A North Atlantic tephrostratigraphical framework for 130-60 ka b2k: new tephra discoveries, marine-based correlations, and future challenges
A North Atlantic tephrostratigraphical framework for 130-60 ka b2k: new tephra discoveries, marine-based correlations, and future challenges
复制标题
130-60 ka b2k 的北大西洋火山地层框架：新的火山岩发现、基于海洋的相关性和未来的挑战
DOI：
10.1016/j.quascirev.2014.03.024
复制
发表时间：
2014
影响因子：
4
通讯作者：
Davies S
中科院分区：
文献类型：
--
作者：
Davies S
建立跨越130-60 ka b2 k的替代序列的年代框架受到困难和不确定性的困扰。然而，北大西洋地区的最新发展肯定了火山灰年代学的潜力，特别是寻找隐火山灰。在这里，我们回顾了火山灰地层学提供的130-60 ka b2 k序列的潜力。我们结合联合收割机新发现的隐石矿床从NGRIP冰芯和海洋核心从冰岛盆地与以前公布的数据从冰和海洋领域构建第一个火山灰地层框架，这一时间间隔。43个火山碎屑岩或隐火山碎屑岩矿床被纳入这一框架;在格陵兰冰芯中发现了23个火山碎屑岩矿床，其中包括9个新的NGRIP火山碎屑岩，并在北大西洋的各种海洋层序中保存了20个独立的矿床。主要，次要和微量元素的结果，提出了新的NGRIP视野与年龄估计的基础上，他们的位置内的冰芯记录。冰岛起源的玄武质火山岩占主导地位的框架，只有八个流纹岩组成的火山岩发现。新的结果，从海洋核心MD 99 -2253也说明了一些评估海洋隐火山岩矿床的沉积完整性的复杂性和挑战。火山灰在海洋环境中的相关性为这一时间间隔提供了独立的联系点，并突出了扩大火山灰年代学应用的潜力。然而，需要进一步的调查，结合联合收割机强大的地球化学指纹和火山灰沉积过程的严格评估，以跟踪两个沉积领域之间的同生事件。
Building chronological frameworks for proxy sequences spanning 130–60 ka b2k is plagued by difficulties and uncertainties. Recent developments in the North Atlantic region, however, affirm the potential offered by tephrochronology and specifically the search for cryptotephra. Here we review the potential offered by tephrostratigraphy for sequences spanning 130–60 ka b2k. We combine newly identified cryptotephra deposits from the NGRIP ice-core and a marine core from the Iceland Basin with previously published data from the ice and marine realms to construct the first tephrostratigraphical framework for this time-interval. Forty-three tephra or cryptotephra deposits are incorporated into this framework; twenty three tephra deposits are found in the Greenland ice-cores, including nine new NGRIP tephras, and twenty separate deposits are preserved in various North Atlantic marine sequences. Major, minor and trace element results are presented for the new NGRIP horizons together with age estimates based on their position within the ice-core record. Basaltic tephras of Icelandic origin dominate the framework with only eight tephras of rhyolitic composition found. New results from marine core MD99-2253 also illustrate some of the complexities and challenges of assessing the depositional integrity of marine cryptotephra deposits. Tephra-based correlations in the marine environment provide independent tie-points for this time-interval and highlight the potential of widening the application of tephrochronology. Further investigations, however, are required, that combine robust geochemical fingerprinting and a rigorous assessment of tephra depositional processes, in order to trace coeval events between the two depositional realms.