Exploring abrupt climate change induced by comets and asteroids during human history

Cosmic Soil in Human History II: Marie-Agnes Courty’s Dirty Work Through The Years

1998 Article



2007 Abstract


2012 AGU, San Francisco:

Formation of vitrous char that occur in ancient charcoal assemblages have remained unsolved. Laboratory experiments refuted vitrification to resulting from high temperature charring of green or resinous wood. This puzzling problem has been refreshed by showing the association to the charcoal and vitrous char of plastics that were originally supposed to only be produced by petroleum industry. Extraction of similar polymers within geological glassy products from cosmic airbursts has suggested impact processes to possibly forming the carbonaceous polymorphs. The pulverisation at the ground in the Angles village (French Eastern Pyrenees) following the 2011 August 2nd high altitude meteor explosion of exotic debris with vitrous char and polymers, just alike the puzzling ones of the geological and archaeological records, has provided potential reference materials. We present here their microanalysis by Environmental SEM with EDS, Raman micro-spectrometry and FTIR, XRD, TEM, ICP-MS and isotope analyses. The characterization helps elucidating how the carbonaceous polymorphs formed by transient heating and transient high pressure of atmospheric aerosols. Under TEM the vesicular, dense, vitrous char show high structural organization with a dense pattern of nano-sized graphitized domains, metals and mineral inclusions. The coupled Raman-ESEM has allowed identifying a complex pattern at micro scales of ordered “D”ù peak at 1320-1350 cm-1 and the graphitic, ordered peak at 1576-1590 cm-1, in association to amorphous and poorly graphitic ordered carbon. The later occurs within plant cells that have been extracted from the dense vitrous char by performing controlled combustion under nitrogen up to 1000 °C. In contrast, the brittle, vesicular vitrous char and the polymers encountered at the rear of the pulverised airburst debris reveal to be formed of agglutinated micro spherules of amorphous carbon with rare crystallized carbon nano-domains and scattered mineral inclusions. They completely vaporised at 300 °C under stepped-heating without leaving extractable residues. The link established between the structure of these exceptional carbon polymorphs and their forming processes provide diagnostic keys for interpreting vitrous carbon in ancient charcoal assemblage. The hardest ones offer reliable impact markers with their distinctive nanostructure produced by the transient high pressure and heating of carbonaceous aerosols by cosmic airbursts. In contrast, the weakly graphitised ones with distinctive plant structures would possibly express moderate effects of the airburst shock wave on vegetation at the ground. Thus micro-structural characterization of charcoal in archaeological assemblages would help tracing possible exploitation of blasted wood forest and related fossil fuel produced by ancient cosmic airbursts.

10 Responses

  1. Hi George

    The caravan passes, and dogs bark. Another study hush the least curious people. More things will keep popping up and giving concreteness the frequency of meteoritic events. We continue at the mercy of them. And it can be any time, without notice.

    I like these photos with people holding impactites with their own hands. Excellent.


  2. Thanks a lot for presenting exactly this article at this time…. We identified the cosmic impact and
    its whereabouts with all the details….Our paper will be out until the end of March. Mrs. Courty´s
    work fits as an exact puzzle piece, resolves a variety of impact questions….just great.
    Until soon. JSei

  3. It would be a fine development for my own project if the findings here are further implicated with a cosmic impact. Specifically, the proposed hydrated consistency of the deposit, along with the absence of “essential” impact markers such as shocked quartz, would go a long way towards encouraging the expansion of allowable ejecta compositions. I have often wondered what a hydrated silicate comet impact might look like, vs an iron or stony asteroid.

  4. What do you think of the post at http://tallbloke.wordpress.com/2013/03/05/andrew-cooper-were-the-recent-asteroid-flyby-and-chelyabinsk-meteor-strike-events-linked/
    If anybody is interested Mike Baillie is speaking at the SIS AGM on May 11th (in England) and the subject is the 776AD and 1258AD C14 anomalies, but he is just as likely to bring up the Russian meteor. With his permission we may put up a video of his talk on our web site – not sure what will happen on this front.

  5. Looking forward to seeing Mike’s talk on the Society of Interdisciplinary Studies site, Carol. The Tusk gets a lot of hits from England so I will post a note to this effect. Where will the talk be?

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