For the first time, geologists revealed a process behind the construction of coastal mountains in the Asian east, which dramatically altered the climate of a vast continent over 100 million years ago. Those results have long puzzled science as questions about the Asia climate during the Cretaceous period have remained unsolved up until now.
According to new research published in Science Advances, a sudden change in the movement of tectonic plates beneath the continent, about 120 million years ago, resulted in the thickening of the Earth's crust along the eastern and southeastern coast of China. The result was mountain ranges, some as high as 2,500 meters above sea level.
Peter Cawood, a Professor of geology in Monash University’s School of Earth, Atmosphere and Environment, collaborated with researchers in China and Canada to complete the research.
He said the findings set the scene for further research into the implications of climate change on evolution of plants and wildlife during the Cretaceous period.
“What we are able to learn from studying the formation of these mountain ranges is that it changed global atmospheric circulation patterns and increased rainfall in the area”, Professor Cawood said.
“Changes like this can affect the land significantly, and in this case we found inland aridity climbed by about 15 per cent, which saw the eastward expansion of the desert".
“So our research presents a more complete picture of the Earth at that time, which can then be applied to different aspects of plant and animal life, and later humans, to see the impact on evolution".
“This research presents a more complete picture of Earth at that time, filling significant gaps in our existing understanding of the climate during this period, and providing clues on how plant, animal and later human life evolved”.
The findings came from the analysis of hundreds of granite rocks from the region, aged between 160 and 80 million years, which can provide evidence of the conditions in the area at the time.
“This is a huge belt of hundreds of thousands of square kilometres of granitic rock, which has elemental ratios in part related to the thickness of the Earth’s crust", Professor Cawood said.
“We can not only tell the age of rocks from the elemental composition, but the crustal thickness through time.
“We can then apply a climate model and check for various types of rock to gather information about the atmospheric conditions at that time”.
