DANA MEDAL | ELASTIC GEOBAROMETRY FOR SUPER-DEEP DIAMONDS

Natural diamonds are among the most studied geological materials for their ability to carry on “direct” information about the deepest and oldest regions of our Planet. When these rare and precious stones capture mineral inclusions during their ascent toward the Earth’s surface, they deliver actual fragments of the deep mantle directly to our hands. In detail, not only we know that diamonds were formed between 3.5 and 0.2 Ga ago but their inclusions indicate that they can crystallize at depths between 140-150 and even 1000 km. Super-deep diamonds are those stones that form within the deepest regions of the Earth down to the lower mantle and represent only 1% of all diamonds studied so far. These are definitively the most intriguing diamonds not only because they provide extremely precious information on the deep Earth but because all famous diamonds, from the Cullinan to the Hope Diamond are super deep. But how can we determine at which depth within the deep mantle these rare and enigmatic diamonds crystallize? Here I will show the most recent develop of elastic geobarometry applied to super-deep diamonds and their mineral inclusions, which appear to be a very reliable approach to calculate their pressure of formation.