利用14C测年法确定新月形沙丘移动速率  

A case study on determining the migration speed of barchans based on carbon-14 dating

作　　者：何晨晨 王振亭 王宗礼[3] He Chenchen;Wang Zhenting;Wang Zongli(Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China;MOE Key Laboratory of Western China's Envi-ronmental Systems,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]中国科学院西北生态环境资源研究院,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]兰州大学西部环境教育部重点实验室,甘肃兰州730000

出　　处：《中国沙漠》2024年第1期119-121,共3页Journal of Desert Research

基　　金：国家自然科学基金区域创新发展联合基金项目(U21A2001);国家自然科学基金面上项目(42371005)。

摘　　要：在沙丘移动过程中,背风坡底部经常掩埋致死低矮沙生植物,而迎风坡坡脚则因风蚀而出露植物残体。通过14C测年法测定植物死亡时间,并根据沿沙丘移动方向从迎风坡坡脚至背风坡边缘的水平距离,即可计算沙丘在这段时间内的平均移动速率。据此,利用灌木植物木质茎残体作为测年材料,得到了民勤绿洲上风向外围区域内3个新月形沙丘的移动速率。通过与高分遥感影像解译结果对比,发现14C测年法能够成功确定新月形沙丘在数十年内的最大平均移动速率。In the migration of active dunes,small psammophytes often die while being buried by the lee of the dune,and subsequently plant residues appear at the toe of the windward because of wind erosion.The mean mi-gration speed of the dune during this time can be computed according to the death time measured by carbon-14 dating and the horizontal distance from the windward toe to the lee edge along the migration direction.Based up-on this principle and selecting the residues of shrub stems as dating materials,the migration speeds of three barchans at the upwind marginal area of the Minqin oasis are obtained.Compared with the more accurate results given by the interpretation of remote sensing images,it is found that carbon-14 dating can successfully determine the maximum time-averaged migration speed of barchans during several decades.

关 键 词：新月形沙丘 移动速率 植物残体 14C测年 

分 类 号：P597[天文地球—地球化学]