海南岛海岸沙丘岩的特征、成因及其环境意义

 对海南岛海岸沙丘岩的沉积结构与构造进行了实地调查和实验分析。研究表明,海岸沙丘岩的沉积构造和结构特征有别于其他海岸沉积类型,既有风成特征,也有成岩作用特征。海岸沙丘岩的形成需要具备物源、气候和水分3个条件,并经历初始沉积物堆积、初步胶结和溶解—沉淀3个形成阶段。海岸沙丘岩具有一定的环境指示意义,即海岸沙丘岩形成于冰后期的相对高海面时期,能指示风力较弱、沙丘固定和湿热的气候条件。近1 000多年来,研究区的季风风向与现代盛行风风向基本一致。

Characteristics and Genesis of Coastal Eolianite and Its Environmental Significance along Hainan Island of China

The coastal eolianite was found along the western and northeastern coast of Hainan Island, China. It is different from the other kinds of coastal sediments with the aeolian and diagenesis characteristics. The coastal eolianite is weak in diagenesis, keeping in large porosity, being in the early diagenesis stage. It is included three conditions for forming coastal eolianite: material source, climatic condition, and water condition. The process of development and formation eolianite was formed in the slightly-regressive stage of the highstanding period in the Late Holocene. The regional wind direction of Hainan Island was consistent with the modern northeastern monsoon in the past 1 000 years. Compared with the loose sand layer, the coastal eolianite layer can reflect that the wind power decreased, the dunes more stable and hot and humid climate.