Dino killing asteroid impact triggered a global hail of carbon beads

Washington, May 6 : A new research by scientists has revealed that the asteroid presumed to have caused the mass extinction of the dinosaurs 65 million years ago, struck the Earth with such force that carbon deep in the Earth's crust liquefied, rocketed skyward, and formed tiny airborne beads that blanketed the planet.

The beads, known to geologists as carbon cenospheres, cannot be formed through the combustion of plant matter, contradicting a hypothesis that the cenospheres are the charred remains of an Earth on fire.

If confirmed, the discovery, made by scientists from the US, UK, Italy, and New Zealand, suggests environmental circumstances accompanying the 65-million-year-old extinction event were slightly less dramatic than previously thought.

"Carbon embedded in the rocks was vaporized by the impact, eventually forming new carbon structures in the atmosphere," said Indiana University Bloomington geologist Simon Brassell, study coauthor.

The carbon cenospheres were deposited 65 million years ago next to a thin layer of the element iridium - an element more likely to be found in Solar System asteroids than in the Earth's crust.

The iridium-laden dust is believed to be the shattered remains of the 200-km-wide asteroid's impact.

Like the iridium layer, the carbon cenospheres are apparently common. They've been found in Canada, Spain, Denmark and New Zealand.

Some geologists had thought all carbon particles resulting from the impact was ash from global scale forest fires, but the present research strongly contradicts that assumption.

The scientists examined rock samples from eight marine locations in New Zealand, Italy, Denmark and Spain. They also examined carbon-rich particles from five non-marine locations in the US and Canada.

Following chemical and microscopic analysis, the researchers concluded that the particles were carbon cenospheres, similar to the ones produced by industrial combustion.

But the cenospheres' origin presented a double mystery.

The cenospheres had been known to geologists only as a sign of modern times - they form during the intense combustion of coal and crude oil.

Equally baffling, there were no power plants burning coal or crude oil 65 million years ago, and natural burial processes affecting organic matter from even older ages - such as coals from the 300-million-year-old Carboniferous Period - had simply not been cooked long or hot enough.

"Carbon cenospheres are a classic indicator of industrial activity," said Mark Harvey, the paper's lead author. "The first appearance of the carbon cenospheres defines the onset of the industrial revolution," he added.

According to scientists, the cenospheres could have been created by a new process, the violent pulverization of the Earth's carbon-rich crust.

ANI