Origin and movement of groundwater and major ions in a thick deposit of Champlain Sea clay near Montréal
Origin and movement of groundwater and major ions in a thick deposit of Champlain Sea clay near Montréal
复制标题
DOI：
10.1139/t89-009
复制
发表时间：
1989-02
影响因子：
3.6
通讯作者：
D. Desaulniers;J. Cherry
中科院分区：
文献类型：
--
作者：
D. Desaulniers;J. Cherry
在蒙特利尔附近的一个地点，使用测压计和岩心样本评估了 28 m 厚的尚普兰海粘土沉积物的来源、年龄和地下水运动速率。 3H仅出现在上部3-4 m内，这表明该地表风化带以下的地下水起源于1952年之前。来自最深测压计的水中18O、Na+和Cl−浓度表明深层粘土沉积在约33%海水和67%淡水的混合物中。几种主要离子的分布图显示浓度随深度逐渐增加。当模型中仅包含这些离子向上扩散到表层淡水区域且扩散时间约为 10 000 a 时，Ca2+、Mg2+、K+、Na+ 和 Cl− 垂直迁移的数学模拟与场剖面非常匹配。当模型中包含通过水力梯度和水力传导率现场测量获得的 0.13 cm ∙ a−1 的向下平流速率时，模拟的主离子剖面...
At a site near Montreal, piezometers and core samples were used to assess the origin, age, and rate of groundwater movement in a 28 m thick deposit of Champlain Sea clay. 3H occurs only within the upper 3–4 m, which indicates that groundwater below this surficial weathered zone originated prior to 1952. Concentrations of 18O, Na+, and Cl− in water from the deepest piezometer suggest that the deep clay was deposited in a mixture of about 33% seawater and 67% freshwater. Profiles of several major ions show a gradual increase in concentration with depth. Mathematical simulations of vertical migration of Ca2+, Mg2+, K+, Na+, and Cl− provide close matches to the field profiles when only upward diffusion of these ions into the surficial freshwater zone is included in the model with a diffusion time of approximately 10 000 a. When the downward advection rate of 0.13 cm ∙ a−1 obtained from field measurements of hydraulic gradient and hydraulic conductivity is included in the model, the simulated major-ion profile...