Heavy metal sedimentation in Saanich Inlet measured with 210Pb technique
Heavy metal sedimentation in Saanich Inlet measured with 210Pb technique
复制标题
采用 210Pb 技术测量 Saanich 湾的重金属沉降量
DOI：
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发表时间：
1977
期刊：
影响因子：
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通讯作者：
C. S. Wong
中科院分区：
文献类型：
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作者：
E. Matsumoto;C. S. Wong
在不列颠哥伦比亚省萨尼奇湾最深的盆地中，用盒子取样器采集了220米和200米两个未受扰动的沉积岩芯。在表层30 cm处，由于压实作用，沉积物孔隙度随深度急剧减小。计算了未压实泥沙的校正深度。为了确定Cmyr−1中表层的累积速率，绘制了~(210)Pb剖面与校正深度的关系图。根据累积速率计算了g cm−2yr−1中的沉积速率。深盆末端距底界0.093.2 7g cm−2年−1，距底界0.2 7g cm−2年−1。沉积岩心中的铅、铜、镉、汞含量随深度的增加而降低。目前的金属通量为：210Pb1.9-5.1dpm cm−2年−1，稳定铅3.6-11μg cm−2年−1，铜6.3-14，Cd 0.11-0.48，汞0.029-0.072。利用最近对萨尼奇海湾深盆底附近海水中重金属浓度的测量，推断出210Pb0.08年，稳定Pb0.07年，Cu0.3年，Cd 3年，Hg2年。
Two undisturbed sediment cores at 220 and 200 m in the deepest basin of Saanich Inlet, British Columbia, were collected by a box corer. In the upper 30 cm the sediment porosity exhibited an abrupt decrease with depth due to compaction. The corrected depth of sediments without compaction was calculated. The 210Pb profiles were plotted against the corrected depth in order to determine the accumulation rate at the surface in cm yr−1. The sedimentation rate in g cm−2 yr−1 was calculated from the accumulation rate. A sedimentation rate of 0.093 g cm−2 yr−1 was obtained at the end of the deep basin away from the sill entrance and 0.27 g cm−2 yr−1 near the sill of the deep basin. The Pb, Cu, Cd, and Hg contents in the sediment cores appeared to decrease with depth. A present metal flux of 1.9–5.1 dpm cm−2 yr−1 was inferred for 210Pb, 3.6–11 μg cm−2 yr−1 for stable Pb, 6.3–14 for Cu, 0.11–0.48 for Cd, and 0.029–0.072 for Hg. When some recent measurements of heavy metal concentrations in the seawater near the sill of the deep basin of Saanich Inlet were used, a residence time in the water column of 0.08 years was inferred for 210Pb, 0.07 for stable Pb, 0.3 for Cu, 3 for Cd, and 2 for Hg.