Iingcali ngokuma komhlaba ziye zaphawula inqanaba elitsha kwimbali yomhlaba emva kokufumana ubungqina eMeghalaya, eIndiya
Iminyaka yangoku esiphila kuyo kutshanje yonyulwa ngokusemthethweni 'kwiXesha leMeghalayan' sisikali seXesha leHlabathi lezeJiyoloji. Esi sikali siyahlula imbali yethu iplanethi kwii-eons ezahlukeneyo, amaxesha, amaxesha, amaxesha kunye neminyaka. Ixesha leziganeko ngokwesiseko sokuba la maxesha ahlulahlulwe lihlanganiswa ziingcali zokwakheka komhlaba kunye nabembi bezinto zakudala kwihlabathi liphela kwaye lisekelwe kwiziganeko ezinkulu ezifana nokuqhekeka kwamazwekazi, utshintsho olumangalisayo lweemeko zemozulu, ukuphela okanye ukuvela kwezilwanyana nezityalo ezithile. Iiyunithi zesikali zisekwe phezu kobungqina kunye nobungqina bomaleko wentlenga obuqokelelwe ekuhambeni kwexesha kwaye olu maleko luqulethe intlenga eyahlukeneyo, iifosili kunye neisotopi zemichiza. Ezo strata zithwala ushicilelo ngokuhamba kwexesha elikwadlulisa izehlo zomzimba nebhayoloji ezinxulumeneyo. Oku kubizwa ngokuba yi-geologic age dating apho into nganye enjalo yabelwe iminyaka kwaye izehlo ezinokwenzeka ezikujikelezileyo ziqikelelwe. Le yindlela esazi ngayo namhlanje ukuba umhlaba uneminyaka ezibhiliyoni ezi-4.6 ukho. IKomishoni yaMazwe ngaMazwe ngeStratgraphy (IUGS) inoxanduva oluphambili lokulawula iGeologic Time Scale.
Ixesha langoku esiphila kulo, - iHolocene epoch - lihlaziywe kwaye lahlulwe laba ngamatsha amathathu. iminyaka yokwakheka komhlaba ezizeziNkohlakalo zakuqala ezibizwa ngokuba yiGreenlandian, iHalocene eseMbindini ebizwa ngokuba yiNorthgrippian kunye neLate Halocene ebizwa ngokuba lixesha leMeghlayan. Ixesha leGreenlandian liphawulwa xa ixesha lomkhenkce lafikelela esiphelweni kwaye ukufudumala kwaqala emhlabeni kwiminyaka eyi-12000 eyadlulayo. Ubudala baseNorthgrippian baqala malunga nama-8000 eminyaka eyadlulayo. Zombini ezi minyaka ziphawulwa ngamaqhekeza omkhenkce afumaneka eGreenland. Ubudala obutsha beMeghalayan obuchongiwe ngoku baqala kwiminyaka engama-4,200 eyadlulayo kwaye ukuza kuthi ga ngoku. I-arhente yeManyano yaMazwe ngaMazwe yeSayensi yeJoloji inoxanduva lwale migangatho yezizwe ngezizwe kwijoloji. Uphando luthathe ukuya kutsho kwiminyaka esibhozo ukuphawula imihla yobudala beMeghalayan.
Yonke iminyaka inikwe amagama awodwa ngokusekwe kwimvelaphi okanye ekuqaleni kwayo. Iminyaka yaseGreenlandian kunye neNorthgrippian ithiywe indawo yaseNorthGRIP eGreenland. Le sayithi ibonisa ukufudumala okukhawulezayo kwe iplanethi ebonisa isiphelo sexesha lomkhenkce elilandelwa kukupholisa okukhawulezileyo kwehlabathi jikelele ekuqaleni kwexesha laseNorthgrippian elabangelwa kukungena kwamanzi omkhenkce anyibilike kuMntla weAtlantiki. Ngaphaya koko, malunga neminyaka engama-4,200 eyadlulayo, isigaba sokoma kakhulu okanye ukomisa kuye kwachongwa ngabaphandi abachonge njengesiqalo seMeghlayan Age. Ubudala be-Meghalayan bubizwa ngokuba yi-stalagmite (uhlobo lokwakheka kwamatye) kumqolomba we-Mawmlul obekwe kumantla empuma yelizwe iMeghalaya eIndiya ukuphawula eyona mvelaphi yale minyaka. Ilizwi "Meghalaya' lithetha "indawo yokuhlala yamafu" ngesiSanskrit. Isitampu sexesha lale minyaka siqondwa ngokucacisa ukuba le stalagmite yafakwa kumgangatho womqolomba ukusuka kwiidiphozithi zezimbiwa kumawaka aliqela eminyaka ngenxa yamanzi emvula angena ngaphakathi emqolombeni ngokuvuza kwesilingi. Oku kwenzeka mhlawumbi ngenxa yokutshintsha kolwandle kunye nokujikeleza kwe-atmospheric. Iingqimba zezimbiwa zibonisa utshintsho kwimvula ngokuhamba kwexesha njengoko ukutyikitywa kweekhemikhali kubonisa ukuba utshintsho lwe-stalagmite kwi-athomu ye-athomu ye-oksijini lukhokelele ekubeni ummandla uhlaselwe yi-20-30 yepesenti yokuhla kweemvula zemvula. Oku kuthathwa njengobungqina obubalulekileyo kolu bhaqo. Enyanisweni, ubungqina obunjalo bufunyenwe kuwo onke amazwekazi asixhenxe emhlabeni. Le 'draught mega' yazisa ixesha elitsha lejoloji. Ezo meko zemozulu zimbi kakhulu nazo bezinokushiya ukuwohloka kwempucuko kunye nokuncothulwa kweendawo zokuhlala abantu ngakumbi abo basebenza kwezolimo kufutshane noLwandle lweMeditera, uMbindi Mpuma kunye neAsia njengoko kubonisiwe kwizifundo. Iziphumo zale 'draught enkulu' ibonakala ithathe iminyaka engaphezu kwama-200. Iingcali ezininzi zikholelwa ukuba esi siganeko sinxulumene kakhulu nezentlalo nezoqoqosho.
Esona siganeko sincinci semozulu yehlabathi kwimbali yethu iplanethi iye yafunyanwa okokuqala kwaye iqhubela phambili ukuqonda kwethu imbali epheleleyo yokwakheka komhlaba. Oku kukufumanisa okuphawulekayo kunye nokongezwa kwimbali yeHolocene kunye ne-archaeology. Iingcali zokwakheka komhlaba ziceba ukongeza ixesha elitsha emva kweHolocene ebizwa ngokuba yiAnthropocene eya kuphawula impembelelo yabantu kwijiyoloji yelizwe. iplanethi emva koshishino.
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{Unokufunda iphepha lokuqala lophando ngokunqakraza ikhonkco le-DOI elinikwe ngezantsi kuluhlu lwemithombo ecatshulweyo (s)}
Umthombo (s)
IKhomishini yaMazwe ngaMazwe kuBuchule. www.stratigraphy.org. [Ifikeleleke ngo-Agasti 5 2018].
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