海岸新月形沙丘的表面粒度分异——以河北昌黎黄金海岸为例  

RESEARCH ON THE DISTRIBUTION OF PARTICLE SIZE ON COASTAL BARCHAN:A CASE STUDY OF CHANGLI GOLD COAST

作　　者：董玉祥[1] 马骏[1] 黄德全[1] 

机构地区：[1]中山大学地理科学与规划学院,广州510275

出　　处：《海洋地质与第四纪地质》2008年第3期15-21,共7页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40571019)

摘　　要：河北昌黎黄金海岸是我国海岸沙丘的集中分布区,选择其中形态典型的新月形沙丘,分不同部位采集了42个沙丘表面沉积物粒度样品,通过对采集样品粒度及其参数的分析与计算,研究了其表面粒度分异。结果表明,昌黎黄金海岸新月形沙丘两翼、迎风坡脚、迎风坡、沙丘顶部、背风坡、背风坡脚的粒度总体上是中砂、分选好、偏度近对称和中等峰态,只有平均粒径在新月形沙丘表面的不同部位存在一定的差异,自迎风坡脚到沙丘顶部粒径变粗,背风坡粒径相对变细,到背风坡脚粒径又变粗,整个沙丘表面粒径顶部最粗、背风坡最细,其分布可以归入沙丘顶部砂物质最粗的分布模式。该粒度分布模式是本区域主风向与强风向交替变化及其风力差异、沙丘两侧不对称和凹型迎风坡形态等组合作用的结果。Changli Gold Coast in Hebei Province is a coastal dune region with diversified dune type, large dune area and typical dune shapes in China. At Changli Gold Coast, 42 samples of particle size were collected on a coastal barchan, which was a typical coastal barchan chosen from all the barchans in this research region. All the samples of particle size were analysed and the particle-size parameters of various samples were figured out. The results showed grain size on the coastal barchan was middle sand of good sorting, symmetrical skewness and middle degree kurtosis. It was also found that the mean particle size at different sites of the typical coastal barchan showed an obvious change. The distribution characteristics of particle size on the coastal barchan showed that the particle size became coarse from windward slope base to dune crest, but became fine on the leeward slope and then became coarse again at the leeward slope base, and the dune crest had coarsest particle size and leeward slope had finest particle size. The particle-size distribution of barchan in the Changli Gold Coast exhibited a model with coarsest sand materials occurring at the dune crest. The distribution pattern of particle size on the coastal barchan at Changli in Hebei Province mainly resulted from the combined effects of alternating variation of the regional prevailing wind directions and strong wind direction and wind fore difference, asymmetry on both sides of the dune, and concave shape of windward slope.

关 键 词：海岸新月形沙丘 粒度分异 河北昌黎黄金海岸 

分 类 号：P737.1[天文地球—海洋地质]