A review of coastal palaeoclimate and relative sea-level reconstructions using δ13C and C/N ratios in organic material
A review of coastal palaeoclimate and relative sea-level reconstructions using δ13C and C/N ratios in organic material
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DOI：
10.1016/j.earscirev.2005.10.003
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发表时间：
2006-03-01
影响因子：
12.1
通讯作者：
Leng, MJ
中科院分区：
文献类型：
--
作者：
Lamb, AL;Wilson, GP;Leng, MJ
由于评估未来海平面可能上升的重要性变得明显，对沿海地区相对海平面的全新世重建和环境变化越来越多。传统上，这是通过综合使用生物和物理指标(例如，花粉、硅藻、有孔虫、粒度等)来实现的。在某些情况下，全新世沉积物中微体化石可能很少或不存在，在这种情况下，可以使用碳同位素比率(C-13增量)和有机碳与总氮的比率(C/N)，因为它们有可能提供关于保存在沿海环境中的有机物质来源的信息。三角洲C-13和On对河口沉积物的不同碳源的区别导致它被广泛用作碳途径的示踪剂和河口储存。最近，这些技术被应用于全新世沉积物，以破译古海岸环境的变化，从而相对于海平面和/或古河流流量的位置，这与古气候有直接关系。本文回顾了利用这一技术的研究，并探索了广泛的沿海环境(盐沼、河口、泻湖、隔离盆地和峡湾)的例子。它还讨论了由于分解过程而导致的地球化学特征的潜在变化。有机质分解已被证明会改变沉积物的C-13和C/N值，因此，为了对全新世三角洲C-13和C/N的古环境解释有信心，有必要了解所涉及的过程，以便对全新世C-13和C/N的古环境解释有信心。联合国，特别是C-13三角洲的分解位移可以在相对较短的时间内发生，然而，解释相对海平面变化的关键是C-13和C/N的变化方向，而不是绝对值，因此这种变化通常被保存下来。(C)2005年《国家能源管制条例》。爱思唯尔出版，版权所有。
Holocene reconstructions of relative sea-level (RSL) and environmental change in the coastal zone have become progressively more numerous since the importance of assessing possible future sea-level rises has become apparent. Traditionally this has been achieved using a combination of biological and physical indicators (e.g. pollen, diatoms, foraminifera, grain size, etc.). In some circumstances, microfossils can be rare or absent from Holocene sediments and in these cases carbon isotope ratios (delta C-13)and organic carbon to total nitrogen ratios (C/N) can be used because they have the potential to provide information as to the origin of organic material preserved in coastal environments. The distinction in delta C-13 and ON of the various sources of carbon to estuarine sediments has led to its wide use as a tracer of carbon pathways and storage in estuaries. More recently these techniques have been applied to Holocene sediments to decipher changes in palaeocoastal environments and thus position relative to sea-level and/or palaeoriver discharge, which have direct relevance to palacoclimate. This paper reviews the studies that have utilised this technique and explores examples from a wide range of coastal environments (saltmarshes, estuaries, lagoons, isolation basins and fjords). It also discusses the potential alteration of geochemical signatures as a result of decompositional processes. Organic matter decomposition has been shown to change sediment delta C-13 and C/N values and thus an understanding of the processes involved is necessary in order to have confidence in the palaeoenvironmental interpretation of Holocerie delta C-13 and C/N. Decompositional shifts in UN, and particularly delta C-13, can occur over a relatively short time-period, however it is the direction of change in delta C-13 and C/N, rather than absolute values, that is key for interpreting changes in relative sea-level and thus such changes are commonly preserved. (c) 2005 NERC. Published by Elsevier B.V. All rights reserved.