Trace metal distribution in the sediments of the whole lake basin for Lochnagar, Scotland: a palaeolimnological assessment
Trace metal distribution in the sediments of the whole lake basin for Lochnagar, Scotland: a palaeolimnological assessment
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苏格兰洛赫纳加整个湖盆沉积物中的痕量金属分布：古湖泊学评估
作者：
Handong Yang;N. Rose;R. Battarbee;D. Monteith
多个沉积物岩芯从整个湖泊盆地的Lochnagar，苏格兰，微量金属分析表明，从稳定值的Pb/Ti和Hg浓度剖面的快速增加的深度偏离提供了一个很好的测年功能为19世纪60年代。在相对较浅的湖泊，推断沉积物积累率和微量金属库存随水深变化，但在深水区，沉积物积累率低于在大多数其他地区的湖泊。1860年以来沉积物中汞、铅、铜和锌的累积量在最深处分别为整个沉积物区相应平均值的61%、64%、73%和56%。这主要是由于深盆沉积物堆积少。这一发现不同于预期的沉积物聚焦模式，并使定量解释的古湖沼学特征，从这个湖的深层区域的沉积物困难。湖盆沉积面积最大的东北侧沉积物聚集对湖泊最深处的影响可能有限，因此东北侧沉积物很难通过沉积物聚集向最深处运移。因此，由于不同类型化石的相对丰度，湖最深处的沉积物可能不能很好地代表整个湖盆。
Analyses of trace metals on multiple sediment cores from the whole-lake basin of Lochnagar, Scotland, show that the depth of departure from stable values towards a rapid increase of the Pb/Ti and Hg concentration profiles provides a good dating feature for the 1860s. In relatively shallow areas of the lake, inferred sediment accumulation rates and the trace metal inventories change with water depth, but in the deep water area, sediment accumulation rates are lower than in most other areas of the lake. Mercury, Pb, Cu and Zn inventories in the sediments accumulated since 1860 in the deepest area are 61%, 64%, 73% and 56% of the corresponding average inventories for the whole sediment area of the lake, respectively. This is mainly due to low sediment accumulation in the deep basin. This finding differs from the expected sediment focusing pattern and makes quantitative interpretations of palaeolimnological features using sediments from the deep area of this lake difficult. The influence of sediment focusing from the north-eastern side, the largest portion of the sediment area of the lake basin, on the deepest area of the lake may be limited, so the sediments in the north-east could be difficult to be transported to the deepest area through sediment focusing. Therefore, the sediments in the deepest area of the lake may not represent the whole-lake basin well for the relative abundances of different types of fossils.