelana nesikhathi seSilurian.