"The Pampas region of Argentina is covered with thick layers of windblown sediment called loess."
Washington, April 19 - Whenever an asteroid or a comet hit the earth in the past, the impact melted tonnes of soil and rock, some of which formed glass as it cooled. Now, a thrilling discovery has found that these impact glasses stored the signatures of ancient life at the time of the impact.

Several such impact glasses have been unearthed from the soil of eastern Argentina, south of Buenos Aires.

These impact glasses are 6,000 to 9 million years old.

One of those impacts, dated to around three million years ago, coincides with the disappearance of 35 animal species as reported earlier, said Pete Schultz, a geologist from Brown University in Rhode Island who led the study.

The discovery also suggests that impact glasses could be a good place to look for signs of ancient life on Mars.

We know these were major impacts because of how far the glass is distributed and how big the chunks are. These glasses are present in different layers of sediment throughout an area about the size of Texas, Schultz noted.

These impact glasses preserve plant morphology from macro features all the way down to the micron scale. It is really remarkable, Schultz added.

The glass samples contain centimetre-size leaf fragments, including intact structures like papillae, tiny bumps that line leaf surfaces.

Chemical analysis of the samples also revealed the presence of organic hydrocarbons, the chemical signatures of living matter.

To understand how these structures and compounds could have been preserved, the lab experiments showed that plant material was preserved when the samples were quickly heated to above 1,500 degrees celsius - at the time of the asteroid or comet impact.

The soil conditions in Argentina that contributed to the preservation of samples in this study are not unlike soils found on Mars.

The Pampas region of Argentina is covered with thick layers of windblown sediment called loess.

Much of the surface of Mars is covered in a loess-like dust, and the same mechanism that preserved the Argentine samples could also work on Mars, Schultz said in the study published in the journal Geology Magazine.


comments powered by Disqus
Read more on:
 WASHINGTON (36571 views)
 RESERVATION (28710 views)
 IMPAC (19826 views)
 JOURNAL (13741 views)
 CARBON (7171 views)
 TEXAS (5483 views)
 ARGENTINA (4703 views)
 BROWN UNIVERSITY (3334 views)
 BUENOS AIRES (2451 views)
 RHODE ISLAND (1601 views)
 STEROID (1350 views)
 HYDROCARBON (721 views)
 ASTEROID (171 views)
 

PERMALINK

http://www.nerve.in/news:2535002368159
You can quote the permanent link above for a direct link to the story. We do not archive or expire our news stories.


STORY OPTIONS
  Email this story to a friend
  XML feed for Americas


 
COPYRIGHTS INFORMATION
All rights reserved for news content. Reproduction, storage or redistribution of Nerve content and articles in any medium is strictly prohibited.
Contact Nerve Staff for any feedback, corrections and omissions in news stories.
 

All rights reserved for the news content. Reproduction, storage or redistribution of Nerve content and articles in any medium is strictly prohibited.