Tephrochronological Synchronisation of the Dead Sea and Lake Van ICDP sediment records in the eastern Mediterranean for the last 130 kyrs (TephroMed)

过去 130 kyrs 地中海东部死海和凡湖 ICDP 沉积物记录的时间同步 (TephroMed)

• 批准号: 457531540
• 负责人: Professor Dr. Achim Brauer
• 金额: --
• 依托单位: Sektion 4.3: Klimadynamik und Landschaftsentwicklung
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/457531540?language=en
• 关键词: Tephrochronological; Synchronisation; Dead; Sea; Lake

This project aims at precise synchronisation of the long ICDP sediment cores from the Dead Sea and Lake Van in order to provide a robust chronological fundament to investigate the assumed regional hydroclimatic differences in the eastern Mediterranean. For both the Dead Sea and Lake Van sediment records independent chronologies based on different relative and absolute dating techniques have been established which, however, suffer from rather large dating uncertainties especially beyond the radiocarbon time scale. This prevents from a detailed comparison and integration of these key palaeoclimatic records in order to investigate regional climatic differences. We will make use of recent advances in the search for cryptotephra (macroscopically invisible volcanic glass shards) in sediment records that have been demonstrated as a suitable tool for regional synchronisation even if a precise dating of the correlating volcanic eruptions is not available. We aim at searching for glass shards in the Dead Sea ICDP core around major climatic transitions during the last glacial/interglacial cycle and correlate these through major and trace element chemistry with glass shards from selected major visible tephra layers in the Lake Van record. In a pilot study we could prove that volcanic glass from Anatolian sources is much more abundant in the Dead Sea sediments than expected. So far, a robust geochemical correlation with early Holocene and late Glacial eruptions of the Erciyes Dag (central Anatolia), Süphan and Nemrut (eastern Anatolia) volcanoes was successful. This makes correlations of Dead Sea tephra with Anatolian volcanic eruptions very promising, even if that presumably will not be possible for all tephra horizons in the Dead Sea due to the large number of Anatolian eruptions with similar geochemistry. We will apply glass shard morphology as well as major and trace element geochemistry for correlations. In addition to the direct link of the Dead Sae and Lake Van cores, we attempt to determine the volcanic centres and where possible the exact eruption of major tephra horizons through correlation with glass chemistry from proximal deposits and other lacustrine sediment records in Anatolia through collaboration with partners. We further attempt correlation with tephra found in archaeological sites in the Levant near the Dead Sea in an ongoing Leverhulme project by our partners in the UK. Even if cryptotephra from Italian and Hellenic volcanic centres is comparably rare in the Dead Sea sediments, we will investigate possible correlations with these sources. Ultimately, a tephra-based synchronisation of the Dead Sea and Lake Van ICDP cores will provide a solid base for testing the independent age models of both cores and reduce present dating uncertainties. Finally, the synchronisation of these two key palaeoclimatic records will allow to temporally quantify and better understand regional hydroclimatic differences in the eastern Mediterranean.

该项目旨在精确地同步死海和湖货车的长ICDP沉积物岩心，以提供坚固的时间顺序基础，以调查地中海东部假定的区域氢化气候差异。对于《死海》和《范德尔湖沉积物》，已经建立了基于不同相对和绝对约会技术的独立年代，但是，这些技术的日期不确定性相当大，尤其是在放射性碳时限之外。这阻止了这些主要古气候记录的详细比较和整合，以研究区域慢性差异。我们将利用最近在沉积物记录中寻找Cryptotephra（宏观上无形的火山玻璃碎片）的进步，这些记录也被证明是适合区域同步工具，即使没有相关火山喷发的精确约定。我们旨在在最后一个冰川/冰川间周期中围绕重大气候过渡的死海ICDP核心中寻找玻璃碎片，并通过主要和微量元素化学反应与来自湖货车记录中选定的主要可见Tephra层的玻璃碎片相关联。在一项试点研究中，我们可以证明，来自安纳托利亚来源的火山玻璃在死海沉积物中比预期的要多得多。到目前为止，Erciyes Dag（Anatolia中部），Süphan和Nemrut（East Anatolia）火山的地球化学与早期全新世和晚期冰川爆发的牢固相关性取得了成功。这使死海tephra与安纳托利亚火山喷发的相关性非常有希望，即使由于大量的安纳托利亚爆发具有类似地球化学的安纳托利亚爆发，死海中的所有泰弗拉（Tephra Horizo​​ns）可能无法实现。我们将应用玻璃碎片形态以及主要和痕量元素地球化学的相关性。除了死去的SAE和湖卫生核心的直接联系外，我们还尝试通过与代理沉积物和其他与合作伙伴合作的Anatolia中的玻璃化学与玻璃化学相关的相关性来确定大型Tephra层次地平线的确切喷发。我们进一步尝试与我们在英国的合作伙伴正在进行的Leverhulme项目中在黎凡特附近黎凡特的考古遗址中发现的Tephra相关。即使来自意大利和希腊火山中心的Cryptotephra在死海沉积物中也很少见，我们也会研究与这些来源的可能相关性。最终，基于TEPHRA的死海和Van ICDP核心的同步将为测试这两个核心的独立年龄模型并减少当前约会的不确定性提供坚实的基础。最后，这两个主要古气候记录的同步将允许暂时量化和更好地理解东地中海东部的区域氢化差异。