Izigaba Ngezigaba Zokudaleka kwe Vredefort Dome

© David Fleminger

Amandla Amakhulu Ngeyona Ndlela

Njengokuba iVredefort bolide yambonzeleka isiza eMhlabeni, isantya sayo siqikelelwa ukuba sasiphakathi kwama 40 000 kunye nama 270 000 ekhilomitha nge yure. Ngethuba intlitheka phantsi, kwaphuma amandla amakhulu ngeyona ndlela. Lamandla enza ukuqhushumba okunamandla angapha kwama 500 ukodlula uLittle Boy, isiqhushumbisi se nuclear esa tshabalalisa eHiroshima.

Kuqikelelwa ukuba oluntlitheko lwalunomlinganiselo oli 14 kwisikali se Ritcher okanye lalinamandla odlula eyona nyikima yakhe yambi, aphindwa phindwe kangangama 100 000. Le bolide yazika emhlabeni kangange shumi lekhilomitha ngaphambi kokuba idubule ngenxa yoxinzelelo. Yaqhekeza amatye ase Transvaal, Ventersdorp, Witwatersrand kunye nee Dominion Supergroups ukuze kuvele umandlalo ongaphantsi wamatye egranite kwilizwekazi lase Kaapvaal.

iDimension Stone

Le crater ikekelele ecaleni yayingazinzanga, yaze yakhawuleza yawohloka kanye emva kontlitheko. Amacala ale crater aqhekeka azingceba ezininzi, nezaya zitshona ngaphantsi komhlaba. Kwimizuzwana nje embalwa, icrater yayisele ibanzi ngakumbi. Yondlaleka kumhlaba omgobongqo ongenzulu kuyaphi, lomgobongqo wawuvuleke kangangama 300 eekhilomitha. Yanwenwa ukusuka ePitoli yaya kutsho eWelkom, kwaye isabonakala ngemisele elandelelanayo (kuquka iWitwatersrand) eyombiwa loluntlitheko.

Ngeli lixa amacala ecrater esiwa, umbindi wale ecrater wasala usenyuka. Oku kwabangelwa kukuba ngethuba ibolide ibetheka, amatye asesiphakathini soluntlitheko ayexinzeleleke ngamandla. Emva kokuba ibolide yabangumphunga, ukuphela koluxinzelelo olungaphezulu kwavumela lamatye ukuba abuyele ngaphezulu. Oku kwabangela ukuba amatye ohlobo lwe Archaean granite akwicala elithile, agqobhozele kumatye aselula apakisheneyo ebengaphezu kwayo.

Amatye olekeneyo eWitwatersrand kunye ne Transvaal Supergroups abekade enabile ukwandlaleka, athi aphoseleka ecaleni aze aphethuleka, aphela erhangqa amatye amakhulu amadala nebekade engaphantsi komhlaba.

Oku kuphakama kwamatye kwaphinda kwathomalala kwakhona, kodwa abe esaphakamile elohlotyana emacaleni ecrater. Kwalile ethubeni lamatye egranite aseVrederfort akudala dala nawayeshiyeke evele ngaphandle ombiwa ngabantu. Zaze izilebhsi zezitena ze ‘Dimension Stone’ zasetyenziswa ukuhombisa iintsika zase Johannesburg airport.

iDome Mountain Land

Emva kwayo yonke le nyaka nyaka lendawo ibonakala ngokuphakama esiphakathini, ze irhangqwe ngamatye aqhekekileyo abizwa nge complex crater kwaye akufanelanga ukuba ithelekiswe ne crater ‘ezilula’, ezifana naleyo ise Tswaing. Eneneni, yilendawo iphakamileyo isesiphakathini kuphela (neyayinomlinganiselo omalunga ne 100 le khilomitha ukubheka pha) eyiyeyona Vrederfort Dome. Enye nenye indawo eseleyo kule crater akukho mthetho wezenkcubeko uyikhuseleyo.

Ngethuba kusenzeka oluntlitheko, umhlaba wawuphakame kakhulu kunomgangatho okuwo namhlanje, kwaye kuleminyaka iyi 2 bhiliyoni, isakhiwo se Vredefort dome sele sibole sakhukuliseka ngeyona ndlela. Kwingxenye ekumzantsi ntshona we crater, amatye amatsha we Karoo Supergroup asigqumile isakhiwo se dome. Namhlanje eyona nto sele isele ye dome sisangqa esihle esilicala semisele emeleneyo nephinyela phakathi kwedolophu yase Potchefstroom kunye neyase Parys. Lommangaliso wokwakheka kwalendawo ngalendlela ucaca kakuhle xa ufotwelwe nge nqwelomoya okanye nge satellite, kwaye ngoku sele usaziwa nge Dome Bergland okanye iDome Mountain Land.