{"id":84624,"date":"2023-06-26T14:51:00","date_gmt":"2023-06-26T12:51:00","guid":{"rendered":"https:\/\/aktuelles.uni-frankfurt.de\/?p=84624"},"modified":"2025-07-03T12:19:17","modified_gmt":"2025-07-03T10:19:17","slug":"earths-turbulent-childhood","status":"publish","type":"post","link":"https:\/\/aktuelles.uni-frankfurt.de\/en\/english\/earths-turbulent-childhood\/","title":{"rendered":"Earth\u2019s turbulent childhood"},"content":{"rendered":"

Diamonds are witnesses to our planet\u2019s transformation billions of years ago<\/h4>\n\n\n\n
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Whereas the lava tends to overflow from the crater when Mount Etna erupts, it seems that during the rare kimberlite eruptions in the geological past the magma shot upwards at up to 250 kilometers per hour, propelling diamonds from great depths as it went. Photo: Fernando Privitera, Shutterstock<\/p>\n<\/div>\n<\/div>\n\n\n\n

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Over four billion years ago, oceans of hot magma shaped Earth\u2019s surface. As our planet gradually cooled down, crusts formed in some places, and later the first continents. Rock samples and state-of-the-art analysis techniques are enabling geoscientist Dr. Sonja Aulbach to study the processes which took place during that period.<\/strong><\/p>\n\n\n\n

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When particularly pure, large and famous diamonds change hands, the buyer usually has to shell out several tens of millions of euros. And diamond jewelry is highly popular as a glittering eye-catcher. Rather baffling, then, when a woman says: \u201cWhat\u2019s really valuable about diamonds is their mineral inclusions.\u201d You mean, those same impurities that significantly reduce a diamond\u2019s value when it comes to cash?<\/p>\n\n\n\n

Sonja Aulbach, whose words these are, sees the gemstones through the eyes of a researcher. And the foreword of a current scientific anthology, which fills a massive 845 pages, shows the scientific view of diamonds and the minerals encapsulated in them: according to the book, the inclusions are \u201cambassadors from another time and another place\u201d, much like \u201clunar rocks, extraordinary meteorites, samples from comet flybys or asteroid landings\u201d. The inclusions deliver information \u201cthat we will not obtain in any other way\u201d about the past of \u201cthe most dynamic and active terrestrial planet in our solar system, our Earth\u201d. Sonja Aulbach from the Department of Geosciences at Goethe University Frankfurt is among the authors of this anthology, which also includes her own research results.<\/p>\n\n\n\n

Gem-quality diamonds are only found in certain regions of continental nuclei where there are no earthquakes. Geoscientists refer to such regions as cratons. And within these cratons, they occur only in a particular kind of igneous rock known as kimberlite. The close link between diamond deposits and cratonic kimberlites is the starting point for many insights into Earth\u2019s childhood. We know from laboratory experiments that producing diamonds from carbon at a temperature of 950 to 1400 \u00b0C requires a pressure at least 40,000 times higher than atmospheric pressure. Such conditions still prevail today at a depth of over 100 kilometers in the rock of Earth\u2019s upper mantle. For this to happen, however, only a minimal amount of oxygen can be present, otherwise carbon dioxide (CO2<\/sub>) will be produced instead of precious stones. Furthermore, at this depth, only one in every 10,000 atoms is a carbon atom, so it is rather the exception that diamonds form there. Even if it were to happen more frequently, diamond prospectors would not be able to get their hands on the gems: no drill has yet penetrated deeper than twelve kilometers into Earth\u2019s interior.<\/p>\n\n\n\n

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IN A NUTSHELL
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