Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Comet cause for climate change theory dealt blow by fungus

17.06.2010
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 climate change 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 comet airburst and/or impact event has remained alive both through written and television media despite growing negative scientific evidence.


Specimen from Arlington Canyon, Santa Rosa Island, California, U.S.A.. (12,800-13,100 cal BP), section through spherule.

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 ½ 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’.

Notes to Editors

For further information contact: Simon Doyle, Senior Press and Communications Officer, Royal Holloway, University of London, 01784 443967; simon.doyle@rhul.ac.uk

Professor Scott co-authored the paper with:
N. Pinter (Southern Illinois University), M.E. Collinson, M. Hardiman (Royal Holloway University of London), R.S. Anderson (Northern Arizona University), A.P.R. Brain (King’s College, London), S.Y. Smith (University of Michigan), F. Marone and M. Stampanoni (Swiss Light Source, Paul Scherrer Institut, Switzerland).

Simon Doyle | RHUL
Further information:
http://www.rhul.ac.uk

More articles from Physics and Astronomy:

nachricht Significantly more productivity in USP lasers
06.12.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>