Washington, June 12 : A new research has revealed that 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.
An international team led by Florida State University (FSU) geologist Yang Wang carried out the research.
During their research on Tibet's desolate Himalayan-Tibetan Plateau, the team was surprised to find thick layers of ancient lake sediment filled with plant, fish and animal fossils, which are 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 as being 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 the literally groundbreaking possibility that major tectonic changes on the Tibetan Plateau may have caused it to attain its towering present-day elevations.
This rendered 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.
"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," she added.
According to Yang, the uplift chronology of the Tibetan Plateau and its climatic and biotic consequences have been a matter of much debate and speculation because most of Tibet's spectacular mountains, gorges and glaciers remain barely touched by man and geologically unexplored.
"So far, my research colleagues and I have only worked in two basins in Tibet, representing a very small fraction of the Plateau, but it is very exciting that our work to-date has yielded surprising results that are inconsistent with the popular view of Tibetan uplift," she said.