施雅风教授对中国第四纪冰川研究的贡献

ON PROFESSOR SHI YAFENG'S CONTRIBUTION TO QUATERNARY GLACIATION RESEARCH IN CHINA

冰期与间冰期旋回是第四纪最基本的气候特征。第四纪期间规模较大的冰川进退留下了丰富、形态独特的冰川地形,对其研究可以获得冰川的时空演化规律。"将今论古"是地质学最基本的工作原理,也是第四纪冰川研究的基本思路。从20世纪50年代,在施雅风先生的领导下,以现代冰川研究为契机,开展了青藏高原及周边山地的第四纪冰川研究,使我国第四纪冰川研究达到国际水平。在对我国西部地区(105°E以西)第四纪冰川有了相当认识后,进行了我国东部地区(105°E以东)第四纪冰川与环境问题的拨乱反正,将我国东部地区第四纪冰川与环境变化研究引向正确的方向。目前,我国第四纪冰川研究进入了以定年为特征的定量研究阶段。在此背景下,我国第四纪冰川将在测年技术的综合应用、老冰期冰川地形的定年、构造抬升与冰川发育的耦合关系等几个方面展开研究与探讨。

Glaciers advanced and retreated dramatically during glacial-interglacial cycles in Quaternary. Glaciers are important geomorphic agents in shaping the most spectacular landscapes of glaciated regions. These landscapes contain considerable information on past glacial processes in the form of moraines and other landforms. Study on these landforms could be used to deduce the former properties of the glaciers, and lead to a good understanding of the temporal and spatial shifts of the past glaciers. From the 50s of the last century, under the leadership of Professor Shi Yafeng,Chinese scholars carried out fieldwork on modern glaciers and Quaternary glaciations in the Qinghai- Xizang Plateau and surrounding areas. At the same time,Lanzhou Institute of Glaciology and Geocryology,Chinese Academy of Sciences, was established, an institute specifically focusing on the study of glaciers. The glacial landforms of the last glaciation were well-preserved, based on the landforms and absolute dating results. Professor Shi and his research group reconstructed the glaciers and related environments during the last glaciation. The outstanding work is the equilibrium-line altitude （ELA） reconstruction. According to this map, it is very clear that the ELAs are decreased about 300m in the northwestern and interior of the Qinghai-Xizang Plateau, but more than 1000m in the southeastern part of it. Their studies also demonstrated that the hypothesis of the Qinghai-Xizang Ice Sheet was not correct. On the basis of the understanding of the glacial landforms and glaciations in the Qinghai- Xizang Plateau and surrounding mountains, the problems on Quaternary glaciations and environments in eastern China（eastern part beyond 105~E）have also been resolved. During the past several decades, dating techniques, including cosmogenic radionuclide （CRN）, optically stimulated luminescence （OSL）and electron spin resonance （ESR） ,which can directly determine the potential ages of glacial landforms and sediments have been refined and widely applied. Research on Quaternary glaciations has entered a new stage with the emphasis on accurate dating. Under this condition, the comparison schema between Quaternary Glaciations in China and the Marine Oxygen Isotope Stage（MIS） during the past 800ka has been improved. By reviewing the past and looking into the future, the Quaternary glaciations and their related environments need further investigation. It should be emphasized that the absolute dating and dating techniques should be comprehensively applied. According to the principles of geomorphology and stratigraphy,the dates of most of the older glacial landforms have not been determined,and this problem should be resolved. The relationship between the uplift and glacier development should be further discussed. Chinese scholars should do more work to popularize the knowledge of the Quaternary glaciations and their related environments.