This week we’ve got a geological bonanza, as Lesley chats with Hartwig Frimmel about the genesis of the Witwatersrand (Wits) gold deposit in South Africa.
The geological anomaly has received renewed attention thanks to a recent discovery by Novo Resources (TSXV: NVO; USOTC: NSRPF), which reported on July 12 that it had found gold nuggets up to 4 cm long during trenching at its Purdy’s Reward gold prospect in Western Australia. The question has been raised: Are there potential similarities with mineralization in the Witwatersrand basin?
Novo has traced the nugget-rich, 2.7-billion-year-old conglomeratic package almost continuously along an 8 km strike length. The rocks dip 10 degrees southeast under a cover of basalts.
Frimmel explains that the “biggest controversy” behind the Wits remains the source of the gold. He argues that acidic rain liberated gold from the crust and gold-rich streams flushed across the hinterland, depositing gold in chemically-reactive algal mats. Those algal mats only started to blossom around 2.9 billion years ago – which is why the richest part of the Wits is 2.9 billion years. He believes these algal mats were then eroded and flushed into the basin.
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Timeline
Novo Resources 17:50
Greenstone belts across the world 33:45
Dating gold-porphyry deposits 36:55
Wits 2.0: Is there a twin? 40:00
Sponsored by:
Music Credit:
“Cool Rock” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
creativecommons.org/licenses/by/3.0/
“Isolated” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
creativecommons.org/licenses/by/3.0/
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