Resolute Mining forks out further $50 million to Mali for detained employees
The miner's top boss Terence Holohan and two other employees were released by Mali government, the company said in a statement on Nov. 21.
The group also found evidence that suggests orangeites were formed from lava produced by massive volcanic eruptions several tens of millions of years ago.
A team of Australian scientists have unveiled a ground-breaking study that identifies, for the first time, the exact source of diamond-bearing rocks known as orangeites.
Published Monday in the April edition of Nature Communications, the paper reveals that orangeites —until now believed to be common only to South Africa— may be present in much higher abundance worldwide, especially in Australia.
Rough on the outside, these rocks contain not only treasured diamonds but also tiny fragments of mantle and crustal rocks. By using highly sophisticated geochemical and isotopic analytical techniques, the scientists were able to link those fragments to the source of the orangeites, deep in the interior of the planet.
“We found strong evidence that orangeites are sourced from MARID (Mica-Amphibole-Rutile-Ilmenite-Diopside) mantle, which up until recently had only been recognised in South Africa,” leading author, Professor Fiorentini — from The University of Western Australia — said in a statement. “However, ongoing studies suggest that MARID mantle may occur in other continents, including here in Australia.”
The group also found evidence that suggests orangeites were formed from lava produced by massive volcanic eruptions several tens of millions of years ago. Until now, the common belief was that diamonds were formed about 990 million years ago.
3 Comments
LAMB
I wonder if ‘ORANGEITES’ occur in CANADA in it’s diamond mines? Everyone talks of Kimberlites, so what is the relation between the two rock-types?
bobby44
My basic understanding of orangeites is that they are not associated directly with kimberlites. The kimberlites were passed through the mantle to the surface following a ‘weak spot’ in the mantle. Orangeites are from massive volcanic eruptions and contain pieces of mantle. Both originate about 20 km down and several million years apart in formation. Both materials are good!
Short answer — you are not likely to find orangeites in a diamond mine.
rockhound17
As an Engineering Geologist I find this quite interesting!