Sikhatsi Lesilandzelako
Ngetulu kweminyaka lengetulu kwemakhulu latigidzi, lo Mhlaba wacala kuphola ngendlela letsite kwatsi letinkhatimulo letaticindzetelwe tancipha, kungenteka kuba incumbi yetintfo letibhomako kumaplanethi nakutinkhanyeti tetfu setivele tidzilike taba yintfo lenye noma setivele ‘tisetjentiswe’. Umoya wemanti, icaborn dioxide kanye naleminye imimoya lephuma kutintfo letishisako teMlaba letihlephukile bese ticala lesimo. Litulu licala kuna bese tivunguvungu ticala kudvonsa ematje lasemhlabatsini. Emanti langetulu bekakhona cishe ngeminyaka ya 3.9 yetinkhulungwane tetigidzi eminyakeni leyendlule.I-Archaean Era
Loku kucala kwe Archaean era (kusho ‘endvulo’) kwaphindze kwatsatsa sikhatsi lesaba ngu 2.5 yeminyaka letinkhulungwane tetigidzi. Ngalesi sikhatsi, emabhande etintfo – lebetibitwa iGranite-Greenstone ematje lebekakheka, lebekacala sicalelo setintfo tendalo. Indlela yesibonelo lencono yekugcina iArchaean era yemhlabatsi isabonakala Emhlabeni ingatfolwa eMpumalanga, ngasedolobjeni le Barberton, lapho khona iGranite-Greenstone yandvulo yagucuka yase iyabhoma ngetulu. Lawa matje entsabamlilo, labitwa nge komatiities akha umbhedze welwandle ndvulo emkhatsini wa 3.6 na 3.2 wetinkhulungwane tetigidzi eminyakeni lemidzala. Indzaba yabo ikhomba kutsi yakheka ngesikhatsi kushisa emantle kucala kubasetulu kunalendlela langiyo namuhla, lekukhomba kutsi loMhlaba uchubeke waphola etincenyeni letitsintsekako teminyaka.Njengoba umhlabatsi wawuchubeka ucina, tintfo te silica lenemsoco (lebeyikadze inciphe kunesimo lesincibilikako ngentasi) beyifuna kuphakama bese icokelela ngetulu kwe mantle. Kusukela yaba ‘lula’ kunayo yomibili imantle kanye nesiyilo selwandle, lawa matje e silica-lenemsoco bekaphusheki kuya phansi kepha bekandanda ngetulu, ekugcineni ngekuba nesisindvo lesenele kukhuphukela ngetulu kwemanti njenge tichingi.
Tincenye Temhlaba
Ekuhambeni kwesikhatsi, tichingi letinsha letakheka tachubeka takhweshela ngetulu kwe mapulete ekunyakateni kwemhlaba, ashayisana phindze ahlangane, kuze linani leticucu tendzawo takheka etindzaweni letehlukene eMhlabeni. Leti tinchazelo tibitwa nge ‘tincenye temhlaba letincane’. Kwenteka ngesikhatsi sinye, ematje abhoma ngetulu kwemanti lilayini lachubeka laphazanyiswa ngumoya kanye nekugijima kwemanti, kantsi nematje laphansi atsintsa tintfo lebetingaphandle emkhatsini wendzawo kanye nelwandle njengoba umhlaba wawuhlangene, ematje esihlaba nematje eludzaka. Indzawo yekucala yayitsatsa kuma.Kujuba indzaba ibe yimfisha, lenandzawo lencane leyayikhona kundanda yachubeka yakhula yase, ngoba tatinesisindvo lesilula kunesiyilo selwandle, takhombisa bulukhumi bekuyaphansi. Letinye tincenye talendzawo yemhlabatsi yasuke yasala kakhulu noma kancane kwaba minyaka lemakhulu latigidzi letintsatfu yeminyaka. Ngabe tahlukana tase tiyahlangana tikhatsi letimbadlwana, kepha atilimalanga tona. Namuhla, sibita loku ticucu letema tandvulo temhlaba, ‘tincenye temhlaba’.
Incenye Yemhlaba ye Kaapvaal
Yinye yetincenye temhlaba yasekucaleni kulomhlaba yi Kaapvaal, lesolo isahlala enhlitiyweni ye Ningizimu Afrika. Linani lelingilo lalencenye yemhlabatsi liyatiwa, kepha labachazako basibonisa kutsi incenye yemphumalanga ye Ningizimu Afrika, incenye yenshonalanga ye Australia, eNdiya nase Madagascar tonkhe tahlangana kanyekanye endzaweni yandvulo. Ekuhambeni kweminyaka, emaleya lamasha elitje andlaleka phansi ngetulu kwe ncenye yemhlabatsi ye Granite-Greenstone, kanyekanye nelinani lelijabulisako letintfo balulekile. Le Ncenye yemhlabatsi we Kaapvaal itophindze ibe luphawu lwesisindvo se Vredefort.Incenye yekucala yematje lamasha lakatokwakheka kuncenye yeKaapvaal ibitwa ngekutsi licembu Lelibusako. Litfwala incenye lencane yematje lakhekile langeteleleke ngencenye lecinile yematje ngekhatsi. Ematje lakhiwe tintfo letincane akheka uma kuhlukana kwematje lahhohlokako kuya endzaweni lensha bese kancane kancane aba litje, ngemsebenti lobitwa ngekucokelela. Kwakheka kwemathe, ngalenye indlela, akheka ngentsabamlilo ku mantle lesetulu nasemhlabatsini, lapho khona indlela yetintfo ijoveka ngekugedvuka kwemhlaba kuze kube ngulapho iphula khona bese iyacina. Litje lelincibilikako leligeletako lelivela ngetulu kweMhlaba nalo lingakha ematje lakhekako.Translated by Phindile Malotana