An Improved Method for Extracting, Sorting, and AMS Dating of Pollen Concentrates From Lake Sediment
An Improved Method for Extracting, Sorting, and AMS Dating of Pollen Concentrates From Lake Sediment
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从湖泊沉积物中提取、分选和 AMS 测定花粉浓缩物的改进方法
DOI：
10.3389/fevo.2021.668676
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发表时间：
2021
影响因子：
4.5
通讯作者：
Christiane A. Hassel
中科院分区：
文献类型：
--
作者：
I. Tunno;S. Zimmerman;T. Brown;Christiane A. Hassel
高分辨率年表对古环境重建至关重要，对陆地古气候的湖泊记录尤其具有挑战性。陆地大化石的加速器质谱（AMS）放射性碳测量是建立湖泊沉积物岩心年龄模型最常用的技术，但它依赖于沉积物中陆地大化石的存在。在缺乏足够的宏观化石的情况下，花粉浓缩物代表了建立高分辨率年表的有价值的日期来源。然而，正如不同作者在过去几十年的工作中所报道的那样，花粉分离和定年可能会带来一些挑战。本文提出了一种改进的流式细胞术提取、纯化和放射性碳定年的方法，以提高提取效率和花粉浓缩液的纯度。总的来说，沉积物的性质和花粉的丰度是获得足够的花粉粒和足够的碳来测定年代的主要考虑因素。此外，需要将花粉与其他形式的有机物完全分离，以确保日期的准确性。我们将该方法应用于内华达山脉（加利福尼亚州）东侧两个对比湖盆的地表样本和沉积物岩心，并描述了可用于优化各种沉积物花粉制备的变化。
High-resolution chronologies are crucial for paleoenvironmental reconstructions, and are particularly challenging for lacustrine records of terrestrial paleoclimate. Accelerator Mass Spectrometry (AMS) radiocarbon measurement of terrestrial macrofossils is the most common technique for building age models for lake sediment cores, but relies on the presence of terrestrial macrofossils in sediments. In the absence of sufficient macrofossils, pollen concentrates represent a valuable source of dates for building high-resolution chronologies. However, pollen isolation and dating may present several challenges, as has been reported by different authors in previous work over the last few decades. Here we present an improved method for extracting, purifying and radiocarbon-dating pollen concentrates using flow cytometry to improve the extraction efficiency and the purity of the pollen concentrates. Overall, the nature of the sediments and the abundance of the pollen represent major considerations in obtaining enough pollen grains and, consequently, enough carbon to be dated. Further, the complete separation of pollen from other forms of organic matter is required to ensure the accuracy of the dates. We apply the method to surface samples and sediment cores recovered from two contrasting lake basins on the eastern side of the Sierra Nevada (California), and describe the variations that may be used to optimize pollen preparation from a variety of sediments.
更新世-全新世过渡期间莫诺湖（内华达山脉东部）的古生产和环境变化
DOI：
10.1016/j.palaeo.2019.109565
发表时间：
2020
期刊：
Palaeoecology
影响因子：
--
作者：
Hodelka, Bailee N.;McGlue, Michael M.;Zimmerman, Susan;Ali, Guleed;Tunno, Irene
通讯作者：
Tunno, Irene