地理科学 ›› 1986, Vol. 6 ›› Issue (4): 293-304.doi: 10.13249/j.cnki.sgs.1986.04.293

• 论文 •    下一篇

中国贝壳堤发育及其对海岸线变迁的反映

赵希涛   

  1. 中国科学院地质研究所 北京
  • 出版日期:1986-07-20 发布日期:1986-07-20

DEVELOPMENT OF CHENIERS IN CHINA AND THEIR REFLECTION ON THE COASTLINE SHIFT

Zhao Xitao   

  1. Institute of Geology, Academia Sincca, Beijing
  • Online:1986-07-20 Published:1986-07-20

摘要: 本文记述了中国沿海与邻近陆架地区贝壳堤的分布及其地貌与沉积特征,概括了现已发表的贝壳堤样品的14C年代数据,并在评述样品的代表性、可靠性及其影响因素的基础上,讨论了中国大多数贝壳堤的形成时代,分析了影响贝壳堤形成的条件,勾绘了24,000年来古海岸线的位置,并阐明了海岸发育的历史及主要影响因素。

Abstract: Chenier, a special beach ridge characteristic of silty or muddy coasts, is widely distributed on the coastal plains and the adjacent shelves of eastern and southern China (Fig. 1). Along the west coast of the Bohai Gulf, four cheniers have been found, respectively(Fig.2A). In the central part of North Jiangsu plain,there are four cheniers which are called Xigang, Zhonggang,Donggang and Xinggang, respectively(Fig.2B). In the southern part of the Changjiang Delta,a series of cheniers have been found, respectively(Fig. 2C). The 14C datings of 68 shell samples from cheniers in China are listde in Table 1. The reliability of these datings and their affecting factors have been reviewed. Based on the 14C dates, the development of the cheniers in China can be divided into three periods of 24,000-15,000BP, 7,000-5,000BP and since 5,000 BP.The chenier groups of various periods are distributed on different geomorphologic positions and each group consists of a few cheniers formed in various stages. The main conditions for the formation of cheniers in China are: (1) Relative stability of sea level; (2) changes of yield of river sediments especially frequent Changes of river mouths, and growth and decline of the littoral dynamic factors; and (3) certain grain size of sediments and slope of beach. Based on the geomorphologic positions and ages of formation of cheniers in China, the paleocoastline positions of various periods since 24,000 BP have been plotted on the distribution maps of cheniers along the coast and on the adjacent shelf of eastern China (Figs. 1 and 2). The history of the coastline shifts and the features of the sea level changes in China during the last 24,000 years are also discussed in this paper.