福建长乐海岸沙丘砂释光性质及环境演变研究

Luminescence Character of Changle Coastal Dune Sand:Environmental Significance Based on OSL Dating

海岸沙丘蕴含着丰富的过去海岸带风沙活动的信息,在精确的年代学框架基础上才能提取接近实际的海岸风沙活动序列。本研究选取福建长乐海岸3个代表性海岸沙丘剖面进行光释光测年研究,应用不同年代模型计算比较光释光测年结果,发现Weighted Mean年代模型所测得的等效剂量值相较于CAM年代模型和Mean年代模型呈现出系统性偏小的特征,Mean年代模型所测得的等效剂量值的误差偏大,因此本研究选用CAM年代模型作为年代测算的模型。海岸沙丘砂OSL年代学研究表明,在0.9 ka以来,福建长乐海岸带产生明显的风沙堆积和发育海岸沙丘事件,可能是由于中世纪以来,尤其是小冰期福建沿海处于总体寒冷的背景下,区域气候呈现较大幅度的冷暖波动变化,经历了海平面波动下降、海岸线风大沙多的环境演变过程。

chronology profiles in Coastal dune contains rich information about aeolian activities in the past. Based on precise fFame Changl we can obtain ponderable sand drift activity. e, Fujian province to demonstrate the optical In this paper, we selected three typical stimulated luminescence （OSL） dating technique in coastal aeolian deposit. Using different age models to compare their equivalent dose （De） results. The results suggested that Weighted Mean age model＇s results less than Central Age Models （CAM） and Mean age model＇s result. Mean age model＇s error is larger than CAM. So, we choose the CAM as calculation model. The oslg research shows that the coastal dune in the study area has accumulated since -0. 9 ka, which means the development of coastal dune correlate the climatic change, the descending of sea 1 evel, the recession of a shoreline and the process of desertification.