Fungi, Feces Show Comet Didn’t Kill Ice Age

Mammals?

Image courtesy AGU
John Roach
for National Geographic News
Published June 22, 2010

Excerpted:

What About the Nanodiamonds?

In fact, most experts acknowledge that carbon spherules are found throughout the geological record, including biological forms associated with wildfires, said James Kennett, an emeritus geologist at the University of California, Santa Barbara, who supports the cosmic-impact hypothesis.

However, the spherules are not often found in large quantities, he said, and there is “a peak in carbon spherules at the Younger Dryas boundary.”

What’s more, those spherules are found alongside microscopic diamonds, or nanodiamonds, which often form under the conditions caused by extraterrestrial impacts.

The new study does not report evidence of nanodiamonds, Kennett noted, which is expected, since the team wasn’t directly looking for them.

“So their [reported] data is consistent,” Kennett said.

Study leader Scott said that his team has studied the nanodiamond issue, but he’s not yet able to discuss the results.

He did, however, hint that the particles might not be nanodiamonds at all: Fungal spores the team examined have similar microscopic features.

And, Scott said, “obviously [spores] are not nanodiamonds.”