Ngaphakathi kokuma komhlaba kunegatsha elibizwa ngokuthi i-stratigraphy Lokho ekwenzayo ukutadisha ubukhulu bezintambo bese unikeza amadwala iminyaka. Ngaphakathi kwaleli gatsha kunelinye igatsha elikhethekile elibizwa ngokuthi umagazine. Izazi zokwakheka komhlaba zikwazile ukusungula iminyaka yobudala yamadwala asezintabeni ngenxa yemigomo ye-stratigraphic kanye nomgomo wokufana. Kodwa-ke, ukuze sikwazi ukwakha ikholomu ye-stratigraphic global, elinye ithuluzi liyadingeka elivumela ukusungulwa kweminyaka yazo zonke izingqimba ezahlukahlukene zezingxenye zomhlaba nokuzihlobanisa. Lokhu kungumsebenzi we-biostratigraphy.
Kulesi sihloko sizokutshela konke odinga ukukwazi ngaleli gatsha lesayensi.
Kufundani i-biostratigraphy
Leli gatsha lesayensi lazalelwa ukuxazulula ezinye zezinkinga eziphakanyisiwe ngenkathi kusungulwa iminyaka yamatshe kanye nayo yonke ikholomu yomugqa womhlaba. Izazi zesayensi yokwakheka komhlaba zakudala zaphakamisa umgomo wokulandelana kwezilwane kulandelana ngokweqile. Lo mgomo wokulandelana kwezilwane usitshela lokho Amayunithi we-lithological kufanele ethule uchungechunge lwezinsalela zeminyaka yobudala bazo. Lezi zinsalela aziveli kuphela kule yunithi kepha kufanele ziphindwe kokunye nakokunye. Imivubukulo ephawuleka kakhulu kufanele yehluke futhi ibuye ibonakale ezinhlotsheni ezahlukahlukene zamadwala entlenga.
Izinsalela ezimele kakhulu zingcono kakhulu ezisebenza ukubamba iminyaka yobudala yamadwala. Le mivubukulo ebaluleke kakhulu ibizwa ngama-index fossil. Ziyaziwa futhi ngamagama ezinsalela zomhlahlandlela. Le mivubukulo yethulwe ngendlela eyandisa indawo yonke ngokwendawo. Zivame kakhulu futhi zivame ukulondolozwa kahle. Ngaphezu kwalokho, zonke izinhlobo kufanele zivele ngesikhathi esifushane. Kodwa-ke, uhlobo nalo lungaziveza esikhathini eside esandisiwe.
Kumele kukhunjulwe ukuthi, ukuze sibe neminyaka yalezi zifundo, kufanele sisebenzise i- isikhathi sokuma komhlaba. Lesi sikhathi sokuma komhlaba yisona esikhomba isikhathi lapho uhlobo luvela khona futhi lusakazeka cishe endaweni efanayo yesikhathi. Kuwo wonke umlando nezikhathi zokwakheka komhlaba ezenzekile emhlabeni wethu, kukhona lezo lapho ukuqothuka okukhulu kwenzeke emhlabeni jikelele.
Kumele siqhathanise imininingwane izinsalela zezinkomba ezisinika yona, izinsalela ze-facies okuyilezo ezibonakala zihambisana nedwala elithile. Lezi zinsalela zihlala zingashintshi isikhathi eside.
Ama-biohorizons nama-biozones
Yimiqondo emibili esungulwe egatsheni lesayensi elibizwa nge-biostratigraphy. Lokhu kusho ukuthi insalela ngayinye ivela eqenjini elithile lendlela. Akukho edwaleni elitholakala ngaphakathi nendawo nasengxenyeni engenhla yekholomu ye-stratigraphic okufanele liqukethe izinsalela zalesi silwane futhi. Izakhiwo ze-lithological yilezo ezinciphisa ubukhona bezinsalela futhi zibizwa ngokuthi ama-biohorizons. Njengoba igama layo liphakamisa, kukhombisa indawo lapho leyo fossil yayikhona ngaphandle kokunye.
