1954, 37-year-old Liu Dongsheng participated in the investigation of the Loess Plateau for the first time.
This summer, Liu Dongsheng and a comprehensive investigation team composed of paleontologists, geologists and other scientific researchers came to Huixing Town, Henan Province. In the evening, many members of the investigation team went out for a walk. Liu Dongsheng found that there were rows of neat lights not far away, which was puzzling in the silent night. The next day, he got up early and looked in the direction he saw last night.
It turned out that the rows of lights that Liu Dongsheng saw at night came from the caves where villagers lived. These caves have two floors, and the villagers use the firmness of soil deposition in the local loess to make the top of the cave, which is equivalent to the natural ceiling. The architectural structure of this cave aroused great interest of Liu Dongsheng, who originally studied paleontology. Liu Dongsheng went to consult the soil scientist Zhu Xianmo. Zhu Xianmo told him that the stratum that his teacher Mr. Yang called "red soil" was the location of this part of the cave, which actually belonged to the loess stratum.
In the mid-1950s, China Academy of Sciences had an important research project to solve the problem of soil and water conservation in the middle reaches of the Yellow River. Inspired by the cave dwelling of fellow villagers in Huixing Town, Liu Dongsheng plunged into the study of the Loess Plateau.
Liu Dongsheng designed a large-scale grid route investigation scheme for the study of China Loess Plateau, which was finally supported by decision makers. Each expedition team insisted on completing every route, and completed the investigation of the east-west and north-south 10 Wan Li section of the Loess Plateau, and collected a lot of first-hand information, which took the first step for the loess research in China on the world stage. Liu Dongsheng and his colleagues preliminarily determined that the loess in China has a history of 2.5 million years.
"The vicissitudes of nature have carved three complete history books on the earth: one is the deep-sea deposits that completely preserve the information of ancient environmental changes, the other is the polar glaciers that systematically reflect climate change, and the third is the loess deposits in China. These three books are the best literature archives for us to understand the natural history, climate and biological changes of the earth. " On April 12, 2003, Professor Cohen, a member of the jury, described the unique loess sedimentary geological phenomenon in China with accurate and poetic language, and also spoke highly of the outstanding achievements made by China scientists represented by Liu Dongsheng in loess research.
For half a century, it is generally believed that the information of paleoenvironmental changes is best preserved in deep-sea sediments, and polar ice can also systematically reflect climate change, but its coverage span is not as long as that of deep-sea sediments. However, the land sediments closest to human living space have not been paid due attention for a long time because of their poor continuity and easy weathering. Chinese scientists have chosen the loess sediments unique to China as the research object, and Liu Dongsheng is recognized as the father of loess sequence paleoenvironment research in China for his pioneering research work.
▲ Keshan disease survey shows the emergence of environmental geology.
/kloc-one night in the winter of 0/970, Li Shirong, a colleague who studied Keshan disease together, came back from a business trip in Beijing and stayed at the Keshan County Committee Guest House not far from Harbin to Qiqihar Railway Branch! The good news that Li Shirong reported to Liu Dongsheng is that not long ago, Premier Zhou Enlai invited a Japanese journalist to give a world environmental report in the Great Hall of the People. Endemic diseases such as Keshan disease caused by environmental pollution have attracted great attention of Premier Zhou Enlai and relevant central leaders!
Due to the arrival of the "Cultural Revolution", many researchers in Liu Dongsheng and Guiyang Institute of Geochemistry of Chinese Academy of Sciences have been hit. Later, the central government set up a local disease prevention institute to conquer Keshan disease, and it was necessary to investigate the water and soil problems of Keshan disease. Liu Dongsheng and several researchers studying geochemistry and soil were ordered to come to Keshan County, Heilongjiang Province. The county guest house where he lives is a simple "master's hut", and many experiments are carried out with the help of the small laboratory of the county epidemic prevention station.
Keshan disease was first discovered in Keshan County, Heilongjiang Province, so it is called Keshan disease. "At that time, medical workers found that the disease was regional and related to geology. Our comrades who study geochemistry also believe that this disease is largely related to the soil where local people live, so it is necessary for us to investigate the soil and water in the ward. " Liu Dongsheng told reporters.
"The research group needs an expert who studies loess to participate in the soil and water survey in the ward, so I started to investigate in Shaanxi and other places from 1969. In my investigation, I found that there is basically no Keshan disease in some flat areas of the Loess Plateau, and there are more cases of Keshan disease in areas with crisscross gullies. It is not difficult to draw a conclusion that the cause of Keshan disease is related to trace elements in water and soil. Later, some comrades further studied and found that this was because of the lack of selenium in the water, which seriously led to the occurrence of Keshan disease among local people. " Liu Dongsheng said: "According to the records of relevant foreign documents, selenium is also lacking in the soil, and animals eat local grass, which leads to muscle necrosis. In connection with the occurrence of Keshan disease in China, we have studied and analyzed the local water, soil, grain, human hair and nails in Shaanxi, Heilongjiang and other provinces, and found that selenium is generally lacking in the ward, not in the ward. "
After that, Liu Dongsheng took a pickle steamed bread, leafed through his loose-leaf card notes made by reading literature in recent years, spent a week writing a paper with more than 5,000 words: The Emergence of Environmental Geology, and then carved hundreds of wax papers and mailed them to relevant scientific research departments and leaders. Soon, he revised this paper slightly and published it in the internal publication Environment and Health of Guiyang Institute of Geochemistry, Chinese Academy of Sciences, which attracted the attention of domestic academic circles at that time.
