【摘要】 根据上百个钻孔的岩性岩相资料及数十个钻孔的微体古生物、地下水化学及土壤易溶盐等方面的分析资料,结合古地磁、¹⁴C测年成果,讨论了黄河三角洲地区第四纪海进、海退特征及海进对地下咸水形成与分布的影响,勾划了全新世海进盛期此区的海岸线,讨论了全新世海岸线的变迁过程。更多还原

【Abstract】 Based on studies of biostratigraphy, magnetostratigraphy, lithostratigrapfay, ground-water chemistry and salinity of Quaternary sediments in the Huanghe River (Yellow River) Delta, Quaternary marine transgressions and their characteristics have been demonstrated. It is found that the sea transgressed into the delta land for twelve times during the past three million years. According to magnetostratigraphy, radiocarbon data and sedimentation rate, the transgressions are estimated to have happened during 3.00 Ma. B. P., 2.23-2.20 Ma. B.P., 1.57-1.50 Ma.B.P., 1.27-1.17 Ma.B.R, 0.60-0.50 Ma. B. P., 0.40-0.30 Ma.B.P., 0.25-0.20 Ma.B.P., 0.18-0.15 Ma.B.P., 0.12-0.10 Ma.B.P., 0.09-0.07Ma. B. P., 0.04-0.025 Ma.B.P., and 8,000-4,000 a.B.P. respectively.Average rate of tectonic subsidence in Brunhes was about two times that in Matsuyama in the delta. Because of the accelerating of tectonic subsidence, marine transgression occurred more frequently and exerted greater effects on the Huanghe River Delta in Brunhes than in Matsuyama. As a result of that, salt ground water has a larger distribution in the upper Quaternary than in the lower.The coastline at the maxiumum of Holocene transgression is also drawn through analysis of a hundred cores. At that time, the coastline was 80-100 kilometers more landward in the Huanghe River (Yellow River) Delta.更多还原