Cryptotephrochronology of the Eemian and the last interglacial-glacial transition in the North East Atlantic
Cryptotephrochronology of the Eemian and the last interglacial-glacial transition in the North East Atlantic
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埃米亚时期的密码年代学和东北大西洋最后一次间冰期-冰期过渡
DOI：
10.1002/jqs.2641
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发表时间：
2013
影响因子：
2.3
通讯作者：
ABBOTT P
中科院分区：
文献类型：
--
作者：
ABBOTT P
Eemian间冰期和随后的冰期的开始是当前间冰期气候系统自然运行的最新模拟。在这一时期发生了明显的气候振荡，但由于测年的限制和不同地区和档案之间未知的相位关系，人们对它们的性质和模式知之甚少。灰岩年代学提供了相当大的潜力，通过追踪常见的等灰岩层位，保存这些快速气候转变的证据，不同的古气候档案的精确相关性。我们概述了三个以前未知的cryptotephra地平线内的海洋核心从罗卡尔槽，东北大西洋的识别。该序列保留了该间隔的高分辨率记录，碎片大小，地球化学异质性和碎片浓度与冰筏碎片数据的协方差被用于证明主要空气降落是最可能的运输和沉积途径。这些层位的主要地球化学群体具有类似的过渡性碱性主元素和微量元素组成，表明它们来自一个共同的冰岛源，可能是Öræfajökull火山系统。这些火山灰层位代表了这一时期北大西洋事件地层学的补充，并提出了两个层位与冰岛陆地沉积物的初步相关性。
The Eemian interglacial and the onset of the subsequent glacial period serve as the most recent analogue for the natural operation of the climate system during the current interglacial. Pronounced climatic oscillations occurred during this period, but their nature and pattern are poorly understood due to dating limitations and unknown phase relationships between different regions and archives. Tephrochronology offers considerable potential for precise correlation of disparate palaeoclimatic archives preserving evidence of these rapid climatic transitions through the tracing of common isochronous tephra horizons. We outline the identification of three previously unknown cryptotephra horizons within a marine core from the Rockall Trough, North East Atlantic. This sequence preserves a high‐resolution record of this interval and shard size, geochemical heterogeneity and the co‐variance of shard concentrations with ice‐rafted debris data are utilized to demonstrate that primary airfall was the most likely transport and depositional pathway. The main geochemical populations of these horizons have similar transitional alkali major and trace element compositions, suggesting that they were derived from a common Icelandic source, potentially the Öræfajökull volcanic system. These tephra horizons represent additions to the North Atlantic event stratigraphy for this period and tentative correlations to Icelandic terrestrial deposits are proposed for two horizons.