This is a paper by Kurbatov, Mayewski, Steffensen, West, the Kennetts, Bunch, and others which can be downloaded free in full text from http://cosmictusk.com August 31st. Recommended reading. Basically, a small layer of free nanodiamonds in very high abundances implies an unprecedented influx of extraterrestrial material that occurred over the last glacial episode. From that layer nanodiamonds and hexagonal diamonds (lonsdaleite) of the order of many times grreater than background levels in adjacent younger and older ice. This is the first enriched discrete layer observed in glacial ice anywhere and it’s presence indicates that ice caps are important archives of extraterrestrial events of various magnitudes. Using a preliminary ice chronology based on oxygen isotopes and dust stratigraphy the layer appears to be coeval with the Younger Dryas boundary.
Note … the evidence does not come from deep ice cores such as GISP or GRIP from central Greenland but from the ice margin in western Greenland. The ice was in fact sampled to obtain a stratigraphic sequence from the last deglacial through the Holocene – in co-operation with Nova (TV documentaries). The sampling was guided by the dusty nature of the YD deposit – which is in itself of great interest. Clear ice marks the early Holocene and the preceding Allerod era (a warm period between the end of the Ice Age and the start of the YD). Another very dusty episode marks the Late Glacial period – presumably the Oldest Dryas Period (or Heinich One as it is now known). This raises the possibility we also have an extraterrestrial event associated with the end of the Ice Age – it is getting better all the time.
Note 2 …. also the authors mention that nanodiamonds display diffractionlines with values within a few per cent of other minerals – which includes graphite and graphene. This is what the Daulton, Pinter and Scott et al paper accused YD researchers of doing, getting nanodiamonds mixed up with graphene – so how is graphene formed? However, the graphene and graphite appears to occur in thin sheets or layers which is quite unlike the spherical nanodiamonds from Greenland ice – so they aren’t expecting any confusion between the two things, real or imagined.