This mimeographed paper "The Emergence of Environmental Geology" has for the first time erected a banner of hunting and flying in China's environmental science field, which not only announced the birth of China's environmental geology research, but also verified the correctness of Liu Dongsheng's view that he should learn to focus on the "future" in scientific research.
▲ Stand on the loess slope of Luochuan and gain insight into the frontier of world science.
Scientific knowledge tells us that tens of millions of years ago, the earth's land plates collided violently, the Qinghai-Tibet Plateau suddenly rose, and the climate and environment evolved violently. The strong northwest wind carries a lot of loess and sand, which is piled up in a place of 270 thousand square kilometers that was originally an ocean. After the rainstorm, the turbulent river, like a ruthless broadsword, cut the Loess Plateau with many scars and changes, forming the unique plateau, beam and headland topography of the Loess Plateau today. Liu Dongsheng and other Chinese and foreign scientists who study geology regard these loess profiles as "century rings" without exception. Because the loess section in Heimugou, Luochuan County-paleosol sequence is continuous and complete, rich in fossils, and a lot of information about climate, environment and life is preserved. A soil profile is the climate cycle of100,000 years or 200,000 to 300,000 years, which is an excellent carrier to reveal the mystery of the Quaternary.
As early as 1955, Liu Dongsheng accompanied the famous Soviet geologist Pavlinov to Luochuan, and he was deeply impressed by the unique loess landform in Luochuan. Liu Dongsheng told reporters: "In the 1980s, a Japanese geological survey team came to China. A member of the investigation team is older than me and has a serious heart disease. After the old Japanese scientist came to Heimugou, Luochuan, he wanted to go down anyway, but people didn't listen to his advice. He said,' I can see this place with my own eyes when I am an old woman, and I will die without regret.' Why? Because the loess profile in Luochuan is a living textbook that geologists all over the world must read. The' historical record' here is invisible in other parts of the world, and it is a natural laboratory. "
Foreign scientists' yearning for Luochuan is like a monk on a pilgrimage to Mecca, which is actually a high recognition of China scientists' achievements in geological and environmental research represented by Liu Dongsheng. Liu Dongsheng said: "Every field trip to Luochuan will yield different degrees, and it is also a field trip to it, which has triggered many scientific thoughts on the global environment and its climate change."
We may say that China's loess research can go to the world from now on, largely due to Mr. Liu Dongsheng's foresight. Standing on the high slope of plain loess in Heimugou, Luochuan, we can clearly see the frontier of world science.
▲ Feel the same hot and cold all over the world from the "roof of the world"
Liu Dongsheng is a legend in itself. Liu Dongsheng, who is 87 years old this year, is not deaf and has good eyesight. What is even more surprising is that he has a youthful vitality, and his thinking is as agile as his actions. He proudly told reporters: this is because I was engaged in geology when I was young and ran in the wild for many years!
People may not know this, but Liu Dongsheng is also the chairman of the China Society for Scientific Exploration.
From 65438 to 0964, Liu Dongsheng participated in an unprecedented scientific expedition in China led by glaciologist Shi Yafeng, climbed Mount Xixiabang, and investigated the debris flow in Bomi section of Sichuan-Tibet Highway. In Tibetan, Xixiabangma means the harsh alpine climate here. Its peak was the only one of the 14 peaks in the world with an altitude of over 8,000 meters at that time that had never been set foot on by human beings, and its altitude was also inconsistent with previous documents and maps. Liu Dongsheng and his comrades-in-arms went into Mashan, Xixia State, the highland of the world, and carried out some routine basic work done by geologists on scientific blank areas. He knows that these works are not contrary to the study of the Loess Plateau and environmental science: this year coincides with the opening of the Sino-Nepalese highway, and the road builders cut the way. Rock boulders, which have existed for hundreds of millions of years, show their rugged features for the first time in front of the world, which is really a godsend opportunity for geologists to get twice the result with half the effort.
On an ordinary summer evening, the members of the expedition returned to their headquarters from the wild. Zhang, a teacher of Beijing Institute of Geology, showed Liu Dongsheng a stone, saying that it was a plant fossil found in a rock beside a glacier at an altitude of 5,900 meters. Liu Dongsheng carefully studied this fossil with clear outline and distinct veins, and his eyes lit up: This is clearly a fossil of leaves of broad-leaved trees!
Broadleaf trees usually grow at an altitude of 3000 meters in the southeast of Tibet, which is the upper limit, but similar fossils appear at twice the upper limit. What does this mean? At that time, international geologists thought that the height of the Qinghai-Tibet Plateau had existed for a long time, but its uplift time was not raised as a problem. Will this fossil appear in a relatively recent age? Back in Beijing, Liu Dongsheng immediately found Ren Xu, an expert from Beijing Institute of Botany, China Academy of Sciences. The result is very satisfactory. This fossil belongs to the genus Quercus, which is only over 2 million years old! This extraordinary discovery means that the dramatic uplift of the Qinghai-Tibet Plateau is a recent event, rising by 3,000 meters in more than 2 million years!
The unexpected discovery of Quercus alpiniae fossils has caused Liu Dongsheng and other China scientists to discuss the topic of "the time, extent and stage of the uplift of the Qinghai-Tibet Plateau". Later, scientists' research on the uplift of the Qinghai-Tibet Plateau also provided a strong scientific basis for global climate change.