Integrating the Holocene tephrostratigraphy for East Asia using a high-resolution cryptotephra study from Lake Suigetsu (SG14 core), central Japan
Integrating the Holocene tephrostratigraphy for East Asia using a high-resolution cryptotephra study from Lake Suigetsu (SG14 core), central Japan
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DOI：
10.1016/j.quascirev.2017.12.013
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发表时间：
2018-03-01
影响因子：
4
通讯作者：
Smith, Victoria C.
中科院分区：
文献类型：
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作者：
McLean, Danielle;Albert, Paul G.;Smith, Victoria C.
火山灰(Tephra)层有可能在区域到半球尺度上同步不同的古环境档案。高生产力的弧区，如东亚的弧区，提供了相当多的广泛的等时线，但在使用这些层对记录进行自信地关联之前，需要对这些喷发事件建立一个精致和完整的框架。在这里，我们介绍了东亚第一个高分辨率的全新世隐形虫研究，使用了日本中部的Suigetsu湖沉积档案。利用隐顶提取技术，全新世火山灰地层已从4层扩大到20层，该技术整合了来自朝鲜/中国、韩国和日本弧线的爆炸性喷发沉积。这是目前东亚火山活动最全面的记录，也是该地区层序对比的关键地点。给出了层序中特弗拉层的主要元素玻璃地球化学成分，并与最近的数据集进行了比较，以将它们与其火山源和特定的喷发联系起来。这项研究显著地扩大了许多关键全新世标志层的火山灰扩散范围，并首次发现了乌伦多火山和长白山火山的等时线远端产状。利用高精度的Suigetsu湖年代学，我们能够提供Tephra层的受限喷发年龄，这些年龄可以转换到包含这些标记的其他特定地点的年龄模型中。这一新的框架表明，几条等时线在地层学上代表了日本的突然气候间隔，可以用来精确地评估这些事件的区域和半球同步性。(C)2018爱思唯尔有限公司。保留所有权利。
Tephra (volcanic ash) layers have the potential to synchronise disparate palaeoenvironmental archives on regional to hemispheric scales. Highly productive arc regions, like those in East Asia, offer a considerable number of widespread isochrons, but before records can be confidently correlated using these layers, a refined and integrated framework of these eruptive events is required. Here we present the first high resolution Holocene cryptotephra study in East Asia, using the Lake Suigetsu sedimentary archive in central Japan. The Holocene tephrostratigraphy has been extended from four to twenty ash layers using cryptotephra extraction techniques, which integrates the deposits from explosive eruptions from North Korea/China, South Korea and along the Japanese arc. This Lake Suigetsu tephrostratigraphy is now the most comprehensive record of East Asian volcanism, and the linchpin site for correlating sequences across this region. Major element glass geochemical compositions are presented for the tephra layers in the sequence, which have been compared to proximal datasets to correlate them to their volcanic source and specific eruptions. This study has significantly extended the ash dispersal of many key Holocene marker layers, and has identified the first distal occurrence of isochrons from Ulleungdo and Chang-baishan volcanoes. Utilising the high-precision Lake Suigetsu chronology, we are able to provide constrained eruption ages for the tephra layers, which can be transferred into other site-specific age models containing these markers. This new framework indicates that several isochrons stratigraphically bracket abrupt climate intervals in Japan, and could be used to precisely assess the regional and hemispheric synchronicity of these events. (C) 2018 Elsevier Ltd. All rights reserved.