Two billion age ago an enormous asteroid slammed into what is now South Africa . It left behind the big and second old confirmed impact crater , the 300 kilometre - wide ( 190 - mile ) Vredefort Crater . The classifiable volcanic crater shape has eroded away over the grade of almost half the Earth ’s life , but its legacy remains significant . Geologists canvass the crater have found I. F. Stone carvings render it was a place of considerable apparitional significance to ancient mass , as well as making potential the Earth ’s richest gold mine .
The Vredefort Crater is almost twice the size of the one atChicxulubthat stop the Cretaceous Era . The asteroid that made it is thought to have been much large as well – some 10 to 15 kilometers ( 6 to 9 naut mi ) across . Despite the geologic forces that have play on it we can still make out features such as its primal noodle , parts of the crater rim and wring rock candy that once rest below the volcanic crater floor . The land site furnish us with a rare opportunity to study a very large impact site without having to go to the Moon .
Geologists from South Africa ’s University of the Free State are in the operation of investigating it , and while much of their study is still to be done , they have already arrive up with some exciting finding outside their subject field .
The flooring of the crater is brand by granophyre dykes , felspar and vitreous silica rocks that can stretch for miles while being only a few meter all-embracing . A theme inGeologyconcludes molten material produced in the impact sank into the ground and beguile rock fragments on its descent that would otherwise have erode away over the subsequent billion of geezerhood . To geologists , these are a rich rootage of information about ancient stone establishment that would otherwise have been lose .
G of years ago what is now northerly South Africa was inhabited by the Khoi - San citizenry . While studying the dyke , Dr Matthew Huberand colleagues found carvings leave on some of them by the Khoi - San . Although they would have been unaware of their remarkable origin , the Khoi - San apparently recognise how strange the dike are , and select them as sites for their ceremonial occasion .
Despite the carving being known for years by the world-wide scientists and geologist working in the region , Huber discovered that they were not known to archaeologists . “ What is amazing is that the same dykes that we recognize to have the most geological significance also had the most phantasmal significance for these former habitant , ” Huber toldNewsweek .
The sculpture appear to represent creatures such as rhinoceroses , Hippopotamus amphibius , and horse then common to the area . artefact straw around the carvings have been dated to 8,000 twelvemonth ago . Archaeologists think their shapes cue the Khoi - San of snakes , which were tie in with rain in that culture .
The mobilization of minerals when so much rock melted after the shock lead to the density of antecedently existing Au deposits into one spot , and brought them closer to the surface . This made possible the world ’s richest gold deposits – from which more than a fifth of the worldly concern ’s mined gold has come – and the establishment of Johannesburg .
Several crater even larger , and in one case older , than Vredefort have been identified , but in each case geologist proceed to debate whether these really are impingement craters , or if they were formed through other cognitive operation .
