Abstract
The 2.89- to 2.76-gigayear-old conglomerates of the Central Rand Group of South Africa host an immense concentration of gold. The gold and rounded pyrites from the conglomerates yield a rhenium-osmium isochron age of 3.03 ± 0.02 gigayears and an initial 187Os/188Os ratio of 0.1079 ± 0.0001. This age is older than that of the conglomerates. Thus, the gold is detrital and was not deposited by later hydrothermal fluids. This Middle Archean gold mineralization event corresponds to a period of rapid crustal growth in which much of the Kaapvaal craton was formed and is evidence for a significant noble metal flux from the mantle.
Original language | English (US) |
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Pages (from-to) | 1856-1858 |
Number of pages | 3 |
Journal | Science |
Volume | 297 |
Issue number | 5588 |
DOIs | |
State | Published - Sep 13 2002 |
ASJC Scopus subject areas
- General