Rapid Carbon Fluctuations During Cretaceous May Have Done For Dinos

[hatrack]

New research into a missing link in climatology shows that the Earth was not overcome by a greenhouse period when dinosaurs dominated, but experienced rapid fluctuations in temperature and sea level change that resulted in a balance of the global carbon cycle. The study is being published in the March issue of Geology.
"Most people think the mid-Cretaceous period was a super-greenhouse," says Darren Gröcke, assistant professor and Director of the Stable Isotope Biogeochemistry Laboratory at McMaster University. "But in fact it was not to dissimilar to the climates over the past 5 million years."

By using high-resolution stable-isotope analysis from 95-million-year-old fossilized wood collected from Nebraska, Gröcke and his team were able to precisely correlate the terrestrial carbon cycle with that from deep-sea records. However, when they compared the carbon curves from both records, it was evident that a chunk of about 500,000 years was missing from the terrestrial record. Other records already indicated a drop in sea level, a 2-4ºC drop in oceanic temperature and a breakdown in oceanic stratification coincident with a marine extinction event.

"Rapid, large falls in sea-level in the ancient record are typically only produced by a glaciation, and so the combination of all the data during the mid-Cretaceous period suggests a short-lived glaciation during a period generally considered to be a super-greenhouse," says Gröcke. "Whatever hits the water causes a ripple effect on land," says Gröcke. "Earth often undergoes rapid temperature fluctuations, and this new information may help us to understand how the biosphere will respond to human-generated alterations of CO2 concentration."

EDIT

http://www.terradaily.com/reports/Carbon_Balance_Killed_The_Dinos.html

[xchrom]

1. ''may help us to understand how the biosphere

will respond to human-generated alterations of CO2 concentration."

human-generated alterations of co2 concentrations.

human generated.

maybe this will help explode just one more freeper head.

[Odin2005]

2. There has been speculation of a mid-Cretaceous ice age for a while.

The first evidence was dropstones, terrestrial rocks carried out to sea by icebergs, in marince sediments and large scale iceberg formation requires large ice ice sheets that reach the coast. This contradicted previous assumptions of Cretaceous climate, and many tried to dispute that the rocks in the sediments were dropstones.