Micrometeorite pre-solar diamonds from Greenland cryoconite?

An acid-resistant residue prepared from Greenland cryoconite has been investigated to determine whether the micrometeorite component within the cryoconite contains pre-solar material analogous to that found in primitive chondritic meteorites. The residue has been analyzed for carbon content and stable isotopic comparison, by electron probe micro-analysis (EPMA) for major element chemistry and then by a combination of X-ray diffraction (XRD) and transmission electron microscopy (TEM) to elucidate the structure of any constituent mineral phases. The cryoconite sample, which was collected ca. 25 km inland of the ice margin at the latitude of Sondre Stromfjord on the west coast of Greenland, was processed following procedures used on bulk meteorite samples for the isolation of pre-solar dust components.