There was ten times the amount of gold in oceans three billion years ago compared to today, according to new research. Researchers from the University of Tasmania's ARC Centre of Excellence in Ore Deposits (Codes) developed an algorithm which shows how gold levels in the seas have developed over the course of 3.5 billion years.
There was 2,000 times the amount of the Fort Knox gold reserves in the ocean at one point, says the report published in Earth and Planetary Science Letters. Professor Ross Large of Codes explained: "This was a time when the world's greatest gold ore deposits were formed in South Africa in the Witwatersrand Basin.
Large said: "Over the next 400 million years, gold remained high in the oceans and many other important deposits formed, including the Golden Mile in Western Australia. This means peak times of gold in the oceans correspond to the best times in Earth history for gold ore formation.
"Firstly, there was far more volcanic activity and gold was carried in micro-particles in the volcanic magmas and volcanic gases from deep in the Earth and erupted on the Earth's surface. Erosion then transported the gold along with other related elements arsenic, nickel, antimony, tellurium and mercury into the oceans. The very ancient oceans were therefore enriched in gold but highly toxic."
Following this, the research shows that during the Proterozoic period – the time just before the rapid explosion of life on earth – gold hit a record low. However, the amount began to expand again around 550 million years ago with the abundance of new life on the planet as the solubility of gold beneath the ocean was massively influenced by the amount of oxygen in the water.
Large concluded: "When oxygen increased during the explosion of life in the oceans in the Cambrian period, gold also gradually increased and ultimately reached a maximum 525 million years ago."