A massive glacier valley dating back 2.5 million years has been
found in Beijing.
Geologists claimed the special landforms in Bailong Valley in
Mentougou District in western Beijing were formed by the corrosion
of ancient glaciers that existed during the Ice Age of the
Quaternary Period, between 2 and 3 million years ago.
The district is preparing to turn the valley into a glacier
geological park to preserve the relics and provide a research base
for scientists, Liu Dequan, a local government official, said.
Wang Hongjie, a senior engineer of a geological survey team
under the Ministry of Land and Resources, discovered the glacier
relics earlier this year.
"In the middle of the valley, a large boulder caught my eye
immediately because it was quite strange among the surrounding
environment," Wang told China Daily yesterday.
Wang climbed to the top of the 7-m-long boulder and found
glacier scrapes on its top surface.
"The scrapes on the boulder are well preserved," Wang said.
"Hiding in dense forest and weighing about 100 tons, the
boulder, moved by a glacier from a mountaintop, cannot be shifted
by hand. Since the scrape surface faces to the sky, human
activities failed to destroy them."
The boulder's scrape area measures 40 sq m, 40 times that of
Beijing's other large glacier scrape, the Badachu glacier
scrape.
Scientists believe northern China was covered by ice 2 or 3
million years ago.
Three glacier relics have been discovered in the city.
"If the older discoveries can be seen as a flower or a leaf, the
newly discovered relics can be regarded as a garden," Wang
said.
The Bailong glacier valley contains a large number of glacial
landforms including a u-shaped valley, cirques, large glacier
boulders, moraine gravel and glacial depression, experts said.
"Geologists have very limited knowledge of ancient glacier
distribution in northern China," Han Tonglin, a professor of the
Chinese Academy of Geological Sciences, said.
"It is the first time that massive glacier relics have been
found in north China, which might help us understand ancient
climate in China, gather information on animals and plants living
more than 2 million years ago, and trace the evolution of ancient
human races," Han said.
The Quaternary Period marked the beginning of the evolution of
human beings.
Han conducted a primary inspection of the 2-km-long valley last
month and predicted that a nearby 1-km valley might also be an
ancient glacier valley.
"Further inspection will begin in winter after the trees shed
leaves to make way for us to enter the valley," Han said.
"Glacier relics can also help us predict global climate trends,
trace the beginning of global warming and predict possible global
cooling in the future.
"Looking back on the climate history of the Earth, we need not
be fussy about the extreme weather events happening in recent years
as they are hardly anything new."
(China Daily September 4, 2007)