中国第四纪冰川研究的现状与争议——兼记首届“中国第四纪冰川与环境变化”研讨会

冰川是塑造地表形态最积极的外营力之一, 对第四纪冰期与间冰期旋回中冰川进退留下的丰富且形态独特的冰川地形的研究, 不仅能重建古冰川时空演化的规律, 在构造活跃的山区还可为山体抬升提供重要的理论参考. 2012年8月, 中国从事冰川地貌与环境变化研究的学者相聚兰州, 总结了以技术定年为主要特征的第四纪冰川研究新阶段取得的成绩与突破, 并探讨了现阶段工作的重点及未来的发展方向. 与会代表认为, 可对冰川地形进行直接定年的测年技术的发展与应用, 促进了我国第四纪冰川研究的发展, 现阶段及今后应着重加强与开展如下几个方面工作: 1)精确年代学框架的建立是现阶段我国第四纪冰川研究的重点; 2)青藏高原及周边山地最老冰碛的追溯及其年代测定是回答我国第四纪冰川开始发育的关键, 也是理解青藏高原构造抬升与冰期气候耦合的内在要求; 3)我国东部(105° E以东)第四纪冰川与环境问题需作进一步的研究与澄清, 科普工作亟待加强.

Quaternary Glaciations Research in China: Current Status and Controversy

Glaciers serve as very active geomorphic agents in shaping the landforms of glaciated regions, and are responsible for producing some of the most spectacular landscapes on Earth. During the glacial-interglacial cycles of the Quaternary, Glaciers advanced and retreated dramatically. As a consequence, abundant glacial landforms and sediments were presented in the glaciated regions. Studies of them can define the time, extent, properties and type of ancient glaciers. The relevant information could be used to reconstruct the spatial and temporal variations of the palaeo-glaciations. In tectonically active regions, these studies also can provide potential information on the history of uplift. In August, 2012, Chinese scholars, whose studies focus on the glacial geomorphology and environmental variation, gathered in Lanzhou to review the achievements have been made during the past several years and to discuss the research emphases of present and in the future. Participants considered that research on Quaternary glaciations has entered a new stage, when accurate dating of glacial landforms and sediments become an emphasis. The dating techniques, including cosmogenic radionuclides (CRN), optically stimulated luminescence (OSL), and electron spin resonance (ESR), have been developed, refined and widely applied. These dating techniques can potentially provide constraints on the ages of glacial sediments and landforms, which have promoted significant advances in research on Quaternary glaciations in China. Several works should be done at present and in the future. Firstly, to establish an accurate chronology framework for Quaternary glaciations is the critical work for Chinese scholars at present. Secondly, the timing of the oldest glaciations in the Tibetan Plateau and the bordering mountains is a fundamental requirement in understanding the glacier development coupling the uplift of the plateau, which will provide insight into understanding the glacier development in China. Thirdly, more work should be done to make clear that there were no palaeo-glaciers developed in the middle-low mountainous areas in the Eastern China beyond (105°E), except for the Changbai Mountain, Helan Mountain, Taibai Mountain and Taiwan Mountains. Chinese scholars should do more work to popularize the knowledge of Quaternary Glaciations and their related environments.