Uphando Lwe Vredefort Dome

Abaphandi Abangabemi

E-Mzantsi Afrika, kukhangeleka ngathi ukuphucuka nokuphuhla kwe sayensi yontlitheko kuyasiphosa. Ngomnyaka ka 1916,uS.J. Shand waqala wachaza umnqa wokunyibilika kwelitye njenge ‘pseudotachylite’. Kodwa akazange asole intaba mlilo njengemvelaphi yeli litye.

Ingxelo yokuqala ebambekayo malunga nobume bomhlaba wase dome, neyakhutshwa ngomnyaka ka 1925, yafikelela kwisigqibo sokuba idome idalwe kukudubula kwe gesi yentaba mlilo. Ngomnyaka ka 1936, abaphandi ababini bazisa imbono yokuba kukuntlitheka okubange idome, kodwa oku akuzange kuhoywe ngabaphandi abangabemi base Mzantsi Afrika.

Indlela eme ngayo le Dome, yayisenza abaphandi babhideke. Njani untlitheko olusuka phezulu lubangele umhlaba ukuba uphakame ukuqala ngaphantsi. Ngokuqinisekileyo ukuqhushumba okusuka phantsi komhlaba kuko okwakunamathuba amaninzi okuphakamisa umhlaba kunontlitheko olusuka phezulu esibhakabhakeni. Kuthe kusenjalo, ngomnyaka ka 1947 ingcali yemo yomhlaba (geologist) egama lingu R.A. Daly walandelela ekhondweni loluqikelelo lontlitheko, waze waza nembono yokuba kusenokwenzeka ukuba ukwehla koxinzelelo emva kontlitheko kwabangela amatye angaphantsi aphethukele ngaphezulu abe ke anyusa ukumila kwesakhiwo se dome.

Lo makhwekhwetha wezokumila komhlaba kwase Mzantsi Afrika, uAlex du Toit, washiyeka engaliginyi ncam eli yena waze wenza ingxelo yokuba idome yadalwa zii tectonic process.

Uphikiswano Lwaqhubeka

Iminyaka emininzi, oluphikiswano lwaqhubeka. Imbono yamazwe ngamazwe yayithande ukukekelela kwelicala lontlitheko. Kodwa abaphandi baseMzantsi Afrika bona baqhubeka nokubhala amaphepha athetha ngemvelaphi yangaphantsi komhlaba (magmatic okanye tectonic). Kwiminyaka yoo 1960, ingxelo esuka kwi saveyi ebizwa nge Geological Survey of Ottawa yabonakalisa umahluko phakathi kwendidi ezimbini ze crater: Ezo zinobubanzi obungaphantsi kwe khilomitha eziliqela, nezazivamise ukubanokumila okumgobongqo, kunye nezo zizikhilomitha ezinkulu, nezazivamise ukuphakama embindini wamatye amadala arhangqwe ngamatye olekeneyo aselula noko.

Le phatheni ye crater iyindida yangena twatse eVredefort. Noxa kunjalo, ososayensi abangabemi boMzantsi Afrika baqhubeka ngomsebenzi wabo, babe bethathela phezulu nomsebenzi kamakhwekhwetha kwi crypto explosion kumazwe ngamazwe, ogama lingu Walter Bucher. Lo makhwekhwetha wayeme kwelithi idome yabangwa luqhushumbo lwegesi eshushu neyaphuphuma kwiintanda ze ezisemathunjini oMhlaba.

iShock Metamorphics

Nangona abaphandi beze sayensi base Mzantsi Afrika babesamile kwiimbono zabo, ukuqonda nolwazi lwe metamorphics lwaya lusanda. Ngomnyaka ka 1968, kwabanjwa inkomfa yamazwe ngamazwe ngalomba, kwadibana iingcali eziphuma kumazwe amaninzi. Oku kwenza ukuba abo bakholelwa kuntlitheko babenomdla owongezelelekileyo. Kwiminyaka eliqela elandela lonkomfa, uphando lwafumanisa iimbono ezandileyo.

Iingxelo ngee terrestrial craters, isampuli zamatye akwezinye iiplanethi ezingaphandle kwaseMhlabeni kunye neziphumo zokuhlolwa kwase labhorethri, zathontelana ukuphuma zabe zonke zingqinelana. Kancinci kancinci kwaye kucaca ukuba ubungqina bukekelela kwimbono yontlitheko. Kwathi kuphela umnyaka ka 1970, kwabe sele kubonwe iindawo zontlitheko ezili 120 kwiindawo ezahlukeneyo kwihlabathi jikelele. Kwaye namatye afanayo aqhele ukufunyanwa kwii crater ezininzi abe sele efunyenwe. Lamatye xa edibene abizwe nge ‘impactites’-igama elikwenza ucinge ngeklasi ye aerobics okanye abantu abagcwele kwi khetshi.

Ngeminyaka yoo 1980, uninzi lwochwephesha bamazwe ngamazwe babesele bengqinelana noluntlitheko, kwaye nee dyunivesithi zamanye amazwe zazisele zifundisa ukuba iVrederfort Dome yadalwa sisiganeko sontlitheko. Kodwa hayi eMzantsi Afrika. Apha, onkanishe (bekhokelwe yi geologist uLouis Nicolaysen) babambelela kwinkolelo yabo yokuba imvelaphi ye dome yintaba mlilo yohlobo lwe crypto volcanic.

Ekugqibeleni, kwabizwa inkomfa ukusombulula okukungavisisani. Yabanjelwa eParys ngomnyaka ka 1987 kwaye ochwephesha bamacala omabini bathetha kulentlanganiso. Lentlanganiso yohluleka kukufikelela esigqibeni. Kwanyanzeleka ke ukuba kuvotwe ekupheleni kwentlanganiso, ze uninzi lwabathathi nkxaxheba lwabonakalisa inkxaso yabo kwi mvelaphi eyi exogenic (untlitheko olusuka ngaphandle kwaseMhlabeni).

Kwi Atomic Level

Ukwenza ibali libe lifutshane, iminyaka elishumi elandela oko kwathontelana iingxelo ezisuka kubaphandi base Mzantsi Afrika nakwihlabathi jikelele. Idome yehliwa amahlongwane zii ngcali zokumila komhlaba, kancinci kancinci ubungqina bayondelelana. Kwafumaneka iiCoesite kunye nee Shishovite, micro-deformations zikwi quartz crystals nazo zabhaqwa kwaze kwahlolwa neyona ndalo nokumila kwe metamorphism ematyeni. Ekugqibeleni, ngomnyaka ka 1997 uHughes Leroux wathi wakwazi ukuhlalutya isampuli zamatye kwisigaba se atomic.

Uphando lwakhe lwafumanisa ukuba iVredefort Dome yahlaselwa sisiganeko sontlitheko olusuka esibhakabhakeni, nolwathi lwatshintsha ukumila kwamatye angaphantsi komhlaba ngeyona ndlela. Babe boyisakele njalo abo bebekade bengakholwelwa koluntlitheko.