Switepe swaku endliwa ka Vredefort Dome

© David Fleminger

Matimba lawa kulu swinene

Loko bolide ya Vredefort yita tshunela kuya chayisa misava, rivilo ra yona ri ehleketeleriwa kuva rive kun’wani ka kwalomuya kale xikarhi ka 40 000 na 270 000 wati kilomitara hi awara. Loko yi chayisa misa, matimba lawakulu swinene yantshuxiwile eka kubuluka loku akuri kwalomu ka kutlula 5000 ka minkarhi hi matimba kutlula Little Boy, tlharhi ra nuclear leringa thyiwa leringa hlasela Hiroshima. Swi hleketeleriwa leswaku ku chayisiwa loku kungava ku pimiwe 14 eka Richter Scale, kumbe 100 000 waminkarhi wa matimba kutlula ndzhinginiko wa misava lowunga tshama wupimiwa.

Bolide leyi yinghenelele kwalomu ka 10 wati kilomitara kuya ehansi ka misava loko kunga seva naku buluka hikwalaho ka ntshikelelo. Kunghenelele hile xikarhi ka maribye ya Transvaal, Ventersdorp, Witwatersrand na Dominion Supergroups kuva yisiya ehandle granite etshakwini ra Kaapvaal Continent.

Ku anama ka ribye

Swirhengele leswi aswiri na switepisi aswinga tshamisekangi, kambe, nakona hiku hatlisa swihatlise swiwela ehansi endzhaku kaloko kuve naku tlumbiwa. Makumu ya swirhengele ya vuye ya tshovekela kuhuma swirhengele leswinga longoloka, leswinga ya emahlweni swiwela ehansi ka ndhichi leyi ayi vumbekile. Endzhaku ka timinete, xirhengele axi anamile xivumba xirhendzevutani lexi axiri kwalomu ka 300 wati kilomitara loko xihelerile. Xindlandlamukile kusuka e Pretoria kuya e Welkom, naswona xaha vonaka hikokwalaho ka makumu yaxona (kukatsa na Witwatersrand) lexi axi voyamile nyana hikokwalaho ka ku chayisiwa loku.

Hinkarhi walowo swipetlu-petlu aswiri eku phemekeleni swiwa, akusungula ku tlakuka exikarhi ka xirhengele. Leswi aswivangiwa, hiku loko bolide yi ba, maribye exikarhji ka xirhengele lexi endzhaku kaloko ku chayisiwile aya tshikeleriwile swinene. Endzhaku kaloko bolide yitava yihangalakile, ntshikelelo kusuka e henhla wupfumelele leswaku maribye lawa yatlakukela ehenhla kuva yata ringanana. Ku chuciwa loku ku vange xiyenge xa Archaean granite kuva ya tshikelela exikarhi ka ti leyara ta maribye lawa yanga le henhla.

Khale ka maribye lawa aya ndlalekile e Witwatersrand na Transvaal Supergroups ya hangalasiwile kutani yah aha yaya ematlhelo kutani ya hundzuluka kutani yaya tshama e henhla ka maribye yan’wana ya khale lawa ayari e tshakwini. Ku tlakuka loku kuvuye ku tshamiseka nakambe, kambe aku phohla nakambe hile henhla ka xirhengele lexi. Endzhaku ka nkarhi, maribye yak hale ya Vredefort granite lawa aya tlakusiwile naku humela ehandle ya vuye ya ceriwa, naswona xilebe xa ‘dimension stone’ axi tirhisiwa ku khavisa tiphuphu ta muako wuntshwa wale rivaleni ra swihaha-mphuka ra Johannesburg laha ku khandziyiwaka leswa laha ekaya.

Dome Mountain Land

Leswi misava yinga sala yitshamise xiswona, leswinga vangiwa hiku tlakuka loku kale xikarhi aku rhandzeriwile hi ribye rikulu ro phambarhala xikanwe na lawa yanga tshoveka leyi vitaniwaka complex crater naswona aya fanelangi ya fannisiwa na swirhengele leswintsongo, kufana na leswinga e Tswaing. Kahle kahle, akuri exikarhi ntsena laha aku tlakukile (ekusunguleni ayi pimiwe kwalomu ka 100 wati kilomitara loko yihelerile) leswinga ringanela kuva Vredefort Dome. Leswinga sala tani hi xivumbeko xa xirhengele aswi sirheleriwanga hi nawu na unwe wa swa ndzhaka.

Hinkarhi waku chayisiwa loku, misava ayiri ehenhla nyana kutlula leswi yinga xiswona namuntlha naswona, kutlula malembe ya 2 wa mabiliyoni wa malembe, xivumbeko xa Vredefort dome axi khukhuriwile swinene. Hile dzongeni vupela dyambu bya xirhengele lexi, maribye yantshwa ya Karoo Supergroup aya funengete xivumbeko xa dome, laha masalela yan’wana aya tatile hinkwako etlhelo ka dome. Namuntlha, xitsundzuxo xin’we lexi vonakaka xa dome i swipetlu leswinga longoloka swa xirhendzevutani xoka xinga helelangi, leswi voyamaka exikarhi ka madoroba ya Potchefstroom na Parys. Xivumbeko lexi xankoka xa geometric xivonaka kahle loko uxi languta hile henhla kumbe hi swifaniso swa satellite, naswona sweswi xitiveka tani hi Dome Bergland kumbe Dome Mountain Land.

Translated by Ike Ngobeni