Taking varves to bits: Scanning electron microscopy in the study of laminated sediments and varves
Taking varves to bits: Scanning electron microscopy in the study of laminated sediments and varves
复制标题
将水藻分解：扫描电子显微镜在层状沉积物和水藻研究中的应用
DOI：
10.1023/a:1008069514445
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发表时间：
1999
影响因子：
2.1
通讯作者：
B. Zolitschka
中科院分区：
文献类型：
--
作者：
J. Dean;A. Kemp;D. Bull;J. Pike;Gunilla Patterson;B. Zolitschka
各种沉积物的常规高分辨率研究能够识别碎屑纹层和生物纹层，但往往无法分辨其中所包含的细小尺度纹层的性质。这种年内信号为我们提供了来自沉积记录的最高潜在分辨率，并可以使用扫描电子显微镜(SEM)进行解析。从湖泊和海洋环境中提出了六个案例研究，以说明在层状沉积物中通常发现的碎屑和生物组构类型的组合。碎屑纹层组构包括由颗粒沉积而来的组构和“事件沉积”组构。如果要按时间顺序使用VARVE，正确识别事件沉积是至关重要的。基于扫描电子显微镜的生物纹层组构研究已经确定了季节性的动物群演替，其中单个纹层的厚度可能小于100μ，最近的一次是夏季硅藻群落的深层叶绿素极大值(DCM)，提供了对季节性尺度过程的洞察。高分辨率的纹层组构研究可以为产生季节和年际变化的记录提供基础，从而有助于我们理解湖泊和海洋过程以及古环境解释。
Conventional high resolution studies of varved sediments are able to identify clastic and biogenic laminae, but are often unable to resolve the nature of fine-scale lamination contained therein. This intra-annual signal provides us with the highest potential resolution from the sedimentary record and can be resolved using scanning electron microscopy (SEM). Six case studies from lacustrine and marine settings are presented to illustrate the combination of clastic and biogenic fabric types typically found in laminated sediments. Clastic laminae fabrics include those which originate through grain settling and those which are ‘event deposits’. The correct identification of event deposits is essential if varves are to be used chronologically. SEM-based biogenic laminae fabric studies have identified seasonal faunal successions where individual laminae may be less than 100 μ thick and most recently, deep chlorophyll maxima (DCM) summer diatom floras, providing an insight into seasonal scale processes. High resolution lamina fabric studies can provide a basis for generating records of seasonal and inter-annual variability, thus contributing to our understanding of lacustrine and marine processes and palaeoenvironmental interpretation.