Now About that 65 Million Year Old Carbon Layer!

he asteroid presumed to have wiped out the dinosaurs 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, say scientists from the U.S., U.K., Italy, and New Zealand in this month's Geology.

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 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 and former adviser to the paper's lead author, Mark Harvey.

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.

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," Harvey said. "The first appearance of the carbon cenospheres defines the onset of the industrial revolution."

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

For a time it was thought this carbon layer was a sign of a global conflagration: the asteroid impact incinerated the world, essentially. However, they ought to be more large chunks of charcoal scattered about the KT Boundary. AFAIK, this hasn't been found, except in a few places, yet there was this fine layer of carbon made of cenospheres more globally. That was odd because as far as we knew, these could only be made through industrial processes. What the researchers are proposing here is that Chicxulub Impact event vaporized a lot of carbon rich content (oil, iirc) and that was spread across the world. The suggestion is that the impact would be able to generate the cenospheres. Interestingly, the cenosphere mass distribution centered their origin on the Chicxulub Crater: the closer the researchers sampled to the crater, the heavier the cenospheres became.

It makes for an interesting - and difficult - item for the vulcanists to explain unless there were tons of exposed coal fields in the path of the lava flows...they'd have to be exposed only at the time of the KT boundary being laid down - not before! not after! - since the Deccan Traps erupted for a long time (over 2 million years). Furthermore, why it'd be centered on Chicxulub is even more difficult to explain.

Now seriousness aside, if the only way we have seen is to produce the cenospheres by industrial methods...sounds like an sf book plot not yet written! Y'know, if you ignore some important science bits. Unless, of course, the lone sapient dinosaurian city was centered on Chicxulub and the impact was an alien race's way of wiping out a future problem. hmmmm...