Kunezinhlobo ezimbili zama-biohorizons. Ngakolunye uhlangothi kukhona lezo zokubonakala kokuqala futhi ngakolunye uhlangothi, lezo zokubonakala kokugcina. Imvamisa uhlobo oluthile luyashintsha futhi kuncane okushodayo. Ukwehlukaniswa okuvame ukuba nalezi zinhlobo kulandela indlela yokuziphendukela kwemvelo. Uma uhlaziya ama-horizons ungabona ukuthi ayindida. Kodwa-ke, kwezinye izikhathi kwakuyizinqubo zokuqothulwa kwabantu abaningi, njengoba sishilo ngaphambili, okwenza amaqembu amaningi ezinhlobo zezilwane nezitshalo aqedwe ngesikhathi esifushane. Isibonelo salokhu ukuqothulwa okukhulu kwama-dinosaurs okukhomba ukuphela kwesikhathi seCretaceous.
Ama-Biohorizons yilawo amaka ukuqothulwa kwesisindo futhi acace bha. Ngakolunye uhlangothi, sinama-biozones. Lawa ngamayunithi we-lithological aletha inkomba yezinsalela noma okuqukethwe kwe-paleontological okubaluleke kakhulu. Sinezinhlobo ezithile zama-biozones:
- Ama-biozone esewonke yilezo ezimele ukuhlangana kwezinsalela eziningana ngokwemvelo ngaphakathi kwesigaba se-stratigraphic.
- Ama-biozones wokucindezeleka yilezo ezihambelana nama-biozone akhula ngokuvundlile noma ngokuvundlile. Imaka umehluko phakathi kwamacu.
- Ama-biozone we-apogee yilezo ezimaka ubuningi obukhulu bezinhlobo, uhlobo lomndeni ngisho nomndeni. Lokhu kukhethekile kakhulu.
- Ama-biozone wesikhawu yilawo amele amadwala phakathi kwama-biohorizons amabili ezinsalela ezihlukene.
Ukubaluleka kwesikhathi se-geological ku-biostratigraphy
Lesi sikhathi se-geological sikhona kuzo zonke izifundo ze-stratigraphic. I-Biostratigraphy ibiyithuluzi elihle kakhulu elisisize ukubhekana nobudala bamadwala ngendlela ehambisanayo. Onke amadwala ase-sedimentary ezingeni lomhlaba wonke aphethwe futhi, ngaphezu kwalokho, asize ekwakheni isigaba se-stratigraphic world. Yonke imininingwane ihlobene futhi ayishongo lutho mayelana nobudala bomhlaba. Ngakho-ke, ososayensi bazozama ukubala le minyaka besebenzisa i-biostratigraphy.
Kunezivivinyo eziningi nososayensi abanikeze imibono ehlukile ukuze kubalwe iminyaka yeplanethi yethu. Lezi zivivinyo zadala ukuphikisana nempikiswano enkulu, njengezinye eziphakamisa ukuthi iplanethi yoMhlaba yayineminyaka engama-75.000 kuphela ubudala. Indaba yaxazululwa ngokucwaninga ngemisebe kanye nokuhlolwa kokubhukuda kwe-radiometric. Ngale ndlela, okuqukethwe kwezinto ezinemisebe ye-radio kanye nokwahlazeka kwazo kwezinye izakhi sekufundwe. Lokhu kwenzeke ngenxa yokubala iminyaka ephelele yamadwala entaba-mlilo ngenxa ye-stratigraphy.
Le minyaka ebaliwe ingezwa esikalini esihambisanayo kanye nesilinganiso sesikhathi se-geologic esaziyo namuhla ukuthi sidaliwe. Lesi silinganiso yiso esikhomba ulwazi lweplanethi yethu cishe cishe eminyakeni eyizigidi eziyizinkulungwane ezingama-4.600 edlule kanye nokuvela kwamadwala okuqala asalondolozwe cishe iminyaka eyizigidi eziyizinkulungwane eziyi-3.600.
Njengoba ukwazi ukubona, izinsalela zamathambo ziyithuluzi elikhulu lokufunda ngomlando weplanethi yethu. Ngiyethemba ukuthi ngalolu lwazi ungafunda kabanzi ngokusetshenziswa okuhle kwe-biostratigraphy.