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 SF State astronomer searches for signs of life on Wolf 1061 exoplanet
20.01.2017 | San Francisco State University

nachricht Molecule flash mob
19.01.2017 | Technische Universität Wien

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>