Haggerty argues against the long-held view that the carbon in diamond comes from the remains of plants and marine organisms as they decayed under the high temperatures and pressures of the Earths deep interior. The invited review is titled, A Diamond Trilogy: Superplumes, Supercontinents, and Supernovae.
Many in the scientific community have long theorized that diamonds are primarily the result of organic materials that were dragged into the Earths interior as one continental plate was thrust beneath another in a process called subduction.
This theory holds that the organic material, when exposed to the extreme heat and pressure within the Earth for millions of years, produced the carbon in diamonds. But the fossil record, and the dating of diamonds, indicate that this carbon is at least three billion years older than animal and plant life.
Haggerty suspects that some of the carbon in these diamonds was in fact produced in supernovae: the explosions of dying stars. The carbon was incorporated into our solar system, where it is the fourth most abundant element.
This carbon, plus some that was brought to Earth on meteorites, may well be the source of diamonds, Haggerty says. The study of diamond has seen a recent burst of activity as new research methods have become available. The new theory is based on an evaluation of this scientific literature, he notes.
Evidence lending weight to the stardust theory includes the antiquity of the diamonds, and the similarity of carbon isotopic ratios to those found in meteorites, Haggerty says.
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