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

Breaking: Dirt balls — not diamonds?

Comet cause for climate change theory dealt blow by fungus

(Press Release, Royal Holloway, University of London) — A team of scientists – led by Professor Andrew C Scott of the Department of Earth Sciences at Royal Holloway, University of London – have revealed that neither comet nor catastrophe were the cause for abrupt climate change some 12,900 years ago.

Theories of impacts and their influence on animal extinctions and  are receiving increasing attention both in the scientific and popular literature. Despite increasing evidence to dispute the theory, the idea that onset of the Younger Dryas (‘Big Freeze’) climate interval, mega-faunal extinctions, including mammoths, the demise of the North American Clovis culture, and a range of other effects, is due to a  airburst and/or impact event has remained alive both through written and television media despite growing negative scientific evidence.

One key aspect of this claim centers on the origin of ‘carbonaceous spherules’ that purportedly formed during intense, impact-ignited wildfires. Theorists have used these ‘carbonaceous spherules’ as evidence for their comet impact-theories, but this new study concludes that those supposed clues are nothing more than fossilized balls of fungus, charcoal, and fecal pellets. These naturally-occurring organic materials also date from a period thousands of years both before and after the Younger Dryas period began, further suggesting that there was no sudden impact event.

The research team examined organic residues from some of the proposed sites to investigate the nature of these organic spheres and ‘carbon elongates’ that ranged in size from 1/2 to 2mm (1/10 inch).

Samples from Pleistocene-Holocene sedimentary sequences in the California Channel Islands and other sites show that carbon spherules and elongate forms are common in samples dating to before, during, and well after the 12,900-year time horizon, including from modern samples. Professor Scott says, “Importantly, we were able demonstrate that these organic spheres were found commonly in both modern and ancient sediments and were not just restricted to any particular layer”.

The researchers undertook a series of microscopic studies, including using the advanced Swiss Light Source to probe their internal structure using Synchrotron Radiation X-ray Tomographic Microscopy (SRXTM) to show that carbon spherules have morphologies and internal structures identical to fungal sclerotia (such as Sclerotium and Cenococcum). In investigating these objects, Professor Scott commented: “These spherules had been commonly seen by researchers but little attention was paid to them and so few images existed in the literature. Perhaps it is not surprising that they have been misidentified. Some of the elongate forms described in other pa pers by the impact supporters are arthropod fecal pellets, some almost certainly from termites”.

Professor Scott points out that “we should always have a skeptical attitude to new theories and to test them thoroughly and if the evidence goes against them they should be abandoned”. Professor Pinter, one the report’s authors, from Southern Illinois University, adds, “I think we have reached that stage with the Younger Dryas impact theory”.

The paper, entitled ‘Fungus, not comet or catastrophe, accounts for carbonaceous spherules in the Younger Dryas ‘impact layer’, is published in the journal ‘Geophysical Research Letters’.

Provided by Royal Holloway, University of London

8 Responses

  1. I wonder if Pinter & Scott can come up with a convincing model to get those little particles of carbonized bug poop, and fungus, embedded into a Mammoth tusk.

  2. Dennis, that was never claimed and never happened. CS is not embedded and cannot embed itself in mammoth tusk.

  3. I know George.
    Sorry, that was a weak attempt at a little sarcastic humor. I think Pinter,and Scott come off sounding a bit pompous. I figured I’d fire a shot.;)

  4. It never ceases to amaze me how a whole hypothesis can be written off, as Dr. Scott appears to do re: The cosmic hypothesis of the Younger Dryas simply on one aspect of the wide ranging (not at all jusy confined to nanodiamonds and carbon spherules),admittedly the most controversial of the lines of evidence associated with the Younger Dryas. I do think that though the nanodiamond and carbon spherules proxy, though very important should not detract from the other pieces of evidence that strongly support the cosmic premise. Attention must be focused on these apsects as well!

  5. It’s update time. From  Evidence from central Mexico supporting the Younger Dryas extraterrestrial impact hypothesis

    Potential Misidentification of Markers.

