BBC News, 4 March 2010: An international panel of experts has strongly endorsed evidence that a space impact was behind the mass extinction event that killed off the dinosaurs. They reached the consensus after conducting the most wide-ranging analysis yet of the evidence.
Writing in Science journal, they rule out alternative theories such as large-scale volcanism.
The analysis has been discussed at the 41st Lunar and Planetary Science Conference (LPSC) in the US.
A panel of 41 international experts reviewed 20 years’ worth of research to determine the cause of the Cretaceous-Tertiary (K-T) mass extinction, around 65 million years ago….
Xinhua News Agency, 22 August 2011: Dinosaurs in NE Asia not killed by asteroid smash — study
New findings suggest that a prehistoric asteroid collision is not solely responsible for wiping out the dinosaur population in northeast Asia 65 million years ago.
Scientists now claim that the end of the long-gone reptile’s reign in some regions of northeast Asia can be linked to several other factors, including volcanic eruption, climate change and drops in sea level.
A new China-led study by 30 scientists from eight different countries has yielded powerful evidence challenging the dominant, decades-old scientific theory that dinosaurs were wiped out after an asteroid collided with the earth…
The scientists, including experts from Russia, the U.S., Germany, Belgium, Britain, Japan and the Republic of Korea, were led by Sun Ge of Jilin University in northeast China. Together, they have spent the past ten years studying the extinction of dinosaurs.
The study showed that in Jiayin the K-T boundary, the geologic boundary between the rocks of the Cretaceous and Tertiary periods, does not contain high-levels of iridium, a radioactive element that linked an asteroid strike to the extinction of dinosaurs.
The asteroid theory has dominated dinosaur studies for several decades after scientists found high-levels of iridium in the K-T boundaries in North America and other regions. The element is rare on Earth, but found in extraterrestrial objects, including asteroids, according to Sun Ge.
Among conflicting and controversial hypotheses explaining dinosaur extinction, the asteroid theory is the only one that has been proven by scientific evidence and is universally recognized by scientists, Sun said.
Scientists believe a giant asteroid that hit the earth about 65 million years ago sealed the fate of dinosaurs forever by throwing up gusts of dust or chemical clouds that blocked sunlight from reaching the planet, or by igniting global wildfires.
However, the new study suggests that volcanic activities around that time greatly impacted the environment of the Jiayin area and could be to blame for the species’ extinction….