长江三角洲地区晚第四纪古土壤地球化学特征

• 作 者: 刘宝柱 李从先 业治铮
• 机 构: 青岛海洋大学海洋地球科学学院,同济大学海洋地质系,地矿部南京地质矿产研究所
• 出 处: 青岛海洋大学学报
• 发表日期: 1998年01期
• 关键词: 古土壤层 晚第四纪 地球化学特征 硅铝率 全量分析 海相层 土壤特征 中国黄土 比值变化 古土壤学

首次研究长江三角洲地区晚第四纪古土壤的地球化学特征。本区第一“暗绿色硬粘土层”的硅铝率在２．８０～３．３７之间，说明该层已经发生了较强的土壤化作用，可以确定为古土壤。古土壤层土体样品与胶体样品的化学全量分析结果之间有很大的差异，只能用胶体样品来研究古土壤特征。在古土壤中，ＳｉＯ２、Ａｌ２Ｏ３、ＭｇＯ、ＴｉＯ２、Ｋ２Ｏ相对积聚，而Ｆｅ２Ｏ３、ＣａＯ、ＭｎＯ、Ｎａ２Ｏ、Ｐ２Ｏ５相对淋溶。在剖面上，ＳｉＯ２／（ＭｇＯ＋ＣａＯ）的分子比值变化规律表明气候逐渐湿润

For the first time, the geochemical characteristics of the Late Quaternary paleosol in the Yangtze River Delta were studied. The area of ​​the first “dark green hard clay” has a Si / Al ratio between 2.80 and 3.37, indicating that the layer has undergone strong soil compaction and can be identified as paleosol. There is a big difference between the results of chemical full-scale analysis of soil samples and colloidal samples in ancient soils. Only the colloidal samples can be used to study paleosol characteristics. In ancient soils, SiO2, Al2O3, MgO, TiO2 and K2O accumulate relatively while Fe2O3, CaO, MnO, Na2O and P2O5 are relatively leached. In the section, the change rule of the molecular ratio of SiO2 / (MgO + CaO) shows that the climate is gradually moist