    Surovell et al. reported finding no YDB MSp peaks, although claiming to follow the protocol of Firestone et al. for quantification of MSp, and concluded that Firestone et al. misidentified and/or miscounted the MSp. Later, Lecompte et al. independently examined two YDB sites common to Firestone et al. and Surovell et al. They reported that “spherule abundances are consistent with those of Firestone et al.” and “inconsistent with the results of Surovell et al.” They also concluded that Surovell et al. altered the prescribed MSp protocol in fatal ways, particularly by not observing requirements for sample thickness, sample weight, and size sorting. We consider these discrepancies significant enough to negate the conclusions of Surovell et al.

    Daulton et al. found no YDB NDs at Arlington Canyon, California, or at Murray Springs, Arizona, as earlier reported in Kennett et al. They searched for NDs in “microcharcoal aggregates” from the Murray Springs YDB site and, finding none, claimed to refute the previous results. However, Kennett et al. never claimed to find NDs in charcoal, and instead, observed NDs at Murray Springs in acid-resistant residues from bulk sediment, which Daulton et al. did not investigate.

    Daulton et al. further speculated that Kennett et al. misidentified YDB NDs, observing copper instead, which displays d-spacings nearly identical to n-diamond and i-carbon. In addition, Daulton et al. pointed out that graphene and/or graphane have d-spacings similar to lonsdaleite and that the lonsdaleite diffraction pattern reported from Arlington Canyon by the Kennett et al. was missing the lonsdaleite diffraction line at 1.93 Å. However, in YD-aged ice in Greenland, Kurbatov et al. identified lonsdaleite with the 1.93- Å line, which definitively demonstrates that those Greenland nanoparticles cannot be graphene or graphane.

    At Lake Cuitzeo, numerous NDs have been identified with the 1.93 Å line, as shown in Fig. 8 A and B and Fig. 11B, eliminating the possibility that these crystals are graphene or graphane. SAD and all other analyses conclusively show that the Cuitzeo nanoparticles analyzed have d-spacings consistent with lonsdaleite and other NDs. In independent support of NDs in the YDB, Tian et al. and Van Hoesel‡ identified cubic NDs in the YDB layer in Europe.

    Regarding CSp, Scott et al. speculated that those found at YDB sites are simply charred fungal sclerotia, which are ball-like clusters of long, branching filamentous structures, common to some fungi. The CSp from Cuitzeo and other YDB sites are unmistakably different from sclerotia in numerous critical characteristics. In particular, charred and uncharred sclerotia have textured, filamentous, low-reflectivity interiors, whereas at Cuitzeo, SEM imaging demonstrates that CSp have smooth, glassy, highly reflective interiors with no evidence of filamentous structure observed in fungal sclerotia (or cellular structure found in charcoal) (SI Appendix, Fig. 5). Cuitzeo CSp also contain numerous noncarbon particles, including aluminosilicates, indicating that these cannot be primary biological entities, such as sclerotia. In support of this, several lines of evidence support the formation of CSp during biomass burning. For example, Firestone et al.  reported the production of CSp in modern wildfires, and laboratory experiments have demonstrated the production of CSp from charred tree resin at approximately 500 °C***. These CSp are morphologically identical to those found in the YDB but contain no NDs. Also, CSp similar to those found in the YDB have been reported by Harvey et al. , who observed vesicular CSp in the impact layer at the KPg, and suggested that CSp, along with aciniform soot, formed during impact into carbon-rich target rocks.

  6. chicken little –

    WTF are you talking about? Your comment has absolutely NOTHING to do with this topic. If you can’t comment ON topic, would you just go away? PLEASE.


  7. CL, as usual, your comment is non sequitur, and ridiculous to the point of being absurd.

    If you had even the remotest clue what kind of conditions it takes for nanodiamonds to form you wouldn’t ask such a stupid question.

    But then again, most of us have given up on reading a comment from you that shows any evidence whatsoever of intelligent conscious thought. As Forest Gump may have said it: “Stupid is as stupid says”.

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