Tibetan Pliocene Fossils

About 15,000 feet up on Tibet's desolate Himalayan-Tibetan Plateau, an international research team led by Florida State University geologist Yang Wang was surprised to find thick layers of ancient lake sediment filled with plant, fish and animal fossils typical of far lower elevations and warmer, wetter climates.

Back at the FSU-based National High Magnetic Field Laboratory, analysis of carbon and oxygen isotopes in the fossils revealed the animals' diet (abundant plants) and the reason for their demise during the late Pliocene era in the region (a drastic climate change). Paleo-magnetic study determined the sample's age (a very young 2 or 3 million years old).

That fossil evidence from the rock desert and cold, treeless steppes that now comprise Earth's highest land mass suggests a literally groundbreaking possibility:

Major tectonic changes on the Tibetan Plateau may have caused it to attain its towering present-day elevations -- rendering it inhospitable to the plants and animals that once thrived there -- as recently as 2-3 million years ago, not millions of years earlier than that, as geologists have generally believed. The new evidence calls into question the validity of methods commonly used by scientists to reconstruct the past elevations of the region.

"Establishing an accurate history of tectonic and associated elevation changes in the region is important because uplift of the Tibetan Plateau has been suggested as a major driving mechanism of global climate change over the past 50-60 million years," said Yang, an associate professor in FSU's Department of Geological Sciences and a researcher at the National High Magnetic Field Laboratory. "What's more, the region also is thought to be important in driving the modern Asian monsoons, which control the environmental conditions over much of Asia, the most densely populated region on Earth."

The fossil findings and implications are described in the June 15, 2008 issue of the peer-reviewed journal Earth and Planetary Science Letters. The journal can be accessed online.

hmmm. That's the second sweeping statement about geology in as many days. hmmm.